84174-28-7

Upstream product

• 43145-40-0 azido(5,10,15,20-tetra-p-tolylporphinato)chromium(III) 
• 89653-20-3 aquaazido(tetraphenylporphinato)chromium(III) 
• 43145-39-7 chlorochromium(III) meso-tetrakis(4-methylphenyl)porphyrinate 
• 84174-29-8 nitridochromium(V) octaethylporphyrinate 
• 84206-82-6 nitridomanganese(V) octaethylporphyrinate 

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• 90939-34-7 aqua[(methylamido)dimethoxophosphato][5,10,15,20-tetrakis(4-methylphenyl)porphyrinato]chromium(III) 

Relevant academic research and scientific papers

Inter-Metal Nitrogen Atom Transfer Reactions between Nitridochromium(V) and Chromium (III) Porphyrins

Reactions of nitridochromium(V) porphyrins with chromium(III) porphyrins resulted in reversible, inter-metal nitrogen atom transfer between the two chromium porphyrin complexes. The progress of these reactions was followed spectrophotometrically. Kinetic analysis of the spectral data obtained over time for a variety of substituted porphyrins showed the reactions to be first order in each of the reactants and second order overall. Equilibrium constants were computed from the spectral data and ranged from 0.56 to 2.1 for the reactions between nitridochromium(V) octaethylporphyrin and a series of chlorochromium(III) tetraphenylporphyrins possessing phenyl ring substituents. Forward rate constants were determined for this reaction series and ranged from 6.8 to 1420 M-11 s-1. Electron-withdrawing substituents enhanced the forward rates but diminished the equilibrium constants. It is proposed that the reactions proceed by nucleophilic attack of the nitridochromium porphyrin donor on the cationic chromium(III) porphyrin nitrogen atom acceptor facilitating a net, two-electron redox process mediated by a homobimetallic μ-nitrido intermediate.

Stereoelectronic Aspects of Inter-Metal Nitrogen Atom Transfer Reactions between Nitridomanganese(V) and Chromium(III) Porphyrins

Reactions of nitridomanganese(V) porphyrins with chromium(III) porphyrins resulted in the irreversible formation of nitridochromium(V) porphyrins and manganese(III) porphyrins. The progress of these reactions has been followed spectrophotometrically, electrochemically, and spectroscopically by EPR. Kinetic analysis of the spectrophotometric data obtained during these reactions for a variety of substituted porphyrins showed the reactions to be first order in each of the reactants. Rate constants were dependent upon the electronic and steric effects of the porphyrin substituent, upon the identity of the anion bound to the chromium(III) reactant, and upon the solvent dielectric constant. We propose that the mechanism of these nitrogen atom transfer reactions involves the nucleophilic attack of the nitridomanganese porphyrin donor on the cationic chromium(III) porphyrin acceptor facilitating a net, two-electron redox process mediated by a heterobimetallic μ-nitrido intermediate. This report represents the first systematic study of the stereoelectronic effects involved in the complete, inter-metal nitrogen atom transfer between two metalloporphyrins.

Metal Complexes with Tetrapyrrole Ligands XXXIII. Preparation of Azidochromium(III)-, Azidomanganese(III)-, and Azidoiron(III) Porphyrins and their Photolysis to Terminal or Bridged Nitridometal Porphyrins

Azidometal(III) porphyrins, e.g.M(TTP)N3 1 Aa - 1 Ca (M = Cr, Mn, Fe), are transformed into nitrido complexes on irradiation with ultraviolet light.Thus, Cr(III) or Mn(III) complexes, e.g.Cr(TTP)N3 or Mn(TTP)N3, yield Cr(V) and Mn(V) complexes with terminal nitride ligands, e.g.Cr(TTP)N (1 Ab) or Mn(TTP)N (1 Bb) with concomitant liberation of 1 mol of N2.However, the Fe(III) complex Fe(TTP)N3 produces the mixed-valence μ-nitrido-bis complex, 2N (1 Cg) and about 1.2 mol of N2 per mol of Fe.The azidometal(III) porphyrins are prepared from the corresponding hydroxo- or μ-oxo-metal(III) porphyrins and hydrazoic acid in benzene. - Key words: Chromium Porphyrins; Manganese Porphyrins; Nitridometal Complexes; Photolysis of Azido Complexes

Metal complexes with tetrapyrrole ligands. 29. Synthesis and electron spin resonance spectra and electron nuclear double resonance investigations of nitridochromium(V) porphyrins

Mononuclear pentacoordinated nitridochromium(V) porphyrins, nitrido(tetra-p-tolylporphinato)chromium(V), CrN(TTP), and nitrido(octaethylporphinato)chromium(V), CrN(OEP), are prepared by hypochlorite oxidation of the corresponding chromium(III) porphyrins, CrOH(TTP)-2H2O and CrOH(OEP)·1/2H2O, in the presence of ammonia. These remarkably stable species are identified by UV/vis, IR, and mass spectra. An investigation of these paramagnetic compounds by ESR and ENDOR spectroscopy has furnished evidence for the CrV(d1/dxy) state of the central metal and the coordination of a single axial nitrogen. The X- and Q-band ESR as well as the 14N ENDOR spectra are identical for both CrN(TTP) and CrN(OEP): At room temperature we find an isotropic signal at g0 = 1.9825 and an isotropic 53Cr hyperfine splitting a0(53Cr) = 2.83 mT. A superhyperfine splitting a(14N) = 0.27 mT due to five apparently equivalent 14N nuclei is observed. At 77 K an anisotropic ESR signal with g⊥ = 1.9945 and g∥ = 1.9583 and anisotropic hyperfine values of a⊥(53Cr) = 2.24 mT and a∥(53Cr) = 4.01 mT have been determined. 14N ENDOR spectra measured at 3.6 K serve to discern the axial and equatorial superhyperfine splitting constants: For Npyrrole, a⊥1 = 0.36, a⊥2 = 0.14, and a∥ = 0.31 mT, and for Naxial, a⊥1 = 0.37, a⊥2 = 0.34, and a∥ = 0.13 mT. The ESR and ENDOR parameters are characteristic for a d1 system with strong spin localization in the dxy orbital and nearly no spin localization in dz2, which may be the reason for the high stability of these complexes.

Synthesis and molecular structure of a nitrido(porphyrinato)chromiuin(V) complex

Irradiation of solutions of azido(5,10,15,20-tetra-p-tolylporphyrinato)chromium(III) in methylene chloride or benzene gave nitrido(5,10,15,20-tetra-p-tolylporphyrinato)chromium(V) (1) in yields of 59% and 82%, respectively. Solutions of 1 showed well-resolved EPR spectra at room temperature (g = 1.985, A53Cr = 2.85 mT, AN = 0.279 mT). The IR spectra of nitrido(5,10,15,20-tetra-p-tolylporphyrinato)chromium(V) (1) and 1-15N showed bands at 1017 and 991 cm-1, which were assigned to vCr≡14N and vCr≡15N, respectively. The molecular structure of 1·C6H6 indicated a chromium-nitrogen distance of 1.565 A?, with the chromium 0.42 A? above the mean plane of the pyrrole nitrogens. The periphery of the porphyrin ring was saddle-shaped with excursions 0.56 A? below and 0.29 A? above the plane of the pyrrole nitrogens.