A. V. Pavlova

Metal-metal bond cleavage in [Cp(CO)2Fe-Fe(CO)2Cp] under the action of organotellurium(IV)tribromides

The oxidation of [CpFe(CO)2]2 by RTeBr3 allowed the corresponding organotellurodibromide complexes CpFe(CO)2TeBr2R (R=Ph, cyclo-(C8H12)(OMe). Their structural features (as determined by single-crystal X-ray diffraction analysis) are discussed.

First structural evidence of a Se–Br–Br halogen-bonded molecular complex

The halogenation of 2,6-dibromo-9-selenabicyclo[3.3.1]-nonane 1 with 1 equivalent of molecular dihalogens (Br2 and I2) afforded a 1 : 1 molecular complex 1–X2 (X = Br (2); X = I (3)), while an excess of Br2 resulted in the ionic species [C8H12Br2SeBr]Br5− (4). X-ray crystallographic data and the nature of Se⋯Br non-covalent bonding in the solid state and solution is discussed.

Dicarbonylcyclopentadienyltellurophenyliron complexes as ligands

The reaction of CpFe(CO)2TePh (I) with ferricinium hexafluorophosphate as an oxidant affords ionic complex {[CpFe(CO)2]2(μ-TePh)}+PF6− (II) with the simultaneous formation of diphenylditellurium. The decarbonylation of compound II by Me3NO followed by the addition of complex I affords trinuclear complex {[CpFe(CO)2(μ-TePh)]2Fe(CO)Cp}PF6 (III). The corresponding tetrafluoroborate (IV) is synthesized similarly. The heating of compound I with PPh3 gives CpFe(CO)(PPh3)TePh (V) that reacts with ionic complex [CpMn(CO)2(NO)]PF6 (VI) to form binuclear heterometallic ionic complex [CpFe(CO)(PPh3)(μ-TePh)Mn(CO)(NO)Cp]PF6 (VII). A similar reaction of Cp′Fe(CO)2TePh (Cp′ is methylcyclopentadienyl) with compound VI affords heterometallic [Cp′Fe(CO)2(μ-TePh)Mn(CO)(NO)Cp]PF6 (VIII). The structures of compounds II, IV, VII, and VIII are determined by X-ray diffraction analysis (CIF files CCDC 963285, 963286, 963288, and 963289, respectively).

Phenyltellurolate-bridged heterometallic complexes combining rhenium tricarbonyl with (dicarbonyl)(cyclopentadienyl)iron or bis(diphenylphosphino)ethaneplatinum

A reaction of CpFe(CO)2TePh with Re(CO)3(THF)2Cl in THF gave the heterometallic complex [CpFe(CO)2(μ-TePh)]2Re(CO)3Cl (I). Either iron atom in complex I is linked to rhenium by only one Phenyltellurolate bridge. When treated with (Dppe)Pt(TePh)2, complex I underwent transmetalation by elimination of two CpFe(CO)2TePh molecules followed by the formation of the heterometallic chelate complex (Dppe)Pt(μ-TePh)2Re(CO)3Cl (II). Complex II was also obtained in an independent way from (Dppe)Pt(TePh)2 and Re(CO)3(THF)2. Structures I and II (II · MePh and II · CDCl3) were identified by X-ray diffraction (CIF file, CCDC nos. 981467, 981468, and 981469, respectively).

CpFe(CO)2TePh as a ligand for organometallic dihalides Fe(CO)4I2, (p-Cymene)RuI2, and Me5C5RhI2: Synthesis and molecular structures

CpFe(CO)2TePh (I) can substitute one carbonyl group in Fe(CO)4I2 providing Fe(CO)3I2(μ-TePh)Fe(CO)2Cp (II) or play role of ligand to monomeric fragments [(p-Cymene)RuI2] and [Сp*RhI2] (p-Cymene = (η6-1-isopropyl-4-methylbenzene); Сp* = η5-pentamethylcyclopentadienyl) provides the complexes (p-Cymene)RuI2(μ-TePh)Fe(CO)2Cp (III) and Cp*RhCl2(μ-TePh)Fe(CO)2Cp (IV), respectively. The single-crystal X-ray diffraction of complexes II–IV (CIF files CCDC nos. 1038124 (II), 1038127 (III), 1038125 (IV)) revealed the shortening of М–Те bonds and the presence of intramolecular I…Te contacts.