Functional Group Chemistry Flashcards
what does ADME stand for?
absorption, distribution, metabolism, excretion
name 4 features of a nucleophile
- nucleus-loving
- electron rich
- negative charge/lone pair of electrons
- double bonds
name 3 features of an electrophile
- electron-loving
- electron poor
- positive charge
what are leaving groups?
terminology used for ions or neutral molecules that are displaced from a reactant as part of a mechanistic sequence
how are leaving groups formed?
a consequence of a nucleophile attacking an electrophile, where the electrophile carries a suitable leaving group
what makes a good leaving group?
those that form stable ions or neutral molecules after they leave the substrate
what is heterolysis?
bond breaks such that both of the electrons stay with one of the atoms
what is homolysis?
bond breaks so that each of the atoms retains one of the bonding electrons
what is standard free energy?
the different energy levels between the reactants and the products
what is activation energy?
the energy difference between the starting material and the transition state
what happens to the boiling point of alkanes as molecular weight increases?
it increases
what are the ONLY intermolecular forces present in alkanes?
weak London forces
are alkanes reactive or unreactive?
unreactive
what do alkanes produce during combustion?
CO2, H2O and heat
during halogenation, what do alkanes react with?
chlorine and bromine
when can halogenation occur?
- at high temperatures
- in the presence of high energy light
what mechanism is halogenation?
radical mechanism
what are the three steps in a radical mechanism?
- initiation
- propagation
- termination
what happens during initiation?
- formation of radical
- light induced formation of chlorine radicals through homolysis from neutral chlorine
what happens during propagation?
- one radical is used to generate another radical
- the chlorine radical can now abstract a hydrogen from another neutral molecule CH4 producing a methyl radical
what happens during termination?
-the combination of two radicals to produce a neutral species
what is hyperconjugation, how does it occur and what does it result in?
it is a stabilising interaction that occurs when the electrons in a o bond interact with an adjacent unfilled p orbital or pi orbital. it results in an extended molecular orbital that increases the stability of the system
what two radicals are more stable than expected and why?
benzyl and allyl due to resonance:
- delocalisation of electrons
- partial radicals residing over several atoms instead of just one
what is resonance used to describe?
electron charge and delocalisation
why are cis isomers less stable than trans isomers?
there is a strain between the two larger substituents on the same side of the double bond