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ORGANIC CHEMISTRY
Definitions
Organic chemistry - study of carbon-containing compounds
Hydrocarbons - compounds made of only carbon and hydrogen
Biochemistry - organic chemistry involved in life processes
Bonding
(1) Single
bond
H
H-C-H
H
Each - represents 2 electrons
(2) Double
Bond
H-C=C-H
H H
Double and triple bonds are referred to as "unsaturated"
(3) Triple
Bond
H-C/
C-H 2 single bonds between C-H
Formulas
(1) Molecular formula-number and kinds of atoms, but no idea what it looks
like C4H10
Structural formula - order of attachment of atoms in a molecule.
H H H H
H-C-C-C-C-H
CH3CH2CH2CH3
H H H
H
Condensed structural formula
expanded structural formula
Dimensional formula - geometry stressed
ALKANES
Single Bonds
Paraffins
Types of Alkanes
Straight
Chain
H H
H-C-C-H
CH3CH3 or C2H6
H H
H H
Cyclic
HC - CH
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HC - CH
H H
Branched
C- C- C- C-C- C
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C C
Nomenclature
CH4 -
methane
C6H14 - Hex__________
C2H6 -
ethane
C7H16 - Hept_________
C3H8 - propane C8H18 - _____________
C4H10 - butane C9H20 - non__________
C5H12 - pentane C10H22 - dec_________
AlkANES end in ANE
Look at the numbers:
1,4; 2,6 ;3,8; 4,10; 5,12; 6,____; 7,_____
CnH2n+2 - general formula for alkanes
How many hydrogens are there in the alkane having 22 carbons?
CH4 - natural gas
C2H6 - also in natural gas
C3H8 - heating gas
C4H10 - heating
pet ethers - C5 C6
C7 mixture - solvent
alkanes 4 to 12
heating oils
lubricating oils
waxes
C12 C15
C15Oils - C20
Waxes - C26-C30
straight chain
normal octane - straight chain
C-C-C-C-C-C-C-C
branched chain
C
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C-C-C-C-C
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C C
Names
methyl CH3
C
ethyl C2H5
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propyl C3H7
C-C-C-C-C-C-C
C4H9
3-methyl heptane
C
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C C C C C C C
3,3 dimethyl heptane
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C
Having the same molecular formula but different structural formulas
-isooctane
Isomers
the longest straight chain (you can count around corners)
groups on the chain
C
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(a) C-C-C-C-C-C
________________________ hexane
C C
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(b) C-C-C-C-C-C
________________________ hexane
C
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(c) C-C-C-C-C
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C - C
_________________________
Drill
(1) n-pentane
(2) cyclopentane
(3) 2-methyl propane
(4) 3,3 dimethyl pentane
Name
(1) C-C
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C-C C-C
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C-C C-C
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(4) C-C
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C-C-C-C-C-C
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C
________________________________
Reactions of Alkanes
although generally unreactive, these reactions do occur
1. Halogenation
Ultraviolet
light
CH4 + CCl2 ------> CH3Cl + CH2Cl2 + CHCl3
+ CCl4 + HCl
2. Combustion burning in oxygen
spark
CH4 + 2O2 ------> CO2 + 2H2O + energy
Alkenes
Alkenes and in ENE
Have one or more double bonds
C-C=C-C butene
Formula for alkenes Why? 2 hydrogens are replaced by a double bond.
CnH2n
Where can the double bond be?
C=C-C-C-C
1-pentene
C-C=C-C-C
2-pentene
C-C-C=C-C
_________
C-C-C-C=C
_________
2 double bonds - called diene
3 double bonds - called triene
Samples
CH2=CH-CH=CH2
4 carbons buta
2 double bonds butadiene
Where are the = located 1,3-butadiene
Name
(1) C-C=C-C=C-C-C-C-C
(2) C-C=C-C=C-C=C-C-C
(3) C-C-C-C-C-C-C-C
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C=C
Which is the parent chain of #3? 8 C alkane or 7C alkene? Ans: Alkene
Isomers
C-C
Carbons can turn in a single bond (sigma bond).
C=C Carbons can't turn in a double bond so we get isomers (pi bond).
Cis - same side
Cl Cl
Cl H
C - C
C - C
H H
H Cl
Trans - across - opposite
trans have to have at least 2 different groups on the carbon atom
Reactions of Alkenes
Hydrogenation
H H
H H
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C = C ------> H C - C H
H H
H H
ethene or ethylene
Animal fats are solid. The vegetable fats (oils) are liquid. Crisco in the
can is solid but is made with vegetable oils. To make it solid, the oils are hy
Halogenation
Br Br
H-C=C-H + Br2 ----------> H-C-C-H
H H
H H
Oxidation
(1) mild oxidation - alcohol OH
(2) strong oxidation - acid COOH
Polymerization
(1)
H2C=CH2 -----------------------> -(CH2CH2CH2CH2CH2CH2)n
ethene or ethylene Polyethylene
(2)
H H
H H H H H
H
C=CH -------------------> -(C - C - C - C - C - C-)
H Cl
H Cl H Cl H Cl
vinyl chloride
Polyvinyl Chloride
PVC
(3) H H
H H H H H
H
C=C ---------------> -C - C - C - C - C - C
H F
H F
H F
H F
Styrene Polystyrene (styrofoam)
benzene ring F
ALKYNES
Presence of triple bond
Ending in 'yne'
HC CH
ethyne or actylene
H3CC CCH3 2-butyne
Triple bond very reactive
ORGANO HALIDES
Halides are the halogens Cl, F, Br, I
(a) Chain-straight, branched or cyclic - alkyl halide
(b) Aromatic ring (benzene) Aryl Halide
Naturally occurring halogen compounds
thyroxin
chloroform CHCl3
Nomenclature
(a) find longest chain - parent - then give position of halogen
H Cl H H
H-C-C- C-C-H
2-chlorobutane
H H H H
(b) sometimes use "ide"
CH3Br methylbromide
CH3CH2Cl ethyl chloride
Important halogenated hydrocarbons
*(1) chloroform CHCl3
*(2) carbon
tetrachloride CCl4
(3) freon CCl3F CCl2F2 C2F4Cl2
(4) Vinyl chloride C2H3Cl
(5) DDT dichlorodiphenyltrichlorethane
Reactions of halides
Substitution
CH3CH2Br + Na (OH)- -----> CH3CH2OH + NaBr-
CH3CH2Br + H2O -----> CH3CH2OH +
HBr-
AROMATIC RING STRUCTURES
Called aryl for aromatic. (Aroma - odor) Non-ring compounds are called alkyl.
Have a ring structure with double bonds.
Benzene
Benzene - a 6 carbon ring with alternating double bonds C6H6
When one hydrogen of a benzene ring is replaced by an element or ring, the
ring is called phenyl (C6H5) or benzyl (C6H5). Phenylalanine = amino acid Benzyl
oxide = zits medicine
Toluene also called methyl benzene Phenol
Naming ring structures (o,m,p order me pizza)
ortho - two groups are adjacent
meta - a carbon is between the groups
para - two carbons are between the groups
Ortho
Meta
Para
1,2-dichlorobenzene
1,3-dichlorobenzene
1,4-dichlorobenzene
Naphthalene - two rings joined together
Anthracene - three rings joined together also known as PAH polyaromatic
hydrocarbons.
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