Silyl Iodide Research Articles

The silyl group as an electron acceptor—II the reaction of silyl iodide with tetramethylhydrazine

Silyl iodide reacts with tetramethylhydrazine in the gas phase and in solution to yield a 1 : 1 adduct. In the liquid phase, a 2 : 1 compound is also formed. The basic character of tetramethylhydrazine is discussed.

The silyl group as an electron acceptor

The reaction of silyl iodide with anhydrous hydrazine has been studied, and the compound tetrasilylhydrazine, N 2(SiH 3) 4, has been isolated and characterized. It is stable in vacuo at 90°, detonates in air, and is a powerful reducing agent. The compound has been found to be monomeric and to form no adducts with silyl iodide or trimethylamine, and these facts are interpreted in terms of “internal compensation” involving the use of dative π-bonds.

Phosphine and arsine derivatives of monosilane

The reaction of silyl iodide with phosphorus, phosphine, arsenic and the arsenides of potassium and mercury has been studied. The compounds P(SiH 3)I 2 and As(SiH 3)I 2 have been isolated and characterized. Both decompose below 100°. Evidence is presented for the existence of the compounds P(SiH 3) 2I, P(SiH 3) 3, P(SiH 3) 4I, As(SiH 3) 2I, As(SiH 3) 3 and As(SiH 3) 4I which, however, have not yet been fully characterized. Silyl iodide forms 1:1 addition compounds with trimethylamine, triethylamine, trimethyl phosphine, triethylphosphine and trimethyl arsine. The first four are only slightly dissociated, but the arsenic compound dissociates readily. Silyl iodide also forms a compound SiH 3I . 1·8 N(CH 3) 3 in its reaction with trimethylamine under pressure. This compound gives a non-conducting solution in acetonitrile, whereas the compounds with one mole of trimethylamine and triethylphosphine give conducting solutions and are therefore salt-like. These results are related to current theories of the formation by silicon of compounds with co-ordination number in excess of four, and of the utilization of d orbitals in bond formation.