Chiral Chromium(III) Complexes as Promising Candidates for Circularly Polarized Luminescence

Abstract

The search for chiral chromophores with efficient circularly polarized luminescence (CPL) is an on-going hot topic in chemistry due to their potential applications in emerging fields such as spintronics and photonics. Beyond the largely exploited p-block, 4d/5d-block and f-block chiral entities, chiral chromium (III) complexes have recently attracted interest because of the abundancy of chromium in the earth’s crust, its kinetic inertness and its promising metal-centered Cr(2E) and Cr(2T1) phosphorescence. The associated spin-flip transitions could provide large dissymmetric factor (glum) and high luminescence quantum yields (ϕ) when six-membered strong-field chelate rings are coordinated to chiral six-coordinate Cr(III) centers. In this minireview, we intend to focus our attention on the state-ofthe- art for the design of pseudo-octahedral chiral mononuclear Cr(III) complexes for which chiroptical properties were investigated. The promising electronic properties of these complexes together with their low cost make these underexplored systems appealing candidates for CPL applications.