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The ground- and excited-state properties of three novel complexes [ReCl(CO)3(Ln-κ2N)] bearing 2,2′:6′,2′′-terpyridine, 2,6-di(thiazol-2-yl)pyridine and 2,6-di(pyrazin-2-yl)pyridine functionalized with 9-carbazole attached to the central pyridine ring of the triimine core via phenylene linkage were investigated by spectroscopic and electrochemical methods and were simulated using density functional theory (DFT) and time-dependent DFT. To get a deeper and broader understanding of structure–property relationships, the designed Re(I) carbonyl complexes were compared with previously reported analogous systems – without any groups attached to the phenyl ring and bearing pyrrolidine instead of 9-carbazole. The results indicated that attachment of the N-carbazolyl substituent to the triimine core has less influence on the nature of the triplet excited state of [ReCl(CO)3(Ln-κ2N)] than the pyrrolidine group. Additionally, the impact of the ligand structural modifications on the light emission of the Re(I) complexes under external voltage was preliminarily examined with electroluminescence spectra of diodes containing the synthesized new molecules in an active layer. [ABSTRACT FROM AUTHOR]

The influence of albumin and amino acids ( l-serine, glycine, l-histidine, l-tryptophan, l-cysteine) on the properties of aluminum octacarboxyphthalocyanine hydroxide (Al(OH)PcOC) was investigated in a phosphate buffer (pH 8.0). Particular attention was paid to the spectroscopic properties and photostability of Al(OH)PcOC. The effect of albumin or amino acids on the photodegradation of Al(OH)PcOC was examined in water using red light: 685 nm and daylight irradiation. Analysis of kinetic curves indicated that interaction with those molecules increases the photostability of Al(OH)PcOC. The molecular structure of Al(OH)PcOC complexes (in vacuum and in water) with axially or equatorially coordinated amino acids was studied by the B3LYP/6-31G* method, and the effects on molecular structure and electronic absorption spectrum were investigated on the basis of the density functional theory. The calculation results revealed that axial coordination significantly reduces the non-planarity of the phthalocyanine ring, and, thus, alters the electronic structure. On the other hand, hydrogen bonding of phthalocyanine side COOH groups with amino acids, in equatorial complexes, does not change the structure within the center of the phthalocyanine, and causes only a slight increase in UV-vis bands intensity, which is in perfect agreement with experimental data. [ABSTRACT FROM AUTHOR]

The title complex was synthesized and characterized by IR, NMR and UV-VIS spectroscopy and X-ray crystallography; the electronic structure of the complex was calculated using the density functional theory. [Copyright &y& Elsevier]

In this study, the synthesis and physicochemical properties (thermal, electrochemical and optical) of three phenanthro[9,10-d]imidazole derivatives with N-donor substituents (PI-1 - PI-3) was presented. All compounds were obtained by condensation reactions with a yield in the range of 61–70%. Their structure was confirmed by NMR spectroscopic methods (1H, 13C, H–H COSY, H–C HMQC and H–C HMBC). The synthesized derivatives were characterized by high thermal stability (above 300 °C). Two of them (PI-1 and PI-3) showed a fully reversible oxidation process, which allowed detailed spectroelectrochemical and electrochemical studies. Absorption and emission properties were tested in four solvents of different polarity. These compounds showed high quantum yields in the range from 18 to 80%. Studies on physicochemical properties have been extended to include detailed theoretical considerations. Image 1 • A series of phenanthro[9,10-d]imidazole derivatives with N-donor substituents were investigated. • All derivatives were showed high thermal stability. • These compounds were characterized by high quantum yields in the range from 18 to 80%. • Detailed theoretical calculation were performed for electrochemical and photophysical studies. [ABSTRACT FROM AUTHOR]