Isomorphous free-base, Ni(ii)- and Cu(ii)-5,10,15,20-tetra(4-hydroxyphenyl)porphyrin nitrobenzene hexasolvates with tetragonal 3D hydrogen-bonded network structures
Electrochemical metallation with Ni(II) and Al(III) of 5,10,15,20-tetrakis(p-hydroxyphenyl)porphyrin: Effect of ultrasound
摘要:
The electrochemical synthesis of Ni(II) and Al(III) metalloporphyrins by reaction of the dianion radical of the 5,10,15,20-tetrakis(p-hydroxyphenyl)porphyrin (TpOHPP) with Ni(II) and Al(III) ions is reported. The electrosynthesis conditions were established by cyclic voltammetry of TpOHPP. The electrosynthesis process was carried out in an undivided cell at the potential corresponding to the formation of the porphyrin dianion radical. A sacrificial anode of Ni or Al was used to electrogenerate the ions. The experiments were carried out in aprotic and protic solvents. The effect of the application of 20 kHz ultrasound on the electrochemical process was evaluated. The electrosynthesis products were characterized by spectroscopy and electrochemical techniques. The results indicate the formation of metalloporphyrins in the different solvents in silent conditions and with ultrasound. The application of 20 kHz ultrasound and protic solvents enhance the reaction yields without affecting the structure of the obtained products. 2013 Elsevier Ltd. All rights reserved.
A new general one-pot method for the synthesis of various metalloporphyrins has been developed from pyrrole and substituted aldehydes using transition metal salts. This method allows higher working concentrations than those previously reported. Along with the reported metalloporphyrins, some new metalloporphyrins were synthesized in good yield.