Structure and physicochemical properties of substituted porphyrins

Reactions of substituted porphyrins: 2,3,7,8,12,13,17,18 -octabromo-5,10,15 ,20-tetraphenylporphine, 2,3,7,8,12,13,17,18-octamethyl-5,10,15,20-tetraphe nylporphine, and dodecaphenylporphine with organic bases (pyridine, piperid ine, dimethylformamide, dimethyl sulfoxide) and acetic acid were studied by spectrophotometry. Acid-base interaction between porphyrins and organic ba ses and formation of ionic species in toluene solution containing an organi c base were revealed for the first time. The effect of electronic and struc tural factors on the acid-base interactions of porphyrin ligands with organ ic bases is discussed. The stability constants were calculated for complexe s of 2,3,7,8,12,13,17,18-octabromo-5,10,15,20-tetraphenylporphine with orga nic bases, and electronic absorption spectra of substituted porphyrins in b asic organic solvents were recorded.