54438-77-6Relevant articles and documents
Low temperature NO disproportionation by Mn porphyrin. Spectroscopic characterization of the unstable nitrosyl nitrito complex MnIII(TPP) (NO)(ONO)
Martirosyan, Garik G.,Azizyan, Arsen S.,Kurtikyan, Tigran S.,Ford, Peter C.
, p. 1488 - 1489 (2007/10/03)
Reaction of NO gas with sublimed layers of the MnIITPP (TPP = meso-tetraphenylporphyrinato2-) at low temperature leads to nitric oxide disproportionation. UV-Vis and FTIR spectroscopy with isotopically substituted nitrogen oxides rev
Photoluminescent properties of cadmium selenide in contact with solutions and films of metalloporphyrins: Nitric oxide sensing and evidence for the aversion of an analyte to a buried semiconductor-film interface
Ivanisevic, Albena,Reynolds, Mark F.,Burstyn, Judith N.,Ellis, Arthur B.
, p. 3731 - 3738 (2007/10/03)
The band-edge photoluminescence (PL) intensity of etched n-CdSe single crystals is quenched reversibly by adsorption of the trivalent metalloporphyrins, MTPPCl (TPP = tetraphenylporphyrin; M = Mn, Fe, Co) in nitrogen-saturated methylene chloride solution. The PL responses are concentration dependent and can be fit to the Langmuir adsorption isotherm model to yield binding constants of ～103-104 M-1. The MTPPCl compounds react irreversibly with NO in solution to form nitrosyl adducts, and these compounds reversibly enhance the CdSe PL intensity when adsorbed onto the semiconductor surface, also with binding constants of ～103-104 M-1. Films of MTPPCl were prepared on CdSe substrates by solvent evaporation. These coatings serve as transducers for NO detection: while the bare CdSe surface shows no response to NO gas relative to N2, the coated surfaces reversibly enhance the PL intensity (CoTPPCl) or quench it (MnTPPCl and FeTPPCl), with binding constants on the order of ～1 atm-1. In contrast to the PL results, which are particularly sensitive to the semiconductor-film interface, electronic and IR spectral changes of the bulk film induced by NO binding were irreversible. The UV-vis and IR spectra could be spectroscopically mimicked by preformed nitrosyl adduct films that were prepared by solvent evaporation of MTPPCl (M = Co, Fe) and MTPP (M = Co) solutions that had been exposed to NO. These films, however, lack transduction capability, as the PL intensity is the same in NO and N2 ambients. For the films prepared from FeTPPCl and CoTPPCl, the saturation of IR and UV-vis spectral changes occurs at NO pressures at least 10-fold lower than observed for PL changes. These results indicate that NO has a strong aversion to binding at the semiconductor-film interface as opposed to the bulk film environment. Steric and electronic contributions to these observed effects are discussed.
Laser Flash Photolysis Studies of Nitritomanganese(III) Tetraphenylporphyrin. Reactions of O2, NO, and Pyridine with Manganese(II) Tetraphenylporphyrin
Hoshino, Mikio,Nagashima, Yutaka,Seki, Hiroshi,De Leo, Malcolm,Ford, Peter C.
, p. 2464 - 2469 (2008/10/08)
Laser photolysis of nitritomanganese(III) tetraphenylporphyrin. MnIIITPP(ONO) (1), in degassed toluene gives manganese(II) tetraphenylporphyrin, MnIITPP (2), plus NO2. The quantum yield, Φ, for the formation of MnII-TPP is dependent on the excitation wavelength: Φ = 0.045 at 355 nm and Φ = 0.0064 at 532 nm. Continuous photolysis studies reveal that the quantum yield for the net photodecomposition of 1 is much smaller (10-4). Thus, MnIITPP produced by laser photolysis of MnIIITPP(ONO) mostly returns to 1 by recombination with NO2 according to second-order kinetics with a rate constant 2.2 × 109 M-1 s-1. The kinetics for the reactions of MnIITPP with O2, NO, and pyridine were investigated in detail. In aerated toluene, MnIITPP reversibly reacts with oxygen to yield the dioxygen adduct, MnTPP(O2) (3). The rate constants, kf(O2) and kb(O2), for the formation and dissociation of 3 at 300 K were determined to be 1.93 × 107 M-1 s-1 and 9.0 × 104 s-1, respectively, and the equilibrium constant, kf(O2)/kb(O2), is therefore 2.1 × 102 M-1. MnIITPP reacts with pyridine to give MnII-TPP(Py) with a rate constant of 9.5 × 108 M-1 s-1. MnIITPP reacts with NO to yield nitrosylmanganese porphyrin, MnIITPP(NO), with the rate constant 5.3 × 108 M-1 s-1. The association reactions of MnIITPP with NO, pyridine, O2, and NO2 are discussed in comparison with those of other metalloporphyrins.
Photochemistry of nitrosyl metalloporphyrins: Mechanisms of the photoinduced release and recombination of NO
Zavarine, Igor S.,Kini, Abhay D.,Morimoto, Bruce H.,Kubiak, Clifford P.
, p. 7287 - 7292 (2007/10/03)
A series of substituted nitrosylmetalloporphyrins of the type M(NO)(meso-tetra(p-X)phenylporphyrin) (M = Co, Mn; X = H, NO2, OMe) were prepared and studied by laser flash photolysis. The kinetics of the recombination reactions between the metalloporphyrins and NO in THF were examined. The recombination mechanism appears to be more complicated than the simple second-order process previously reported. Out-of-plane puckering of the porphyrin ring immediately after denitrosylation is one possible explanation. Kinetic experiments and NO transfer studies between manganese and cobalt porphyrins suggest that these compounds exist in equilibrium with NO in solution. Varying the substituents in the phenyl ring of the tetraphenylporphyrin ligand has little effect on rates of recombination with NO.
Electrochemical and spectroelectrochemical characterization of intermolecular nitrosyl transfer between iron and cobalt porphyrins
Mu,Kadish
, p. 1031 - 1036 (2008/10/08)
The transfer of a nitrosyl ligand between neutral and oxidized iron and cobalt metalloporphyrins in dichloromethane solutions was investigated by electrochemistry and FTIR or ESR spectroelectrochemistry. The transfer of NO from (P)Co(NO) to (P)Fe, from [(P)Co(NO)]+ to (P)FeClO4, and from [(P)Fe(NO)]+ to (P)Co was demonstrated for complexes where P = the dianion of tetraphenylporphyrin (TPP), meso-tetrakis(2,4,6-trimethylphenyl)porphyrin (TMP), or octaethylporphyrin (OEP). The driving force in these reactions is related to both the nature and oxidation state of the central metal in (P)M(NO) or [(P)M(NO)]+, where M = Fe or Co, and follows the order (P)Fe(NO) > (P)Co(NO) > [(P)Fe(NO)]+ > [(P)Co(NO)]+.
Photochemistry of Nitrosyl Porphyrins in the Temperature Range 180-300 K and the Effects of Pyridine on Photodenitrosylation of Nitrosyliron Tetraphenylporphyrin
Hoshino, Mikio,Kogure, Mieko
, p. 5478 - 5484 (2007/10/02)
Nitrosylmetal tetraphenylporphyrin (NOMTPP, M=Fe,Co, and Mn) in benzene solutions undergoes facile photodenitrosylation to give NO and metal(II) tetraphenylporphyrin, MIITPP.The photodenitrosylation yields of NOFeTPP and NOCoTPP are respectively determined as 0.50 +/- 0.05 and 1.0 +/- 0.05 at both excitation wavelengths 355 and 532 nm.The yield, Φ, in toluene is expressed as a function of temperature: Φ = (1 + 1.56 x 10-2 exp(2400/RT))-1 for NOFeTPP and Φ = (1 + 1.02 x 10-6 exp(5200/RT))-1 for NOCoTPP.Contrary to NOFeTPP and NOCoTPP, the photodenitrosylation yields, Φ, of NOMnTPP are independent of temperature in the range 300-180 K and exhibit excitation wavelength dependence: Φ = 0.78 +/- 0.05 at 355 nm and Φ + 0.62 +/- 0.05 at 532 nm.The effects of the central metal on photodenitrosylation are described.The laser photolysis of NOFeTPP in the presence of low concentration of pyridine revealed that the FeIITPP initially produced reacts with a pyridine molecule, Py, to form five-coordinate (Py)FeIITPP.The five-coordinate (Py)Fe%II%TPP further reacts with Py to give six-coordinate (Py)2FeIITPP, which recombines with NO to regenerate NOFeTPP.The kinetic study has demonstrated that the five-coordinate (Py)FeIITPP which is in equilibrium with (Py)2FeIITPP is responsible for the recombination reaction of (Py)2FeIITPP and NO.
