Intro to Org Chem

Bonding e- are assigned to the more electro-ve atom (gains 1 e-, ON decreases by 1) If a bond is formed b/w 2 atoms of the same element, both atoms have the same electro-vity, no gain/lose of e- Ans: 1/3 (-3-2-1) = -2

Aliphatic hydrocarbons - open chains of C atoms - str. chain hydrocarbons (saturated C-C, unsaturated C = / 三 C) Alicyclic hydrocarbons - closed ring of C atoms (cyclo…) Aromatic hydrocarbons - contains benzene ring

• can be represented by a general formula • differs from the successive member by a CH2 grp • shows a grad change in phy properties such as bp • similar chem properties • can be prepared by similar methods

Hydrocarbons | alkane | - | Cn H2n+2 Hydrocarbons | alkene | C=C | Cn H2n Hydrocarbons | alkyne | C 三 C | Cn H2n-2 Halogen derivatives | halogenoalkane | -X (X = Cl, Br, I) | RX | chloroethane Halogen derivatives | halogenoarene | benzene ring - X | - | chlorobenzene Hydroxy compounds | alcohol | -OH | R-OH | ethanol Hydroxy compounds | phenol | benzene ring -OH | - | phenol O || Carbonyl compounds | aldehyde | - C - H | with a R | ethanal O || Carbonyl compounds | ketone | - C - | with 2 R | propanone O || Carboxylic acid & derivatives | Carboxylic acid | - C - O - H | with R | ethanoic acid O || Carboxylic acid & derivatives | Ester | - C - O - | with 2 R | methyl ethanoate O || Carboxylic acid & derivatives | Acyl/acid halide | - C - X | with R | propanoyl chloride H || Nitrogen compounds | Amine | - N - H (pri amine) | with a R | ethylamine O H || || Nitrogen compounds | Amide | - C - N - H (pri amide) | with a R | propanomide H H O | | || Nitrogen compounds | Amino acid | H - N - C - C - O (pri amine) | same | alanine | | R H Nitrile | - C 三 N | R - C 三 N | propanenitrile

Is made up of an atom or a grp of atoms within the org compound that is responsible for its characteristic chemical properties

Family of compounds having the same functional grp

Empirical - simplest ratio of the diff types of atoms Molecular - shows actual no. Structural ~ Displaced/full structural - show every atom, but C & H atoms in rings are not shown ~ Condensed - show how grps of atoms are Sequentially arranged, bond lines are omitted except for rings, ( ) around similar grps bonded to the same atom ~ skeletal - shows carbon skeleton with any func. grps, H atoms attached to C are not shown (those attached to O are tho) ~ Stereochemical - show spatial 3D struc ‘—-‘ same plane ‘ ||||| ‘ into paper ‘ coloured triangle’ coming out of paper

Straight chain are in /\/\/\/\ format when drawing single bonds, direction is irrelevant (turning thingy) how to draw double n triple bonds when heteroatoms (atoms other than C & H) are bonded to a carbond skeleton, it must be joined directly to the carbon EXCEPT for alkyl grps ( H on the right of C)

Prefix(es) Root Suffix Step 1: suffix n root Suffix = principal func grp (IF there’s >1 func grp, the one with higher priority is listed as the suffix - others as prefix) Root = select longest continuous C chain, containing the prin. func. grp & C-C multiple bond (if any) Meth | eth | prop | but | pent | hex | hept | oct | non | dec (Maggie escaped prison by plane…) Add cyclo in front for an alicyclic system - ethane = ethene 三 ethyne Step 2: Identify prefixes Step 3: Positional no. (1) lowest-principal func grp (2) lowest - C-C multiple bond (3) lowest - position of substituent (if there's a few, the sum should be lowest) Step 4: string prefixes together If same sub. appears, add di-, tri-, tetra- add appropriate positional no. list prefixes in alphabetical order commas separate no., - separate no. & words Step 5: everything together 3 - animo - 2 - chloro - 4,4,5 - trimethylheptanoic acid

refers to the existence of 2 or more compounds with the same molecular formula but diff arrangements of the atoms in their molecules. These compounds are known as isomers.

Constitutional isomerism: Chain isomerism. positional isomerism, functional grp isomerism Stereoisomerism: Cis-trans isomerism, enantiomerism

Existence of 2 or more compounds with the same molecular formula and structural formula but diff spatial arrangement of atoms

• Restricted rotation abt a bond either by the presence of a double bond OR ring struc • For an alkene, each C in the C=C bond must have 2 diff grps attached to it. For a cyclic compound, 2 or more C atoms in the ring must each have 2 diff grps attached to them [no cis-trans for double bond in ring, only OUTSIDE the ring] If the no. of C=C bonds is n, the max no. of cis-trans isomers for the compound is 2^n Cis-trans also possible for N=N, C=N

Cis-but-2-ene (*C shape): Higher bp - slightly higher polarity (net dipole moment), Lower mp - fits into crystalline lattice more poorly Cis & Trans have similar chem properties (just react at diff rates), but diff physical properties

Forms a non-superimposable mirror image / no plane of symmetry has chiral carbon (chiral compounds) - sp3 hybridised with 4 diff grps attached to it

Phy properties are identical except they rotate the plane of plane-polarised light in equal but opp directions Chem properties identical except in their interaction with another chiral molecule Biological properties diff

1 chiral C but has a plane of symmetry has mirror images that are superimposable optically inactive

A molecule with n chiral carbons has a max of 2^n stereoisomers