No abstract

Mit der Ga+‐Quelle [Ga2Cp*][BArF] reagiert [Pt(GaCp*)4] zum Titelkomplex, dessen „nacktes“ Galliumatom terminal an das Platinzentrum koordiniert ist. DFT‐Rechungen ergaben, dass Ga+ als σ‐Acceptor wirkt und dass die Pt‐Ga‐Bindung außerdem durch π‐Wechselwirkungen verstärkt wird. Cp*=C5Me5; BArF=B{C6H3‐3,5‐(CF3)2}4.

Compounds with low-valent Group 13 elements, in particular the series ECp* (E = Al, Ga, In; Cp* = C 5 Me 5 ), are fascinating carbenoid s-donor ligands for transition-metal-metalloid complexes and clusters.[1] Novel homoleptic metal-rich clusters of the type [M a (ECp*) b ] (M = Pd, Pt) were reported in which the mixed-metal cores {M a E b } were enveloped exclusively by Cp* ligands.

The synthesis of the novel AlI compound AlCp*Ph (Cp*Ph = C5Me4Ph) is presented. This compound is characterized by 1H, 13C, 27Al NMR spectroscopy, elemental analysis as well as its reactivity towards the α,ω‐diolefin dvds (dvds = tetramethyl‐divinyl‐disiloxane). Also the reactivity of AlCp* towards dvds is investigated and the product [(dvds)(μ2‐AlCp*)2] characterized by NMR spectroscopy, elemental analysis as well as X‐ray crystallography. Furthermore, two new coordination compounds of AlCp* to d10 metal centers are synthesized and characterized. [Pd(AlCp*)4] is obtained by reaction of [(tmeda)PdCl2] with AlCp*, and [Ni(AlCp*)4] is synthesized from [Ni(cod)2] and AlCp* via ligand substitution. Both complexes are spectroscopically and crystallographically characterized. Finally, preliminary results on the coordination of AlCp*Ph to Ni0 and Pd0 centers will be discussed.

Partial protolysis of GaCp* with [H(OEt2)2]+[BArF]− afforded the GaI compound [Ga2Cp*]+[BArF]− (see structure). Experimental and computational studies confirm the mainly ionic structure of the cation, in which the Ga+ ions are only weakly covalently stabilized by a bridging Cp* ligand. Initial experiments point to the interesting synthetic potential of this compound as a source for Ga+ in solution.