Structure and mechanism of enzymes involved in the assembly of the tetrapyrrole macrocycle

1998 ◽  
Vol 26 (3) ◽  
pp. 326-336 ◽  
Author(s):  
P. M. Shoolingin-Jordan
Keyword(s):  
Tetrapyrrole Macrocycle

scholarly journals A Tetrapyrrole Macrocycle Displaying a Multielectron Redox Chemistry and Tunable Absorbance Profile

2012 ◽  
Vol 116 (32) ◽  
pp. 16918-16924 ◽  
Author(s):  
Allen J. Pistner ◽  
Glenn P. A. Yap ◽  
Joel Rosenthal
Keyword(s):  
Redox Chemistry ◽  
Absorbance Profile ◽  
Tetrapyrrole Macrocycle

scholarly journals SYNTHESIS AND COORDINATION PROPERTIES OF COBALT COMPLEXES OF 5-PHENYL-2,3,7,8,12,18-HEXAMETHYL-13,17-DIETHYLPORPHYRIN AND ITS NITRO-SUBSTITUTED IN ORGANIC SOLVENTS

2018 ◽  
Vol 61 (7) ◽  
pp. 44 ◽  
Author(s):  
Elizaveta M. Kuvshinova ◽  
Maria A. Bykova ◽  
Irina A. Vershinina ◽  
Olga V. Gornukhina ◽  
Tatyana V. Lyubimova ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Organic Solvents ◽  
Reaction Rate ◽  
Bathochromic Shift ◽  
Cobalt Complexes ◽  
Electronic Effects ◽  
Metal Porphyrin ◽  
Absorption Bands ◽  
Coordination Properties ◽  
Tetrapyrrole Macrocycle

5-Phenyl-2,3,7,8,12,18-hexamethyl-13,17-diethylporphyrin (1), 5-phenyl-10,20-dinitro-2,3,7,8,12,18-hexamethyl -13,17-diethylporphyrin (2), 5- (p-nitrophenyl) -2,3,7,8,12,18-hexamethyl-13,17-diethylporphyrin (3) weresynthesized. The kinetics of formation and dissociation of their cobalt complexes in pyridine and acetic acid was studied. It was found that the change in reactivity upon transition from porphyrin 1 to 2 during complexation in acetic acid is due to an increase in the degree of deformation of the tetrapyrrole aromatic nucleus and the electronic effect of nitro groups. This is manifested by a strong bathochromic shift of all absorption bands in electronic spectra. It is shown that the opposite effect of the deformation effect and the i-effect of nitro groups on the rate of the reaction of formation of metal porphyrin leads to an insignificant change in the kinetic parameters. In pyridine, which has weakly basic properties, the reaction rate increases sharply with the introduction of nitro groups at position of 10, 20 of the porphyrin core. This is due to the fact that the deviation of the tetrapyrrole macrocycle from planarity leads to an increase in the reaction rate. It was found that a spherical distortion of the planar structure of porphyrins (1-3) in the series 1<3<2 relatively slightly influence on the rate of dissociation of their cobalt complexes. Apparently, this is due to the fact that coordination of the cobalt cation leads to a more flat structure of the tetrapyrrole macrocycle and the electronic effects of the nitro groups is the main contribution to the rate of the dissociation reaction of porphyrins (1-3).Forcitation:Kuvshinova E.M., Bykova M.A., Vershinina I.A., Gornukhina O.V., Lyubimova T.V., Semeikin A.S. Synthesis and coordination properties of cobalt complexes of 5-phenyl-2,3,7,8,12,18-hexamethyl-13,17-diethylporphyrin and its nitro-substituted in organic solvents. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 7. P. 43-48

A binucleating “accordian” tetrapyrrole macrocycle

1984 ◽  
Vol 25 (31) ◽  
pp. 3269-3270 ◽  
Author(s):  
Francis V. Acholla ◽  
Kristin Bowman Mertes
Keyword(s):  
Tetrapyrrole Macrocycle
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