3-DIMENSIONAL COORDINATION POLYMERS OF RUTHENIUM(2-DIISOCYANOBENZENE LIGANDS AND THEIR CATALYTIC ACTIVITY() WITH 1,4)

Organometallic compounds have been playing an increasingly important r ole in a variety of technologically relevant fields such as catalytic processes and solid-state devices. Of special technological interest a re organometallic materials which contain several metal sites, e.g., c lusters. Multiple metal centers in a single complex may be achieved by utilizing multifunctional, nonchelating, rigid ligands such as aryldi isocyanides, which when coordinated to metal atoms, would act as bridg es and would give rise to template polymerization. There are no studie s to date concerning the coordination chemistry of the d6 transition e lements, e.g., Ru(II), Os(II), and Rh(III) with diisocyanide ligands. Since most of the complexes of these transition metals in these oxidat ion states exhibit octahedral geometry, template polymerization may be obtained, resulting in three-dimensional coordination polymers. In th is paper we shall examine the polymerization process of Ru(II) with 1, 4-diisocyanobenzene, the physical and spectral properties of the polym ers formed, and their potential catalytic activity. Depending on the s tarting ruthenium carbonyl complex, it is possible to obtain two disti nctly different materials, both in their structure and in their cataly tic properties. The first compound, polymer A, has a three-dimensional structure with a tetragonal geometry, having Ru-Ru stacking interacti ons in the z direction, while the second compound, polymer B, has a cu bic geometry, having all the Ru atoms separated by the 1,4-diisocyanob enzene ligands. Polymer A is the catalytically active compound, in spi te of exhibiting an induction period, and its activity is enhanced by UV irradiation prior to the catalytic reaction, accompanied by the eli mination of the induction period.