Clusters [M_a(GaCp*)_b(CNR)_c] (M = Ni, Pd, Pt): Synthesis, Structure, and Ga/Zn Exchange Reactions

Abstract

Reactions of homoleptic isonitrile ligated complexes or clusters of d(10)-metals with the potent carbenoid donor ligand GaCp* are presented (Cp* = pentamethylcyclopentadienyl). Treatment of [Ni4(CNt-Bu)7], [{M(CNR)2}3] (M = Pd, Pt) and [Pd(CNR)2Me2] (R = t-Bu, Ph) with suitable amounts of GaCp* lead to the formation of the heteroleptic, tri- and tetranuclear clusters [Ni4(CNt-Bu)7(GaCp*)3] (1), [{M(CNt-Bu)}3(GaCp*)4] (M = Pd: 2a, Pt: 2b), and [{Pd(CNR)}4(GaCp*)4] (R = t-Bu: 3a, Ph: 3b). The reactions involve isonitrile substitution reactions, GaCp* addition reactions, and cluster formation reactions. The new compounds were investigated for their ability to undergo Ga/Zn exchange reactions when treated with ZnMe2. The novel tetranuclear Zn-rich clusters [Ni4GaZn7(Cp*)2Me7(CNt-Bu)6] (4) and [{Pd(CNR)}4(ZnCp*)4(ZnMe)4] (R = t-Bu: 5a, Ph: 5b) were obtained and isolated. The electronic situation and geometrical arrangement of atoms of all compounds will be presented and discussed. All new compounds are characterized by solution (1)H, (13)C NMR and IR spectroscopy, elemental analysis (EA), liquid injection field desorption ionization mass spectrometry (LIFDI-MS) as well as single crystal X-ray crystallography.

Zn⋯Zn interactions at nickel and palladium centers

“…2,8 Similarly the Pd-CN t Bu bond lengths are all in a similar range to other palladium–isonitrile complexes. 9 …”

“…8 This concept is transferable to heteroleptic starting materials [L m M(GaCp*) n /2 ] (L = Cp*, CO, X, PMe 3 …), where the ligands L have been able to control the reaction selectivity and product formation. 9–12 A reaction pattern dependent on the co-ligands of a metal complex and thus the electronic properties of a system is also reported for the coordination of H 2 to transition metal fragments. Not only are simple oxidative addition reactions, resulting in dihydride complexes known, the “side-on” coordination of H 2 under the preservation of the H–H bond has also been widely studied and reported, especially by Kubas et al 13–15 The triangular clusters [Zn 3 Cp* 3 ] + and [Zn 2 CuCp* 3 ] can be regarded as the first examples with an H 2 analogous “side-on” coordination mode of [Zn 2 Cp* 2 ] at the two isoelectronic, unsaturated fragments [ZnCp*] + and CuCp*.…”

Intermetalloide Cluster: Moleküle und Festkörper im Dialog

“…[75,112,113] Aufd em Wegh in zu zinkgebundenen Übergangsmetall-Koordinationsverbindungen wurden interessanterweise auch gemischtschalige Ga/Zn-Intermediate der allgemeinen Form [M(GaR) n (ZnR) m ]( R= Me,C p*) isoliert. [103,114] ZnMe 2 gebildet. [113a] Die letztgenannte besitzt ein deca-koordiniertes Zentaurpolyeder,d as durch Fusion eines Würfels und eines Ikosaeders konstruiert ist und mit dem VGa 10 -Polyeder aus der binären V 8 Ga 41 -Phase in Beziehung steht.…”

“…Die Verringerung 4 ], deren Ga/Zn-Atomlagen nur durch quantenchemische Rechnungen zugeordnet werden konnten. [103] Insbesondere die Anwesenheit von dirigierenden Coliganden mit geeigneten elektronischen Eigenschaften und moderatem sterischen Anspruch scheint ausschlaggebend fürd ie Stabilisierung von mehrkernigen TM/ Zn-Spezies zu sein, da vergleichbare Reaktionen mit homoleptischen GaCp*-gebundenen Komplexen [M n (GaCp*) m ] (n ! [112] Der Einfluss dirigierender Coliganden im selektiven Ga/ Zn-Austausch wurde anhand heteroleptischer Precursorverbindungen des Ty ps [M a (GaCp*) b L c ]( L = CO,P R 3 ,C NR) untersucht.…”

Potent in vitro antiproliferative properties for a triplatinum cluster toward triple negative breast cancer cells

“…Molecular platinum clusters have been intensely investigated during the last three decades for their attractive and peculiar chemical and electronic properties [1][2][3][4]. A variety of Pt clusters were thus prepared and characterised mostly containing a number of Pt atoms ranging from 3 to 50 [5][6][7][8].…”