Unexpected formation of a fused double cycle trinuclear gold(i) complex supported by ortho-phenyl metallated aryl-diphosphine ligands and strong aurophilic interactions

Abstract

The first homoleptic trinuclear arylgold(I) complex, [Au3(L')2](NO3) (3), based on ortho-phenyl metallated aryl-diphosphine ligand (L' = o-C6H4PPh(C15H10O)PPh2), has been obtained through a new thermolytic reaction of the corresponding diauracycle, [Au2(L)2](NO3)2 (L = xantphos). The formation of 3 involves the activation of the ortho-phenyl C-H bond of the xantphos ligands. The presence of the Au−C bonds in this new gold-diphosphine cluster is not its only remarkable feature, since it also displays two 12-membered rings fused together and a linear {Au3} chain with aurophilic interactions. Complex 3 exhibits strong sky-blue luminescence that can be assigned to triplet metal-metal ( 3 MM) transition partially mixed with ligand-to-metal-metal charge transfer ( shows AIEE-activity, and is a selective luminescent chemosensor for metal ions.

Luminescence Thermochromism of Gold(I) Phosphane–Iodide Complexes: A Rule or an Exception?

“…The molecular structures of 5 and 6 (Figure and Figure S2 in the Supporting Information) are very much alike; unsurprisingly, the latter is also akin to complexes [(AuHal) 2 (XantPhos)] (Hal=Cl, Br) . The main difference can be seen in the distortion of the backbone of diphosphane, which is less pronounced in the case of 5 (P‐C‐C‐P torsion angle is 17.5° versus 37.6° in 6 ), seemingly due to a somewhat larger separation between phosphorus atoms in 5 (4.732 Å) relative to that in 6 (4.657 Å).…”

Excimer and Exciplex Formation in Gold(I) Complexes Preconditioned by Aurophilic Interactions

“…An unsymmetrical dimetallacyclic complex with carbene/phosphine‐functional ligands has recently been reported by Danopoulos, Braunstein, and co‐workers . The single most significant feature of their P^C^P ligand in coordination and spectrochemical contexts are the two exo phosphine groups, one of which is dangling in P , while all three donor groups are coordinatively involved in the linear trinuclear Au 3 chain found in complex Q , [Au 3 L 2 ](OTf) 3 , which is reminiscent of the [Au 3 (dmpm) 2 ] 3+ chelates investigated by Yam and Wong, and of a mixed complex salt described by Deák and co‐workers . Only compound Q exhibits a band of an intense, almost pure MC absorption in solution ( λ max =345 nm) in addition to other bands of higher energy with ligand orbital involvement.…”

“…[168] Thesingle most significant feature of their P^C^P ligand in coordination and spectrochemical contexts are the two exo phosphine groups, one of which is dangling in P,while all three donor groups are coordinatively involved in the linear trinuclear Au 3 chain found in complex Q,[ Au 3 L 2 ](OTf) 3 ,w hich is reminiscent of the [Au 3 (dmpm) 2 ] 3+ chelates investigated by Yama nd Wong, [194] and of am ixed complex salt described by Deµk and co-workers. [207] Only compound Q exhibits ab and of an intense,a lmost pure MC absorption in solution (l max = 345 nm) in addition to other bands of higher energy with ligand orbital involvement. Theimportant role of the ds* 1 ps 1 configuration and significant AuÀ ÀAu covalent bonding in the excited state has been demonstrated by resonance-enhanced Raman spectroscopy following the MC transitions,s howing the excited-state vibrations of the Au À À Au bonds.H ere we mainly concentrate on the results for Q.T his compound displays an arrow,i ntense,b lue-violet radiation band at 446 nm, essentially independent of solvent polarity,s tate (solution, glassy matrix, neat powder), and temperature,a nd with the nature of an MC 3 [5ds*6ps]t riplet state.…”

“…The excited state was found to be powerfully reducing with a redox potential of −1.6 V. Similar results were found for trinuclear analogues . Transannular aurophilic contacts have also been followed up in structural, spectroscopic, and theoretical studies of di‐ and trinuclear gold(I) complexes of a variety of diphosphine donors based on the xanthene skeleton, in recent cases also with dicyanoaurate(I) anions …”

Dinuclear Gold Complexes Supported by Wide Bite Angle Diphosphines for Preorganization-Induced Selective Dual-Gold Catalysis

“…Basic coordination chemistry of these potentially dinucleating ligands toward gold has already been established by several groups [30][31][32]. Furthermore, Koshevoy et al investigated the formation and photochemical properties of bis-gold complexes with the related ligand Xantphos [33][34][35][36][37][38]. We herein report on the formation of μ-chlorido and σ,π-alkynide derivatives of Au2Cl2(κ 2 -P;P-DBFPhos) and Au2Cl2(κ 2 -P;P-DPEPhos) and catalytic activity of these well-defined dinuclear species vs. mononuclear benchmarks in the intramolecular hydroamidation of functionalized amido-alkenes.…”