Search

The high-yield synthesis of gold-tellurollate clusters [[Au.sub.8]([mu]-TeR).sub.8][[(PR'.sub.3]).sub.4]] (TeR = TePh, TeTol, [PR'.sub.3] = P[Ph.sub.3], P[Ph.sub.3]py) is described. The gold-tellurium complexes are novel due to their special structural features and luminescent behavior in solid state and in solution.

The reaction of [AuCI(PR′3)] with KTeR, prepared from RTeTeR and K-selectride, gives the gold-tellurolate clusters [Au8(μ-TeR)8(PR′3)4] (R = Ph, Tol; PR′3 = PPh3, PPh2py) in high yield. This result contrasts with the one obtained from the reaction with thiolates or selenolates, from which mononuclear complexes are synthesized. The structures of these species have been determined and consist on three layers of gold and tellurium atoms in the ratio Au3-Te2:Au2Te4:Au3Te2. There are short gold⋯gold interactions ranging from 2.9463(7) to 3.31132(7) Å, and the clusters are composed of di- and tri-coordinated gold centers. The result is unprecedented in gold-chalcogenolate chemistry from which mononuclear species are expected and represents one of the few examples of gold-tellurolate derivatives. These species show an interesting luminescent behavior in the solid state (at 77 K) and in solution (both at 298 and 77 K). [ABSTRACT FROM AUTHOR]

[2-(Me2NCH2)C6H4]HgCl (1) was prepared by reacting HgCl2 with [2-(Me2NCH2)C6H4]Li in diethyl ether. The reactions of 1 with the sodium or ammonium salt of the appropriate thiophosphinato ligand, in 1:1 molar ratio, afford the isolation of [2-(Me2NCH2)C6H4]Hg[S(S)PR2] [R=Me (2), Et (3), Ph (4)], [2-(Me2NCH2)C6H4]Hg[S(O)PPh2] (5) and [2-(Me2NCH2)C6H4]Hg[S(S)P(OiPr)2] (6). The compounds were investigated by IR and multinuclear NMR (1H, 13C and 31P) spectroscopy. The molecular structures of 1 and 4 were determined by single-crystal X-ray diffraction. Due to the strong intramolecular coordination of the N atom of the pendant CH2NMe2 arm [Hg(1)–N(1) 2.764(6) and 2.725(4) A˚ in 1 and 4, respectively] both compounds exhibit a T-shaped (C,N)HgX core in the molecular unit, with almost linear arrangement of the covalent bonds [C(1)–Hg(1)–Cl(1) 176.93(18)° in 1, and C(1)–Hg(1)–S(1) 169.54(16)° in 4]. The crystals of 1 contain discrete monomeric molecules, while the crystals of 4 contain dimer associations built through asymmetric bridging dithiophosphinato ligands [Hg(1)–S(1) 2.3911(16) A˚, Hg(1)⋯S(2a) 3.102(2) A˚], thus resulting in an overall pseudo-trigonal bipyramidal (or seesaw) (C,N)HgS2 core, with the nitrogen atom and the weekly bonded sulfur atom in equatorial positions [N(1)–Hg(1)⋯S(2a) 82.01(10)°]. [Copyright &y& Elsevier]

The reactions between PhHgCl or PhHgAc and M[(XPR2)(YPR′2)N] (M=Na, K; X, Y=O, S; R, R′=Me, Ph, OEt), in 1:1 molar ratio, have been investigated. PhHg[(XPR2)(YPR′2)N] derivatives were isolated as microcrystalline powders and were characterised using IR and NMR (1H, 13C and 31P) spectroscopy and mass spectrometry. The molecular structure of PhHg[(OPR2)(SPPh2)N] [R=Me (1), Ph (2)] was investigated by X-ray diffraction. In the monomeric unit, PhHg[(OPR2)(SPPh2)N], the mercury atom forms the primary bonds with the carbon of the phenyl group and the sulfur atom of the phosphorus ligand [Hg(1)–S(1) 2.405(1) A˚ for 1, 2.398(2) A˚ for 2]. These primary bonds are significantly deviated from the expected linear arrangement [C(1)–Hg(1)–S(1) 166.4(2)° for 1, 165.0(2)° for 2]. Both compounds exhibit dimeric associations in the crystal through S,O-bridging organophosphorus ligands [Hg(1)–O(1) 2.556(4) A˚ for 1, 2.588(4) A˚ for 2], thus resulting in a distorted T-shaped arrangement of the CHgSO coordination core.. The formation of a 12-membered Hg2O2S2P4N2 ring with different conformation in 1 and 2, respectively, results in different additional chalcogen atoms being in the proximity of the metal atom. Weak transannular Hg⋯O [2.753(4) A˚] are also established in 1, leading to a tricyclic ladder structure with a planar central Hg2O2 ring. [Copyright &y& Elsevier]