Complexes photophysics

Luminescent gold(l) acetylide complexes. Photophysical and photoredox properties and crystal structure of [ Au(C = CPh) 2 (p-Ph2PCH2CH2PPh2)]. Journal of the Chemical Society, Dalton Transactions, 2929-2932 (d) Che, C.-M., Wong, W.-T., Lai, T.-F. and Kwong, H.-L. (1989) Novel luminescent binuclear gold(I) isocyanide complexes. Synthesis, spectroscopy, and X-ray crystal structure of Au2(dmh)(CN)2 (dmb = 1,8-di-isocyano-p-menfhane). Journal of the Chemical Society, Chemical Communications, 243-244. 

The photophysics of fluorophores undergoing photoinduced charge transfer and/or internal rotation(s) is often complex. Time-resolved fluorescence experiments, transient absorption spectroscopy measurements, quantum chemical calculations, and comparison with model molecules are helpful in understanding their complex photophysical behavior. 

A. Juris, V. Balzani, F. Barigellitti, S. Campagna, P. Belser, andA. vonZelewsky, Ru(II) Polypyridine complexes Photophysics, photochemistry, electrochemistry, and chemiluminescence, Coord. Chem. Rev. 84, 85-277 (1988). 

An active area of research in transition metal complex photophysics has been the preparation of complexes exhibiting blue or green phosphorescence with high quantum yields for emission, for potential application in electro-... 

Reports have appeared concerning the photophysics of several families of complexes that contain either Re(I) or Os(II) metal centers directly coordinated to aromatic amine electron donors [87,88]. These complexes display unusual, albeit complex, photophysics associated with photoinduced ET from the amine donor to the metal. By analogy with the systems discussed in the preceding section, in these complexes electronic coupling between the metal and amine donor is strong and consequently the dynamics of ET are not easily analyzed in the context of conventional nonadiabatic ET theories. However, the complexes display interesting and rather unusual properties and therefore are briefly discussed herein. 

L. Atabekyan and A. Chibisov, Spiropyran complexes with metal ions. Kinetics of complexation, photophysical properties and photochemical behavior, Mol. Cryst. Liq. Cryst., 246, 262-266 (1994). 

Photophysics of Rhenium(I) Diimine Complexes A. Electronic Structure of Rhenium(I) Diimine Complexes Photophysical Relaxation Process of Rhenium(I)... 

Keywords Rhenium complex Photophysics Photochemistry Photocatalyst. 

Luminescent Cyclometalated Diimine Platinum(II) Complexes Photophysical Studies and Applications... 

The format of this year s report is unchanged. The past twelve years growth in the field of polymer photochemistry has continued, not least because of the industrial applications in such fields as photopolymerization. In fact, a new journal specifically devoted to polymer photochemistry is now available (see later references). Modern techniques such as laser flash photolysis, time-resolved emission, and derivative spectroscopy are being used to unravel the complex photophysical and photochemical processes involved in polymers. 

Juris A, Balzani V, Barigelletti F, Campagna S, Belser P, von Zelewsky A (1988) Ru(II) polypyridine complexes photophysics, photochemistry, eletrochemistry, and chemiluminescence. Coord Chem Rev 84 85-277... 

The complex photophysics of luminescence makes lumi-nophores sensitive to their immediate and macro-environments, so they can change emission characteristics in response to minor changes in the environment. Intrinsic fluorescence of amino acids was used to monitor the... 

The extent of new and insightful knowledge regarding metal complex photophysics that can now be derived from a diverse variety of time-resolved pump-probe spectroscopic techniques is illustrated by recent examples in the field of spin-state crossover complexes. This is especially so in the solution state/ but also in the solid, crystalline state straddling several time domains, from the steady-state to femtoseconds. Examples are discussed in Section 4 below on Molecular bi-stability in solution and the solid state . First however we look at recent examples where Raman spectroscopy in both steady-state and time-resolved modes has been applied to the investigation of metal-centred species of bioinorganic and catalytic interest. 

The results of extensive ab initio calculations of the PE surfaces reported above provide the quantitative basis for a qualitative interpretation of the complex photophysics of ESIPT systems. On the basis of the results one can distinguish two basic mechanisms responsible for the ESIPT process and its dynamics, depending on the geometry of the proton transferring center. 

Juris, A. Balzani, V Barigelletti, F Campagna, S. Belser, P. Von Zelewsky, A. Ru(II) Polypyridine Complexes Photophysics, Photochemistry, Electrochemistry, and Chemiluminescence, Coord. Chem. Revs. 1988, 84, 85-277. 

Illumination of the sample by a light whose energy is greater than Eg and simultaneous recording of the infrared and/or electronic spectra allow probing of the structure and properties of the electronic excited state. The complex photophysics of photoexcitation and subsequent relaxation phenomena have been studied in detail by various groups, and excellent reviews are available [75,76]. 

In fact, it is well known that Cr(lll) polypyridyl complexes are reduced to the labile Cr(ll) species upon irradiation with 351 nm laser, in agreement with their strong oxidant character in the excited state. Flash-photolysis experiments showed transient decay constants in the ps and sub-ps timescale that could be quenched by both, oxidants ([Ru (NH3)6]) and reductants (F, triethanolamine and alcohols) [39]. A very complex photophysic and photochemical behavior were described. 

Only information about the photophysical properties of meso A5 has been reported. The fluorescence spectrum of meso A5 in isooctane at room temperature shows predominant broad excimer emission with maximum at 480 nm (Ijv/Ij =23). Lowering the temperature de creases the excimer emission (Ij /Im 0.08 at 183 K). The fluorescence decay curves of meso A5 in the monomer region (377 nm) are analyzed as the sum of a two exponential function. The decay curves in the excimer region are fitted to a triple exponential function. One of the exponents has a negative preexponential factor. The complex photophysical behaviour of meso A5 cannot be interpreted with the one ground state conformation present if one does not include the possibility of aryl rotamers and consequently the existence of partial overlap excimers. The existence of more than one excimer is confirmed when fluorescence decay curves in function of wavelength of detection in the excimer region were analyzed. The shorter... 

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