Cyclometalated Cluster Complex with a Butterfly-Shaped Pt₂Ag₂ Core

Abstract

The cyclometalated platinum complex [PtMe(bhq)(dppy)] (1), in which bhq = benzo{h}quinoline and dppy = 2-(diphenylphosphino)pyridine, was prepared by the reaction of [PtMe(SMe(2))(bhq)] with 1 equiv of dppy at room temperature. Complex 1 contains one free pyridyl unit and was readily characterized by multinuclear NMR spectroscopy and elemental microanalysis. The reaction of complex 1 with 1 equiv of [Ag(CH(3)CN)(4)]BF(4) gave the cyclometalated cluster complex [Pt(2)Me(2)(bhq)(2)(mu-dppy)(2)Ag(2)(mu-acetone)](BF(4))(2) (2) in 70% yield. The crystal structure of complex 2 was determined by X-ray crystallography, indicating a rare example of a butterfly cluster with a Pt(2)Ag(2) core in which the Ag atoms occupy the edge-sharing bond. In solution, the bridging acetone dissociates from the cluster complex 2, but as shown by NMR spectroscopy, the Pt(2)Ag(2) core is retained in solution and a dynamic equilibrium is suggested to be established between the planar and butterfly skeletal geometries.

Synthesis and structure of the cyclometalated hetero-binuclear Pt-Au complexes with bridging 2-diphenylphosphinopyridine ligand

“…The complexes [PtMe(bhq)(dppy)], 1 [5], AuCl(SMe 2 ) [10], AuCl(PR 3 ) [10] and [PtMe(bhq)(SMe 2 )] [5,11] were prepared as described previously. DFT and TD-DFT calculations by hybrid Becke's three-parameter exchange functional combined with the Lee, Yang, and Parr correlation (B3LYP) [12] method and def2-TZVP basis set [13] were performed.…”

“…The crystal structure of complex 5 reveals a slightly distorted square planar geometry about the Pt(II) center with C(1)-Pt(1)-N(1) and C(10)-Pt(1)-N(2) angles of 171.9(1) and 176.58 (9) , respectively. The Pt-Au vector is tilted by 10.28(6) with respect to the normal line of the platinum coordination plane and the dihedral angle P(1)-Au(1)-Pt(1)-N(2) is À23.33 (5) . The Pt-Au distance in 5 [(2.86(14) Å] is comparable with the sum of the covalent radii of gold and platinum atoms (2.72 Å) indicating a dative bond between platinum and gold centers.…”

“…Recently, we have prepared the cyclometalated platinum (II) complex [PtMe(bhq)(dppy)], 1, in which bhq ¼ benzo-{h} quinoline and dppy ¼ 2-(diphenylphosphino)pyridine, has an electron-rich Pt center and an uncoordinated pyridyl group, and this creates the possibility of synthesizing new bi-and multiheteronuclear complexes containing cyclometalated platinum units. The cluster complex [Pt 2 Me 2 (bhq) 2 (m-dppy) 2 Ag 2 (m-acetone)](BF 4 ) 2 , 2 [5], has been prepared by the reaction of 1 with 1 equiv of [Ag(CH 3 CN) 4 ]BF 4 and the bi-or trinuclear complexes [PtMe(bhq)(dppy)Tl]PF 6 , 3, and [Pt 2 Me 2 (bhq) 2 (dppy) 2 Tl], 4, -have been prepared by the reaction of 1 with 1 and ½ equiv TlPF 6 respectively [6]. The heteropolynuclear complexes 2e4 display intense emissions in the solid state and in glassy solutions.…”

Neutral benzoquinolate cyclometalated platinum(II) complexes as precursors in the preparation of luminescent Pt–Ag complexes

“…A few ''Pt 2 Ag 2 sandwiches '' containing Pt-Ag bonds have been reported [12,47,[73][74][75][76]. Of these it is only in complex [Pt(2,3-bis(2,6-dichlorophenylimino)butane)Me 2 Ag(SO 3 CF 3 )] 2 [12] that each silver center is simultaneously bonded to the two Pt atoms, with similar Pt-Ag distances (2.829, 2.910 Å), the ''Pt 2 Ag 2 '' core forming a rhombus, and no ligand acting as a bridge between Pt and Ag.…”

Synthesis, characterization and optical properties of a new cationic cyclometalated platinum(ii) complex

“…Recently tris‐cyclometalated platinum(IV) complexes with the general formula [Pt(ppy) 2 (bpy)] 2+ and fac ‐[Pt(ppy) 3 )] + have been prepared that show similar green emissions from a 3 LC state in deaerated solutions at room temperature . Based on these finding and our interest in synthesis of new cyclometalated platinum complexes and study of their optical properties, herein we report synthesis of the new cyclometalated platinum(II) complex [Pt(ppy)(ppyH) 2 ][OTF], 2 , containing one cyclometalated and two non‐cyclometalated 2‐phenylpyridine ligands. Complex 2 shows a green emission both in solution (in the presence of O 2 ) and solid state at room temperature.…”