Halide derivatives of palladium-gold cluster compounds. X-ray crystal and molecular structure of (I)Pd(AuPPh3)7(AuI)2

✍ Scribed by Kathryn L. Craighead; Anna Maria P. Felicissimo; Donald A. Krogstad; Lissa T.J. Nelson; Louis H. Pignolet

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 984 KB
• Volume: 212
• Category: Article
• ISSN: 0020-1693
• DOI: 10.1016/s0020-1693(00)92305-3

✦ Synopsis

The reaction chemistry of [Pd(AuPPh&](NO 3 ) 2 with the halide ions Cl-, Br-and I-and with the pseudohalide CN-has been studied. Acetone solutions of Pd(AuPPh,),, reacted with these ions to give the new Pd-Au clusters (I)Pd(AuPPh&(AuI)2, [Pd(AuPPh,),(AuBr),]+, Pd(AuPPh,),(AuCl), and Pd(AuPPh&(AuCN),, respectively. In the presence of added acid the reaction with Cl-yielded the catiomc cluster [Pd(AuPPh,),(AuCl),]+. The structure of (I)Pd(AuPPh,),(AuI), has been determined by X-ray dtffractton (unit cell: K?,/n, n =37.29, b=22.69, c=16.639 A, /3=114.61", Z=4, I'=12800 &, refinement: R =0.069).

The geometry of this cluster is that of a Pd-centered tcosahedral fragment m accord with its eighteen-electron configuration.

The coordinated rodme anion of this cluster can be displaced by reaction with CO to give [(CO)Pd(AuPPh,),(AuI),]+, while the sixteen-electron clusters [Pd(AuPPh,),(AuBr),]+ and [Pd(AuPPh,),(AuCl),]+ reacted cleanly with CO to give simple adducts. The eighteen-electron clusters Pd(AuPPh,),(AuCl), and Pd(AuPPh,),(AuCN), showed no reaction with CO. The mechanism of these interesting cluster fragmentation and growth reactions 1s discussed.