Organometallics 2.1

Question 1

what are metal hydrides

Answer 1

M–H bonds

Question 2

what is the bond strength of metal hydrides?

Answer 2

very strong
200 kj mol-1, +- 50 kj mol

Question 3

metal hydride bonds are not as strong as

Answer 3

C-H bonds

Question 4

why are metal hydrides important?

Answer 4

They are used as transition states/molecules in many catalytic reactions and in making metal alkyls

Question 5

what is the polarity with metal hydrides?

Answer 5

H- with low transition mentals
H+ with high transition metals

Question 6

where are the metal hydrides found in h nmr?

Answer 6

0- 60 ppm
high field

this cannot be answered by shielding or deshielding but rather the influence the d orbital has on the complex

Question 7

IR

Answer 7

2000 cm-1
to know it is M-H M-D can be used

Question 8

list 3 methods to make metal hydrides

Answer 8

Nucleophilic hydride sources
Protonation
H2 oxidative addition

Question 9

H2 oxidative addition

Answer 9

trans-[Ir(Cl)(CO)(PPh3)2]

H2

[Ir(Cl)(H)2(CO)(PPh3)2]

Question 10

Protonation

Answer 10

Fe(CO)5 ——–Na——[Fe(CO)4]2–—-H2— FeH2(CO)4

Question 11

Nucleophilic hydride sources

Answer 11

NaBH4

Question 12

b-Hydrogen migration

Answer 12

This involves the making/breaking alkene/metal alkyl.

Question 13

alkene insertion

Answer 13

the formation of metal alkyl with a vacant site on the metal from an alkene and metal hydride

Question 14

draw the mechanism of alkene insertion

Question 15

b-hydrogen elimination

Answer 15

hydrogen moves to the vacant site of metal alkyl and the alkene forms leaving the metal hydride