Quadratic and Cubic Optical Nonlinearities of Y-Shaped and Distorted-H-Shaped Arylalkynylruthenium Complexes.

Straightforward syntheses of bis[bis{1,2-bis(diphenylphosphino)ethane}ruthenium]-functionalized 1,3,5-triethynylbenzene-cored complexes via a methodology employing "steric control" permit facile formation of Y-shaped Sonogashira coupling products and distorted-H-shaped homo-coupled quadrupolar products. Cyclic voltammetric data from these products reveal two reversible metal alkynyl-localized oxidation processes for all complexes. The wavelengths of the linear optical absorption maxima are dominated by the nature of the peripheral alkynyl ligand rather than the substituent at the unique arm of the "Y" or at the quadrupolar complex "core".

Effect of pnictogen ligand substitution on a tripalladium ditropylium core.

A combination of multinuclei NMR, UV-vis spectroscopy, and single crystal X-ray diffraction was used to characterize a new series of tripalladium ditropylium sandwich complexes [Pd(3)Tr(2)(E)(3)][BF(4)](2) (E = PPh(3), AsPh(3), and SbPh(3) and PEt(3)). Ligand substitution leads to a systematic shift of the (1)H and (13)C NMR tropylium resonances and is correlated with the electron donating properties of the substituent group. Replacement of the ligand increases the palladium-pnictogen bond length in the order P < As < Sb; however, this only slightly alters the internal Pd-Pd bond lengths, supporting the hypothesis that there are only weak Pd-Pd bonding interactions.

Monomers and polymers of tripalladium(0) ditropylium halides.

The synthesis and characterization of a series of polymeric complexes based upon a central tripalladium ditropylium (Tr) unit [Pd(3)Tr(2)] and containing different halide ligands are reported. The complexes were synthesized in good yield and characterized by multinuclei NMR spectroscopy, mass spectrometry, microanalysis, and X-ray crystallography. An unexpected product was an inorganic polymer consisting of linked individual tripalladium ditropylium units [Pd(3)Tr(2)X(2)](infinity) (X = Cl, Br, and I); this is the first reported, crystallographically characterized example of polymeric tripalladium complexes with halide ligands.