Журнал "Макрогетероциклы"

 

Dedicated to Corresponding member of Russian Academy of Sciences Prof. Oscar I. Koifman on the occasion of his 70th birthday

^aMolecule Structure Research Center of the Scientific and Techological Center of Organic and Pharmaceutical Chemistry NAS RA, 0014 Yerevan, Armenia

^bYerevan State Medical University after M.Heratsi, 0005 Yerevan, Armenia

^cResearch Institute of Macroheterocycles, Ivanovo State University of Chemical Technology, 153000 Ivanovo, Russia

 

DOI: 10.6060/mhc140923k

Macroheterocycles 2014 7(3) 233-239

 

Sublimed layers of 5-(pyridin-4-yl),10,15,20-triphenylporphyrinato)cobalt(II) and 5-(pyridin-3-yl),10,15,20-triphenylporphyrinato)cobalt(II) {Co(M4PyTPP)} (I) and {Co(M3PyTPP)} (II), respectively} form coordination oligomers upon standing. Interaction of NO(¹⁵NO) gas with these systems results in formation of the penta and hexacoordinate nitrosyl complexes, the sixth coordination site of which is occupied by the pyridyl group of the adjacent molecule in the layer. The FTIR spectral data demonstrate that the long-term exposure of these systems under O₂ results in oxidation of the nitrosyl complexes with formation of the hexacoordinate nitrato complexes and the reaction proceeds predominantly with the hexacoordinate nitrosyls. Мechanism of oxidation more likely includes the dissociation of NO from the hexacoordinate complex followed by O₂ trapping of the resulting (-4(3)Py)Co(M4(3)PyTPP) to give (- 4(3)Py)Co(M4(3)PyTPP)(O₂), which then reacts rapidly with NO by the nitric oxide dioxygenation reaction.