GoldGold Interaction—Stannaborate [SnB₁₁H₁₁]²⁻ Coordination Chemistry

Abstract

We are currently investigating the coordination chemistry and ligand properties of the dianionic stanna-closo-dodecaborate cluster [SnB 11 H 11 ] 2À (1). So far, in a variety of transition-metal complexes, the ligand was found to coordinate exclusively as a terminal ligand with the formation of a tin-metal bond.[1]Here we present the surprising results of preliminary investigations on the stannaborate chemistry with gold electrophiles. 2À :[(Ph 3 P)AuCl]). Interestingly, 50 % of the starting material [(Ph 3 P)AuCl] is still present in the mixture. The other signals in the 31 P NMR spectrum exhibit tin satellites, which provides direct spectroscopic evidence for the formation of a covalent Au À Sn bond. In this solution the anion of 3 is the major Au-Sn component (35 %) and exhibits a characteristic signal in the 31 P NMR spectrum at d = 54.4 ppm with a 2 J(Sn,P) coupling constant of 109.4 Hz. The anion of 2 was identified in solution by a small signal (3 %) at d = 62.9 ppm ( 2 J(Sn,P) = 186.9 Hz). A bis(triphenylphosphane) substitution product ([(Ph 3 P) 2 Au(SnB 11 H 11 )] À ) is also present in solution (5 %) and displays a signal in the 31 P NMR spectrum at d = 44.5 ppm ( 2 J(P, 117 Sn) = 984.2 Hz, 2 J(P, 119 Sn) = 1027.5 Hz). This compound was synthesized in a separate experiment from nucleophile 1, PPh 3 , and [(Ph 3 P)AuCl] in reasonable yield and details will be published later. Treatment of the [(Ph 3 P)AuCl] with 1.5 equivalents of heteroborate 1, led to an increase in the amount of Au 2 Sn 3 cluster 3 formed (68.6 % yield).The geometry of the metal core in the anions of 2 (Figure 1) and 3 (Figure 2)

Synthesis, structure and bonding of a digold complex with bridging triphenylstannyl ligands

“…This is probably due to the rotational conformation of the SnPh 3 group. These distances are much longer than that to the terminally coordinated tin ligand in compound 2, Au -Sn = 2.5651(13) Å [7], but are similar to the bridging Au-Sn distances reported for the compounds 3, 2.8150 7 [9] and the dianion 5, 2.737(1) Å and 2.761(1) Å [10] (see Scheme 2). The Au -Sn -Au angle in 6 (53.08°) is slightly smaller than the Au-Sn-Au angle (57.03°) in 5 as a result of the shorter Au -Au distance in 6.…”

“…In the solid state the molecule lies on a crystallographic two-fold rotation axis that lies perpendicular to the Au -Au bond. The Au -Au distance in 6 is short, 2.5590(5) Å, and is shorter than the Au-Au bond distance found in the SnB 11 H 11 -bridged digold dianion of compound 5, Au -Au = 2.625(1) Å (Scheme 2) [10]. The P -Au -Au i angle in 6, 170.74(5) o , is almost linear and is similar to that in 5, 178.78(4) o .…”

Double Jahn–Teller Distortion in AuGe Complexes Leading to a Dual Blue–Orange Emission

“…and in recent work from our laboratory, the first complex with an unsupported gold(I)–lead(II) interaction . For germanium and tin, 26 and 22 complexes have been structurally characterized, respectively. Two synthetic strategies have been employed: reaction of gold halides with alkaline metal salts of the type [MR 3 ] − (M=Sn, Ge) and insertion of MX 2 groups in Au−X bonds (X=halogen) in the presence of tertiary phosphines, where structural variations of the phosphine determine the structure of the final complex …”

Synthesis and characterization of heterometallic Rh/Ru complexes supported by 1,2-dichalcogenolato-o-carborane ligands

“…Moreover, the nidocarborane anions [C 2 B 9 H 11 ] 2À , which resembles the well-known p-bonding cyclopentadienide ion, can be prepared by the removal of a BH 2+ (3,6) unit from the parent carborane under certain conditions [19][20][21][22][23][24]. Following the synthesis of the first metallacarborane by Hawthorne et al in 1965, nido-carborane have proved to be excellent bulky and stable building blocks that can be used to enhance the solubility of the metal complexes [25][26][27][28][29]. The two best developed areas of inorganic cluster chemistry --polyhedral boranes and metal clusters are thus combined, which present us rich cluster chemistry [30].…”