Organic Chemistry 1 Flashcards
What are isomers?
Chemical compounds that have the same molecular formula but differ in structure (e.g. atomic connectivity or spatial orientation)
What are structural/constitutional isomers?
Compounds that have the same molecular formula but differ in where and how atoms are connected to each other
What are stereoisomers?
Compounds that have the same connectivity between their atoms and differ in the way their atoms are orientated
E.g. cis-trans isomers, enantiomers, disastereomers, meso compounds, conformational isomers
What are diastereomers?
Stereoisomers that are not mirror images
What are meso compounds?
Molecules with multiple chiral centers that have an internal plane of symmetry, not optically active
What is generally the weaker bond (Pi or sigma)?
Pi bonds
What is a primary, secondary carbon?
Primary carbon -> bonded to only one other carbon atom
Secondary carbon -> bonded to 2 carbons
Do branched alkanes have higher or lower melting and boiling points?
Lower bc surface area reduces and LDF decrease
What is a nucleophile?
Molecules attracted to positive charge, typically electron rich and negatively charged
What is protic vs aprotic solvent?
Protic solvent-> solvent able to form hydrogen bonds
Aprotic solvent -> solvent cannot form hydrogen bonds
What is the best leaving groups?
Weak bases that can accept a negative charge and dissociate to form a stable ion
What are the steps of an SN1 reaction?
Dissociation of substrate into carbocation and leaving group followed by combination of carbocation with nucleophile to form the substituted product
What are the steps of a free radical substitution product?
Initiation: Diatomic halogens are cleaved by either UV light (UV or hv) or peroxide resulting in free radicals
Propagation: free radical reacts with alkane removing hydrogen creating HX and alkyl radical which reacts with X2 to generate another radiation
Termination: 2 free radicals combine with one another to form a stable molecule
What is a combustion reaction?
Alkane + O2 -> CO2 + H2O + heat
What is pyrolysis?
Also called cracking, molecule is broken down by heat in the absence of oxygen
What have higher mp and bp, internal or terminal alkenes?
Internal alkenes have higher mp and bp
What are the steps of an E1 reaction?
The leaving group leaves producing a carbocation, then a proton is removed by a base and the double bond forms
How do you manipulate the competition between E1 and SN1 reactions?
Adding heat favors E1 reaction
What are the steps of an E2 reaction?
A strong base removes a proton while simultaneously a halide ion anti to the proton leaves resulting in the formation of a double bond, more substituted double bond is preferential
How do we manipulate the competition between SN2 and E2 reactions?
Steric hinderance affects SN2 reactions more than E2
Strong bulky bases favor E2 over SN2 while SN2 is favored over E2 by strong nucleophiles that are weak bases
What is catalytic hydrogenation?
Reductive process of adding H2 to a double bond with aid of metal catalyst (Pt, pd or Ni) and 2 hydrogens add to same face of double bond
ADDITION REACTION TYPES
ON WRITTEN CUE CARDS AND IN NOTES
What reaction conditions does polymerization need?
High temperature and pressure
What has the higher BP, terminal or internal alkynes?
Internal alkynes boil at higher temperatures than terminal alkynes