Search

Re(CO)5Cl reacts with salophenH2 to yield Re(I)2(salophenH)(CO)6Cl. A crystal structure determination has shown that this binuclear complex contains two Re(CO)3 fragments which are bridged by a chloride and a heavily constrained salophenH– anion as ligands. Under ambient conditions in solution and in the solid state, the complex displays an orange emission which originates from the lowest-energy IL/MLCT triplet. In solution, this phosphorescence is completely quenched by oxygen. [ABSTRACT FROM AUTHOR]

The salts (NnBu4)[Zn(caffeine)Cl3] and (AsPh4)[Pt(caffeine)Cl3] were prepared and their crystal structures determined by single crystal X-ray diffraction. The free ligand caffeine, as well as the complex anions [M(II)(caffeine)Cl3]− with M = Zn and Pt show an absorption spectrum with an intense band at λmax = 275 nm, which is attributed to an IL π–π* transition of the caffeine. A second band at ca. 300 nm is much weaker and largely obscured by the π–π* band. This second band is assigned to an IL n–π* transition. Both complex anions exhibit a photoluminescence (fluorescence), which originates from the n–π* state. The position of the n–π* state is recognized by the excitation band which distinctly overlaps with the fluorescence band. [ABSTRACT FROM AUTHOR]

The salt [NHEt3][Re(I)(quinaldate)(CO)3Cl] was obtained by the reaction of Re(CO)5Cl with quinaldic acid and triethylamine in toluene. The crystal structure analysis of this salt revealed the presence of the complex anion [Re(quinaldate)(CO)3Cl]−, with the d6 Re(I) metal center in a pseudo-octahedral environment. The electronic spectra in absorption and emission exhibit bands which are attributed to quinaldate IL and CT transitions at comparable energies. The longest-wavelength emission originates from a Re(I) to quinaldate MLCT triplet, which can be quenched in solution by oxygen or triethylamine. [ABSTRACT FROM AUTHOR]

The salt [Rh(III)(phpy)2(dtoxa)]Cl with phpy = 2-(2-pyridyl)phenyl anion and dtoxa = dithiooxamide has been characterized by its crystal structure and its electronic spectra. Since Rh(III) is rather redox-inert, the lowest-energy excited state of the complex cation is of the IL (dtoxa) type. In the solid state as well as in solution the complex is luminescent and displays a dtoxa IL phosphorescence at λmax = 607 nm with φϕ = 10−3 and τ = 3.7 ns in CH2Cl2. [ABSTRACT FROM AUTHOR]

The complex Ag(I)(flavonolate)(PPh3)2 has been prepared and characterized including the crystal structure. This compound shows in degassed solution two emission bands, a fluorescence at λmax=505 nm and a phosphorescence at λmax=780 nm. Both emissions originate from lowest-energy flavonolate intraligand excited singlet and triplet states, respectively. In the presence of oxygen, the phosphorescence disappears and the complex becomes light-sensitive. The flavonolate ligand undergoes a photooxidation by oxygen. [ABSTRACT FROM AUTHOR]

The binuclear complex Re(I)2(μ-4,4′-bipyridine)(8-quinolinolato)2(CO)6 has been prepared and characterized including the crystal structure. This complex shows, dependent on the conditions, three emissions, which originate from the quinolinolate IL excited state (fluorescence and phosphorescence) and from a Re(I) to 4,4′-bipyridine MLCT state (phosphorescence). [ABSTRACT FROM AUTHOR]

The binuclear complex Re(I)2(μ-4,4′-bipyridine)(8-quinolinolato)2(CO)6 has been prepared and characterized including the crystal structure. This complex shows, dependent on the conditions, three emissions, which originate from the quinolinolate IL excited state (fluorescence and phosphorescence) and from a Re(I) to 4,4′-bipyridine MLCT state (phosphorescence). [ABSTRACT FROM AUTHOR]

Baltic amber shows a greenish photoluminescence upon UV illumination. When amber is dissolved in organic solvents such as ethanol, an emission spectrum is observed, which resembles that of pyrene. At higher concentrations, pyrene undergoes an aggregation, which shifts the emission to longer wavelength. In solid amber, an analogous aggregation apparently takes place. Depending on the size of the solid amber particles, a bluish (λmax = 450 nm) to greenish (λmax = 480 nm) luminescence appears. [ABSTRACT FROM AUTHOR]