Near-infrared absorbing metal functionalized diketopyrrolopyrroles

Abstract A symmetrical cobalt-dithiolene functionalized diketopyrrolopyrrole (DPP) Co-DPP-Co was designed and synthesized. Its photophysical, thermal, electrochemical and computational studies were compared with symmetrical ferrocenyl Fc-DPP-Fc . The electronic absorption spectrum of Co-DPP-Co exhibited absorption in Vis-NIR region with shoulder band in longer wavelength region. The thermogravimetric analysis shows good thermal stability of Co-DPP-Co . The density functional theory (DFT) investigation exhibited the cis geometry of cobalt-dithiolene ring with respect to DPP in Co-DPP-Co whereas trans geometry was observed for ferrocenyl unit in Fc-DPP-Fc .