Synthesis of a Heptanuclear Rhenium−Iridium Carbido Carbonyl Cluster and of (Triphenylphosphine)gold(I) Derivatives

Abstract

The octanuclear cluster [Re 5 Ir(µ 6 -C)(CO) 17 (µ 3 -Re(CO) 3 ) 2 ] 2-loses a [Re(CO) 3 ] + capping unit in refluxing acetonitrile to give the heptanuclear cluster [Re 5 Ir(µ 6 -C)(CO) 17 (µ 3 -Re(CO) 3 )] 3-. The latter compound can be capped with [AuPPh 3 ] + groups to form the monogold and digold derivatives [Re 6 IrC(CO) 20 (AuPPh 3 )] 2-and [Re 6 IrC-(CO) 20 (AuPPh 3 ) 2 ] -. These three new anionic clusters have been isolated as PPN + and/or PPh 4 + salts and are formulated on the basis of microanalytical and FAB mass spectrometric data. The solid-state structure of [PPh 4 ][Re 6 -Ir(µ 6 -C)(CO) 20 (µ 3 -AuPPh 3 ) 2 ]‚CH 2 Cl 2 has been determined by X-ray diffraction. Crystal data: triclinic, space group P1 h, a ) 13.1182 (1) Å, b ) 15.1806(1) Å, c ) 23.4061(3) Å, R ) 74.251(1)°, ) 82.058(1)°, γ ) 70.306(1)°, Z ) 2. Further information on the structures of the compounds in solution has been derived from 13 C and 31 P NMR studies.

Carbidohexarhenate Cluster Cores Bicapped by Mercury with Acetate or Thiolate Ligands

“…Further study of our mercury(II) derivatives [Re 7 C(CO) 21 HgY] 2- 7-9 has revealed a new decapping reaction in which one rhenium cap is removed and replaced by a second mercury cap (see Scheme ). Rhenium vertex removal has been carried out previously with such reagents as carbon monoxide, phosphines, or acetonitrile, which typically stabilize the eliminated metal vertex as a mononuclear complex. − In the present case the decapping reagent is mercury acetate in the presence of methanol, and the eliminated rhenium carbonyl fragment is isolated as a dinuclear complex with bridging methoxy and acetate ligands. Furthermore, ligand exchange with the initially formed Hg 2 Re 6 cluster readily replaces the acetate ligands attached to mercury by thiolate ligands.…”

Gold–Heterometal Interactions and Bonds

“…A considerable number of clusters based on C-centered [161,221,434,456,457] or B-centered [376][377][378][379]404] octahedral homo-and heterometal frameworks have been structurally characterized for all three Group 9 metals. Heptanuclear clusters include species with a m 3 -Au(PPh 3 ) group, for example [NEt 4 ][(Ph 3 P)AuCo 6 (m 6 -C)(m-CO) 5 (CO) 8 ] 331 [434], (Ph 3 P)Au(cis-Rh 2 )Ru 4 (m 6 -B)(m-CO) 3 (CO) 11 (m 4 -nbd) 332 [377] or (Ph 3 P)Au(trans-Rh 2 )Ru 4 (m 6 -B)(m-CO) 4 (CO) 12 333 [378], or a phosphine-gold unit spanning the Ir-Ir bond in (Cy 3 P)Au(cis-Ir 2 )Ru 4 (m 6 -B)(m-CO)(CO) 15 334 [376].…”

“…Heptanuclear clusters include species with a m 3 -Au(PPh 3 ) group, for example [NEt 4 ][(Ph 3 P)AuCo 6 (m 6 -C)(m-CO) 5 (CO) 8 ] 331 [434], (Ph 3 P)Au(cis-Rh 2 )Ru 4 (m 6 -B)(m-CO) 3 (CO) 11 (m 4 -nbd) 332 [377] or (Ph 3 P)Au(trans-Rh 2 )Ru 4 (m 6 -B)(m-CO) 4 (CO) 12 333 [378], or a phosphine-gold unit spanning the Ir-Ir bond in (Cy 3 P)Au(cis-Ir 2 )Ru 4 (m 6 -B)(m-CO)(CO) 15 334 [376]. Examples of octanuclear species with an Au-Au fragment connected to the octahedral core are [(Ph 3 P)Au] 2 Co 6 (m 6 -C)(m-CO) 4 (CO) 9 335 [434] or [(Ph 3 P)Au] 2 Rh 6 (m 6 -C)(m-CO) 7 (CO) 6 336 [456], while as nonanuclear clusters with two or three isolated phosphine-gold units the clusters [PPh 4 ][{(Ph 3 P)Au} 2 IrRe 6 (m 6 -C)(CO) 20 ] 186 [221] and [(Cy 3 P)Au] 3 (trans-Rh 2 )Ru 4 (m 6 -B)(m-CO) 3 (CO) 12 337 [404] can be considered.…”