Silane gas precursor compounds having the formula (I): ##STR00001## wherein R.sub.1, R.sub.2, and R.sub.3 each can independently be hydrogen or halogen and wherein the cyclohexadiene ring can have one or more substituents selected from the group consisting of a saturated or unsaturated, straight chain or branched alkyl group, a halogen, NO.sub.2, and C.ident.N are disclosed. In one form, the silane gas precursor compound is cyclohexadien-2,4-ylsilane, an air-stable liquid, that can be thermolyzed in a pyrolysis process to efficiently generate high purity silane gas. The compounds of the present invention can thus serve as a "point-of-use" precursor for silane gas.