Inorganic GQ8

CO

weak o donor

strong pi backbonder

Phosphines (PR3)

o donors AND pi backbonders

o donation/acceptance is inversley correlated

o donation depends on groups attached to P

Hydrides

o donors

H2

forms o complex

o donor thru H-H o bond

pi backbonding metal to H-H o* orbital

alkenes and alkynes

bind n-1 and n-2 to metal ion

n-2 binding is o-donation from pi-bond and pi-backbonding

carbenes (CR2)

only have 6 electrons around C atoms

fisher carbenes

singlet, w lone pair

electrophillic

Schrock carbenes

triplet, with unpaired electrons

sterically bulky

nucleophillic

hapticity

number of contigous atoms in a ligand bonded to the metal

what happens if pi-backbonding is so much that the H–H bond breaks in a M–H2 complex? Draw the resulting complex.

when H-H bond breaks, 2 metal-hydrides are formed

increases oxidation state by 2, oxidative addition

What happens if the pi-backbonding is so much that the C=C pi-bond breaks in a metal-alkene complex? D

when pi bond breaks, metallocyclopropane is formed

1-1 insertions

one ligand inserts itself into another ligand

CO ligands

1,2 insertions

one ligand inserts itself into another ligand

typical for alkenes and alkynes

B-hydride eliminations

opposite of 1,2

creates metal-hydride bond and new pi-bond

metathesis

split C-C bond and reattach with another partner

oxidative addition

oxidation state of metal increases by 2

coordination number of metal increases by 2\

Break X-Y bond

Reductive elimination

oxidation state of metal decreases by 2

coordination number of metal decreases by 2

make X-Y bond