Gas phase ion chemistry of biomolecules. part 51 - 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)..