Facile formation and redox of benzoxazole-2-thiolate-bridged dinuclear Pt(ii/iii) complexes

Abstract

Reaction of [Pt(L)(μ-Cl)](2) (L = ppy (2-phenylpyridine) or bzq (benzo[h]quinoline)) with 2-mercaptobenzoxazole (NOSH) and NaOAc in THF at r.t. yields the dinuclear Pt(II) d(8)-d(8) complexes [Pt(2)L(2)(μ-NOS-κN,S)(2)] (L = ppy, 1; L = bzq, 2) and the Pt(III) d(7)-d(7) complexes [Pt(2)(ppy)(2)(μ-NOS-κN,S)(2)(NOS-κS)(2)] (L = ppy, 3; L = bzq, 4) in one pot. The C,N-cyclometalated ligand is chelating whereas the N,S-donating benzoxazole-2-thiolates doubly bridge the two metal centers. The Pt···Pt separations of 3.0204(3) and 2.9726(8) Å in 1 and 2 contract to 2.685(1) Å in 3 and 2.6923(3) Å in 4, respectively, when two S-bound thiolate ligands coordinate trans- to the Pt···Pt axis. However, cyclometalation is preserved and there is minimum perturbation of the bridging ligands. Complexes 3 and 4 can be also obtained by oxidative addition of the thiolate ligand. In the presence of NaBH(4), 3 and 4 can be reduced to 1 and 2, respectively. At r.t., 1 and 2 exhibit intense orange-red luminescence at 625 nm and 631 nm, respectively. The electrochemical properties of 1-4 have been also discussed.

Supramolecular Assembly of Metal Complexes by (Aryl)I⋅⋅⋅d[PtII] Halogen Bonds

“…Complexes 1-3 undergo electrochemically reversible (2: to Pt III 2 /Pt III 2 accordingly to ref. [41,[69][70][71][72] (Table 5, Figure S19 in the Supporting Information).…”

The luminescence properties of multinuclear platinum complexes

“…Symmetrical (N^C* = N^C) and asymmetrical (N^C* ≠ N^C) complexes of type 36 reported by Thompson and coworkers [58], and the heterometallic Ir-Pt 37 synthesised by Bruce and co-workers for liquid crystalline properties [59]. refer to the complex doped into a thin film; 39, 40 [65], 41 [67], 42 [63,64], 43 [68], 44 [63,64], 45 [68], 46 [69], 47 [70].…”

Half-Lantern Pt(II) and Pt(III) Complexes. New Cyclometalated Platinum Derivatives

“…Tzeng and co-workers prepared the dinuclear diimine complexes syn-or anti-[Pt 2 (μ-NS) 2 (dtbpy) 2 ] 2+ dtbpy = 4,4'-di-tert-butyl-2,2'-bipyridine, NHS = pyridine-2-thiol (Hpyt), 2-mercaptobenzothiazole (HNS 2 ), 2-mercaptobenzimidazole (HN 2 S), 2-mercaptobenzoxazole (HNOS)) by reaction of the mononuclear derivative [Pt(dtbpy)Cl 2 ] with the corresponding HNS in the presence of NaOMe [11,12] [17]. All three complexes show an anti configuration, with the N of the bridging groups coordinated at the trans position to C, and intermetallic distances of 2.91 Å, 2.97 Å (bzq) and 3.02 Å (ppy).…”