Block 1 - Foundations Flashcards
Anhydride functional group
O O
ll ll
C-C-O-C-C
anhydride nomenclature
alkanoic anhydride
nitrile functional group
-C=_N
nitrile nomenclature
alkane nitrile
thiol functional group
-C-SH
thiol nomenclature
alkane-n-thiol
phenol functional group
benzene ring with -OH
phenol nomenclature
alkylphenol
nomenclature priority
-COOH > ester > amide > nitrile > -CHO > ketone > alcohol > amine > C=C > alkyne > alkane > ether > alkyl halide = alkyl
DBE formula
1/2 (2n4 + n3 - n1 + 2)
newman projection terminology
staggered vs. eclipsed (anti, gauche and syn)
electrostatic potential map colours
red = electron-rich (high electron density) blue = electron-poor (low electron density)
types of intermolecular forces
- momentary dipole-dipole attractions (dispersion forces)
- dipole-dipole interactions
- hydrogen bonding
chromatography components
- solvent/mobile liquid phase = relatively non-polar
- absorbent/solid stationary phase = polar
chromatography mechanism
if solute is:
- polar = more strongly attracted to polar stationary phase thus moves slowly
- non-polar = less attracted to polar stationary phase thus moves rapidly
substitution bond changes
same type of bonds (sigma) broken and formed
substitution DBE changes
DBE remains same
addition bond changes
1 pi bond broken and 2 sigma bonds formed
addition DBE changes
DBE decreases
- product less unsaturated/more saturated
elimination bond changes
2 sigma bonds broken and 1 pi bond formed
elimination DBE changes
DBE increases
- product more unsaturated
reaction subclassifications
1) polar/non-polar
2) nucleophilic/electrophilic reagent
3) nature of substrate (alkyl - chain base, aryl - aromatic ring etc.)
conditions of aromatic ring
- planar
- cyclic
- all atoms have p orbital
- ring contains pi electrons
non-polar reactions
- reactions of free radicals
- bond breaking/making may take place simultaneously
free radicals
neutral species with an unpaired electron
polar reactions
- one bonding partner supplies electron pair while the other receives it to form a new bond
- reaction between nucleophile and electrophile to form a new covalent bond
nucleophile
- nucleus (+ve charge) lover
- electron rich: either neutral or -vely charged and have either lone e- pair or e- in pi bonds
electrophile
- electron lover
- neutral or +vely charged
types of bond cleavage
- symmetrically: homolytic bond cleavage
- unsymmetrically: heterolytic bond cleavage
homolytic bond cleavage
- 1 e- ends up on each formerly bonded atom
- non-polar reactions
heterolytic bond cleavage
- both e-s end up on one of the formerly bonded atoms
- polar reactions
- e- s move towards more electronegative atom
- carbocations more common than carbanion as C is not very electronegative
determination of nucleophilic/electrophilic reactions
determined by reagent/species doing the replacing
- if unsure, check other reactant as they will be opposites
reaction mechanisms
detailed pathway by which reactants are converted to products
- often require multiple steps (elementary reactions) that require multiple steps
- reactive intermediates are unstable and short-lived (formed in one step then used up in the next)
types of nucleophilic substitution
Sn1 and Sn2
Sn1
stepwise so bond breaking THEN bond making
Sn2
single step so bond breaking/forming simultaneous
alkenes and alkynes are
nucleophiles (electron rich - e-s in pi bond) thus undergo electrophilic addition
bonds in benzene
in reality, 6 identical 1.5 bonds but drawn as 1 of 2 resonance forms
resonance energy
conjugated double bonds give extra stability
simple benzene nomenclature
___benzene (e.g bromobenzene)
complex benzene nomenclature
phenyl____
benzene common names
- NH2 = aniline
- CHO = benzaldehyde
- CO2H = benzoic acid
- OH = phenol
- CH3 = toluene
disubstituted benzenes
- 1,2-substituted = ortho
- 1,3-substituted = meta
- 1,4-substituted = para
why are double bonds more polar?
relative mobility of pi electrons as they are not held as tight being further from the nuclei
