Controlling Near-Infrared Chromophore Electronic Properties through Metal-Ligand Orbital Alignment

J Am Chem Soc. 2017 Feb 22;139(7):2808-2815. doi: 10.1021/jacs.6b13085. Epub 2017 Feb 10.

Abstract

Transition-metal complexes of radical ligands can exhibit low-energy electronic transitions in the near-infrared (NIR) spectral region. NIR band energy and intensity sensitively depend on the degree of electronic coupling of the chromophore. Using the example of open-shell complexes derived from platinum and a 1,4-terphenyldithiophenol, we present a novel approach toward spectroscopically distinct NIR dyes for which the degree of electronic coupling correlates with the relative orientation of radical ligand and metal orbitals. Ligand/metal orbital alignment is modulated by auxiliary phosphine donors and selectively results in electron localized Class II-III or delocalized Class III structures that display distinct NIR transitions at 6500 and 4000 cm-1.

Publication types

  • Research Support, Non-U.S. Gov't