The effect of deuteriation on the emission lifetime of inorganic compounds

The application of deuteriation of both ligands and solvents on the photophysical properties of transition metal complexes in solution and glassy matrices is reviewed. The reduction in amplitude and frequency of vibrational modes due to deuterium's increased mass, relative to hydrogen, has a significant effect on non-radiative deactivation processes, which can occur through both intra- and inter-molecular vibrational coupling. The effect of deuteriation on excited state lifetimes has allowed for its application in probing the nature of excited state decay processes. The effects of isotopic exchange on vibrational spectroscopies such as resonance Raman and low temperature high-resolution emission spectroscopies are also addressed briefly

A new luminescent Ru(terpy) complex incorporating a 1,2,4-triazole based σ-donor ligand

The mononuclear compound [Ru(terpy)L], where H2L is 2,6-bis(1,2,4-triazol-3-yl)pyridine, shows an emission lifetime of 65 ns, about 300 times longer than that observed for the parent [Ru(terpy)3]2+ complex

Nickel oxide photocathodes prepared using rapid discharge sintering for p-type dye-sensitized solar cells

This paper compares the photoelectrochemical performances of nickel oxide (NiO) thin films processed using two different sintering procedures: rapid discharge sintering (RDS) and conventional furnace sintering (CS). Prior to sintering, NiO nanoparticles were sprayed onto substrates to form loosely adherent nanoparticulate coatings. After RDS and furnace sintering the resultant NiO coatings were sensitized with erythrosine B dye and corresponding p-type dyesensitized solar cells were fabricated and characterized. NiO electrodes fabricated using the RDS technique exhibited a fourfold enhancement in electroactivity compared to CS electrodes. A possible explanation is the smaller sintered grain size and more open mesoporous structure achieved using the microwave plasma treatments

Modulation of internuclear communication in multinuclear Ruthenium(II) polypyridyl complexes

The syntheses and characterisation of a series of mononuclear and dinuclear ruthenium polypyridyl complexes based on the bridging ligands 1,3-bis-[5-(2-pyridyl)-1H-1,2,4-triazol-3-yl]benzene, 1,4-bis-[5-(2-pyridyl)-1H-1,2,4-triazol-3-yl]benzene, 2,5-bis-[5-(2-pyridyl)-1H-1,2,4-triazol-3-yl]thiophene, 2,5-bis-[5-pyrazinyl-1H-1,2,4-triazol-3-yl]thiophene are reported. Electrochemical studies indicate that in these systems, the ground state interaction is critically dependent on the nature of the bridging ligand and its protonation state, with strong and weak interactions being observed for thiophene- and phenylene-bridged complexes, respectively

Elucidating excited state electronic structure and intercomponent interactions in multicomponent and supramolecular systems

Rational design of supramolecular systems for application in photonic devices requires a clear understanding of both the mechanism of energy and electron transfer processes and how these processes can be manipulated. Central to achieving these goals is a detailed picture of their electronic structure and of the interaction between the constituent components. We review several approaches that have been taken towards gaining such understanding, with particular focus on the physical techniques employed. In the discussion, case studies are introduced to illustrate the key issues under consideration

SYNTHESIS OF STAR POLY(4-VINYLPYRIDINE) ARCHITECTURE BY NITROXIDE MEDIATED POLYMERISATION

This study proposed multifunctional alkoxyamine 2-({tert-butyl [[1- (diethoxyphosphoryl)-2,2-dimethylpropyl]amino}oxy)-2-methylpropanoic acid (MAMA-SG1) initiators for the ‘grafting-from’ method to obtain star architecture of poly 4-vinylpyridine (P4VP) from JEFFAMINE®. The structure of macroinitiator was confirmed by amide bond present in NMR and FTIR spectroscopy. Furthermore, the macroinitiator was used to polymerise 4VP. P4VP from JEFFAMINE-SG1 shows a monomodal peak in the SEC chromatogram, indicating more control polymerisation process

A 2:1 Co-Crystal of Hydroquinone and 3,5-Bis(2-pyridyl)-1,2,4-triazole

The title compound, 2C₁₂H₉N5₅.C₆H₆O₂, exhibits a three-dimensional hydrogen-bonded network of N-H...N, C-H...N, O-H...N, C-H...O, C-H...π and π...π interactions

Ni(0) catalysed homo-coupling reactions: a novel route towards the synthesis of multinuclear ruthenium polypyridine complexes featuring made-to-order properties.

A new synthetic procedure for the efficient preparation of dinuclear ruthenium(II) polypyridyl complexes is reported. The compounds synthesised are [(bpy)2Ru(BPBT)Ru(bpy)2](PF6)2 and [(bpy)2Ru(BPZBT)Ru(bpy)2](PF6)2 (bpys2,29-bipyridine; H2BPBTs5,59- bis(pyridin-2-yl)-3,39-bis(1,2,4-triazole); H2BPZBTs5,59-bis(pyrazin-2-yl)-3,39-bis(1,2,4-triazole). Electrochemical experiments show that the two dinuclear systems investigated exhibit pH switchable intercomponent interactions

Photochemically induced isomerisation in ruthenium polypyridyl complexes

The synthesis and characterisation of a series of ruthenium polypyridyl complexes containing pyridyltriazole ligands in different coordination modes are described. The electrochemical and electronic properties of the compounds are reported and discussed with respect to the coordination mode of the pyridyltriazole ligand. Upon photolysis of the complex containing the 1-methyl-3-(pyridin-2-yl)-1,2,4-triazole ligand irreversible ligand isomerisation is observed

Ground vs. excited state interaction in ruthenium-thienyl dyads:implications for through bond interactions in multicomponent systems

The vibrational and photophysical properties of mononuclear ruthenium(II) and ruthenium(III) polypyridyl complexes based on the ligands 2-(5'-(pyridin-2"-yl)-1'H-1',2',4'-triaz-3'-yl)-thiophene, 2-(5'-(pyrazin-2"-yl)-1'H-1',2',4'-triaz-3'-yl)-thiophene, are reported. The effect of the introduction of the non-innocent thiophene group on the properties of the triazole based ruthenium(II) complex is examined. The pH sensitive 1,2,4-triazole group, although influenced by the electron withdrawing nature of the thiophene group, does not facilitate excited state interaction of the thiophene and Ru(II) centre. Deuteriation and DFT calculations are employed to enable a deeper understanding of the interaction between the two redox-active centres and rationalise the difference between the extent of ground and excited state interaction in this simple dyad. The results obtained provide considerable evidence in support of earlier studies examining differences in ground and excited state interaction in multinuclear thiophene-bridged systems, in particular with respect to HOMO- and LUMO- mediated superexchange interaction processes.