H2 Chemistry 9 - Intro to organic chem

alkanes; C_nH_2n+2

alkenes; C_nH_2n

cycloalkanes; C_nH_2n

arenes; C₆H_{6(-1 if group attached)}

halogenoalkanes/alkyl halides; C_nH_2n+1X

aryl halides; C₆H₅X

alcohols; C_nH_2n+1OH

phenols; C₆H₅OH

carboxylic acids; C_nH_2nCOOH

acyl chlorides; C_nH_2nCOCl

amines; C_nH_2n+1NH₂

nitriles; C_nH_2n+1CN

specific group of atoms attached to C backbone, common to series of organic compounds, determines principal chemical properties of series

covalent bond breaks such that each bonded atom takes 1 of 2 bonding e^-, form free radicals >

occurs when 2 bonded atoms similar electronegativity

covalent bond breaks such taht only 1 bonded atom takes both bonding e^- form anion, remaining molecule becomes cation >

occurs when 2 bonded atoms diff electronegativity, > electronegative takes both e^-

ion w/ +vely charged C atom

e^--deficient species, accept e^- & attack e^--rich centre of organic molecule >

lewis acid

e^--rich species, donate e^- & attack e^--deficient centre of organic molecule >

lewis base

organic molecule reacts w/ another molecule, give only 1 product

1 atom/group of atoms in organic molecule replaced by another atom/group of atoms

small molecule removed(b/w 2 adjacent C) from organic reactant

2 molecules combined, form larger molecule w/ elimination of small molecule

molecule split into 2 by action of H₂O

removal of H/addition of O/loss of e^-

represented by [O]

addition of H/removal of O/gain of e^-

represented by [H]

mixing atomic orbitals to form new hybrid orbitals

1 2s orbital + 3 2p orbitals = 4 equivalent sp³ hybrid orbitals; degenerate arranged 109.5^o to EO tetrahedrally >

4 sp³ orbitals used to form σ bonds >

in methane, C uses 4 sp³ orbitals for head-on overlap w/ 4 1s orbitals of 4 H atoms, form 4 equivalent C-H σ bonds, arranged tetrahedrally

1 2s orbital + 2 2p orbitals = 3 equivalent sp² hybrid orbitals; degenerate, arranged 120^o to EO on same plane in trigonal planar >

3 sp² orbitals used to form σ bonds, unhybridised 2p orbital used to form π bond >

in ethene, each C uses 3 sp² orbitals for head-on overlap w/ 1 sp² orbital of another C & 2 1s orbitals of 2 H, form σ bonds >

unhybridised 2p orbital of 1 C undergoes sideway overlap w/ unhybridised 2p orbital of another C, form π bond

1 2s orbital + 1 2p orbital = 2 equivalent sp hybrid orbitals; degenerate, arranged 180^o to EO on same plane linearly >

2 sp orbitals used to form σ bonds, 2 unhybridised 2p orbitals used to form π bonds >

in ethyne, each C uses 2 sp orbitals for head-on overlap w/ 1 sp orbital of another C & 1 1s orbital of H, form σ bonds arranged linearly >

2 unhybridised 2p orbitals of 1 C undergo sideway overlap w/ 2 unhybridised 2p orbitals of another C, form π bonds

for polar organic reaction mechanisms(w/ nucleophiles/electrophile), e^- pairs always flow from e^--rich site to e^--deficient site illustrated by full curly arrow

compounds have same molecular formula but different structural formulae >

chain isomerism; arises due to branching of C chain, > branched, <m.p/b.p

positional isomerism; functional group placed @ diff position

functional group isomerism; diff FG, diff chemical/physical properties

occurs when there is;

1. restricted rotation about C=C double bond/C-C single bond in ring structure

2. 2 diff groups of atoms on each C >

cis- isomers; identical groups on same side of DB

trans- isomers; identical groups on opposite sides of DB

chiral carbon; i.e asymmetric C bonded to 4 diff groups of atoms

given molecule is chiral if;

1. contains chiral C

2. no plane of symmetry

identical physical & chemical properties, but different biological properties >

each enantiomer in a pair rotates plane-polarised light(i.e. optically active) w/ same magnitude but diff direction >

if soln contains equal proportion of 2 enantiomers, rotating power of 1 cancel out that of the other, no net rotation of plane-polarised light; racemic mixture(optically inactive)

2ⁿ, where n = no. of stereocentres, i.e. chiral C + cis-trans centre

identify chiral C centres(mark w/ *) >

draw 3D tetrahedral arrangement around chiral C; dashed line = into plane, triangular line = out of plane, straight line = on plane >

draw dotted line represent mirror, draw mirror image >

label pair as 'non-superimposable mirror images'