Platinum(II) diimine dithiolates. New solution luminescent complexes

• Published in: Coordination chemistry reviews Vol. 97; pp. 47 - 64
• Main Authors: Zuleta, Juan A., Burberry, Mitch S., Eisenberg, Richard
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Lausanne Elsevier B.V 1990; Elsevier
• Subjects: Atomic and molecular physics; Exact sciences and technology; Molecular properties and interactions with photons; Physics
• ISSN: 0010-8545; 1873-3840
• DOI: 10.1016/0010-8545(90)80079-9

A series of Pt(diimine)(dithiolate) complexes has been synthesized and characterized spectroscopically. The diimine ligands include 2,2′-bipyridine (bpy), 1,10-phenanthroline (phen), 4,4′-dimethyl-2,2′-bipyridine (dmbpy), 4,4′-diphenyl-2,2′-bipyridine (dpbpy) and 4,7-diphenyl-1,10-phenanthroline (dpphen) while the dithiolates are maleonitriledithiolate (mnt), 2,2-dicyano-1,1-ethylenedithiolate (i-mnt) and ethyl-2-cyano-3,3-dithiolatoacrylate (ecda). The complexes are solvatochromic showing a linear correlation of absorbance with solvent polarity. The most notable feature of the complexes is that they luminesce in fluid solution. The luminescence differs depending on the nature of the dithiolate - mnt complexes show structured emissions while i-mnt and ecda complexes do not - but the emitting state appears to be d-π *(dithiolate) for all complexes. The relative quantum yields for emission have been determined, as have lifetime measurements at 298 K and 77 K in both rigid and fluid media. Quenching studies have been done for Pt(dpphen)(mnt) and Pt(dpphen)(ecda) using dimethylaniline (DMA) as a donor and o-nitrobenzaldehyde (ONB) as an acceptor. Good Stern-Volmer behavior is observed for both reductive and oxidative quenching.