Excited State Localization and Internuclear Interactions in Asymmetric Ruthenium(II) and Osmium(II) bpy/tpy Based Dinuclear Compounds

Abstract

Raman spectra. The interaction between the two metal centers, mediated by the bridging 1,2,4-triazolato moiety in the mixed valent state, is assigned as type II based on the observation of metal to metal charge transfer absorption bands at 7090 and 5990 cm -1 for 1a and 2a, respectively. The extent of localization of the emissive excited state was determined by transient resonance Raman and emission spectroscopy. Both 1a and 2a show phosphorescence at the same wavelengths; however, whereas for compound 1a the emission is based on the Ru(tpy)Cl-center, for 2a the emissive state is localized on the Os(bpy) 2 -unit. This indicates that also in the excited state there is efficient interaction between the two metal centers.

Luminescent Anion Sensing by Transition‐Metal Dipyridylbenzene Complexes Incorporated into Acyclic, Macrocyclic and Interlocked Hosts

“…Dibromo‐ m ‐xylene 1 was oxidised using aqueous KMnO 4 to afford 2 which was transformed to the methyl ester 3 via reaction in acidic methanol solution. The target ligand 4 was then obtained in 58 % yield by Pd II catalysed Stille coupling between 3 and 2‐tributylstannyl pyridine and combined with the appropriate metal‐halide precursor (M=Pt, K 2 [PtCl 4 ]; M=Ru, [Ru(4‐tolylterpyridine)Cl 3 ]) to obtain 5⋅Pt and 5⋅Ru⋅PF 6 cyclometallated esters. De‐esterification using basic conditions produced the target isophthalic acid functionalised synthons 6⋅Pt and 6⋅Ru⋅PF 6 .…”

“…UV/visible experiments were carried out on a PG instruments T60U spectrometer at 293 K. Steady‐state fluorescence spectra were recorded on Jobin–Yvon–Horiba Fluorolog‐3 spectrophotometer or a Varian Cary‐Eclipse spectrometer. 2,4‐dibromo‐1,5‐dimethylbenzene 1 , 2‐tributylstannylpyridine, 4‐tolyl‐2,2′:6′,2′′‐terpyridine, 4‐tolyl‐2,2′:6′,2′′‐terpyridine ruthenium trichloride, diamine 8 , 3,5‐bis‐hexylamide pyridinium chloride 9⋅Cl and pyridinium axle⋅Cl 11⋅Cl , were synthesised as previously described.…”

Electrochemical and Photoelectrochemical Properties of Nickel Oxide (NiO) With Nanostructured Morphology for Photoconversion Applications

“…A further evolution in the design of the photocathode for solar driven H 2 generation is represented by nanostructured TMOs of p -type, which are decorated with a supramolecular assembly (Figure 4; Dini et al, 2015b). The latter species combines a photosensitive moiety (PS) electronically conjugated to the catalytic center (Cat) (Halpin et al, 2009, 2010). The whole molecular assembly operates in the surface-immobilized state (heterogeneous mode).…”

Unexpected reversible pyrazine based methylation in a Ru(ii) complex bearing a pyrazin-2′-yl-1,2,4-triazolato ligand and its effect on acid/base and photophysical properties

“…1 H NMR (400 MHz, Bruker), UV/Vis absorption (Specord600, AnalyticJena) and emission (JASCO-7200 spectrofluorimeter) spectroscopy, mass spectrometry and electrochemistry (CH-Instruments CH600B potentiostat, GC working electrode, Pt counter electrode and SCE reference electrode), 40 resonance Raman, 41 and transient resonance Raman (TR 2 ), 42 were carried out as reported previously.…”