Organogallium- and organozinc-rich palladium and platinum clusters

Abstract

The heteroleptic, binuclear compounds [M2(GaCp*)3(PMe3)2] (M = Pd: 1a, Pt: 1b, Cp* = pentamethylcyclopentadienyl) can be obtained if [Pd2(dvds)3] (dvds = 1,3-divinyl-1,1,3,3-tetramethyldisiloxane) or [Pt(COD)2] (COD = cyclooctadiene) were treated with a 3 : 2 ratio of GaCp* and PMe3. A trinuclear complex [Pd3(GaCp*)3(PMe3)3] (2) was isolated from in situ prepared [Pd(PMe3)2Me2] and treatment with GaCp*. The new complexes were used as starting compounds for selective Ga/Zn exchange reactions to afford the dinuclear palladium compound [Pd2(ZnCp*)(ZnMe)3(PMe3)5] (3a) and the mononuclear platinum compound [Pt(ZnCp*)2(ZnMe)2(PMe3)2] (3b). The effects of a final transition metal count in organozinc ligated compounds and stabilization of Lewis acidic fragments like [Pd(PPh3)3], [Ni(C2H4)3] or [Mo(CO)5] were presented and discussed. All compounds have been fully characterized by (1)H, (13)C, and (31)P NMR spectroscopy, mass spectrometry using a liquid injection field desorption ionization (LIFDI) method, elemental analysis, and single crystal X-ray diffraction studies and the coordination polyhedra were analysed by the method of continuous shape measure (CShM).

Zn⋯Zn interactions at nickel and palladium centers

“…All Pd–Zn distances (2.471(1)–2.563(1) Å) are elongated as compared to the terminally coordinated ZnR groups (R = Me, Cp*) in 4 (2.428(1)–2.484(1) Å) and [Pd(ZnMe) 4 (ZnCp*) 4 ] (2.417(1)–2.459(1) Å) 8 but well in the range of other ZnR ligands found in bridging positions. 10 The central atom (Pd3) is located in the center of a pseudo-hexagon with one vacant vertex, consisting of alternating zinc and palladium atoms. Thus, Zn1 (0.186 Å), Zn3 (0.336 Å) and Zn6 (0.093 Å) as well as all three palladium atoms are almost perfectly coplanar with deviations from the plane of 0.186 Å (Zn1), 0.336 Å (Zn3) and 0.093 Å (Zn6).…”

(Multi‐)Metallic Cluster Growth

“…[83] For this cluster,p olynuclear complexes were chosen as starting material, combinedw ith av ariety of co-ligands (CO, Cp*) for exploration of their selectivity regarding Ga/Zn exchange and clusterf ormation. [84] Although the exact mechanisms remain unclear,aclear tendency to retain electron precision, and steric reasons, are the most important factorso nt he wayt oz inc-rich transition metal clusters. Figure 33.…”

“…Until now, most of the larger heteroatomic clusters were generated by using TrCp*, whereas homometallic clusters with higher nuclearity did not prove suitable starting compounds, with the exception of the formation of [Pd 2 Zn 6 Ga 2 Cp* 5 Me 3 ] . For this cluster, polynuclear complexes were chosen as starting material, combined with a variety of co‐ligands (CO, Cp*) for exploration of their selectivity regarding Ga/Zn exchange and cluster formation . [M 2 (GaCp*) 3 (PMe 3 ) 2 ] (M=Pd, Pt) and [Pd 3 (GaCp*) 3 (PMe 3 ) 3 ] were obtained from reactions of [Pd 2 (dvds) 3 ] (dvds=1,3‐bis‐vinyl‐1,1,3,3‐tetramethyldisiloxane), [Pt(cod) 2 ], or [Pd(tmeda)Me 2 ], respectively, [GaCp*], and PMe 3 with [ZnMe 2 ].…”

From the discovery of field ionization to field desorption and liquid injection field desorption/ionization-mass spectrometry—A journey from principles and applications to a glimpse into the future

“…56 In fact, the majority of publications mentioning LIFDI deals with compounds such as reactive transition metal complexes and catalysts. 56,138,[204][205][206][207][208][209][210][211][212][213][214][215][216][217] Another group belongs to the field of petroleomics applications as LIFDI turned out to be compatible to FT-ICR instrumentation. 59,[140][141][142]164,218 As LIFDI also serves as a general replacement for FD, there are miscellaneous applications in addition.…”