Chapter 1-Continue Introduction to Organic Chemistry

Writing Dot Lewis Structure with multiple center atoms Carbons will also be the center atom in the organic molecule ◦ -C-C-C- chains Hydrogen is connected to carbon unless it’s an oxyacids (HClO, etc..) or Carbon has no more valence electrons to share Order of increasing EN ◦ (least) C  N  O  F (most)

Write a Dot Lewis structure for CH3COOH

Example Write a Dot Lewis Structure for CH 3 NH 2

VSEPR Theory VSEPR theory proposes that the geometric arrangement of terminal atoms, or groups of atoms about a central atom in a covalent compound, or charged ion, is determined solely by the repulsions between electron pairs present in the valence shell of the central atom

VSEPR Thoery Common shape and angles ◦ Linear (180 o ) ◦ Tetrahedral (109.5 o ) ◦ Trigonal planar (120 o ) See table 1.2 page 5

Examples Complete the following Dot Lewis structure by adding the missing lone- pair then predict the bond angles a. b. c.

9 Elements in Organic Compounds In organic molecules, carbon atoms bond with four bonds. mostly with H and other C atoms. sometimes to O, N, S. sometimes to halogens F, Cl, and Br. Table 1.3 page 7

10 Functional groups are a characteristic feature of organic molecules that behave in a predictable way. composed of an atom or group of atoms. groups that replace a hydrogen atom in the corresponding alkane. a way to classify families of organic compounds. Functional Groups

Alcohol An alcohol contains the hydroxyl (-OH) functional group. R-OH

Writing structural formulas of Alcohol CH 4 O Molecular formula CH 3 OH Condensed formula

Writing structural Formulas of Alcohols Draw Lewis structure and condensed structural formulas for the four alcohol with molecular formula C 4 H 10 O. Classify each alcohol as primary, secondary or tertiary. ◦ Hints: Consider the connectivity of the four carbon atoms; they can be bonded either four in a chain or three in a chain with the fourth carbon as a branch on the middle carbon. Then consider which carbon should connect to OH with having the same molecule

Amines In amines, the functional group is a nitrogen atom. RNH2, R2NH or R3H | —N —

Examples Draw structural formulas of the three secondary amines with the molecular formula C 4 H 11 N

Carboxylic Acids Carboxylic acids contain the carboxyl group, which is a carbonyl group attached to a hydroxyl group. –COOH O ║ — C—OH

Examples Draw condensed structural formulas for the two carboxylic acids with molecular formula C 4 H 8 O 2

Carboxylic esters An ester contains the carboxyl group between carbon atoms. –COOR or –CO2R

Examples Draw structural formulas for the four esters with the molecular formula C 4 H 8 O 2

20 Learning Check Classify each of the following as: alcohol, ether, aldehyde, ketone, carboxylic acid, ester, amine, or amide. 1)CH 3 ─CH 2 ─CH 2 ─OH 2) CH 3 ─O─CH 2 ─CH 3 3) CH 3 ─CH 2 ─NH 2 O O ║ ║ 4) CH 3 ─C─OH 5) CH 3 ─C─O─CH 3

Examples Consider the formula C 4 H 8 O 2. Write the structural formula for this molecular formula with ◦ A carboxyl group ◦ Ketone group and a 2 o alcohol group ◦ An aldehyde and a 3 o alcohol group ◦ A carbon-carbon double bond and a 1 o alcohol