Mass Spectrometry Instrumentation

Size: px
Start display at page:

Download "Mass Spectrometry Instrumentation"

Transcription

1 Mass Spectrometry Instrumentation A mass spectrometer is composed of an inlet system (which introduces the sample to the instrument and vaporizes the sample) A molecular leak (which produces a steady stream of the vapor), an ionization chamber (where a beam of high energy electrons bombards the vapor), A mass analyzer (a series of charged plates which focuses and accelerates the beam of ions into a curved tube with an applied magnetic field which separates the ions by mass), A detector (a simple counter which produces a current every time an ion strikes it), and A recorder (which produces the mass spectrum). A schematic for a typical mass spectrometer is shown in Figure 1.

2 Figure 1. Schematic diagram of mass spectrometer.

3 Ionization In mass spectrometry, a small sample of a chemical compound is vaporized, bombarded with high energy electrons to Ionize the sample, and the ions produced are detected based on the mass to charge ratio (m/z) of the ions. A typical ionization process is shown in Scheme 1 for benzamide. Scheme 1. Ionization process in the EI mass spectrometry of benzamide. The beam of high energy electrons in the ionization chamber remove an electron from the molecule resulting in the formation of a molecular ion (M+) and a second free electron.

4 Several different types of ions can be produced during this process. If the compound loses only one electron, then a molecular ion (frequently symbolized by M+), having the same mass as the original compound, is produced.this m/z of the molecular ion gives the nominal molecular weight of the compound. The stream of high energy electrons is sufficiently powerful so that chemical bonds in the molecule may be broken, producing a series of molecular fragments. These positively charged fragments are detected by the instrument, producing the mass spectrum. Organic chemical compounds will often fragment in very specific ways depending upon what functional groups are present in the molecule (see Scheme 2 for the common fragments produced by benzamide). Analysis of the fragmentation pattern can lead to the determination of the structure of the molecule.

5 Accurate Mass In the example above involving benzamide (C 7 H 7 NO), the molecular ion (M+) has a mass-tocharge ratio (m/z) of 121. This value is calculated using the most abundant isotopes of the elements present in the molecule: 7 * 12 C = 84 7 * 1 H = 7 1 * 14 N = 14 1 * 16 O =

6 Nitrogen Rule If a compound contains an even number of nitrogen atoms(or no nitrogen atoms), Its molecular ion will appear at an even mass number. If, however, a compound contains an odd number of nitrogen atoms, then its molecular ion will appear at an odd mass value. This rule is very useful for determining the nitrogen content of an unknown compound. In the case of benzamide (Figure 1),the molecular ion appears at m/z 121, indicating an odd number of nitrogen atoms in the structure.

7

8 The complete mass spectrum of benzamide is given in Figure 1.

9 Straight Chain Alkanes When an alkane is ionized by EI, it will lose an electron to form a radical cation. This radical cation has the same mass as the parent compound (minus one electron) and is the molecular ion (M+.). Height of parent peak decreases as the molecular mass increases. The most intense peaks are due to C 3 and C 4 ions at m/z 43 and m/z 57 resp. The relative abundances of the formed ions depends upon a) stability of positively charged ion (3 o > 2 o > 1 o > methyl ) b)stability of the radical which is lost(greater the disposal of odd electron,greater the stability of free radical)

10 Mechanism of fragmentation for pentane.

11 The ions of m/z 57 and 43 result from the loss of methyl and ethyl radical, respectively. The ions of m/z 29 and 15 result from the subsequent loss of ethene from these two higher mass fragments. In general, once a radical is lost, the subsequent losses are of neutral molecules. This is called the even electron (EE) ion rule. That is, once an even electron ion is formed, it fragments by rearrangement to give other EE ions. For instance, in decane (see Figure 4): M [M 15] [M ] or [M ] or [M ]. The same can be said for M - 29 [M ], etc. This is how that characteristic EE ion series: 29, 43, 57, 71, 85 arises in hydrocarbon MS.

12 . Mass spectrum of pentane

13

14 Branched Alkanes Branched alkanes tend to fragment very easily owing to the presence of 2 o, 3 o, and 4 o carbon atoms in the structure. When branched alkanes fragment, stable secondary and tertiary carbocations can form. the molecular ion is much less abundant than for straight-chain alkanes. The most important mode of fragmentation in branched alkanes usually occurs at the branch point. Scheme shows the mechanism of fragmentation for isobutane, Notice the reduced intensity of the molecular ion (m/z 58).

15

16 Cyclic Alkanes The fragmentation patterns of cycloalkanes may show mass clusters in a homologous series, as for the alkanes. However, Additionally, if the cycloalkane has a side chain, loss of that side chain is also a favorable mode of fragmentation.. The mass spectrum of cyclohexane has an abundant ion of m/z 56 arising by the loss of ethylene. the most significant mode of cleavage of the cycloalkanes involves the loss of ethylene from the parent molecule or from intermediate radical-ions.

17

18 Straight Chain Alkenes This is probably due to the loss of a p-bonding electron, leaving the carbon skeleton relatively undisturbed. The most important fragmentation events for alkenes involve cleavage of the allylic (favored) and vinylic (less favored) carbon-carbon bonds. For terminal alkenes, allylic fragmentation forms an allylic carbocation of m/z 41. The fragmentation mechanism for 1-butene shown in Scheme illustrates these points. The complete mass spectrum of 1-butene is given in Figure.

19 Straight Chain Alkenes Mechanism of fragmentation for 1-butene.

20

21 Cyclic Alkenes The mass spectra of cycloalkenes show distinct molecular ions. It may be impossible to locate the position of a double bond due to migration. The mechanism of fragmentationis according to Mclafferty rearragment for cyclic alkenes give intense peak One noteworthy characteristic is the fragmentation of cyclohexenes to undergo a reverse Diels-Alder reaction as indicated in Scheme. This rearrangement is characteristic of many isoprenoid natural products and of tetralin derivatives, and is useful for assigning structure and distinguishing isomers. The complete mass spectrum of cyclohexene is given in Figure.

22 Mechanism of fragmentation for cyclohexene.

23 Mass spectrum of cyclohexene

24 Alkynes The mass spectra of alkynes are virtually identical to those of alkenes. The molecular ion is usually more abundant, and fragmentation parallels that of the alkenes. Two differences are worth mentioning: terminal alkynes fragment to form propargyl ions (m/z 39), and can also lose the terminal (or an a-) hydrogen, yielding a strong M - 1 ion. These two modes of fragmentation are outlined in Scheme for 1- butyne, and the complete mass spectrum of 1-butyne is given in Figure.

25 Mechanism of fragmentation for 1- butyne

26 An alternative way to describe the loss of hydrogen radical from an alkyne would involve a 1,2-hydride shift (converting a vinylic radical cation to a more stable allylic radical cation) that subsequently loses hydrogen radical to give the M - 1 ion. This alternate mechanism is outlined in Scheme. Alternate mechanism of fragmentation for 1-butyne.

27 Aromatic Compounds The mass spectra of most aromatic compounds show distinct and abundant molecular ions. This is probably due to the loss of an electron from the p system, leaving the carbon skeleton relatively undisturbed. When an alkyl side-chain is attached to the ring, fragmentation usually occurs at the benzylic position, producing initially a benzyl ion, which often rearranges to the tropylium ion (m/z 91). However, fragmentation can also occur at the attachment point to the ring producing the phenyl cation (m/z 77). If the side-chain is a propyl group or larger, then the McLafferty rearrangement is a possibility, producing a fragment of m/z 92. Formation of a substituted tropylium ion is typical for alkylsubstituted benzenes producing an ion of m/z 105. Each of these possible fragmentation events is described Scheme.

28 Mechanism of fragmentation for propylbenzene.

29 The phenyl cation will fragment further. One route involves the loss of acetylene yielding a fragment with formula C 4 H 3+ (m/z 51). Another route involves the loss of presumably an allene diradical with formula C 3 H 2, forming probably the simplest aromatic species of the formula C 3 H 3+ (m/z 39), namely the cyclopropenyl ion. Aproposed mechanism for the formation of these fragments is given in Scheme. Note that this mechanism is complete conjecture, and only serves as one possible explanation. Proposed mechanism for phenyl cation fragmentation

30 Mass spectrum of propylbenzene

31 Aldehydes The molecular ion is usually observable, although it can be of low relative abundance. The important a- and b-cleavage patterns (as well as the McLafferty rearrangement) are illustrated in Scheme

32 Mechanism of fragmentation for hexanal

33 The complete mass spectrum of hexanal

34 Ketones It appears that the loss of the larger alkyl group is favored in ketones in the a-cleavage process as shown in Scheme. For interpretation purposes,the rule that the larger alkyl group is lost is effective in interpretation. Fragmentation patterns mimic those of the aldehydes. The molecular ion is usually quite abundant.

35 . Mechanism of fragmentation for 2-pentanone.

36 Mass spectrum of 2-pentanone

37 For aromatic ketones, a-cleavage usually involves cleavage of the alkyl group leaving behind an acylium ion. This is subsequently followed by a loss of carbon monoxide from the molecule as indicated in Scheme. If the aromatic ketone has a 3 carbon alkyl chain (or longer), then McLafferty rearrangements (as described above for 2-pentanone) are possible. Aromatic ketone fragmentation illustrated for acetophenone

38 Mass spectrum of acetophenone

39 Esters The molecular ion is usually of low abundance but generally observable for esters. As in all carbonyl compounds, a-cleavage is an important fragmentation process. In general, cleaving the C-O ester bond occurs most readily leading to the favorable loss of an alkoxy radical. Table summarizes this cleavage process for the most common types of esters. Table. Alkoxy Radicals formed from the most common esters. Alkoxy Radical Ester Ion to Observe Formed methyl CH 3 O M - 31 ethyl CH 3 CH 2 O M - 45 propyl (and isopropyl) CH 3 CH 2 CH 2 O M - 59 phenyl C 6 H 5 O (PhO ) M - 93 benzyl C 6 H 5 CH 2 O (BzO ) M - 105

40 Mechanism of fragmentation for methyl butyrate

41 Mass spectrum of methyl butyrate

42 Benzyl and phenyl esters undergo a rearrangement involving hydride transfer from the a-carbon to the ester oxygen. The resulting fragments include a neutral ketene and a charged alcohol as described in Scheme below. Most common fragmentation involving benzyl and phenyl esters

43

44

45 Most common fragmentation involving benzoate and ortho substituted benzoate esters.

46 Mass spectra of methyl benzoate (top) and methyl 2-aminobenzoate

47

48 Amides The molecular ion is usually observable, and will be a good indication of the presence of an amide (invoke the nitrogen rule!). An important fragmentation pattern involves a-cleavage (breaking either bond to the carbonyl carbon) as shown in Scheme.

49 Mechanism of fragmentation for butyramide.

50 Mass spectrum of butyramide

51 Carboxylic Acids The molecular ion is often of low abundance for carboxylic acids, but generally observable. As is indicated in Scheme, the loss of hydroxyl radical (leading to an M - 17 ion) is indicative of the presence of the carboxylic acid functionality. All the important fragmentation events for carboxylic acids are illustrated in Scheme. As for all other carbonyl compounds, a-cleavage, b-cleavage, and McLafferty rearrangements rule the day.

52 Mechanism of fragmentation for butyric acid

53 Mass spectrum of butyric acid

54 As was seen with esters, benzoic acids substituted with alkyl, amino, or hydroxy substituents at the ortho position readily dehydrate via proton transfer from the ortho substituent to the hydroxyl group (ortho effect). Water is lost, resulting in a major M - 18 ion in the mass spectrum. Scheme 19 outlines this process for o-toluic acid. The ortho effect fragmentation of o-toluic acid.

55 Mass spectrum of o-toluic acid

56 Amides The molecular ion is usually observable, and will be a good indication of the presence of an amide (invoke the nitrogen rule!). An important fragmentation pattern involves a-cleavage (breaking either bond to the carbonyl carbon) as shown in Scheme.

57 Mechanism of fragmentation for butyramide.

58 Mass spectrum of butyramide

59 Anhydrides Aliphatic acid anhydrides rarely afford a molecular ion in their mass spectra whereas aromatic anhydrides usually do. Understanding and interpreting the mass spectra for anhydrides is quite straight forward, as they fragment by following the general rules set forward for all carbonyl compounds: a-cleavage on either side of the carbonyl carbon contributes to the major ions observed in the mass spectrum as shown in Scheme for butyric anhydride. Mechanism of fragmentation for butyric anhydride

60 Mass spectrum of butyric anhydride

61 Aromatic anhydrides show evidence of the molecular ion and undergo a similar fragmentation as seen for butyric anhydride. However, an additional rearrangement where carbon monoxide is lost from the molecule is evident in nearly all mass spectra of aromatic anhydrides. The cleavage pattern for benzoic anhydride is given in Scheme. Mechanism of fragmentation for benzoic anhydride.

62 Mass spectrum of benzoic anhydride

63 It is interesting to note that the ortho effect (as described above for ortho substituted esters and carboxylic acids) applies to aromatic anhydrides as well. The fragmentation for o-toluic anhydride (given in Scheme 23) Is an example of this general effect.

64 Mechanism of fragmentation for o-toluic anhydride.

65

66 spectra of o-toluic anhydride (top) and p-toluic anhydride (bottom).

67 Acid Halides Acid halides afford very low abundance, if not entirely absent, molecular ions in their mass spectra. This is true even for aromatic acid halides. Again, as with all carbonyl compounds, a-cleavage is a very facile process with loss of a halogen radical perhaps the most common event. Acid chlorides can also lose HCl from the molecule; this is not a probable event with acid bromides. Keep in mind that the two common isotopes for chlorine ( 35 Cl and 37 Cl in a 3:1 ratio) and bromine ( 79 Br and 81 Br in a 1:1 ratio) will lead to the production of M + 2 observed ions in the spectra. Since the molecular ion is not abundant, the M + 2 ions are typically very difficult to ascertain. Scheme 24 contains the common fragments formed for butyryl chloride.

68

69 Mass spectrum of butyryl chloride

70 Alcohols The molecular ion is usually of very low abundance or absent for aliphatic alcohols. Just as with carbonyl compounds, cleavage on either side of the alcohol carbon (a-cleavage) is the most important feature in alcohol fragmentation. This will typically involve the loss of an alkyl group, and, often, it is the largest alkyl group that is preferentially lost. If the alkyl chain attached to the alcohol carbon is at least of three carbons in length, then a process similar to McLafferty rearrangements seen for carbonyl compounds can take place. Transfer of a g-hydrogen to the alcohol oxygen leads to the loss of water from the molecule. This dehydration can be a very important indication for the presence of an alcohol functionality. The mechanism for alcohol fragmentation is given in Scheme for 2-pentanol.

71

72

73 Unlike for aliphatic alcohols, the molecular ion for phenols can be quite abundant. Phenols can lose the elements of carbon monoxide to give abundant fragment ions at M - 28, and can also lose the elements of the formyl radical (HCO ) to give abundant fragment ions at M No attempt will be made to explain this fragmentation mechanistically. However, Figure 27 contains the mass spectrum of phenol, which highlights the production of the fragment ions.

74

75 Thiols Loss of H 2 S (analogous to dehydration of alcohols) is mainly evident in primary thiols. Just as with alcohols, cleavage on either side of the thiol carbon (a-cleavage) is the most important feature in thiol fragmentation. This will typically involve the loss of an alkyl group, and, often, it is the largest alkyl group that preferentially fragments. If the alkyl chain attached to the thiol carbon is at least of three carbons in length, then a process similar to McLafferty rearrangements seen for carbonyl compounds can take place. Transfer of a g-hydrogen to the thiol sulfur leads to the loss of hydrogen sulfide from the molecule.

76

77 Mass spectrum of 1-pentanethiol

78 Ethers higher abundance than the molecular ions of alcohols. Important fragments arise from cleavage of the carbon-oxygen bond (ipso-cleavage), cleavage of the carbon-carbon bond adjacent to the oxygen (a-cleavage), and transfer of hydride from the b-carbon to the ether oxygen (a rearrangement of the ion produced from initial a-cleavage). All of these processes are outlined in Scheme 27 for dibutyl ether.

79 Mechanism of fragmentation for dibutyl ether

80 Mass spectrum of dibutyl ether

81 Sulfides. Important fragments arise from cleavage of the carbon-sulfur bond (ipso-cleavage), cleavage of the carbon-carbon bond adjacent to the sulfur (a-cleavage), and transfer of hydride from the b-carbon to the sulfide sulfur (a rearrangement of the ion produced from initial a-cleavage). All of these processes are outlined in Scheme 28 for dibutyl sulfide.

82 Mechanism of fragmentation for dibutyl sulfide.

83

84 Amines The molecular ion is of low abundance or not detectable. When observable, its odd mass (when an odd number of nitrogens is present) is a good indication of the presence of an amine (nitrogen rule). Important fragments arise from cleavage of the carbon-carbon or carbon-hydrogen bond adjacent to the nitrogen (a-cleavage), and hydrogen transfer from the b-hydrogen to the nitrogen. These processes are outlined in Scheme 29 for dipropyl amine. If two or more alkyl groups of different length are attached to the alpha carbons, then loss of the largest alkyl group is preferred.

85 Mechanism of fragmentation for dipropyl

86

87 Nitriles The molecular ion is usually of too low an abundance to be observed. However, the loss of hydrogen radical (via an a-cleavage process) will almost always produce an observable ion. For nitriles then, the M - 1 ion is usually more prominent than the M+. As for the carbonyl compounds, McLafferty rearrangement involving transfer of a g-hydrogen to the nitrile N occurs readily for nitriles containing four or more carbons in an n-alkyl chain. The fragmentation events described for nitriles are given in Scheme for pentanenitrile.

88

89

90 Nitro Compounds The molecular ion for aliphatic nitro compounds is seldom observed. The mass spectrum observed for aliphatic nitro compounds is usually due to the fragmentation of the alkyl portion of the molecule.however, there are two fragment ions that are indicative of the nitro group: one is NO + ion (m/z 30), and another is the NO 2+ ion (m/z 46). The complete mass spectrum of 1-nitrobutane is given in Figure 35, which illustrates these points.

91

92 Mass Spectrometry Summary of Fragmentation Patterns Alkanes Alkenes Cycloalkanes Aromatics good M+ 14-amu fragments distinct M+ m/e = 27 CH 2 =CH+ m/e = 41 CH 2 =CHCH 2 + M-15, M-29, M-43, etc... strong M+ loss of alkyl M-28 loss of CH 2 =CH 2 M-15, M-29, M-43, etc... strong M+ loss of alkyl m/e = 105 C 8 H 9 + m/e = 91 C 7 H 7 + m/e = 77 C 6 H 5 + m/e = 65 (weak) C 5 H 5 +

93 Halides Alcohols Phenols M+ and M+2 Cl and Br m/e = 49 or 51 m/e = 93 or 95 CH 2 =Cl+ CH 2 =Br+ M-36, M-38 loss of HCl M-79, M-81 loss of Br M-127 loss of I M+ weak or absent M-15, M-29, M-43, etc... loss of alkyl m/e = 31 m/e = 45, 59, 73,... m/e = 59, 73, 87,... CH 2 =OH+ RCH=OH+ R 2 C=OH+ M-18 loss of H 2 O M-46 loss of H 2 O and CH 2 =CH 2 strong M+ strong M-1 loss of H M-28 loss of CO

94 M+ weak or absent Nitrogen rule Amines m/e = 30 M-15, M-29, M-43, etc... weak M+ m/e = 29 CH 2 =NH 2 + (base peak) loss of alkyl HCO+ M-29 loss of HCO M-43 loss of CH 2 =CHO Aldehydes m/e = 44, 58, 72, 86,... strong M+ M-1 McLafferty rearrangement aromatic aldehyde aromatic aldehyde loss of H

95 M+ intense Ketones M-15, M-29, M-43, etc... m/e = 43 m/e = 55 m/e = 42, 83 m/e = 105, 120 M+ weak but observable loss of alkyl CH 3 CO+ +CH 2 CH=C=O in cyclohexanone in aryl ketones M-17 loss of OH Carboxylic Acids M-45 loss of CO 2 H m/e = 45 CO 2 H+ m/e = 60 CH 2 C(OH) 2 + M+ large aromatic acids M-18 ortho effect

96 Esters M+ weak but observable methyl esters M-31 methyl esters loss of OCH 3 m/e = 59 methyl esters CO 2 CH 3 + m/e = 74 methyl esters CH 2 C(OH)OCH 3 + M+ weaker higher esters M-45, M-59, M-73, etc... loss of OR m/e = 73, 87, 101 CO 2 R+ m/e = 88, 102, 116 m/e = 61, 75, 89 m/e = 108 m/e = 105 M-32, M-46, M-60 CH 2 C(OH)OR+ RC(OH) 2 + (long alkyl ester) loss of CH 2 =C=O (benzyl, acetate) C 6 H 5 CO+ (benzoate) loss of ROH (ortho effect)

Structural Determination Of Compounds

Structural Determination Of Compounds EXPERIMENT 10 Mass Spectroscopy Structural Determination Of Compounds. Introduction - In mass spectrometry, a substance is bombarded with an electron beam having sufficient energy to fragment the molecule.

More information

Teory of Mass Spectrometry Taslim Ersam

Teory of Mass Spectrometry Taslim Ersam Teory of Mass Spectrometry Taslim Ersam I. Fragmentation Chemistry of Ions 1. ne bond σ-cleavages: a. cleavage of C-CC C C C C b. cleavage of C-heteroatom C Z C Z 15/09/2011 1 I. Fragmentation Chemistry

More information

2. Separate the ions based on their mass to charge (m/e) ratio. 3. Measure the relative abundance of the ions that are produced

2. Separate the ions based on their mass to charge (m/e) ratio. 3. Measure the relative abundance of the ions that are produced I. Mass spectrometry: capable of providing both quantitative and qualitative information about samples as small as 100 pg (!) and with molar masses in the 10 4-10 5 kdalton range A. The mass spectrometer

More information

Mass Spectrometry. Introduction EI-MS and CI-MS Molecular mass & formulas Principles of fragmentation Fragmentation patterns Isotopic effects

Mass Spectrometry. Introduction EI-MS and CI-MS Molecular mass & formulas Principles of fragmentation Fragmentation patterns Isotopic effects Mass Spectrometry Introduction EI-MS and CI-MS Molecular mass & formulas Principles of fragmentation Fragmentation patterns Isotopic effects 1 Introduction to MS Mass spectrometry is the method of analysis

More information

MASS SPECTROMETRY: BASIC EXPERIMENT

MASS SPECTROMETRY: BASIC EXPERIMENT http://science.widener.edu/svb/massspec/ei.html relative abundance Pavia 8.1-8.5 MASS SPECTROMETRY: BASIC EXPERIMENT scienceaid.co.uk -e Molecule Molecule +. + 2e base peak [Fragments] +. fragment peaks

More information

3 Use of Mass Spectra to Obtain Structural Information

3 Use of Mass Spectra to Obtain Structural Information 3 Use of Mass Spectra to Obtain Structural Information 1 Mass Spectrometry One of the most sensitive and versatile analytical tools More sensitive than other spectroscopic methods (e.g. IR spectroscopy)

More information

CHAPTER 2. Fragmentation and Interpretation of Spectra

CHAPTER 2. Fragmentation and Interpretation of Spectra 2.1 Introduction CHAPTER 2 Fragmentation and Interpretation of Spectra Before discussing fragmentation and interpretation, it is important to understand the many ways mass spectra are utilized. For the

More information

Mass Spectrometry. 2000, Paul R. Young University of Illinois at Chicago, All Rights Reserved

Mass Spectrometry. 2000, Paul R. Young University of Illinois at Chicago, All Rights Reserved Mass Spectrometry 2000, Paul R. Young University of Illinois at Chicago, All Rights Reserved Mass Spectrometry When a molecule is bombarded with high-energy electrons, one of the process that can occur

More information

OAT Organic Chemistry - Problem Drill 19: NMR Spectroscopy and Mass Spectrometry

OAT Organic Chemistry - Problem Drill 19: NMR Spectroscopy and Mass Spectrometry OAT Organic Chemistry - Problem Drill 19: NMR Spectroscopy and Mass Spectrometry Question No. 1 of 10 Question 1. Which statement concerning NMR spectroscopy is incorrect? Question #01 (A) Only nuclei

More information

Mass Spectroscopy. Dr. Sapna Gupta

Mass Spectroscopy. Dr. Sapna Gupta Mass Spectroscopy Dr. Sapna Gupta What is Mass Spectroscopy It is an analytical technique for measuring the mass-tocharge ratio (m/z) of ions in the gas phase. Mass spectrometry is our most valuable analytical

More information

CHEM 241 UNIT 5: PART A DETERMINATION OF ORGANIC STRUCTURES BY SPECTROSCOPIC METHODS [MASS SPECTROMETRY]

CHEM 241 UNIT 5: PART A DETERMINATION OF ORGANIC STRUCTURES BY SPECTROSCOPIC METHODS [MASS SPECTROMETRY] CHEM 241 UNIT 5: PART A DETERMINATION OF ORGANIC STRUCTURES BY SPECTROSCOPIC METHODS [MASS SPECTROMETRY] 1 Introduction Outline Mass spectrometry (MS) 2 INTRODUCTION The analysis of the outcome of a reaction

More information

Chapter 20. Mass Spectroscopy

Chapter 20. Mass Spectroscopy Chapter 20 Mass Spectroscopy Mass Spectrometry (MS) Mass spectrometry is a technique used for measuring the molecular weight and determining the molecular formula of an organic compound. Mass Spectrometry

More information

ORGANIC - BRUICE 8E CH MASS SPECT AND INFRARED SPECTROSCOPY

ORGANIC - BRUICE 8E CH MASS SPECT AND INFRARED SPECTROSCOPY !! www.clutchprep.com CONCEPT: PURPOSE OF ANALYTICAL TECHNIQUES Classical Methods (Wet Chemistry): Chemists needed to run dozens of chemical reactions to determine the type of molecules in a compound.

More information

MASS SPECTROSCOPY (MS)

MASS SPECTROSCOPY (MS) MASS SPECTOSCOPY (MS) Castor seeds icin (toxic protein) INTODUCTION Does not involve absorption of electromagnetic radiation. It is a spectroscopic technique, by virtue of its use in structure elucidation.

More information

CHAPTER 6. GC EI and CI Fragmentation and Interpretation of Spectra

CHAPTER 6. GC EI and CI Fragmentation and Interpretation of Spectra 1 1 1 1 1 1 1 1 0 1 0 1 CAPTER GC EI and CI Fragmentation and Interpretation of Spectra.1 Introduction Before discussing fragmentation and interpretation, it is important to understand the many ways mass

More information

More information can be found in Chapter 12 in your textbook for CHEM 3750/ 3770 and on pages in your laboratory manual.

More information can be found in Chapter 12 in your textbook for CHEM 3750/ 3770 and on pages in your laboratory manual. CHEM 3780 rganic Chemistry II Infrared Spectroscopy and Mass Spectrometry Review More information can be found in Chapter 12 in your textbook for CHEM 3750/ 3770 and on pages 13-28 in your laboratory manual.

More information

Identification of functional groups in the unknown Will take in lab today

Identification of functional groups in the unknown Will take in lab today Qualitative Analysis of Unknown Compounds 1. Infrared Spectroscopy Identification of functional groups in the unknown Will take in lab today 2. Elemental Analysis Determination of the Empirical Formula

More information

A N I N T R O D U C T I O N T O... MASS SPECTROMETRY. A self-study booklet

A N I N T R O D U C T I O N T O... MASS SPECTROMETRY. A self-study booklet A N I N T R O D U C T I O N T O... MASS SPECTROMETRY A self-study booklet 2 Mass Spectrometry MASS SPECTROMETRY Introduction Theory A mass spectrum can be thought of as being the record of the damage done

More information

Chapter 25: The Chemistry of Life: Organic and Biological Chemistry

Chapter 25: The Chemistry of Life: Organic and Biological Chemistry Chemistry: The Central Science Chapter 25: The Chemistry of Life: Organic and Biological Chemistry The study of carbon compounds constitutes a separate branch of chemistry known as organic chemistry The

More information

12. Structure Determination: Mass Spectrometry and Infrared Spectroscopy

12. Structure Determination: Mass Spectrometry and Infrared Spectroscopy 12. Structure Determination: Mass Spectrometry and Infrared Spectroscopy Determining the Structure of an Organic Compound The analysis of the outcome of a reaction requires that we know the full structure

More information

Unit 5: Organic Chemistry

Unit 5: Organic Chemistry Unit 5: Organic Chemistry Organic chemistry: discipline in chemistry focussing strictly on the study of hydrocarbons compounds made up of carbon & hydrogen Organic compounds can contain other elements

More information

Alkanes and Cycloalkanes

Alkanes and Cycloalkanes Alkanes and Cycloalkanes Families of Organic Compounds Organic compounds can be grouped into families by their common structural features We shall survey the nature of the compounds in a tour of the families

More information

Chapter 12 Structure Determination: Mass Spectrometry and Infrared Spectroscopy

Chapter 12 Structure Determination: Mass Spectrometry and Infrared Spectroscopy Chapter 12 Structure Determination: Mass Spectrometry and Infrared Spectroscopy Figure 12.1 - The electron-ionization, magneticsector mass spectrometer Representing the Mass Spectrum Base Peak Parent

More information

Chem 1075 Chapter 19 Organic Chemistry Lecture Outline

Chem 1075 Chapter 19 Organic Chemistry Lecture Outline Chem 1075 Chapter 19 Organic Chemistry Lecture Outline Slide 2 Introduction Organic chemistry is the study of and its compounds. The major sources of carbon are the fossil fuels: petroleum, natural gas,

More information

Chapter 5. Mass spectrometry

Chapter 5. Mass spectrometry ionization and fragmentation Chapter 5. Mass spectrometry which fragmentations? mass and frequency, m/z and count rate Reading: Pavia Chapters 3 and 4 Don t need 3.3 B-D, 3.4 B-D Use the text to clarify

More information

CHEMISTRY Topic #3: Using Spectroscopy to Identify Molecules: Radicals and Mass Spectrometry (MS) Spring 2018 Dr.

CHEMISTRY Topic #3: Using Spectroscopy to Identify Molecules: Radicals and Mass Spectrometry (MS) Spring 2018 Dr. CHEMISTRY 2600 Topic #3: Using Spectroscopy to Identify Molecules: Radicals and Mass Spectrometry (MS) Spring 2018 Dr. Susan Findlay Mass Spectrometry: How Does It Work? In CHEM 1000, you saw that mass

More information

AP Chemistry Chapter 22 - Organic and Biological Molecules

AP Chemistry Chapter 22 - Organic and Biological Molecules AP Chemistry Chapter - Organic and Biological Molecules.1 Alkanes: Saturated Hydrocarbons A. Straight-chain Hydrocarbons 1. Straight-chain alkanes have the formula C n H n+. Carbons are sp hybridized The

More information

(2) Read each statement carefully and pick the one that is incorrect in its information.

(2) Read each statement carefully and pick the one that is incorrect in its information. Organic Chemistry - Problem Drill 17: IR and Mass Spectra No. 1 of 10 1. Which statement about infrared spectroscopy is incorrect? (A) IR spectroscopy is a method of structure determination based on the

More information

ORGANIC - EGE 5E CH UV AND INFRARED MASS SPECTROMETRY

ORGANIC - EGE 5E CH UV AND INFRARED MASS SPECTROMETRY !! www.clutchprep.com CONCEPT: IR SPECTROSCOPY- FREQUENCIES There are specific absorption frequencies in the functional group region that we should be familiar with EXAMPLE: What are the major IR absorptions

More information

3. Organic Compounds: Alkanes and Cycloalkanes

3. Organic Compounds: Alkanes and Cycloalkanes 3. Organic Compounds: Alkanes and Cycloalkanes Based on McMurry s Organic Chemistry, 6 th edition, Chapter 3 2003 Ronald Kluger Department of Chemistry University of Toronto 1 Families of Organic Compounds!

More information

Chapter 9. Organic Chemistry: The Infinite Variety of Carbon Compounds. Organic Chemistry

Chapter 9. Organic Chemistry: The Infinite Variety of Carbon Compounds. Organic Chemistry Chapter 9 Organic Chemistry: The Infinite Variety of Carbon Compounds Organic Chemistry Organic chemistry is defined as the chemistry of carbon compounds. Of tens of millions of known chemical compounds,

More information

FAMILIES of ORGANIC COMPOUNDS

FAMILIES of ORGANIC COMPOUNDS 1 SCH4U October 2016 Organic Chemistry Chemistry of compounds that contain carbon (except: CO, CO 2, HCN, CO 3 - ) Carbon is covalently bonded to another carbon, hydrogen and possibly to oxygen, a halogen

More information

Chapter 11. Introduction to Organic Chemistry

Chapter 11. Introduction to Organic Chemistry hapter 11 Introduction to rganic hemistry Properties of arbon and its compounds 2 Properties of arbon and its compounds 3 Properties of arbon and its compounds 4 Properties of arbon and its compounds 5

More information

Introduc)on to Func)onal Groups in Organic Molecules

Introduc)on to Func)onal Groups in Organic Molecules Introduc)on to Func)onal Groups in rganic Molecules CH 3 H 3 C N C C N C C N N CH CH 3 Caffeine Func)onal Group Func%onal group - collec)on of atoms at a site that have a characteris)c behavior in all

More information

Carbon Compounds. Chemical Bonding Part 2

Carbon Compounds. Chemical Bonding Part 2 Carbon Compounds Chemical Bonding Part 2 Introduction to Functional Groups: Alkanes! Alkanes Compounds that contain only carbons and hydrogens, with no double or triple bonds.! Alkyl Groups A part of a

More information

Organic Chemistry. A. Introduction

Organic Chemistry. A. Introduction Organic Chemistry A. Introduction 1. Organic chemistry is defined as the chemistry of CARBON compounds. There are a huge number of organic compounds. This results from the fact that carbon forms chains

More information

Qualitative Organic Analysis CH 351 Mass Spectrometry

Qualitative Organic Analysis CH 351 Mass Spectrometry Qualitative Organic Analysis CH 351 Mass Spectrometry Bela Torok Department of Chemistry University of Massachusetts Boston Boston, MA General Aspects Theoretical basis of mass spectrometry Basic Instrumentation

More information

Mass Spectrometry. General Principles

Mass Spectrometry. General Principles General Principles Mass Spectrometer: Converts molecules to ions Separates ions (usually positively charged) on the basis of their mass/charge (m/z) ratio Quantifies how many units of each ion are formed

More information

Electronegativity Scale F > O > Cl, N > Br > C, H

Electronegativity Scale F > O > Cl, N > Br > C, H Organic Chem Chapter 12 Alkanes Organic chemistry is the study of carbon compounds. Carbon has several properties that are worth discussing: Tetravalent Always forms 4 bonds Can form multiple bonds (double

More information

Mass Spectrometry: Introduction

Mass Spectrometry: Introduction Mass Spectrometry: Introduction Chem 8361/4361: Interpretation of Organic Spectra 2009 Andrew Harned & Regents of the University of Minnesota Varying More Mass Spectrometry NOT part of electromagnetic

More information

12/27/2010. Chapter 15 Reactions of Aromatic Compounds

12/27/2010. Chapter 15 Reactions of Aromatic Compounds Chapter 15 Reactions of Aromatic Compounds Electrophilic Aromatic Substitution Arene (Ar-H) is the generic term for an aromatic hydrocarbon The aryl group (Ar) is derived by removal of a hydrogen atom

More information

Chapter 3. Organic Compounds: Alkanes and Their Stereochemistry

Chapter 3. Organic Compounds: Alkanes and Their Stereochemistry Chapter 3. Organic Compounds: Alkanes and Their Stereochemistry Functional Group: Be able to identify and name any of the functional groups listed on Table 3.1, pages 76-77. Summary of important functional

More information

Table 8.2 Detailed Table of Characteristic Infrared Absorption Frequencies

Table 8.2 Detailed Table of Characteristic Infrared Absorption Frequencies Table 8.2 Detailed Table of Characteristic Infrared Absorption Frequencies The hydrogen stretch region (3600 2500 cm 1 ). Absorption in this region is associated with the stretching vibration of hydrogen

More information

Look for absorption bands in decreasing order of importance:

Look for absorption bands in decreasing order of importance: 1. Match the following to their IR spectra (30 points) Look for absorption bands in decreasing order of importance: a e a 2941 1716 d f b 3333 c b 1466 1.the - absorption(s) between 3100 and 2850 cm-1.

More information

15.04.jpg. Mass spectrometry. Electron impact Mass spectrometry

15.04.jpg. Mass spectrometry. Electron impact Mass spectrometry Mass spectrometry Electron impact Mass spectrometry 70 ev = 1614 kcal/mol - contrast with energy from IR (1-10 kcal/mol) or NMR (0.2 cal/mol) - typical C-C bond = 100 kcal/mol Point: lots of energy in

More information

Chapter 22. Organic and Biological Molecules

Chapter 22. Organic and Biological Molecules Chapter 22 Organic and Biological Molecules The Bonding of Carbon Organic chemistry is the chemistry of compounds containing carbon. Because carbon can form single, double, and triple bonds, the following

More information

Organic Chemistry. It s all about the charges!

Organic Chemistry. It s all about the charges! Organic Chemistry It s all about the charges! Hydrocarbons So far, we ve mostly looked at hydrocarbons: alkanes, alkenes, alkynes, and benzene. Hydrocarbons are NON-polar molecules: the C-H bond has an

More information

Lecture notes in EI-Mass spectrometry. By Torben Lund

Lecture notes in EI-Mass spectrometry. By Torben Lund 1 Lecture notes in EI-Mass spectrometry By Torben Lund RUC 2015 1. Basic advise: 1) Identify the mole peak M +. 2) Nitogen rule: Determine number of N 3) A+2 elements: Cl, Br, S, Si 4) N C = 100 [M+1]/([M]

More information

Chapter 2: An Introduction to Organic Compounds

Chapter 2: An Introduction to Organic Compounds Chapter : An Introduction to Organic Compounds I. FUNCTIONAL GROUPS: Functional groups with similar structure/reactivity may be "grouped" together. A. Functional Groups With Carbon-Carbon Multiple Bonds.

More information

Isomerism CH 4 C 2 H 6 C 3 H 8 C 4 H 10 C 5 H 12. Constitutional isomers...

Isomerism CH 4 C 2 H 6 C 3 H 8 C 4 H 10 C 5 H 12. Constitutional isomers... Isomerism 4 2 6 3 8 4 10 5 12 onstitutional isomers... 3 8 Positional isomers... Functional isomers... ow many constitutional isomers are there for the formula 4 8? arbon atoms are often classified as

More information

Chapter 1 Reactions of Organic Compounds. Reactions Involving Hydrocarbons

Chapter 1 Reactions of Organic Compounds. Reactions Involving Hydrocarbons Chapter 1 Reactions of Organic Compounds Reactions Involving Hydrocarbons Reactions of Alkanes Single bonds (C-C) are strong and very hard to break, therefore these compounds are relatively unreactive

More information

MASS Spectrometry. CHAPTER. Introduction: 58 MASS Spectroscopy

MASS Spectrometry.   CHAPTER. Introduction: 58 MASS Spectroscopy 58 MASS Spectroscopy APTER 3 MASS Spectrometry Introduction: In the commonly used electron-impact (EI) mode, a mass spectrometer bombards molecules in the vapour phase with a high-energy electron beam

More information

Fri 6 Nov 09. More IR Mass spectroscopy. Hour exam 3 Fri Covers Chaps 9-12 Wednesday: Review

Fri 6 Nov 09. More IR Mass spectroscopy. Hour exam 3 Fri Covers Chaps 9-12 Wednesday: Review Fri 6 Nov 09 our exam 3 Fri 11-13 Covers Chaps 9-12 Wednesday: Review More IR Mass spectroscopy Good web site for IR, Mass, NMR spectra: http://riodb01.ibase.aist.go.jp/sdbs/cgi-bin/cre_index.cgi?lang=eng

More information

Ch 16 Electrophilic Aromatic Substitution

Ch 16 Electrophilic Aromatic Substitution Ch 16 Electrophilic Aromatic Substitution Mechanism - Aromatic rings typically undergo substitution, where an H is replaced with an electrophile (E+). - The rings do not typically undergo addition across

More information

Chemistry 11 Hydrocarbon Alkane Notes. In this unit, we will be primarily focusing on the chemistry of carbon compounds, also known as.

Chemistry 11 Hydrocarbon Alkane Notes. In this unit, we will be primarily focusing on the chemistry of carbon compounds, also known as. 1 Chemistry 11 Hydrocarbon Alkane Notes In this unit, we will be primarily focusing on the chemistry of carbon compounds, also known as. Why is organic chemistry so important? Many of the compounds that

More information

12.1 The Nature of Organic molecules

12.1 The Nature of Organic molecules 12.1 The Nature of Organic molecules Organic chemistry: : The chemistry of carbon compounds. Carbon is tetravalent; it always form four bonds. Prentice Hall 2003 Chapter One 2 Organic molecules have covalent

More information

Welcome to Organic Chemistry II

Welcome to Organic Chemistry II Welcome to Organic Chemistry II Erika Bryant, Ph.D. erika.bryant@hccs.edu Class Syllabus 3 CHAPTER 12: STRUCTURE DETERMINATION 4 What is this solution Soda Tea Coffee??? 5 What is this solution Soda Tea

More information

Alkanes 3/27/17. Hydrocarbons: Compounds made of hydrogen and carbon only. Aliphatic (means fat ) - Open chain Aromatic - ring. Alkane Alkene Alkyne

Alkanes 3/27/17. Hydrocarbons: Compounds made of hydrogen and carbon only. Aliphatic (means fat ) - Open chain Aromatic - ring. Alkane Alkene Alkyne Alkanes EQ 1. How will I define Hydrocarbons? 2. Compare and contrast the 3 types of hydrocarbons (Alkanes, alkenes, alkynes). Hydrocarbons: Compounds made of hydrogen and carbon only. Aliphatic (means

More information

Chapter 12 Mass Spectrometry and Infrared Spectroscopy

Chapter 12 Mass Spectrometry and Infrared Spectroscopy Organic Chemistry, 6 th Edition L. G. Wade, Jr. Chapter 12 Mass Spectrometry and Infrared Spectroscopy Jo Blackburn Richland College, Dallas, TX Dallas County Community College District 2006, Prentice

More information

Nuggets of Knowledge for Chapter 17 Dienes and Aromaticity Chem 2320

Nuggets of Knowledge for Chapter 17 Dienes and Aromaticity Chem 2320 Nuggets of Knowledge for Chapter 17 Dienes and Aromaticity Chem 2320 I. Isolated, cumulated, and conjugated dienes A diene is any compound with two or C=C's is a diene. Compounds containing more than two

More information

ORGANIC - CLUTCH CH ANALYTICAL TECHNIQUES: IR, NMR, MASS SPECT

ORGANIC - CLUTCH CH ANALYTICAL TECHNIQUES: IR, NMR, MASS SPECT !! www.clutchprep.com CONCEPT: PURPOSE OF ANALYTICAL TECHNIQUES Classical Methods (Wet Chemistry): Chemists needed to run dozens of chemical reactions to determine the type of molecules in a compound.

More information

1. What is the major organic product obtained from the following sequence of reactions?

1. What is the major organic product obtained from the following sequence of reactions? CH320 N N_HW1 Multiple Choice Identify the choice that best completes the statement or answers the question. There is only one correct response for each question. Carefully record your answers on the Scantron

More information

Organic Chemistry. FAMILIES of ORGANIC COMPOUNDS

Organic Chemistry. FAMILIES of ORGANIC COMPOUNDS 1 SCH4U September 2017 Organic Chemistry Is the chemistry of compounds that contain carbon (except: CO, CO 2, HCN, CO 3 2- ) Carbon is covalently bonded to another carbon, hydrogen and possibly to oxygen,

More information

Alkenes. Dr. Munther A. M-Ali For 1 st Stage Setudents

Alkenes. Dr. Munther A. M-Ali For 1 st Stage Setudents Alkenes Dr. Munther A. M-Ali For 1 st Stage Setudents Alkenes Family of hydrocarbons, the alkenes, which contain less hydrogen, carbon for carbon, than the alkanes Structure of ethylene, The carbon-carbon

More information

L.7. Mass Spectrum Interpretation

L.7. Mass Spectrum Interpretation L.7. Mass Spectrum Interpretation Fragmentation reactions Spectrum interpretation Confirmation of ion structural assignment Biomolecule dissociation Fragmentation reactions 1. Fragmentation reactions of

More information

KOT 222 Organic Chemistry II

KOT 222 Organic Chemistry II KOT 222 Organic Chemistry II Course Objectives: 1) To introduce the chemistry of alcohols and ethers. 2) To study the chemistry of functional groups. 3) To learn the chemistry of aromatic compounds and

More information

video 14.4 isomers isomers Isomers have the molecular formula but are rearranged in a structure with different properties. Example: Both C 4 H 10

video 14.4 isomers isomers Isomers have the molecular formula but are rearranged in a structure with different properties. Example: Both C 4 H 10 video 14.4 isomers isomers Isomers have the molecular formula but are rearranged in a structure with different properties. Example: Both C 4 H 10 Butane Methylpropane 1 match the isomers drawing an isomer

More information

Mass Spectrometry (MS)

Mass Spectrometry (MS) Kevin Burgess, February 20, 2017 1 Mass Spectrometry (MS) from chapter(s) in the recommended text A. Introduction Kevin Burgess, February 20, 2017 2 B. Components f Mass Spectrometers mass-to-charge. molecular

More information

ORGANIC - CLUTCH CH ANALYTICAL TECHNIQUES: IR, NMR, MASS SPECT

ORGANIC - CLUTCH CH ANALYTICAL TECHNIQUES: IR, NMR, MASS SPECT !! www.clutchprep.com CONCEPT: PURPOSE OF ANALYTICAL TECHNIQUES Classical Methods (Wet Chemistry): Chemists needed to run dozens of chemical reactions to determine the type of molecules in a compound.

More information

Alkanes, Alkenes and Alkynes

Alkanes, Alkenes and Alkynes Alkanes, Alkenes and Alkynes Hydrocarbons Hydrocarbons generally fall into 2 general groupings, aliphatic hydrocarbons and aromatic hydrocarbons. Aliphatic hydrocarbons contain chains and rings of hydrocarbons,

More information

Mass Spectrometry - Background

Mass Spectrometry - Background Mass Spectrometry - Background In mass spectrometry, a substance is bombarded with an electron beam having sufficient energy to fragment the molecule. The positive fragments which are produced (cations

More information

MOLECULAR REPRESENTATIONS AND INFRARED SPECTROSCOPY

MOLECULAR REPRESENTATIONS AND INFRARED SPECTROSCOPY MOLEULAR REPRESENTATIONS AND INFRARED SPETROSOPY A STUDENT SOULD BE ABLE TO: 1. Given a Lewis (dash or dot), condensed, bond-line, or wedge formula of a compound draw the other representations. 2. Give

More information

Organic Chemistry SL IB CHEMISTRY SL

Organic Chemistry SL IB CHEMISTRY SL Organic Chemistry SL IB CHEMISTRY SL 10.1 Fundamentals of organic chemistry Understandings: A homologous series is a series of compounds of the same family, with the same general formula, which differ

More information

Chapter 15 Reactions of Aromatic Compounds

Chapter 15 Reactions of Aromatic Compounds Chapter 15 1 Chapter 15 Reactions of Aromatic Compounds Electrophilic Aromatic Substitution Arene (Ar-H) is the generic term for an aromatic hydrocarbon The aryl group (Ar) is derived by removal of a hydrogen

More information

TOK: The relationship between a reaction mechanism and the experimental evidence to support it could be discussed. See

TOK: The relationship between a reaction mechanism and the experimental evidence to support it could be discussed. See Option G: Further organic chemistry (15/22 hours) SL students study the core of these options and HL students study the whole option (the core and the extension material). TOK: The relationship between

More information

sample was a solution that was evaporated in the spectrometer (such as with ESI-MS) ions such as H +, Na +, K +, or NH 4

sample was a solution that was evaporated in the spectrometer (such as with ESI-MS) ions such as H +, Na +, K +, or NH 4 Introduction to Spectroscopy V: Mass Spectrometry Basic Theory: Unlike other forms of spectroscopy used in structure elucidation of organic molecules mass spectrometry does not involve absorption/emission

More information

ORGANIC - EGE 5E CH. 2 - COVALENT BONDING AND CHEMICAL REACTIVITY

ORGANIC - EGE 5E CH. 2 - COVALENT BONDING AND CHEMICAL REACTIVITY !! www.clutchprep.com CONCEPT: HYBRID ORBITAL THEORY The Aufbau Principle states that electrons fill orbitals in order of increasing energy. If carbon has only two unfilled orbitals, why does it like to

More information

CHEM 203 Exam 1. Name Multiple Choice Identify the letter of the choice that best completes the statement or answers the question.

CHEM 203 Exam 1. Name Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. CHEM 203 Exam 1 Name Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. 1. Which of the following elements is a large percentage of both the earth's

More information

CH 320/328 N Summer II 2018

CH 320/328 N Summer II 2018 CH 320/328 N Summer II 2018 HW 1 Multiple Choice Identify the choice that best completes the statement or answers the question. There is only one correct response for each question. (5 pts each) 1. Which

More information

CHM 223 Organic Chemistry I Prof. Chad Landrie. Lecture 10: September 20, 2018 Ch. 12: Spectroscopy mass spectrometry infrared spectroscopy

CHM 223 Organic Chemistry I Prof. Chad Landrie. Lecture 10: September 20, 2018 Ch. 12: Spectroscopy mass spectrometry infrared spectroscopy M 223 Organic hemistry I Prof. had Landrie Lecture 10: September 20, 2018 h. 12: Spectroscopy mass spectrometry infrared spectroscopy i>licker Question onsider a solution that contains 65g R enantiomer

More information

CHAPTER 24 Organic Chemistry

CHAPTER 24 Organic Chemistry CHAPTER 24 rganic Chemistry 1. The general formula for alkenes is A. C n H 2n+2 B. C 2n H 2n C. C n H n+2 D. C n H 2n E. C n H 2n 2 2. The general formula of an alkane is A. C n H 2n B. C n H 2n+2 C. C

More information

ALCOHOLS AND PHENOLS

ALCOHOLS AND PHENOLS ALCOHOLS AND PHENOLS ALCOHOLS AND PHENOLS Alcohols contain an OH group connected to a a saturated C (sp3) They are important solvents and synthesis intermediates Phenols contain an OH group connected to

More information

CH 3. mirror plane. CH c d

CH 3. mirror plane. CH c d CAPTER 20 Practice Exercises 20.1 The index of hydrogen deficiency is two. The structural possibilities include two double bonds, a double do 20.3 (a) As this is an alkane, it contains only C and and has

More information

General Infrared Absorption Ranges of Various Functional Groups

General Infrared Absorption Ranges of Various Functional Groups General Infrared Absorption Ranges of Various Functional Groups Frequency Range Bond Type of Compound cm -1 Intensity C Alkanes 2850-2970 Strong 1340-1470 Strong C Alkenes 3010-3095 Medium 675-995 Strong

More information

C h a p t e r F o u r t e e n: Structure Determination: Mass Spectrometry and Infrared Spectroscopy

C h a p t e r F o u r t e e n: Structure Determination: Mass Spectrometry and Infrared Spectroscopy C h a p t e r F o u r t e e n: Structure Determination: Mass Spectrometry and Infrared Spectroscopy Cl OH Cl An electron ionization mass spectrum of 2,5-dichlorophenol CHM 323: Summary of Important Concepts

More information

Chemistry 14C Winter 2017 Exam 2 Solutions Page 1

Chemistry 14C Winter 2017 Exam 2 Solutions Page 1 Chemistry 14C Winter 2017 Exam 2 Solutions Page 1 Statistics: High score, average, and low score will be posted on the course web site after exam grading is complete. Some questions have more than one

More information

DAV CENTENARY PUBLIC SCHOOL, PASCHIM ENCLAVE, NEW DELHI - 87

DAV CENTENARY PUBLIC SCHOOL, PASCHIM ENCLAVE, NEW DELHI - 87 HYDROCARBONS 1. Why do alkenes prefer to undergo electrophilic addition reaction while arenes prefer electrophilic substitution reactions? Explain. 2. Alkynes on reduction with sodium in liquid ammonia

More information

Hydrocarbons and their Functional Groups

Hydrocarbons and their Functional Groups Hydrocarbons and their Functional Groups Organic chemistry is the study of compounds in which carbon is the principal element. carbon atoms form four bonds long chains, rings, spheres, sheets, and tubes

More information

ORGANIC - BRUICE 8E CH.3 - AN INTRODUCTION TO ORGANIC COMPOUNDS

ORGANIC - BRUICE 8E CH.3 - AN INTRODUCTION TO ORGANIC COMPOUNDS !! www.clutchprep.com CONCEPT: INDEX OF HYDROGEN DEFICIENCY (STRUCTURAL) A saturated molecule is any molecule that has the maximum number of hydrogens possible for its chemical structure. The rule that

More information

Structure and Preparation of Alkenes: Elimination Reactions

Structure and Preparation of Alkenes: Elimination Reactions Structure and Preparation of Alkenes: Elimination Reactions Alkene Nomenclature First identify the longest continuous chain that includes the double bond. Replace the -ane ending of the corresponding unbranched

More information

MS Interpretation II. Fragmentation

MS Interpretation II. Fragmentation MS Interpretation II Fragmentation Ionization E Electron Ionization (EI): Even-electron neutrals yield odd-electron radical cations. M(EE) EI - 1e - M (E) Electron can come from anywhere. EI EI even electron

More information

Bio-elements. Living organisms requires only 27 of the 90 common chemical elements found in the crust of the earth, to be as its essential components.

Bio-elements. Living organisms requires only 27 of the 90 common chemical elements found in the crust of the earth, to be as its essential components. Bio-elements Living organisms requires only 27 of the 90 common chemical elements found in the crust of the earth, to be as its essential components. Most of the chemical components of living organisms

More information

MCAT Organic Chemistry Problem Drill 10: Aldehydes and Ketones

MCAT Organic Chemistry Problem Drill 10: Aldehydes and Ketones MCAT rganic Chemistry Problem Drill 10: Aldehydes and Ketones Question No. 1 of 10 Question 1. Which of the following is not a physical property of aldehydes and ketones? Question #01 (A) Hydrogen bonding

More information

Chapter 12. Reactions of Arenes: Electrophilic Aromatic Substitution. Class Notes. A. The method by which substituted benzenes are synthesized

Chapter 12. Reactions of Arenes: Electrophilic Aromatic Substitution. Class Notes. A. The method by which substituted benzenes are synthesized Chapter 12 Reactions of Arenes: Electrophilic Aromatic Substitution Chapter 12 suggested problems: 22, 23, 26, 27, 32, 33 Class Notes I. Electrophilic aromatic substitution reactions A. The method by which

More information

AQA A2 CHEMISTRY TOPIC 4.10 ORGANIC SYNTHESIS AND ANALYSIS TOPIC 4.11 STRUCTURE DETERMINATION BOOKLET OF PAST EXAMINATION QUESTIONS

AQA A2 CHEMISTRY TOPIC 4.10 ORGANIC SYNTHESIS AND ANALYSIS TOPIC 4.11 STRUCTURE DETERMINATION BOOKLET OF PAST EXAMINATION QUESTIONS AQA A2 CHEMISTRY TOPIC 4.10 ORGANIC SYNTHESIS AND ANALYSIS TOPIC 4.11 STRUCTURE DETERMINATION BOOKLET OF PAST EXAMINATION QUESTIONS 1 1. Consider the following reaction sequence. CH 3 CH 3 CH 3 Step 1

More information

Organic Chemistry. Organic chemistry is the chemistry of compounds containing carbon.

Organic Chemistry. Organic chemistry is the chemistry of compounds containing carbon. Organic Chemistry Organic Chemistry Organic chemistry is the chemistry of compounds containing carbon. In this chapter we will discuss the structural features of organic molecules, nomenclature, and a

More information

16. Chemistry of Benzene: Electrophilic Aromatic Substitution جانشینی الکتروندوستی آروماتیک شیمی آلی 2

16. Chemistry of Benzene: Electrophilic Aromatic Substitution جانشینی الکتروندوستی آروماتیک شیمی آلی 2 16. Chemistry of Benzene: Electrophilic Aromatic Substitution جانشینی الکتروندوستی آروماتیک شیمی آلی 2 Dr M. Mehrdad University of Guilan, Department of Chemistry, Rasht, Iran m-mehrdad@guilan.ac.ir Based

More information

Identifying Functional Groups. Why is this necessary? Alkanes. Why is this so important? What is a functional group? 2/1/16

Identifying Functional Groups. Why is this necessary? Alkanes. Why is this so important? What is a functional group? 2/1/16 Identifying Functional Groups The Key to Survival Why is this so important? ver and over again, you will be asked to do reactions, the details to which you will receive in lecture and via your textbook.

More information

16. Chemistry of Benzene: Electrophilic Aromatic Substitution جانشینی الکتروندوستی آروماتیک شیمی آلی 2

16. Chemistry of Benzene: Electrophilic Aromatic Substitution جانشینی الکتروندوستی آروماتیک شیمی آلی 2 16. Chemistry of Benzene: Electrophilic Aromatic Substitution جانشینی الکتروندوستی آروماتیک شیمی آلی 2 Dr M. Mehrdad University of Guilan, Department of Chemistry, Rasht, Iran m-mehrdad@guilan.ac.ir Based

More information

Learning Guide for Chapter 3 - Infrared Spectroscopy

Learning Guide for Chapter 3 - Infrared Spectroscopy Learning Guide for hapter 3 - Infrared Spectroscopy I. Introduction to spectroscopy - p 1 II. Molecular vibrations - p 3 III. Identifying functional groups - p 6 IV. Interpreting an IR spectrum - p 12

More information