RESUMEN
A series of cyano-bridged homotrinuclear Re(I) complexes with the general formula of {[Re]'[Re][Re]'}+ {[Re]' = -[ReI(CO)2(LL)(X)]; [Re] = -[(NC)ReI(CO)2(phen)(CN)]-; LL = diimine, diphosphine, or two carbonyl ligands; X = triphenylphosphine or carbonyl ligand} and the corresponding mononuclear complex analogues were synthesized. The structures of most of the trinuclear Re(I) complexes have been determined by X-ray crystallography. The relative orientations of peripheral to central Re(I) units in these structures vary considerably. The photophysical properties of these trinuclear Re(I) complexes have been examined. Except for the trinuclear Re(I) complex with Br2phen ligand, all the other triads display orange to red photoluminescence derived from the 3MLCT [dπ(Re) â π*(phen)] origin of the central Re(I) unit, suggestive of efficient energy transfer between the peripheral chromophores and the central unit. In addition to the efficient energy transfer processes between the Re(I) chromophores in these trinuclear complexes, the ability of the [NC-Re-CN] bridging ligands for electronic coupling between the rhenium metal centers is evidenced by ca. 0.2-0.3 V separation of the two rhenium metal-based oxidation potentials of the chemically equivalent peripheral units.
RESUMEN
To improve the emission and excited-state properties of luminescent cyanometalates, new classes of highly solvatochromic luminescent cyanoruthenium(II) and cyanoruthenate(II) complexes of the general formulae [Ru(PR3)2(CN)2(NN)] and K[Ru(PR3)(CN)3(NN)], respectively, were developed. These complexes could be readily synthesized through the ligand-substitution reaction of K2[Ru(CN)4(PR3)2] with a diimine ligand. The geometrical isomerism of these complexes was characterized by using various spectroscopic techniques. Their photophysical properties, solvatochromism, and electrochemistry have also been investigated. Our detailed study showed that many of these complexes exhibited extremely environmentally sensitive emissions and significantly improved emission quantum efficiencies and lifetimes compared with the well-studied tetracyanoruthenate systems.
RESUMEN
A new class of dicarbonyl dicyano rhenate(I) diimine complexes, cis,trans-[Re(CO)(2)(CN)(2)(N-N)](-), with highly environmentally sensitive MLCT absorption and emission properties was synthesised and characterised. Preliminary experiments revealed that these complexes are active photocatalysts for CO(2) reduction.
RESUMEN
A series of rhenium complexes with acetylamino- and trifluoroacetylamino-containing 1,10-phenanthroline ligands have been synthesized, characterized and their photophysical and electrochemical properties studied. These complexes were found to show significant UV-vis and emission changes on addition of CN(-), F(-) and AcO(-) anions. Their reactivity towards CN(-), F(-) and AcO(-) anions, was also investigated by UV-vis, emission and (1)H NMR spectroscopy. The reaction product between the trifluoroacetylamino-containing 1,10-phenanthroline ligand and the CN(-) anion has also been structurally characterized by X-ray crystallography.
