ORGANIC CHEMISTRY 1 3 The chemistry of carbon

ORGANIC CHEMISTRY 1. 3 The chemistry of carbon / hydrogen containing compounds 1

HYDROCARBONS THE SIMPLEST TYPE OF ORGANIC COMPOUNDS HYDROCARBONS - CONTAIN ONLY C, H 2

HYDROCARBONS H H HH C H H C C C H H H H HH C H H H C C H H H H ALKYNES H C C C H H at least one triple bond 3

COMMON HYDROCARBON TYPES H Saturated hydrocarbons H H HH C H H C C C H H H H HH C H H H Unsaturated hydrocrabon C H H H C C C C H H H H ALKYNES H H H C C C H H only single bonds at least one double bond at least one triple bond 4

HYDROCARBON DERIVATIVES One or more H’s are replaced with an atom of O, N, S, F, Cl, Br, I 5

HYDROCARBON DERIVATIVES H H H C C Cl H H H H H C H C C OH H H C C C O H H H 6

Saturated Hydrocarbons cont’d Fig. 1. 2 Terms for organic compounds. 3 -6) 7

1. 4 Alkanes • Acyclic (no rings) = alkane H H HH C H H C C C H H H H HH C H H • Cyclic (contains rings) Section 1. 12 H H C C C H H H C C H H H H H C C C H H 8

1. 4 Alkanes (cont. ) q Are acyclic “saturated” hydrocarbons. q Contain only single bonds C-C q Every carbon is sp 3 (tetrahedral) q General formula of alkanes is Cn. H 2 n+2 ØCH 4 Ø C 2 H 6 Ø C 3 H 8 9

1. 4 Alkanes ← Fig. 1. 3 Molecular structures of (a) methane, (b) ethane, and (c) propane, the three simplest alkanes. 10

1. 5 Structural formulas q. Condensed (easier and faster to draw) Methane Ethane Propane CH 4 CH 3 -CH 3 -CH 2 -CH 3 12

1. 5 Structural formulas q. Condensed Octane: CH 3 -CH 2 -CH 2 -CH 3 q. More condensed CH 3 -(CH 2)6 -CH 3 13

1. 6 Alkane Isomerism Linear carbon chain Octane: CH 3 -CH 2 -CH 2 -CH 3 Branched carbon chain (acyclic) CH 3 | CH 3 -CH-CH 2 -CH 3 14

CONSTITUTIONAL ISOMERISM • Same molecular formula, different connectivity of the atoms • As the #C increase the #isomers increases very rapidly (Table 1. 1) 15

1. 7 Conformations of alkanes MOST ATOMS ATTACHED BY A SINGLE BOND ARE FREE TO ROTATE AROUND THE BOND The relative orientation of the atoms is called a CONFORMATION HOW MANY CONFORMATIONS ARE THERE? 16

CONFORMATIONS OF BUTANE SAWHORSE PROJECTIONS OF PREVIOUS SLIDE SYN CH 3 C H H H GAUCHE H CH 3 C C H H CH 3 H C C H H CH 3 H ECLIPSED ANTI H GAUCHE CH 3 H H C C H CH 3 H C C CH 3 H H H CH 3 ECLIPSED H C C H H H 17

1. 8 IUPAC RULES systematic nomenclature I nternational U nion of P ure and A pplied C hemistry colloquially: “eye-you-pac” 18

FEATURES OF THE IUPAC SYSTEM It is a system where every compound (even isomers) has a unique name. If the rules are followed, everyone gets the same name for a given compound. Once given the name, anyone can draw the structure of the compound. STRUCTURE IUPAC NAME WORKS BOTH DIRECTIONS 19

1. 2 20

IUPAC METHOD 1. Find the longest continuous chain of carbon atoms and name it using the linear alkane names. 2. Number the chain starting from the end nearest a branch. 21

IUPAC METHOD 3. Give each substituent a name based on the number of carbon atoms it has. 4. Give each substituent a locant number determined by its location on the chain. 5. Assemble the name. 22

RULE 1. FIND THE LONGEST CONTINUOUS CHAIN OF CARBON ATOMS AND NAME IT C-C-C-C-C-C C 9 it won’t always be the horizontal one as shown here NONANE all possibilites must be examined try these also ……. . C-C C- C-C-C-C C 6 C-C-C-C-C-C C 8 23

RULE 2. Number the chain starting from the end nearest a branch 1 2 C-C nonane 3 4 5 6 7 8 9 C-C-C-C-C C 24

RULE 3. Give each substituent a name based on the number of carbon atoms it has. substituent C-C 1 2 nonane 3 4 5 6 7 8 9 C-C-C-C-C C substituent Groups attached to the main chain are called substituents. 25

(substituents) methyl propyl butyl pentyl hexyl heptyl octyl nonyl decyl 26

RULE 3. Give each substituent a name based on the number of carbon atoms it has. ethyl C-C 1 2 nonane 3 4 5 6 7 8 9 C-C-C-C-C C methyl 27

Rule 4. Give each substituent a locant number determined by its location on the chain. 4 - ethyl C-C 1 2 nonane 3 4 5 6 7 8 9 C-C-C-C-C C 2 - methyl 28

RULE 5. Assemble the name. LOCANT number SUBSTITUENT word MAIN CHAIN STEM word name of the substituent indicates position of the substituent on the chain indicates the number of carbon atoms in the chain ENDING “ane” suffix indicates the type of compound 29

PUNCTUATION RULES 1. Numbers are separated from words by hyphens 2 -methyl……. 2. Numbers are separated from numbers by commas. 2, 3 - ……. . example coming shortly 3. Substituents are named in alphabetical …… 4 -ethyl-2 -methyl…. order 4. All words are joined - no breaks ……methylnonane 30

ASSEMBLING A NAME 4 -ethyl C-C 1 2 nonane 3 4 5 6 7 8 9 C-C-C-C-C C 2 -methyl 4 -ethyl-2 -methylnonane 31

ORGANIC NOMENCLATURE 4 1. find longest chain and name 3 2 1 butane 2 - methyl 2. number from end nearest a branch 3. name substituents 4. locant number 5. assemble name 2 -methylbutane 32

Name this compound 1 2 3 4 5 33

Name this compound 4 3 2 5 6 7 1 34

Use multipliers if there are MORE THAN ONE of the same substituent 2 3 4 5 6 7 8 9 10 DITRITETRAPENTAHEXAHEPTAOCTANONADECA- These are ignored when alphabetizing 35

How would you name this one? Every substituent must get a number 1 2 3 4 5 6 36