Construction of a photoactive supramolecular system based on a platinum(II) bis-acetylide building block incorporated into a ruthenium(II) polypyridyl complex

A new ruthenium(II) polypyridyl-platinum(II) diethynyl triad containing 3-ethynylphenanthroline linked by platinum(II) bis-tributylphosphine organometallics, Ru(II)-Pt(II)-Ru(II), and platinum(II) bis-ethynylphenanthroline complex has been prepared. The ruthenium(II)-metal triads, Ru(II)-M-Ru(II) (M = Pt(II) and Au(I)), showed typical MLCT absorption bands and a lowest energy π-π* absorption involved with the metal perturbation in the 350-500 nm region. Broad emission bands assignable to triplet MLCT transitions were definitely observed in the triads Ru(II)-M-Ru(II), while those of platinum(II) and gold(I) bis-ethynylphenanthroline complexes displayed a phosphorescent band with vibronic progression assignable to the metal-perturbed triplet π-π*(CCphen) transition, which means that the hybrid architecture constructed with Ru(II) polypyridyl and metal bis-acetylide units converts a blue-green metal perturbed π-π* phosphorescence into an orange MLCT-based emission. The transient differential absorption spectra of ruthenium compounds showed the difference of the electron transfer process between [Ru(bipy)(phen)](PF6)2 and triads under the MLCT state. Photophysical data of the triad suggest an efficient energy transfer from the platinum bis-acetylide site to the ruthenium polypyridyl site followed by the supposed charge injection from a ruthenium center to the extended π-conjugated phenanthroline under photo-excitation in this photoactive supramolecular system.application/pdfjournal articl

Alternative preparation and characterization of platinum(II) organometallic dinuclear complexes and oligomers with 3,8-diethynylphenanthroline derivatives

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Crystal structures and single-crystal electron spin resonance spectra of π-π Type molecular complexes of bis(1-methyliminomethyl-2-naphtholato)copper(II)

The donor-acceptor molecular complexes of bis(1-methyliminomethyl-2-naphtholato)copper(II)[CuL2] with 7,7,8,8-tetracyanoquinodimethane (tcnq), tetrachloro-1,4-benzoquinone (tcbq) and 1,3,5-trinitrobenzene (tnb), as well as the parent complex have been subjected to single-crystal X-ray diffraction analysis. The molecular complexes [CuL2]・2tcnq and [CuL2]・2tnb crystallize in the triclinic space group P and [CuL2]・2tcbq crystallizes in the monoclinic space group P21/n, the copper atoms of all complexes being positioned at an inversion centre. The molecular complexes showed a typical π-π type structure consisting of alternately stacked π-electron donor (naphthalene moiety of copper complex) and π-electron acceptor (tcnq, tcbq and tnb) along the c axis (needle axis). The ESR spectrum for a copper(II) doped sample of diamagnetic [NiL2]・2tnb showed simple copper quartet lines due to I=. The X-ray analyses indicated that the donor-acceptor interaction operating along the c axis gives a one-dimensional structure consisting of alternately stacked donor and acceptor molecules, but no distinct two-dimensional interaction.application/pdfjournal articl

Construction of molecular wires based on a gold(I) bis-σ-acetylide building block incorporated into ruthenium(II) polypyridyl complexes

An Ru(II)-Au(I)-Ru(II) triad has been synthesized from [Ru(bpy)2(3-ethynylphenanthroline)]2+ with Au(tht)Cl and characterized by spectroscopic means such as NMR and ESI-MS; the Ru(II)-Au(I)-Ru(II) triad shows an intense emission at 620 nm upon excitation at 360 nm, which suggests an efficient energy transfer from the Au site to Ru sites via extended p-conjugation through the ethynyl units.application/pdfjournal articl

Synthesis and photophysical characterization of ruthenium(II) and platinum(II) complexes with bis-pyridylethynyl-phenanthroline ligands as a metalloligand

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