Unusual luminescent octanuclear stellate platinacycle self-assembled by Pt-Ag bonds.
An unprecedented macrocyclic luminescent octanuclear cluster cyclo-[{Pt(C6Cl5)2(mu-OH)(mu-Ag)}4] (Pt-Ag) 2 was self-assembled by the formation of Pt(II)-Ag(I) bonds; the optical properties of this complex were also investigated.
A route to small clusters: a twisted half-hexagram-shaped M4(OH)4 cluster and its capacity for hosting closed-shell metals.
By combining different oxidation states, coordination indices and bridging systems, it has been possible to obtain the structurally novel M4(OH)4 cluster core (M = transition metal) found in the organometallic compound (NBu4)2[PtIVPt(C6Cl5)8(μ2-OH)2(μ3-OH)2] (1). The cluster is formed by two (μ3-OH) and two (μ2-OH) units that bond platinum atoms in different oxidation states. The cluster core geometry can best be described as a half-hexagram. Compound 1 is an excellent precursor for preparing heterometallic clusters since it can host d10 or s2 Lewis-acid metal centers through Pt→M dative bonds, as demonstrated by its reaction with Ag(i) to produce the heterometallic [Ag2PtIVPt(C6Cl5)8(μ2-OH)2(μ3-OH)2] (2), which has four unbridged Pt-Ag bonds.
Predicted ligand dependence of the Au(I)…Au(I) attraction in (XAuPH3)2
Abstract The dependence of the “aurophilic” attraction in the perpendicular model system (XAuPH 3 ) 2 on the substituent X is studied using 19-valence electron quasirelativistic pseudopotentials for Au. It increases along the series F 3 3 , reaching 25 kJ/mol for the softest ligand, X. The calculated range, R e , depth, V ( R e ), and Au…Au force constant are comparable with available experimental values.