A Theoretical Investigation of the Structure and Electronic Spectra of Porphyrin Homolog Macrocycles. Hexaazacyclophane and its Nickel and Copper Complexes

Spectroscopy and Electrochemistry of Cobalt(Iii) Salophen Complexes

“…22 Electronic spectra: The UV-vis(> 280 nm) spectrum of H 2 salophen in methanol consists of a relatively intense band centred at 337 nm (ε ≈ 14,500), assigned to π → π* transition and a second band at 362nm (ε ≈ 12,100), corresponding to n → π* excitation. 27 After complexation with Co(III), several transition appear below 400nm still involving principally interligand π → π* excitation. Moreover two bands appeared in the visible region.…”

“…Theoretical calculations and experimental evidence lead to assignment of this transition as a d → π* charge transfer transition. 24,27,28 Note that there is a major contribution of d → d transitions in the lowenergy region (Table 1). For example the d → d transitions for 5-nitrosalophen and 5-Brsalophen is completely mixed with d → π* charge transfer and were seen as shoulders.…”

Thermodynamic Study of Cobalt(III) Schiff Base Complexes in Mixed EtOH/H2O

“…The UV-Vis spectum of dsp in methanol consists of a relatively intense band centred at 337 nm assigned to π → π* transition and a second band at 362 nm corresponding to n → π* excitation. 16 After complexation with Co(III) several transitions appear below 400 nm still involving principally interligand π → π* excitation. Moreover, an intense d → π* charge transfer band appears in the 450-550 nm region in the spectra of the complexes studied here.…”