Tuning the gas phase redox properties of copper(ii) ternary complexes of terpyridines to control the formation of nucleobase radical cations

Abstract

Electrospray ionization (ESI) tandem mass spectrometry (MS/MS) of ternary copper(ii) complexes of [Cu(terpyX)(M)]2+ (where terpyX = is a substituted 2,2′:6′,2′-terpyridine ligand; M = the nucleobases: adenine, guanine, thymine and cytosine) was examined as a means of forming radical cations of nucleobases in the gas phase. The following substituents were examined: 4′-NMe2-2,2′:6′,6′-terpyridine; 4′-OH-2,2′:6′,6′-terpyridine; 4′-F-2,2′:6′,6′-terpyridine; 2,2′:6′,6′-terpyridine; 4′-Cl-2,2′:6′,6′-terpyridine; 4′-Br-2,2′:6′,6′-terpyridine; 4′-CO2H-2,2′:6′,6′-terpyridine; 4′-NO2-2,2′:6′,6′-terpyridine and 6,6′-dibromo-2′,2:6′,2′-terpyridine. Each of the ternary complexes [Cu(terpyX)(M)]2+ was mas..