Bis(homoleptic) vs. heteroleptic copper(I) complexes: Electrosynthesis, spectroscopy, and crystal structure of Cu(BIK)2+2Cu4(SR)62-·3(CH3CN)·(RSH); BIK = bis(2-methylimidazol-2-yl)ketone, R = o-tolyl. Zeitschrift fuer Anorganische und Allgemeine Chemie, (622)7:1118--1124, 1996. [PUMA: bishomoleptic bismethylimidazolylketone complex copper crystal heteroleptic;electrosynthesis spectroscopy structure]