Electron spin resonance study of the salts formed by combinations of transition-metal ion chelates of tetracationic porphyrazines with tetra-anionic phthalocyanines

Abstract

The addition of an aqueous solution containing the divalent transition-metal-ion chelate of tetracationic N,N′,N″,N‴-tetramethyltetra-2,3-pyridine porphyrazine (tmtppa) to an aqueous solution containing the divalent transition-metal ion chelate of tetra-anionic 3,10,17,24-tetrasulphonatophthalocyanine (tspc) results in the precipitation of salts containing the tetracationic and tetra-anionic components in 1 : 1 mole ratio. Where the tetracationic or the tetra-anionic component contains a transition-metal-ion centre or where both components each contain a transition-metal centre capable of detection by e.s.r. spectroscopy, in the majority of cases, broad temperature-dependent e.s.r. spectral features are observed. However, salts with the composition VO(IV)tmtppa/Ni^II tspc, VO(IV)-tmtppa/Co^II tspc or Co^II tmtppa/Ni^II tspc give rise to temperature-dependent well resolved e.s.r. spectra from which spin-Hamiltonian magnetic parameters have been obtained and the nature of the magnetic interactions between the metal-ion centres deduced.