In der hochsymmetrischen Titelverbindung 1 liegt ein tetraedrisch von vier Alkylindium(I)‐Liganden InC(SiMe3)3 koordiniertes Ni‐Atom vor. Der Ligand InR ist isolobal zu Kohlenmonoxid, so daß dieses Produkt in bemerkenswerter Weise die Reihe der zu [Ni(CO)4] analogen Verbindungen ergänzt.

In4[C(SiMe3)3]4 (1) reacts with the tricarbonyliron cyclooctatetraene adduct to yield the dark red organoindium iron compound Fe2(CO)6[In−C(SiMe3)3]3 (2), which is one of the very rare examples of a compound with two Fe(CO)3 fragments symmetrically bridged by three main-group elements. 2 exhibits a trigonal-bipyramidal Fe2In3 molecular center with all indium atoms in equatorial positions. The Fe−In bond lengths are as expected (258.2(2) pm), while the equatorial In−In distances of 364.8(1) pm indicate no significant bonding interaction.

No abstract

TeIrahedro-Tetrakis[tris(trimethylsilyl)methyl]tetraindane(4)(1) with a tetrahedral In4 molecular center reacts with an excess of elemental sulfur or tellurium in boiling n-hexane to give in an almost quantitative yield the appropriate In& (2) or In4Te4 derivatives (3). Crystal structure determinations revealed distorted In4X4 (X = S, Te) heterocubane molecular centers for both compounds.The alkylindium(1) derivative Iq[C(SiMe&J4 (1) with a tetrahedral In4 molecular core is synthesized by the reaction of InBr or InCl with LiC(SiMe& . 2 THF['*2]. Compound 1 exhibits a remarkable chemical reactivity, and up to now we found three different types of reaction: (a) Electrochemical reduction leading to the reversible transfer of one electron, as shown by cyclovoltammetric experiments, probably with formation of a radicalic cluster anion which, however, could only be EPR-spectroscopically detected for the Ga4 analogL31. (b) Replacement of carbonyl groups by the monomeric fragment In-C(SiMe3)3 in transition metal carbonyl complexes with formation of e.g. a Mn2(C0)* derivative containing two InR groups bridging the Mn-Mn bondL41. (c) Formation of a cage compound (In4Se4R4) with a heterocubane-type molecular structure by the reaction of 1 with an excess of elemental selenium [']. The reactions of sulfur and tellurium with 1 completing the reactions with the heavier chalcogens are described in this article. Up to now we did not succeed in synthesizing an In404 derivative by reactions with oxygen donors; with moist air 1 gives In404(OH)6[C(SiMe3)3]4rz,~. Reactions of In4[C(SiMe3)3]4 (1) with Sulfur and TelluriumCompound 1 forms deep violet solutions in n-hexane which remain unchanged on treatment with an excess of sulfur or tellurium at room temperature for several days. However, the color of the In4 compound completely disappears when the mixture with sulfur is heated at reflux for only 15 minutes. With tellurium in boiling hexane a much longer reaction time of 19 hours is required for the complete consumption of 1 (eq. l), similar to the reaction of 1 with elemental selenium [']. Probably, this difference is due to the higher solubility of sulfur in hot hydrocarbon solvents. Complete decomposition is observed in boiling toluene with quantitative formation of tris(trimethylsily1)methane. Both indium-chalcogen derivatives were isolated in about 80 YO yield by recrystallization from cyclopentanel toluene mixtures (2; X = S) or from pure pentane (3; X = Te). The crystals of 2 include solvent molecules which are released under very mild conditions, and the crystals become amorphous immediately after they are separated from the solvent even at low temperatures and without evacuation. 3 crystallizes as a strongly intergrown solid with 1 to 1.5 molecules of pentane per formula unit. The properties of 2 and 3 are nearly indistinguishable and very similar to those of the ln4Se4 analog"]. The compounds are sparingly soluble in benzene, and we did not succeed in determining the molar mass by cryoscopic methods. They show the same chemi...

The highly symmetric title compound contains a Ni atom that is tetrahedrally coordinated by four alkylindium(I) ligands InC(SiMe ) . The ligand InR is isolobal with carbon monoxide, and the product is thus a remarkable addition to the class of [Ni(CO) ] analogues.