Hexaazacyclophane and Its Cu II Complex

Gobernado-Mitre et have proposed metal dependent frequencies at 341 

Ard and Gladkov and Solovyov propose, from normal coordinate calculations performed for the copper porphin complex, that bands near 368, 234 and 206 cm contain important contributions of the vCuN mode. From a vibrational study on the non-macrocycle phenantroline copper complexes it has been proposed the vCuN modes near 410 and 288 cm In bipyridine complexes of Cu(II), the vCuN mode is proposed at 297cm a similar assignment is proposed in bipyrimidine complexes.  

The vCC and vCN modes are highly coupled in molecules with extended 7t electronic system. The energy of the corresponding CN bonds near or directly involved in the metal coordination (CuN) are influenced by metal complexation. Then, the identification of the nCuN modes is of paramount importance to characterize the energy of the coordination site . 

The A2g in plane vibrations of metallophthalocyanines (MPc), become Raman active, similar to metalloporphyrins, under resonance conditions. Several infrared and Raman spectra of MPc and MPc containing axial ligands have been reported by many investigators . Hutchinson et alP assigned the M-N stretching modes of different metal isotopes of MPc. The IR active vZnN (Eg) vibration in ZnPc was observed at 329 cm and the observed ZnN distance is 1.980 A .  

The spectral characteristics of this mode are not much different within the series Co(II) VO(II) and Pb(II), including the CuNc molecule (681 cm and strong relative intensity) . The macrocycle ring structure in that series is similar. 

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