Platinum(ii) N-heterocyclic carbene complexes: coordination and cyclometallation.

Stepwise Strategy to Cyclometallated PtII Complexes with N‐Heterocyclic Carbene Ligands: A Luminescence Study on New β‐Diketonate Complexes

“…If we compare the final products of the carbene cyclometallation using the DMSO-derivative, [Pt(C _ C*)(DMSO)Me], [28] with ours, [{Pt(m-Cl)(C _ C*)} 2 ] (4), it seems clear that our system presents a significant advantage over the other. Although the DMSO-derivative has a methyl group and a molecule of DMSO in the coordination sphere of the platinum, none of which are labile li-…”

“…[13b, e-h, 27] To date, the two-step process, that is, coordination and subsequent cycloplatination of N-heterocyclic carbene ligands, has only been reported with [PtMe 2 (DMSO) 2 ]. [28] In this paper, we describe for the first time the use of the chloro-bridge complex [{Pt(m-Cl)(h 3 -2-Me-C 3 H 4 )} 2 ] to achieve this stepwise cyclometallation by isolating the intermediates. Unlike previous studies, [13i] we have been able to prepare and characterize the intermediate complex (compound 3), which subsequently undergoes a regiospecific cyclometallation of the coordinated NHC carbene.…”

(Acetylacetonato-κ2O,O′)[1-(4-bromophenyl-κC2)-3-methylimidazol-2-ylidene-κC2]platinum(II)

“…Their properties differ from the previously known C^N cyclometallating ligands derived from, for example, 2-phenylpyridine (ppy) (Chassot et al, 1984) or from phenylazoles like phenylpyrazole or 2-phenylimidazole. The new class of Pt(C^C*) compounds opens up a new field of photophysically interesting compounds (BASF, 2006(BASF, , 2007Petretto et al, 2010;Unger et al, 2010). Only one solid-state structure of this new class of compounds is known, viz.…”

Chiral Ag(i) and Pt(ii) complexes of ditopic NHC ligands: synthesis, structural and spectroscopic properties

“…The above synthetic procedure afforded the bis-monocarbene complexes, cis-[Pt 2 (μ-NHC)(dmso) 2 Cl 4 ], regardless of the metal to ligand ratio used. 7,8,20 1 : 1 metal to ligand reactions afforded the corresponding cis-[Pt 2 (μ-NHC)(dmso) 2 Cl 4 ] complexes, with the excess imidazolium salt remaining unreacted. Complexes 8-10 are air-and moisture-stable and can be stored for prolonged times in air without any visible decomposition.…”