Metal Tetrahydroborates and Tetrahydroborato Metalates, 16 [1]. An 11B and 113Cd NMR Investigation of the CdI2—MBH4 System in Dimethylformamide and Diglyme [2]

Abstract

CdI2 dissociates in dimethylformamide (DMF) into Cd(DMF)6 2+, CdI(DMF)5 +, CdI3- and CdI4 2-. Rapid scrambling occurs at ambient temperature in DMF solutions containing CdI2 and MBH4 (M = Na, Li). At 213 K these exchange processes are slowed down to allow the detection of CdI4 2-, CdI3 -, CdI3(BH4)2-, CdI2(BH4)2 2-, CdI(BH4)3 2-, CdI(BH4)2- and Cd(BH4)3 - by 113Cd NMR spectroscopy. The BH4 groups are bound to the Cd centre via two hydrogen atoms as derived from the multiplicity of the 113Cd signals. CdI2 dissolves in diglyme as a molecular entity. Its reaction with M BH4 proceeds via solvated CdI(BH4) and Cd(BH4)2 to CdI(BH4)3 2- and Cd(BH4)3 -. Solubility restriction prevent a 113Cd NMR study of solutions in which the MBH4 : CdI2 ratio exceeds 1:1.