Trialkyl Group VA metal compounds

DETAILED DESCRIPTION OF THE INVENTION As used throughout this specification, the following abbreviations shall have the following meanings, unless the context clearly indicates otherwise: .
degree.
C.
=degrees centigrade; NMR=nuclear magnetic resonance; mtorr=millitorr; g=gram; L=liter; ca.
=approximately; mm=millimeters; and mL=milliliter.
"Halogen" refers to fluorine, chlorine, bromine and iodide and "halo" refers to fluoro, chloro, bromo and iodo.
Likewise, "halogenated" refers to fluorinated, chlorinated, brominated and iodinated.
"Alkyl" includes linear, branched and cyclic alkyl.
Unless otherwise noted, all amounts are percent by weight and all ratios are molar ratios.
All numerical ranges are inclusive and combinable in any order.
The present invention provides a method for preparing trialkyl Group VA metal compounds including the step of reacting a Group VA metal trihalide with a Group IIIA compound of the formula R.
sub.
n M.
sup.
1 X.
sub.
3-n in the presence of a tertiary amine in an organic solvent that is free of oxygen substitution, wherein each R is independently selected from (C.
sub.
1 -C.
sub.
6)alkyl; M.
sup.
1 is a Group IIIA metal; X is halogen and n is an integer from 1-3.
Preferred Group VA metals include antimony ("Sb"), arsenic ("As") and bismuth ("Bi").
Suitable Group VA trihalides are those having the general formula MX.
sub.
3, where M is a Group VA metal and each X is independently fluorine, chlorine, bromine or iodine.
It is preferred that X is chlorine, bromine or iodine.
Group VA trichlorides are more preferred.
Particularly suitable Group VA metal halides include, but are not limited to, antimony trichloride, antimony tribromide, antimony triiodide, arsenic trichloride, arsenic tribromide, arsenic triiodide, bismuth trichloride, bismuth tribromide, bismuth triiodide and mixtures thereof.
It will be appreciated that mixed halide compounds may also be advantageously used in the present invention.
Such Group VA metal trihalides are generally commercially available from a variety of sources or may be prepared by a variety of methods known in the literature