Preparation of aluminum hydride

Claim 2

The process of claim 1 wherein the aluminum hydride-tertiary amine adduct is decomposed by heating under vacuum at a temperature below the decomposition temperature of aluminum hydride but above the boiling point of the amine at the pressure used.

Claim 3

The process of claim 1 wherein x is 1, M'' is aluminum, and R is hydrogen.

Claim 4

The process of claim 1 wherein either the corresponding tertiary amine or the aluminum hydride product is removed as it is formed.

Claim 5

The process of claim 5 wherein the corresponding tertiary amine is removed by distillation.

Claim 6

The process of claim 6 wherein the amine is removed by distillation with sweeping with an inert gas.

Claim 7

The process of claim 6 wherein the amine is removed by distillation under vacuum.

Claim 8

The process of claim 6 wherein the purification of the aluminum hydride product further comprises washing the aluminum hydride product with ether, filtering to remove the solid residue and subjecting the solid residue to vacuum distillation at a temperature of less than 90*C.

Claim 9

The process of claim 9 wherein the aluminum hydride is subjected to a pressure of less than about 10 4 mm. Hg. to remove volatile impurities.

Claim 10

The process of claim 1 wherein the reaction mixture comprises a solution of the adduct in a solvent.

Claim 11

The process of claim 11 wherein the corresponding tertiary amine is separated as it is formed by distillation and wherein the boiling point of the tertiary amine is lower than the boiling point of the solvent.

Claim 12

The process of claim 11 wherein the solvent comprises a low boiling liquid and a higher boiling liquid and wherein the decomposition is carried out at atmospheric pressure at a temperature of between about 35*C. and about 90*C., below the boiling point of the high boiling liquid but above the boiling point of the low boiling liquid, so that the corresponding amine is distilled off with a portion of the low boiling liquid which acts as a sweep for the amine, and filtering out the alane product formed.

Claim 13

The process of claim 1 wherein the reaction is carried out at a temperature of between about 35* and about 90*C.

Claim 14

The process of claim 1 wherein the reaction is carried out at a pressure of between about 10 8 mm. to about 50 mm. Hg.

Claim 15

The process of claim 1 wherein the decomposition is carried out at a temperature of between about 35* and 90*C. and at a pressure between about 1 mm. to about 50 mm. Hg., so that the corresponding amine is distilled off as it is formed, and the aluminum hydride product is subsequently purified by washing with a solvent for the tertiary amine-alane adduct and for the metal hydride or organo-metallic catalyst, which is a nonsolvent for the aluminum hydride, and removing the solvent and any additional volatile impurities by subjecting the product to a pressure of less than about 10 4 mm. Hg. at a temperature of less than 90*C.

Claim 16

The process of claim 15 wherein the tertiary amine-alane adduct is first dispersed with a metal hydride or organometallic catalyst in a liquid, the liquid is then removed by vacuum distillation at room temperature to leave an intimate mixture of the tertiary amine-alane adduct and the metal hydride catalyst.

Claim 17

The process of claim 1 wherein the corresponding tertiary amine has the formula:

Claim 18

The process according to claim 17 wherein the R groups are selected from the group consisting of aliphatic, cycloaliphatic, and aromatic substituents.

Claim 19

The process according to claim 18 wherein the tertiary amine is a nitrogen-containing heterocyclic amine.

Claim 20

The process according to claim 18 wherein the tertiary amine is triethylamine.

Claim 21

The process according to claim 18 wherein the tertiary amine is tripropylamine.

Claim 22

The process according to claim 1 wherein the catalyst is lithium hydride.

Claim 23

The process according to claim 23 wherein the catalyst is LiAlH4.

Claim 24

The process according to claim 23 wherein the catalyst is LiBH4.

Claim 25

The process according to claim 23 wherein the catalyst is MgH2.

Claim 26

The process according to claim 23 wherein the catalyst is Mg(AlH4)2.

Claim 27

The process according to claim 23 wherein the catalyst is Mg(BH4)2.