BOROHYDRIDE REDUCTION OF NICKEL AND COPPER IONS IN AQUEOUS AND NONAQUEOUS MEDIA - CONTROLLABLE CHEMISTRY LEADING TO NANOSCALE METAL AND METAL BORIDE PARTICLES

The reduction of Ni2+(aq), Ni2+(diglyme), Cu2+(aq), and Cu2+(diglyme) by NaBH4 has been studied with mechanistic and stoichiometric factors as the focus. The approximate balanced equations were for copper, Cu2(aq) + 2BH(4)(-)(aq) + 6H(2)O --> Cu(s) + 7H(2) + 2B(OH)(3), in the di glyme case a colorless, soluble Cu(BH4)(2) complex was formed first th at upon pyrolysis at 90 degrees C yielded Cu(s), Cu2+(diglyme) + 2BH(4 )(-)(diglyme) --> Cu(BH4)(2)(diglyme) (90 degrees C) --> Cu(s) + H-2 B2H6; nickel, 2Ni(2+)(aq) + 4BH(4)(-)(aq) + 9H(2)O --> Ni2B(s) + 12.5 H(2) + 3B(OH)3, upon air exposure the nanoscale Ni2B was converted to Ni(s) + B2O3 probably by the equation 4Ni(2)B + 30(2) --> 8Ni(s) + 2B( 2)O(3), in the diglyme solution a mixture of, products was formed by t he approximate reaction 2Ni(2+)(diglyme) + 4BH(4)(-)(diglyme) --> Ni2B (s) + Ni(s) + 31/2H(2) + 11/2B(2)H(6). A summary of findings for the a queous and nonaqueous reduction of Fe3+, Fe2+, Co2+, Ni2+, and Cu2+ is presented.