Selective detection of minor prototropic tautomers in low-symmetry tetraazaporphyrin derivatives by the combined use of electronic absorption, MCD, and CI calculations

摘要

A series of low-symmetry metal-free tetraazaporphyrin (TAP) derivatives, i.e. monobenzo-substituted (1H_2), adjacently dibenzo-substituted (2AdH_2), oppositely dibenzo-substituted (2OpH_2), and tribenzo-substituted (3H_2) TAP derivatives, has been investigated by the combined use of electronic absorption, MCD, and CI calculations, proving the existence of two prototropic tautomers in 1H_2 and 3H_2.Recently,various porphyrinic compounds with low-symmetry pi-conjugated systems have been investigated,since control of the pi-symmetry is a promising route to achieving novel properties.