Organic Chemistry Unit 1 Pt 1

molecular formula

number and types of atoms from which a compound is composed

constitutional isomers

compounds that have the same molecular formula but differ in the way the atoms are connected

covalent bond

result of two atoms sharing a pair of electrons

lewis structures

electrons take center stage of drawings

electronegativity

a measure of the ability of an atom to attract electrons the smaller the atom the more electronegative because closer electrons are to protons the higher attraction to outside electrons

non polar covalent bond

if two atoms bonded have similar electornegativity values the electrons in the bond are shared equally

ionic bond

a bond that results from the force of attraction between two oppositely charged irons

bond line structures

all carbon atoms and most hydrogen atoms are implied but not explicitllu drawn in a bond line structure

debroglie

suggested that electrons considered as particles also exhibited wavelike properties

quantum mechanics

a mathematical description of an electron that incorporates its wavelike properties

wave equation

describes the total energy of a hydrogen atom that takes into account the wavelike behavior of an electron that is in the electric field of a proton

psi

each wave function corresponds to an allowed energy level for the electrons. suggesting that an electron in an atom can only exist at discrete energy levels aka the energy of the electron is quantized

psi squared

indicated the probability of finding an electron in that location generating an image of an atomic orbital

electron density

associated with the probability of finding an electron in a particular region of space

atomic orbital

a 3d plot of psi squared of a wave function. its a region of space that can accommodate electron density

nodes

locations where psi is zero in molecular orbitals (no electrons are there)

sign of psi

represents the phase of the wave not the charge of it

aufbaus principle

lowest energy orbital is filled first

pauli exclusion principle

each orbital can accommodate a max of 2 electrons that have the opposite spin (up or down)

hunds rule

when dealing witth degenerate orbital one electron is placed in each degenerate orbital first before electrons are paired up

what are the two theories to describe atomic orbital overlap

valance bond theory, and molecular orbital theory

valence bond theory

a bond is simply the sharing of electrons density between two atoms as a result of constructive interference of their atomic orbitals

consturctive interference

produces a wave with a larger amplitude

destructive interference

results in waves cancelling each other with produces a node

molecular orbital theory

atomic orbitals are mathematically combined to produce new orbitals called molecular orbitals

sigma bond

a bond that is characterized by circular symmetry with respect to the bond axis

difference between atomic and molecular orbitals

atomic orbital is the region of space associated with an individual atom whereas molecular orbital is associated with an entire molecule

bonding molecular orbital

result of constructive interference

antibinding molecular orbital

result of deconstructive interference (higher energy bc of node)

hybridization

mathematically average of orbitals

pi bond

a bond formed by adjacent or overlapping of orbitals

triple bond

formed by sp hybridized (1s orbital and 1 p orbital leaving 2 p orbitals unaffected by averaging leaving 2 unhybridized orbitals

steric number

total number of bonded atoms and lone pairs

dipole moment

the amount of partial charge on either end of a dipole multiplied by distance of separation

intermolecular forces

the attractive forces between molecules which is used to determine physical properties of

electrostatic

occurring as a result of the attraction between opposite charges all intermolecular forces are electrostatic

partially condensed structures

the c-h bonds are not all drawn explicitly

condensed structured

single bonds are not drawn instead groups of atoms are clustered together when possible (OH3)2CHOH

heteroatoms

atoms other than carbon and hydrogen

delocalized

when a charge is shared by two or more atoms

resonance

a series of structures that are melded together to circumvent the inadequacies of bond line drawings

resonance hybrid

a term used to describe the character of a chemical entity exhibiting more than one resonance significant structure

vinylic

a carbon atom of a c—c double bond

allylic

the positions that are adjacent to the vinyllic position

localized lone pair

a lone pair that is in a single location and doesn’t participate in resonance or the lone pair is not allylic to a pi bond