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An incomplete cubane-type cluster reacted with Pd black in aqueous HCl to yield a mixed-metal cubane-type cluster having a novel PdMO3S4 core. The structural properties and synthesis of these compounds were studied as models of active sites in biological catalysts. Mixed-metal sulfur clusters containing noble metals promoted stoichiometric and catalytic reactions.

Three carboxylate- and phosphodiester-bridged dimagnesium(II) complexes are prepared which contain the dinucleating ligand XDK where H2XDK is m-xylenediamine bis(Kemp's triacid imide) and can model enzyme active sites for phosphate ester hydrolysis. The complex Mg2(XDK)(CH3OH)4(H2O)2(NO3) (NO3) has a carboxylate-bridged dinuclear magnesium(II) center. In Mg2(XDK)(DPP)(CH3OH)3(H2O)(NO3).3CH3OH where HDPP is diphenyl phosphate, both bridging and terminal diphenyl phosphate ligands are present.

The synthetic methodology for the preparation of carboxylate-bridged heterodimetallic complexes involves the use of dinucleating carboxylating ligand XDK, where H2XDK is m-xylenediamine bis(Kemp's triacid imide). XDK helps stabilize the carboxylate-bridged heterodimetallics. Formation of heterodimetallic complexes of the type (CoM(XDK)(neocuproine)(X)) by a reaction between alkalic metallic salt and a mononuclear Co(II) complex and (Co(XDK)(neocuproine)) reveals the efficiency of XDK in assembling heterodimetallic complexes.

Studies on the reactivities of the incomplete cubane-type cluster (Mo3S4(H2O)9)4+ show that it is a highly potential precursor for synthesizing mixed-metal sulfido clusters with a cuboidal Mo3MS4 core. Single and double cubane-type clusters with a Mo3PdS4 core derived from (Mo3S4(H2O)9)4+ were synthesized and characterized. (Mo3S4(H2O)8)4+ coordinates an alkene ligand to the unique palladium site surrounded by sulfido ligands.

Hexanuclear copper hydride complexes, [Cu 6 (μ 3 -H) 2 ( meso-L 4 ) 3 (RNC) 4 ](PF 6 ) 4 (R = t Bu (6a), Cy (6b)), were prepared by using a new linear tetraphosphine, meso-Ph 2 PCH 2 P(Ph)(CH 2 ) 4 P(Ph)CH 2 PPh 2 ( meso-L 4 ), and were converted into active catalysts of [Cu 2 (μ-O 2 CH)( meso-L 4 )(RNC) 2 ] + under the reaction conditions of formic acid dehydrogenation, where unsymmetric dinuclear copper sites supported by the tetradentate phosphine and isocyanide ligands were essential to demonstrate effective catalytic activity.