'Clustered Cluster' with a 'Pinwheel' Ligand Array. Synthesis and Structure of a Trinuclear Cupracarborane

摘要

An anaerobic equimolar reaction of a nido charge-compensated substituted dicarbollide ion NIDO-9-(NC5H4CO2CH3)-7,8-C2B9H10 with anhydrous CuCl resulted in the formation of a novel tricopper clustered cluster complex (Cu3(mu-H)3(C2B9H9NC5H4CO2CH3)3). The molecular structure was determined from single-crystal X-ray diffraction data. This trinuclear cupracarborane contains an equilateral Cu3 core (Cu(I)-Cu(I) distance = 2.519(2) Angstrons) and three nido-C2B9 cages which are linked through three Cu-H-B bridges. The presence of three ETA cubed-borallylic, four-electron donor interactions from B3 segments of the C2B3 faces to each dopper atom results in a pinwheel -like ligand array about the 3-fold axis. The complex 3, which is the first example of a clustered cluster species, consists of enantiomers of C3 symmetry with a heptane solvate molecule, disordered around the 3-fold axis in the crystal structure. Carborane; Cupracarborane; Dicarbollide; Copper cluster; Clustered cluster; Organic chemistry. (JES)