Electrochemistry and Spectroelectrochemistry of Cobalt Porphyrins with π-Extending and/or Highly Electron-Withdrawing Pyrrole Substituents. In Situ Electrogeneration of σ-Bonded Complexes

被引:57
作者
Ke, Xiangyi [1 ]
Kumar, Ravi [2 ]
Sankar, Muniappan [2 ]
Kadish, Karl M. [1 ]
机构
[1] Univ Houston, Dept Chem, Houston, TX 77204 USA
[2] Indian Inst Technol Roorkee, Dept Chem, Roorkee 247667, Uttar Pradesh, India
关键词
LIGAND ADDITION-REACTIONS; TETRAPHENYLPORPHYRIN COMPLEXES; CO ATMOSPHERE; OXIDATION; RESONANCE; MEDIA; REDUCTION; PYRIDINE; FACILE; REDOX;
D O I
10.1021/acs.inorgchem.7b02856
中图分类号
O61 [无机化学];
学科分类号
070301 ; 081704 ;
摘要
A series of cobalt porphyrins with pi-extending or highly electron-withdrawing beta-pyrrole substituents were investigated as to their electrochemistry, spectroscopic properties, and reactivity after electroreduction or electroxidation in nonaqueous media. Each porphyrin, represented as PorCo (where Por = TPP(NO2)Y-2 or TPP(NO2)Y-6 and Y = phenyl, phenylethynyl, Br, or CN) was shown to undergo multiple redox reactions involving the conjugated pi-ring system or central metal ion which could exist in a Co(III), Co(II), or Co(I) oxidation state under the application of an applied oxidizing or reducing potential. Thermodynamic half-wave potentials for the stepwise conversion between each oxidation state of [PorCo](n) (where n ranged from +3 to -3) were measured by cyclic voltammetry and analyzed as a function of the compound structure and properties of the electrochemical solvent. UV-visible spectra were obtained for each oxidized or reduced porphyrin in up to six different oxidation states ranging from [PorCo](3-) to [PorCo](3+) and analyzed as a function of the compound structure and utilized electrochemical solvent. Chemically or electrochemically generated Co(I) porphyrins are known to be highly reactive in solutions containing alkyl or aryl halides, and this property was utilized to in situ generate a new series of methyl carbon bonded cobalt(III) porphyrins with the same n-extending or highly electron-withdrawing substituents as the initial Co(II) derivatives. The electrosynthesized carbon-bonded Co(III) porphyrins were then characterized'as to their own electrochemical and spectroscopic properties after the addition of one, two, or three electrons in nonaqueous media.
引用
收藏
页码:1490 / 1503
页数:14
相关论文
共 27 条
[1]  
CALLOT HJ, 1974, B SOC CHIM FR II-CH, P1492
[2]   ELECTROCHEMICAL AND SPECTROELECTROCHEMICAL BEHAVIOR OF COBALT(III), COBALT(II), AND COBALT(I) COMPLEXES OF MESO-TETRAPHENYLPORPHYRINATE BEARING BROMIDES ON THE BETA-PYRROLE POSITIONS [J].
DSOUZA, F ;
VILLARD, A ;
VANCAEMELBECKE, E ;
FRANZEN, M ;
BOSCHI, T ;
TAGLIATESTA, P ;
KADISH, KM .
INORGANIC CHEMISTRY, 1993, 32 (19) :4042-4048
[3]   Asymmetrically Crowded "Push-Pull" Octaphenylporphyrins with Modulated Frontier Orbitals: Syntheses, Photophysical, and Electrochemical Redox Properties [J].
Grover, Nitika ;
Sankar, Muniappan ;
Song, Yang ;
Kadish, Karl M. .
INORGANIC CHEMISTRY, 2016, 55 (02) :584-597
[4]  
Guilard R., 2000, The Porphyrin Handbook, V3, P325
[5]   A SURVEY OF HAMMETT SUBSTITUENT CONSTANTS AND RESONANCE AND FIELD PARAMETERS [J].
HANSCH, C ;
LEO, A ;
TAFT, RW .
CHEMICAL REVIEWS, 1991, 91 (02) :165-195
[6]   INSITU FOURIER-TRANSFORM INFRARED SPECTROELECTROCHEMICAL STUDIES OF THE OXIDATION OF SOME TETRAPHENYLPORPHYRIN COMPLEXES [J].
HINMAN, AS ;
PAVELICH, BJ ;
MCGARTY, K .
CANADIAN JOURNAL OF CHEMISTRY-REVUE CANADIENNE DE CHIMIE, 1988, 66 (07) :1589-1595
[7]  
Kadish K.M., 2000, PORPHYRIN HDB, P1
[8]  
Kadish K.M., 1986, The Electrochemistry of Metalloporphyrins in Nonaqueous Media, V34, P435
[9]  
Kadish K.M., 2000, PORPHYRIN HDB, V9, P1
[10]   Electrooxidation of cobalt(II) β-brominated-pyrrole tetraphenylporphyrins in CH2Cl2 under an N2 or a CO atmosphere [J].
Kadish, KM ;
Li, J ;
Van Caemelbecke, E ;
Ou, ZP ;
Guo, N ;
Autret, M ;
D'Souza, F ;
Tagliatesta, P .
INORGANIC CHEMISTRY, 1997, 36 (27) :6292-6298