Chem 163 mid term

Steric Number

The number of attached atoms and the number of lone pairs

Carbon is ususally bonded to 4 things with

four single bonds (sigma bonds) but you can also have pi bonds

Sec-butyl

R — CH(—CH3)—CH3

Tert-butyl

R—C(—CH3)2—CH3

Acetylene

C2H2

Acetone

CH3C(O)CH3

Vinyl Group

CH2=CH-

Styrene

C6H5CH=CH2

Sigma bonds are formed by

Head -to Head overlap of orbitals these are always single bonds.

Pi bonds are formed though

side to side overlap or orbitals these are in double bonds

A chiral carbon has

4 unique sub stituents

Structural isomer

same formula differnt arrangements of attoms ( Chain (branched or straight) Positon (1-ene 2- ene) Functional (cyclo alkane))

Stereoisomers

Same formula AND same position but different 3d arrangement (Cis/Trans - optical)

Arene

Cyclic unsaturated compounds (benzene) aromatic hydrocarbons, conjugated, the electron density is delocalized the double bonds really move

Geometry of an arene

planar

Hybridization of carbons on an Arene

sp2

Huckels rule

Predicts a planar ring molecule will have aromantic properites if it has 4n+2pi e- when n is a non negative intereger

In Huckels rule when N is not an integer

the compound is Antiaromatic and unstable.

• Alkyl

-CH3

• Alkenyl

-CH=CH2

-Alkynyl

-C=-CH

-Phenyl

C6H5

-amino/ amine

-N(H,R)2

-hydroxyl/ alcohol

-OH

-alkoxy/ether

R-O-R'

• Alkyl Halide

R-F,Br, CL, I

• thiol

-SH

• Aldehyde

-C(=O)-H

-Ketone/-one

R-C(=O)-R

-Ester/- ate

-C(=O)-O-R

-Carboxylic acid / ic Acid

-C(=O)-OH

Amide

-C(=O)-N(H,R)2

OIL

Oxidation is Loss

RIG

Reduction is gain

Oxidation is

the lost of electrons and H and adding oxygen

Reduction

is Gaining electrons and H and losing oxygen

A first degree alcohol

is connected to 1 other carbon

a second degree alcohol

is connected to 2 other carbons

a third degree alcohol

is connected to 3 other carbons

Alcohols can be oxidized to give

Aldehydes and ketones

A primary alcohol can be oxidized to

aldehyde

A Secondary Alcohol can be oxidized to

a Ketone

Aldehyde can be further oxidized to a

carboxylic acid

Replacing the H on an alcohol with a r group gives a

Ether

Replacing the H on a carboxylic acid with an R group gives a

Ester

Ammonia

NH3

Primary Amine

R-NH2

Secondary Amine

R-N(H)-R

Tertiary Amine

N(R)3

Carboxylic acid + a secondary amine yields

Amide + water

Constructive interference

Bonding interaction (No star) no node

Destructive interference

Antibonding interaction (with star) Node

Orthogonal

when p and s orbitals are perpendicular

If one s and p orbital is head to head, and the the other 2 are orthogonal those 2 are

nonbonding

Linear Combination of Atomic Orbitals

LCAO The number of Molecular orblitals is equal to

Ther number of atomic orblitals brought by the atoms that are being combined

LCAO molecular Bonding Molecular orbitals are lower in energy than the

Parent orbitals

LCAO Antibonding orbitals are higher in energy that the

Parent orbitals

LCAO Electrons in the Atomic orbitals are assigned to____ filling from

Molecular orbitals , lowest to higher energy

To form molecular orbital there are 3 requirements

1. AOs are close to each other 2) AO,s have similar energy 3 AO's have same symmetry

Sigma orbitals do not change

Conformation along the axis of bonding

Pi molecular orbitals are ___ to rotation

Antisymmetric

Gerade

symmetric to inversion

Ungerade

asymmetric to inversion

Most electronegative atom has ___ atomic energy

Lower

In Heteronuclear Diatomic molecules, electrons that don't interact with bonding are at the

same energy level

For bonds not involved in resonance the bond order is equal to

the bonds

For bonds involved in resonance you have

fractional bond orders

For bonds involved with resonance take the ___ of the two bond orders

Average

Bond order is equal to ____ minus ____ over___

bonding electrons, antibonding electrons, 2

In Heteronuclear Diatomic molecules, the electronegative species contributes more to the _____ and the less electron negative species contributes more to the ____

Bonding orbitals, Antibonding orbitals

Pz orbitals can have _____ bonding, Px and Py can _____ bond

Sigma, Pi

Sigma bonds are _____ in comparison to pi bonds because there is more _____

Stronger overlap

LUMO stands for

Lowest Unoccupied Molecular Orbital

HOMO stands for

Highest Occupied Molecular Orbital

1,3 butadiene has four p orbitals from lowest to highest energy the conformations are

All bonding, two bonding pairs, one bonding pair, all antibonding

Deprotonation of a carboxylic acid with a _____ will produce a _____

Base, Carboxylate ion [R(=O)-O-]

Carboylate ions have _____, therefore instead of one ____ and one ___ charge, they bothe have ____ charge

resonance, negative, positive, -1/2

Amides can ___ their charge for stability

Delocalize

Alkene + HX yields

Alkyl Halide (Markovnikcov)

Alkene + water (with ___catalyst) yields

Acid, alcohol (Markovnikcov)

Alkene + alcohol (with ___ catalyst) yields

ether (Markovnikov)

Alkene + halogen yields ____ and give ___ product

Dihaloalkane, Trans

Carboxylic acid + alcohol (with ___ catalyst) yields

acid, ester + water

Carboxylic acid + Amine yields

amide + water

Carboxylic acid + -B; yields

Carboxylate + HB+

Alkyl halide + OH- yields alcohol + x-

Markovnikov's rule states

The halogen/ hydroxyl/ alkoxy group will end up on the carbon with the fewest hydrogens

Halogenation is stereoselective meaning

the two halogen atoms will form bonds on opposites sides of the pi bond

Fischer Esterification

adding two groups containing oxygen to make an ester

The acidic hydrogen of carboxylic acids can be removed using

Bronsted lowery bases/ proton acceptors

In alkene hydrogenation, the hydrogens add syn meaning

they add on the same face of the carbon

Nuleophile is

an electron pair donor