Gallium and Gallium Dichloride, New Solid-State Reductants in Preparative Transition Metal Chemistry. New, Lower Temperature Syntheses and Convenient Isolation of Hexatantalum Tetradecachloride Octahydrate, Ta 6 (μ-Cl) 12 Cl 2 (OH 2 ) 4 .4H 2 O, and Synthesis and Solid-State Structure of a Tetraalkylammonium Derivative, [N(CH 2 Ph)Bu 3 ] 4 [Ta 6 (μ