52065-00-6

Upstream product

• 14099-01-5 chloropentacarbonylrhenium(I) 
• 1662-01-7 bathophenanthroline 
• 14099-01-5 rhenium(I) pentacarbonyl chloride 

Downstream Products

• 880468-65-5 fac-(4,7-diphenyl-1,10-phenanthroline)(trifluoromethanesulfonato)tricarbonylrhenium(I) 

Relevant academic research and scientific papers

Vibrational spectroscopy of reduced Re(I) complexes of 1,10-phenanthroline and substituted analogues

IR spectroscopy in concert with DFT calculations and resonance Raman spectroelectrochemistry has been used to identify the molecular orbital nature of the singly occupied molecular orbital (SOMO) in reduced [Re(CO) 3Cl(L)] and [Re(CO)3(4-Mepy)(L)]+ complexes, where L = 1,10-phenanthroline and its 4,7-diphenyl-and 3,4,7,8-tetramethyl- substituted analogues. The SOMO of each reduced species considered was found to be of bi symmetry, rather than the close lying orbital of a2 symmetry (within a C2ν symmetry description of the phenanthroline moiety). This was deduced in a number of ways. First, the average carbonyl band force constants (Δlav -kav{reduced complex} -k av{parent complex}) range from -57 to -41 N m-1 for the series of compounds studied. The value of Δkav relates to the extent of orbital overlap between the ligand MO and the metal dπ MO. These values are consistent with population of a b1 MO because the wave function amplitude at the chelating nitrogens for this MO is significantly greater than that for a2 MO. Second, calculations on singly reduced [Re(CO)3(4-Mepy)(phen)]+ and [Re(CO)3(4-Mepy) (tem)]+ predict population of a b2 SOMO. The spectra predicted for these species are in close agreement with the vibrational spectroscopic data; for the IR data the shifts in the CO bands are predicted to 6 cm-1 and the mean absolute deviation between calculated and measured Raman bands was found to be 10 cm-1.

Improved singlet oxygen generation in rhenium(I) complexes functionalized with a pyridinyl selenoether ligand

The synthesis, characterization, electrochemical and photophysical properties of three novel polypyridine rhenium(I) complexes coordinated to an organoselenide ligand, 4-(phenylseleno)-pyridine (PhSepy), and structurally related polypyridine ligands, fac-[Re(CO)3(NN)(PhSepy)]+ NN = 1,10-phenanthroline (phen), 4,7-diphenyl-1,10-phenanthroline (ph2phen) and pyrazino[2,3-f]-1,10-phenanthroline (dpq), are reported. In addition, their ability to act as a photosensitizer agent for the generation of singlet oxygen was investigated. Cyclic and differential pulse voltammetry experiments showed an overlap of the redox waves characteristic of the 4-(phenylseleno)-pyridine ligand and the Re(I) complex. This finding is consistent with a strong contribution of the pyridine-based ligand on the HOMO levels of the three investigated complexes, further supported by quantum mechanical calculations. Moreover, the lowest energy band observed in the absorption spectra of the complexes was also influenced by the organoselenide ligand, with a combination of the usual MLCTRe→NN transition with a ligand-to-ligand charge transfer (LLCT) one. The three complexes showed typical emission spectra for this class of compounds ascribed to 3MLCTRe→NN, with excellent quantum yields for the singlet oxygen generation (ΦΔ = 0.65–070). Remarkably, these are significantly larger (15–29%) than those for structurally related complexes with non-functionalized pyridyl ligands, revealing a significant ability as a photosensitizer agent. Therefore, we envisage this work to be of interest to those engaged in the development of novel rhenium(I) complexes for optoelectronic applications.

Z to E light-activated isomerization of α-pyridyl-N-arylnitrone ligands sensitized by rhenium(I) polypyridyl complexes

A series of rhenium(I) polypyridyl compounds, bearing photoisomerizable nitrones as ligands, was synthesized and characterized by several techniques. The photochemical and photophysical behaviors of the compounds were investigated. Upon irradiation, acetonitrile solutions of the nitrones, or their respective complexes, exhibit changes in absorption, emission, and FTIR spectra. FTIR revealed the formation of the respective anilide as the photoproducts of irradiation of the uncoordinated nitrones, while irradiation of the complexes resulted in Z → E due to the photosensitized isomerization of the coordinated ligand, also confirmed by HPLC-MS and 1H NMR. The photoisomerization quantum yields are dependent on the nature of the nitrone substituent, which changes the energy of the 3ILZ-NitX excited state, which is populated by photosensitization. 3MLCT becomes the lowest-lying excited state in the E-product and results in an increase in emission intensity. The changes in spectroscopic properties of the Z or E coordinated nitrones can be exploited for molecular devices such as photosensors.

Photophysics and ultrafast processes in rhenium(i) diimine dicarbonyls

In this work, a series of nine Re(i) diimine dicarbonyl complexes of the general molecular formula cis-[Re(N^N)2(CO)2]+ (N^N are various 2,2′-bipyridine (bpy) or 1,10-phenanthroline (phen) derivatives) were prepared and spectroscopically investigated to systematically evaluate the photophysical consequences of various substituents resident on the diimine ligands. These panchromatic absorbing chromophores were structurally characterized, evaluated for their electrochemical and spectroelectrochemical properties, and investigated using static and dynamic electronic absorption, photoluminescence (PL), and infrared spectroscopy from ultrafast to supra-nanosecond time scales. The ultrafast time-resolved infrared (TRIR) analysis was further supported by electronic structure calculations which characterized the changes within the two CO vibrational modes upon formation of the metal-to-ligand charge transfer (MLCT) excited state. The MLCT excited state decay of this series of dicarbonyl molecules appears completely consistent with energy-gap law behavior, where the nonradiative decay rate constants increase logarithmically with decreasing excited state-ground state energy separation, except in anticipated cases where the substituents were phenyl or tert-butyl.

Rhenium(I) carbonyl complex of 4,7-diphenyl-1,10-phenanthroline- Spectroscopic properties, X-Ray structure, theoretical studies of ground and excited electronic states

The paper presents structural studies of the tricarbonyl complexes incorporating 4,7-diphenyl-1,10-phenanthroline (dpphen) - [Re(CO) 3(dpphen)Cl]2·Me2CO (1) and [Re(CO) 3(dpphen)Cl] (2). The absorption and emiss

1H NMR spectroscopy as a tool to determine accurate photoisomerization quantum yields of stilbene-like ligands coordinated to rhenium(I) polypyridyl complexes

In this work, the use of proton nuclear magnetic resonance, 1H NMR, was fully described as a powerful tool to follow a photoreaction and to determine accurate quantum yields, so called true quantum yields (Φtrue), when a reactant and photoproduct absorption overlap. For this, Φtrue for the trans-cis photoisomerization process were determined for rhenium(I) polypyridyl complexes, fac-[Re(CO)3(NN)(trans-L)]+ (NN = 1,10-phenanthroline, phen, or 4,7-diphenyl-1,10-phenanthroline, ph2phen, and L = 1,2-bis(4-pyridyl)ethylene, bpe, or 4-styrylpyridine, stpy). The true values determined at 365 nm irradiation (e.g. ΦNMR = 0.80 for fac-[Re(CO)3(phen)(trans-bpe)]+) were much higher than those determined by absorption spectral changes (ΦUV-Vis = 0.39 for fac-[Re(CO)3(phen)(trans-bpe)]+). ΦNMR are more accurate in these cases due to the distinct proton signals of trans and cis-isomers, which allow the actual determination of each component concentration under given irradiation time. Nevertheless when the photoproduct or reactant contribution at the probe wavelength is negligible, one can determine Φtrue by regular absorption spectral changes. For instance, Φ313 nm for free ligand photoisomerization determined both by absorption and 1H NMR variation are equal within the experimental error (bpe: ΦUV-Vis = 0.27, ΦNMR = 0.26; stpy: ΦUV-Vis = 0.49, ΦNMR = 0.49). Moreover, 1H NMR data combined with electronic spectra allowed molar absorptivity determination of difficult to isolate cis-complexes.