131917-66-3Relevant articles and documents
Successful stabilization of the elusive species {FeNO}8 in a heme model
Pellegrino, Juan,Bari, Sara E.,Bikiel, Damian E.,Doctorovich, Fabio
supporting information; experimental part, p. 989 - 995 (2010/04/01)
Nitroxyl (HNO/NO-) heme-adducts have been postulated as intermediates in a variety of catalytic processes carried out by different metalloenzymes. Hence, there is growing interest in obtaining and characterizing heme model nitroxyl complexes. The one-electron chemical reduction of the {FeNO}7 nitrosyl derivative of FeIII(TFPPBr 8)Cl, FeII(TFPPBr8)NO (1) (TFPPBr8 = 2,3,7,8,12,13,17,18-octabromo-5,10,15,20-[Tetrakis-(pentafluorophenyl)] porphyrin) with cobaltocene yields the significantly stable {FeNO}8 complex, [Co(C5H5)2]+[Fe(TFPPBr 8)NO]- (2). Complex 2 was isolated and characterized by UV - vis, FTIR, 1H and 15N NMR spectroscopies. In addition, DFT calculations were performed to get more insight into the structure of 2. According to the spectroscopic and DFT results, we can state unequivocally that the surprisingly stable complex 2 is the elusive {FeNO}8 species. Both experimental and computational data allow to assign the electronic structure of 2 as intermediate between FeIINO- and Fe INO, which is contrasted with the predominant FeIINO - character of known nonheme {FeNO}8 complexes. The enhanced stability achieved for a heme model {FeNO}8 is expected to allow further studies related to the reactivity of this elusive species.
(19)F NMR Spectra and Structure of Halogenated Porphyrins
Birnbaum, Eva R.,Hodge, Julia A.,Grinstaff, Mark W.,Schaefer, William P.,Henling, Lawrence,et al.
, p. 3625 - 3632 (2008/10/08)
Fluorine-19 NMR spectra of a series of halogenated porphyrins have beenused to create a spectral library of different types of fluorine splitting patterns for tetrakis(pentafluorophenyl) porphyrins (TFPP) complexed with diamagnetic and paramagnetic metal ions. The paramagnetic shift, line broadening, and fine structure of the resonances from the peripheral pentafluorophenyl rings are dependent on the symmetry and core environment of the porphyrin macrocycles. In combination with crystal structuredata, (19)F NMR helps define the behavior of halogenated porphyrins in solution. Six new crystal structures for TFPP and octahalo-TFPP derivatives are reported: H2TFPP in rhombohedral space group R3-, a = 20.327(4) ?, c = 24.368(5) ?, V = 8720(3) ?**3, Z = 9; ZnTFPP in monoclinic space group P21/C, a = 12.653(4) ?, b = 11.883(5) ?, c = 15.261(2) ?, β = 103.87(2)°, V = 2227.6(13) ?**3, Z =2; CuTFPP in rhombohedral space group R3-, a = 20.358(5), c = 24.347(6)?, V = 8739(4) ?**3, Z = 9; H2TFPPCl8 in triclinic space group P1-, a = 11.066(1) ?, b = 14.641(3) ?, c = 14.678(2) ?, α = 88.97(1)°, β = 76.05(1)°, γ = 71.29(1)°, V = 2181.4(6) ?**3, Z = 2; ZnTFPPCl8 in tetragonal space groupP4-21C, a = 19.502(20), c = 10.916(8) ?, V = 4152(6) ?**3, Z = 2; H2TFPPBr8 in monoclinic space group C2, a = 27.634(6) ?, b = 6.926(2) ?, c = 14.844(3) ?, β = 109.64(2)°, V = 2675.8(11) ?**3, Z = 2.
