Chem 3372: Organic Chemistry Summer II 2017, M F 3:30 pm 5:20 pm Fondren Sci Bldg 133

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1 Chem 3372: rganic Chemistry Summer II 2017, M F 3:30 pm 5:20 pm Fondren Sci Bldg 133 Instructor: Professor Alexander R. Lippert, PhD ffice: 141 FSC alippert@smu.edu (please include CHEM 3372 in the subject line) Telephone: ffice hours: TBD TA: TBD TA ffice Hours: TBD Website: Textbook: rganic Chemistry, 4 th Edition, by Janice Gorzynski Smith rganic chemistry focuses on the composition, properties, and behavior of compounds that contain the element carbon, spanning from biological molecules to drugs to materials. This course is the second in a two-semester series to introduce students to the principles, concepts, and practice of organic chemistry. Learning utcomes: Students will be able to identify and draw complex organic molecules. Students will be able to predict the reactivity of basic organic molecules. Students will be able to formulate basic synthetic schemes. Students will be able to solve basic organic structures from spectral data.

2 Assignments and Grades: Homework 10% Exam I 20% Exam II 20% Exam III 20% Final 30% Connect Homework Assignments: Homework assignments will be found on the faculty website and the problems with a (*) will be graded for completion. Assignments should be completed and submitted online before 11:59 pm on the due date. Exams and Finals: Exams and finals will be given during class and will be cumulative. ffice Hours: ffice hours will be held after class and will involve extra practice problems as well as answering one-on-one questions.

3 Class Schedule: Thurs July 6 Chap 15 Mass Spec and IR Fri July 7 Chap 13 Radical Reactions Mon July 10 Chap 14 NMR Tues July 11 Chap 16 Conjugation, Resonance, and Dienes Wed July 12 Chap 17 Benzene and Aromatic Compounds Thurs July 13 Exam 1 Fri July 14 Chap 18 Reactions of Aromatic Compounds Mon July 17 Chap 18 Reactions of Aromatic Compounds Tues July 18 Chap 19 Carboxylic Acids Wed July 19 Chap 20 Intro to Carbonyl Chemistry

4 Tues July 18 Chap 19 Carboxylic Acids Wed July 19 Chap 20 Intro to Carbonyl Chemistry Thurs July 20 Chap 20 Intro to rganometallic Chemistry Fri July 21 Chap 21 Aldehydes and Ketones Mon July 24 Exam II Tues July 25 Chap 21 Aldehydes and Ketones Wed July 26 Chap 22 Carboxylic Acid Derivatives Thurs July 27 Chap 23 Enols and Enolates Fri July 28 Chap 24 Carbonyl Condensation Reactions Mon July 31 Exam III Tues August 1 Chap 25 Amines Wed August 2 Chap 26 Cross Coupling Reactions Thurs August 3 Chap 27 Pericyclic Reactions Fri August 4 Final *Schedule is tentative and subject to change at the instructor s discretion.

5 Disability Accommodations: Students needing academic accommodations for a disability must first be registered with Disability Accommodations & Success Strategies (DASS) to verify the disability and to establish eligibility for accommodations. Students may call or visit to begin the process. nce registered, students should then schedule an appointment with the professor to make appropriate arrangements. (University Policy No. 2.4.) Excused Medical Absences: Verification of medical illness and request for an excused absence from class will be handled in one of two ways. A physician or staff member from health/counseling and testing will provide either (1) a hand written note on a Health Center prescription form or 2) a signed letter written on Health Center stationery. Excused medical absences shall have specific dates of time periods indicated. Encounter Forms and Walk-ut Statements verify a student's visit to the Health Center BUT D NT INDICATE AN EXCUSED MEDICAL ABSENCE. Religious bservance: Religiously observant students wishing to be absent on holidays that require missing class should notify their professors in writing at the beginning of the semester, and should discuss with them, in advance, acceptable ways of making up any work missed because of the absence. (University Policy No. 1.9.) Excused Absences for University Extracurricular Activities: Students participating in an officially sanctioned, scheduled University extracurricular activity should be given the opportunity to make up class assignments or other graded assignments missed as a result of their participation. It is the responsibility of the student to make arrangements with the instructor prior to any missed scheduled examination or other missed assignment for making up the work. (University Undergraduate Catalogue)

6 Study Tips: 1. Review 1 st semester 2. Come to office hours (practice, practice) 3. Make a list of reactions (refer during syntheses)

7 Introduction- In -Chem II, we will really learn how to make molecules. N H NH 2 tamiflu (flu) H H H N H H H H NH 2 tetracycline (antibacterial) HS N H captopril (heart failure)

8 Introduction- In -Chem II, we will really learn how to make molecules. N N H N H NH 2 tamiflu (flu) NH lysergic acid diethylamide H H H N H H 3 C NH 2 H H H NH 2 H 3 C CH 3 tetracycline (antibacterial) mescaline HS N captopril (heart failure) H MDMA HN

9 Introduction- In -Chem II, we will really learn how to make molecules. N N H H N H N H Chapter 22 Chapter 21 NH NH NH Cl Chapter Chapter 18 NH NH

10 Chapters 13 14: Spectroscopy Interactions between light, energy, and matter allow us to "see" molecules. Mass spectroscopy electron beams, electric field (Ch 13 pt 1) IR Spectroscopy infrared light (Ch 13, pt 2) NMR Spectroscopy radio waves and magnetic fields (Ch 14)

11 13.1 Mass Spectrometry A. General Features electron beam ionizes and fragments molecules fragments separated by M/Z ratio M + is called the molecular ion or parent ion

12 13.1 Mass Spectrometry A. General Features M + (molecular ion) breaks into fragments (fragmentation) X-axis: mass-to-charge (m/z) ratio Y-axis: relative abundance tallest peak is called base peak (relative abundance = 100) base peak is not always the molecular ion M+1 peak due to 13 C ( 13 CH 4 ) +

13 13.1 Mass Spectrometry A. General Features Example: Hexane A. B. C. Which peak is the molecular ion? Which peak is the base peak?

14 13.1 Mass Spectrometry A. General Features Example: Hexane Which peak is the molecular ion? m/z = 86 Which peak is the base peak? m/z = 57

15 13.1 Mass Spectrometry B. Analyzing Unknowns by Molecular Ion

16 13.1 Mass Spectrometry B. Analyzing Unknowns by Molecular Ion General Guidelines: Divide molecular ion by 12 = max # Carbons (remainder = #H) Replace12H for 1C Replace 1 for CH 4 Nitrogen: odd #N gives odd molecular ion, even #N gives even molecular ion Try drawing the structure to see if it makes sense Example: Propose possible molecular formulas for m/z = 86.

17 13.2 Alkyl Halides and the M + 2 Peak Chlorine and Bromine have two stable isotopes (giving characteristic fingerprints!): 35 Cl and 37 Cl in a 3:1 ratio 79 Br and 81 Br in a 1:1 ratio C 3 H 35 7 Cl m/z = 78 C 3 H 37 7 Cl m/z = 80 C 3 H 79 7 Br m/z = 122 C 3 H 81 7 Br m/z = 124

18 13.3 Fragmentation A. General Features of Fragmentation Electron beam removes 1 e to form an unstable radical cation Bond cleavage forms more stable (substituted) cation Loss of CH 3 ( 15) Loss of CH 2 ( 14) only charged fragments show up on MS

19 13.3 Fragmentation A. General Features of Fragmentation Example 2,3-dimethyl pentane shows fragments at m/z =85 and 71. Propose structures for these fragments. (on board)

20 13.3 Fragmentation *** B. Fragmentation Patterns of Some Common Functional Groups Aldehydes/Ketones (acylium ion formation by a-cleavage): Alcohols (a-cleavage): Alcohols (dehydration):

21 13.4 ther Types of Mass Spectrometry A. High Resolution Mass Spectrometry (HRMS) Accurate to 4 decimal places Many molecules have similar molecular weight, but can be differentiated with HRMS

22 13.4 ther Types of Mass Spectrometry C. Electrospray Ionization Mass Spectrometry (ESI-MS) ESI is very gentle ionization method Useful for higher molecular weight molecules like peptides and proteins Multiple ionization states (Z) often seen

23 13.4 MS Sample Problems (13.24a, 13.26a, 13.30a)

24 13.5 Electromagnetic Radiation A. Light and Energy Wavelength (l) distance from peak to peak (m) Frequency (n) number of waves per time (Hz = s 1 ) Speed of light (c) = 3.0 x 10 8 m s 1 Planck's constant (h) = 6.63 x J s higher l = lower E higher n = higher E c = ln E = hn = hc/l

25 13.5 Electromagnetic Radiation B. Interaction of Light and Matter Wavelength (l) distance from peak to peak (m) Frequency (n) number of waves per time (s 1 ) Speed of light (c) = 3.0 x 10 8 ms 1 Planck's constant (h) = 6.63 x Js higher l = lower E higher n = higher E c = ln E = hn = hc/l

26 13.6 Infrared Spectroscopy A. Background Infrared radiation: l = µm n = 1.2 x x Hz (hard to report) Wavenumber (n) ~ = 1/ l = cm 1 (easy to report) Energy increases as wavenumber increases Absorption of IR light causes changes in bond vibrations Different bonds vibrate at different frequencies (wave numbers) IR spectroscopy can differentiate bonds and functional groups

27 13.6 Infrared Spectroscopy B. Characteristics of IR Spectrum IR spectrometer scans through the IR spectrum and reports on light absorption Energy increases as wavenumber increases Each peak corresponds to a specific bond X-axis: wavenumber Y-axis: Transmittance Two main regions: Functional Group (> 1500 cm 1 ) Fingerprint (<1500 cm 1 ) H

28 13.6 Infrared Spectroscopy B. Characteristics of IR Spectrum Similar molecules may have similar Functional Group regions but unique Fingerprint regions

29 13.7 IR Absorptions A. Where Particular Bonds Absorb in the IR 1. Bond strength: stronger bonds vibrate at higher energy and higher n~ 2. Atom mass: bonds with lighter atoms vibrate at higher energy and higher ~ n

30 13.7 IR Absorptions A. Where Particular Bonds Absorb in the IR ~ ~

31 13.7B IR Absorptions in Hydrocarbons C sp3 H cm 1 C sp2 H cm 1 C sp3 H cm 1 C C 1650 cm 1 C sp H 3300 cm 1 C sp3 H cm cm 1 C C

32 13.7C IR Absorptions in xygen Compounds H H cm 1 C ~1700 cm 1 precise value can differentiate specific carbonyls no distinctive functional group peaks

33 13.7D IR Absorptions in Nitrogen Compounds N H (2 peaks) 3300, 3400 cm 1 NH 2 N H (2 peaks) 3200, 3400 cm 1 C 1660 cm 1 H 2 N N C N 2250 cm 1

34 13.7E Examples a. b. H c. H d.

35 13.7E Examples a. b. H N c. N d.

36 13.7E Examples a. b. c. H d.

37 13.8 MS and IR to Determine an Unknown

38 13.8 MS and IR to Determine an Unknown