Organometallic Ligands

Question 1

Hapticity, η

Answer 1

No of atoms directly interacting with metal

Question 2

X type

Answer 2

1e- donors

Question 3

Alkylidenes

Answer 3

M=C bonds, X2 ligands

Question 4

Alkylidynes

Answer 4

M triple bond C, X3 ligands

Question 5

Carbon monoxide

Answer 5

L type ligand, :C triple bond O

Question 6

Nitric oxide

Answer 6

Bent: sp2 N with bent geometry, 1e- donor = X
Linear: spN with linear geometry, 3e- donor = XL

Question 7

N-heterocyclic carbenes

Answer 7

Stable carbene = 2 heteroatoms attached to C, L type donor = π-ligands donate electrons from occupied π-orbitals

Question 8

Alkenes

Answer 8

L type ligand = 2e- donated from π-bonding to metal orbitals

Question 9

Alkynes

Answer 9

4e- in to perpendicular π-orbitals, one perpendicular to M-C bond and other parallel to it, assume 2e- donor

Question 10

Linear polyenes

Answer 10

Ligands with > 2C in extended unsaturated chain, can have different hapticities

Question 11

Cyclic polyenes

Answer 11

Planar rings that bind face onto metal which is equidistant from each C