hapters 2 & 25: ovalent bonds & Organic hemistry Read: BLB 2.6, 2.9; 25.1-25.4 (only nomenclature in Table 25.1, NOT reactions) W: BLB 2:43, 45, 69, 76, 77 BLB 25:11, 12, 25, 40a, c-f Packet Organic:1 9 Know: alkanes, alkenes, alkynes & aromatics structural differences properties, reactivity know rules of valence draw structural formula from condensed formulas identify structural isomers identify functional groups No Score from Exam 1? Speak with Mike Joyce ASAP 210 Whitmore or mjj12@psu.edu Dr. Lori Stepan Van Der Sluys 1 Organic
ORGANI EMISTRY Definition: Often includes O, N, S, and halogens, also Millions of organic compounds are known. They are the main constituents of living matter. (DNA, RNA, proteins, enzymes, ) Reasons for the large number of organic compounds 1) arbon atoms form strong, stable bonds to other atoms (thus forming rings, chains, etc.) and to atoms such as, O, N, S, halogens. ( ) 2) arbon atoms form up to 4 bonds simultaneously: ( ) molecules can be branched. 3) arbon atoms form multiple bonds with or with O, N, S: further structural variations are possible. ( ) Dr. Lori Stepan Van Der Sluys 2 Organic
1. YDROARBONS 2. FUNTIONAL GROUP LASSES Example: O l N 2 alcohol halide amine Dr. Lori Stepan Van Der Sluys 3 Organic
lasses of ydrocarbons Dr. Lori Stepan Van Der Sluys 4 Organic
MULTIPLE BONDING IN YDROARBONS Simplest organic compounds ydrocarbons contain only which two elements? Alkanes saturated ( bonds) MAXIMUM number of attached to the skeleton. Alkenes Alkynes Aromatic unsaturated (double/triple bonds) Dr. Lori Stepan Van Der Sluys 5 Organic
Given a Molecular Formula such as 4 how can we deduce the Structure? Dr. Lori Stepan Van Der Sluys 6 Organic
Structure affects Function. The classes of hydrocarbons have significant differences in structural features: these differences affect the (reactions, properties) of the molecules To aid in deducing the structure of molecules given the molecular formula, we use the rules of. The Valence of an atom is: Rules of valence Element # Bonds 1 4 N 3 O, S 2 F, l, Br 1 Dr. Lori Stepan Van Der Sluys 7 Organic
Dr. Lori Stepan Van Der Sluys 8 Organic Know the first 10 Alkanes: In general: n 2n+2 Lewis structures
Structure of Alkanes All atoms have tetrahedral geometry: the bonds point to the vertices of a tetrahedron. Bond angle = an represent the chains as zig-zags or Straight chained octane (n-octane): Branched octane (iso-octane): 3 3 2 3 3 3 Dr. Lori Stepan Van Der Sluys 9 Organic
Structural Isomers have the same, but different. Dr. Lori Stepan Van Der Sluys 10 Organic
YLI ALKANES Alkanes can form rings: n 2n Examples: cyclopentane 5 10 2 2 2 or 2 2 cyclohexane: 6 12 or 1,1-dimethylcyclobutane 3 3 Dr. Lori Stepan Van Der Sluys 11 Organic
STRUTURE VARIATION IN ALKENES ontain one or more double bonds n 2n The = or = angle is 3 ethene (ethylene) propene (propylene) Rotation about double bond is Dr. Lori Stepan Van Der Sluys 12 Organic
STRUTURAL VARIATION There are several possible structures for a chain of 4 carbons with one double bond Butene 4 8 1-butene 2-methylpropene 2-butene cis-2-butene trans-2-butene Dr. Lori Stepan Van Der Sluys 13 Organic
Structural isomers: same molecular formula: different 1-butene 2-methylpropene 2-butene Geometric isomers same molecular formula: different cis-2-butene trans-2-butene cis-isomer: same side trans-isomer: opposite side (across) For geometric isomers: atoms have the same structure (are joined in the same way), but arrangement in space (geometry) is different. For alkenes, geometric isomers occur because of the rotation about the = bond. Dr. Lori Stepan Van Der Sluys 14 Organic
DO ALKYNES AVE ISOMERS? n 2n-2 Alkynes contain what kind of a bond? ethyne (acetylene) 3 propyne bond angle is 3 2 3 3 1-butyne 2-butyne Dr. Lori Stepan Van Der Sluys 15 Organic
Properties and reactions of Alkanes Properties: 1. 2. Reactivity: 1. 2. 3. ombustion: alkanes are fuels 3 2 3 + 5O 2 3O 2 + 4 2 O omplete combustion: Incomplete ombustion: Dr. Lori Stepan Van Der Sluys 16 Organic
Addition Reactions of Alkenes & Alkynes Double and triple bonds are reactive For Alkenes 3 = 2 + Br 2 3 = 3 + X (where X = l, Br, I, O, etc.) For Alkynes 3 + 2Br 2 3 3 + 2l Dr. Lori Stepan Van Der Sluys 17 Organic
Aromatic ydrocarbons ontain alternating single and double - Bonds Benzene is prototypical molecule Usually written: Aromatic hydrocarbons are less reactive than alkenes: WY? Special kind of bonding results in: 1. 2. Dr. Lori Stepan Van Der Sluys 18 Organic
Functional Group classes ontain a representative group of elements in a fixed pattern ave similarities in and (reactivity). Seemingly small changes in structure can have big effect on molecular properties Example: adding an oxygen changes a hydrocarbon into an alcohol or an ether Functional Group Type hydrocarbon alcohol ether 3 2 ethane ethanol di-methyl ether gas bp 89 liquid bp 78 gas bp 24 water soluble Dr. Lori Stepan Van Der Sluys 19 Organic
FUNTIONAL GROUP LASSES (R, R and R = alkyl groups) Alcohol R-O R Amine N N R' R N R' R R R" Ether R-O-R R,R alide R-X X = halogen Groups which have a carbonyl: O O O R R R' Aldehyde Ketone (R, R ) O O O R O R OR' R NR' arboxylic Acid Ester Amide Dr. Lori Stepan Van Der Sluys 20 Organic
The presence and properties of functional groups are responsible for the action of drugs. What functional groups are present in these molecules? Acetyl salicylic acid O O O O 3 Acetaminophen O N 3 O Ibuprofen Dr. Lori Stepan Van Der Sluys 21 Organic
Multiple Bonds: Practice Questions Which of the following hydrocarbon classes does NOT have a double or triple bond? 1 alkane 2 alkene 3 alkyne 4 aromatic Which one of the following functional group classes does not have a double bond? 1 aldehyde 2 ketone 3 amine 4 carboxylic acid Dr. Lori Stepan Van Der Sluys 22 Organic