Inorganic Chemistry, Vol.56, No.12, 7285-7291, 2017
Copper(I) Complexes of a Flexible Bis-phospholane Ligand: Route to Paddle-Wheel- and Box-Type Macrocycles
Two bis-phospholane copper(I) metallamacrocycles were selectively synthesized starting from the same two building blocks, namely, ligand 1 and [Cu(NCCH3)(4)]BF4. Reaction conditions (ligand:metal (L:M) ratio and dilution) can be tuned to obtain either a paddle-wheel- (2, L:M = 3:2) or box-type complex (3, L:M = 8:4). Their structures were unequivocally determined by X-ray crystallography. The solution P-31{H-1} NMR spectrum of complex 2 consists of a broad signal, as is common for such complexes, whereas complex 3 shows splitting of the P-31{H-1} NMR signal into a pseudoquartet due to Cu-63,Cu-65-P-31 coupling, a rare occurrence exhibited only by highly symmetrical copper(I) phosphine complexes.