Controlling aggregation of copper(II)-based coordination compounds: From mononuclear to dinuclear, tetranuclear, and polymeric copper complexes.

The use of a strategy combining ligand design and changes of reaction conditions has been investigated with the goal of directing the assembly of mononuclear, dinuclear, tetranuclear, and polymeric copper(II) complexes. As a result, closely related copper monomers, alkoxo dimers, and hydroxo cubanes, along with a carbonate-bridged polymeric species, have been synthesized using the rigid, aliphatic amino ligands cis-3,5-diamino-trans-hydroxycyclohexane (DAHC), cis-3,5-diamino-trans-methoxycyclohexane (DAMC), and the glutaryl-linked derivative glutaric acid bis-(cis-3,5-diaminocyclohexyl) ester (GADACE). The composition of the monomeric complex has been determined by X-ray crystallography as [Cu(DAHC)2](ClO4)2 (1), the two dimers as [{Cu(DAHC)(OMe)}2](ClO4)2·MeOH (2) and [{Cu(DAMC)(OMe)(ClO4)}2] (3), the three Cu4O4 cubanes as [{Cu(DAHC)(OH)}4](ClO4)4·2.5MeOH (4), [{Cu(DAMC)(OH)}4](ClO4)4·H2O (5), and [{Cu2(OH)2(GADACE)}2]Cl4·2MeOH·6H2O (6), and an infinite-chain structure as [{Cu(DAHC)(CO3)}n] (7). Further...