The photophysical properties of mononuclear Pt-II chromophores of the general structural formulae: Pt(LL)(C CR)(2) and [Pt(LLL)(C CR)](+) (LL = substituted or unsubstituted 2,2'-bipyridine; LLL = substituted or unsubstituted 2,2':6',2"-terpyridine; R = aryl or alkyl) are described. Topics related to their preparation, spectroscopy, photochemistry, and photophysics are reviewed. (c) 2006 Elsevier B.V. All rights reserved.