Year: 2026
Type: preprint
Abstract: We performed a comprehensive electrochemical and spectroelectrochemical study of three transition metal phthalocyanine (Pc) complexes, Pc n-OBu (2−)Mn III Cl, Pc tBu (2−)Mn III Cl and Pc tBu (2−)Cr III Cl (Pc tBu is the dianion of 2,9(10),16(17),23(24)-tetra- tert -butyl-phthalocyanine and Pc n-OBu is the dianion of 1,4,8,11,15,18,22,25-octa-n-butoxy-phthalocyanine), that are relevant for a variety of bond-breaking and forming reactions. Syntheses were optimized for previously reported tert -butylated species. Solvent-dependent voltammetry, spectroelectrochemistry, and for the first time for Mn III and Cr III Pc derivatives, spectroelectrochemical magnetic circular dichroism (MCD), were used to assess ligand- versus metal-centered redox events, electrochemical and chemical reversibilities of electron transfer, and effects of axial ligand coordination in dichloromethane or chloroform (DCM or CHCl 3 ) versus N,N -dimethylformamide (DMF). Comparisons are made to previously reported voltammetry and spectra of both Pc(2−)Mn II and chemically prepared oxidation states of Pc(2−)Cr II . We observe differences in localization of reduction events in P c n-OBu (2−)Mn III Cl versus Pc tBu (2−)Mn III Cl, with a more electron-rich ring promoting formation of MnI over Pc-centered reduction. We observe unique reduction behavior in Pc tBu (2−)Cr III Cl that points towards a mixture of ligand- and metal-centered character. To the best of our knowledge, these studies represent the first complete solvent-dependent spectroelectrochemical characterization of both Mn III and Cr III phthalocyanine derivatives across up to six different oxidation states.
Source: ChemRxiv
Institutions: University of Tennessee at Knoxville, Simon Fraser University
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7211887478