Organic Chemistry I

organic chemistry

branch of science that deals with compounds of carbon

valence shell

outer shell of an atom’s electrons

valence electrons

electrons in valence shell

ion

charged species

anion

negatively charged ion

cation

positively charged ion

octet rule

tendency of atoms to gain or lose electrons to have a noble gas configuration

heisenberg uncertainty principle

the accuracy with which we can determine the velocity and position of a particle is inherently limited

atomic orbital

wave properties of an electron in atom

principal quantum number

number used to designate an energy level

degenerate

identical energies

aufbau principle

orbitals fill up from lowest to highest energy

ground energy

lowest energy state

excited state

a state of higher energy

spin

magnetic property of electrons

pauli exclusion principle

when two electrons occupy the same orbital they have opposite spin

valence orbitals

orbitals containing valence electrons

core electrons

nonvalence electrons

hunds rules

electrons must fill empty orbitals first, all unpaired electrons must have the same spin

nodes

points at which the wave is zero

principal quantum number - 1

number of nodes in an orbital

delocalized

electrons spread over more than one atom

covalent bonds

two-electron bonds

valence bond theory

overlap of orbitals so that two electrons simultaneously share the space between two nuclei

hypervalent compounds

compounds with expanded octets

electrostatic attraction, ionic bond

attraction between oppositely charged ions

potential energy = kq1q2/r

electrostatic law

formal charge

charge assigned to a specific atom

resonance hybrid

“average” of two resonance structure

resonance structures, resonance contributors

the two individual lewis structures connected by a double headed arrow

resonance stabilized

when the actual molecule is more stable than any of the individual fictitious resonance contributors

atomic connectivity, constitution

specification of how atoms are connected

molecular geometry, molecular configuration

specification of how atoms are configured in space

bond length

distance between two bonded nuclei

covalent radius

radius of each bonded atom

bond order

number of covalent bonds shared by two atoms

bond angle

angle between each pair of bonds to the same atom

180 degrees

linear bond angle

120 degrees

bent bond angle

120 degrees

trigonal planar bond angle

109.5 degrees

trigonal pyramidal bond angle

109.5

tetrahedral bond angle

dihedral angle

angle between two planes on a molecule

bond orbital, sigma bond

a merged orbital resulting from the overlap of orbitals from two bonded atoms, looks the same no matter which way it is rotated about the line connecting the two atoms

valence orbitals

which are the only orbitals involved in hybridization

pi bond

bond whose orbitals overlap side to side

terminal atom

atom bonded to only one other atom

molecular orbital theory

theory that says electrons reside in orbitals of the entire molecule rather than bond orbitals

bonding molecular orbital

electrons’ crests and troughs align and reinforce each other to create an area with high electron density (larger wave peak) between the nuclei

antibonding molecular orbital

electrons’ troughs and peaks are added and wave cancellation occurs, creating a node (an area with no electron density) between the nuclei

(electrons in bonding MOs - electrons in antibonding MOs)/2

bond order formula

electronegativity

the tendency of an atom to attract electrons to itself

polar bond

a bond in which electrons are shared unequally

mu = partial charge * distance between charges

formula for dipole moment

bond dipole

dipole moment for an individual bond

polar molecule

molecule with significant dipole moment

hydrocarbons

compounds containing only hydrogen and carbon

aliphatic hydrocarbons

open hydrocarbon chains with single, double, or triple bonds, or non-aromatic hydrocarbon rings

alkanes

hydrocarbons with only single bonds

alkenes

hydrocarbons with carbon-carbon double bonds

alkynes

hydrocarbons with carbon-carbon triple bonds

aromatic hydrocarbons

hydrocarbons whose rings alternate single and double bonds

unbranched

carbons within the chain only bonded to two other carbons and two hydrogens

branched

carbons within the chain bonded to three or four other carbons

cycloalkane

carbon chain with single bonds that forms a ring

skeletal structure

structure where carbons are vertexes

methylene group

CH2

homologous series

a series of compounds that differ by the addition of methylene groups

isomers

different compounds that have the same molecular formula

constitutional isomers

isomers that differ in the connectivity of their atoms

principal chain

longest continuous carbon chain in the molecule

substituents

branching groups are called

alkyl groups

substituents of alkanes

isopropyl group

(CH3)2CH

isobutyl group

(CH3)2CHCH2

secondary butyl group

CH3CH2CHCH3

tertiary butyl group

(CH3)3C

methane

one carbon alkane

ethane

two carbon alkane

propane

three carbon alkane

butane

four carbon alkane

pentane

five carbon alkane

hexane

six carbon alkane

heptane

seven carbon alkane

octane

eight carbon alkane

nonane

nine carbon alkane

decane

ten carbon alkane

undecane

eleven carbon alkane

dodecane

twelve carbon alkane

number name and prefix of alkyl group, principal chain name

nomenclature order for alkanes

the one that gives the lower number to the first point of difference

which order to number carbons on principal chain

primary

carbon bonded to one other carbon

secondary

carbon bonded to two other carbons

tertiary

carbon bonded to three other carbons

quaternary

carbon bonded to four other carbons

newman projection

planar projection across one bond

staggered conformation

one C-H bond bisects the angle between two C-H bonds on the other carbon in a Newman projection

eclipsed conformation

C-H bonds on respective carbons are superimposed on each other in the Newman projection

torsional strain

higher energy of the eclipsed conformation

internal rotation

rotation about a bond