Subtle ring-constraint effects on the formation of metallacycles. Cyclodimer versus cyclotrimer of bis(chloro)-1,4-bis(dimethyl-3 or 4-pyridylsilyl)benzenepalladium(II) complexes.

Stepwise modulation of the ring size of metallacyclic compounds via subtle ring-constraint effects has been established. The reactions of (COD)PdCl 2 with p- or m-psb ligand [COD = 1,5-cyclooctadiene; p-psb = 1,4-bis(dimethyl-4-pyridylsilyl)benzene; m-psb = 1,4-bis(dimethyl-3-pyridylsilyl)benzene] in a mixture of acetone and ethanol at room temperature produce the metallacyclodimers [PdCl 2( p- or m-psb)] 2. The cyclodimeric species of [PdCl 2( p-psb)] 2 at the boiling temperature or via the sonication of the chloroform solution is completely converted to the cyclotrimer [PdCl 2( p-psb)] 3.

First direct-formation and properties of microspherical superstructure. Morphology of diamineplatinum(II) complexes with isonicotinate.

Uniform microspheres (30 microm) of [Pt(en)(iso)(iso.HPF(6))] (en = ethylenediamine; iso = isonicotinate) has been formed without intentional addition of any template, that is, a genuine self-assembly, and their structure, physicochemical properties, and hydrogenation-catalytic activity have been characterized.