Lewis Base Adducts of Barium/Copper tert-Butoxides:  Synthesis and Thermolysis of [BaCu2(OtBu)4]n and [L2Ba2Cu4(OtBu)8] (L = Me3NO and Et3PO). X-ray Crystal Structure of [(Me3NO)2Ba2Cu4(OtBu)8]

Reaction of copper(I) mesityl with [Ba(OtBu)2(t-BuOH)2]4 yields insoluble [BaCu2(OtBu)4]n, which dissolves by adduct formation (L = Me3NO or Et3PO) to form soluble L2Ba2Cu4(OtBu)8. For L = Me3NO, this molecule is shown by X-ray diffraction to have a structure based on a trans-Ba2Cu4 octahedron, with all Ba/Cu edges bridged by μ2-OtBu units; one L binds to each Ba. Bulk thermolysis, TGA, and product analysis have revealed that OtBu units undergo not only O/C cleavage but also C/C cleavage, the latter to form carbonate and nonvolatile hydrocarbon products, in addition to BaO and CuO. The intended oxidant Me3NO shows no great tendency to oxidize Cu(I).