Molecular Assemblies Based on Cp*BiX2 Units (X = Cl, Br, I): An Experimental and Computational Study

作者：Monakhov Kirill Yu; Zessin Thomas; Linti Gerald^*

来源：Organometallics, 2011, 30(10): 2844-2854.

DOI：10.1021/om200169d

A series of pentamethylcyclopentadienyl-substituted bismuth halo complexes were prepared by the reactions of bismuth(III) halides BiX3 (X = Cl, Br, I) with LiCp* (Cp* = C5Me5) in 1:1 ratio. The crystal structures of [Cp*5Bi6Cl12][(thf)(2)Bi2Cl7] (1), [Cp*BiBr2](infinity) (2), {{Cp*5Bi5Br9}{BiBr4}](2) (3), and [Cp*BiI2](infinity) (4) were determined by single-crystal X-ray diffraction analysis. 1-4 display different types of aggregation, polymeric association, and Cp*-BiX2 bond hapticity depending on the halogen atom at Bi. The cationic portion of 1 is a distorted octahedral Bi-6 cage that shows no Bi-Bi bonding, is capped by halo ligands and Cp* rings in eta(5)-fashion, and contains an interstitial Cl atom. The main structural difference in the bismuth halide framework between cationic portions {Cp*5Bi5Br9}(+) in 3 and [Cp*5Bi6Cl12] in 1 is a neutral BiX3 unit complexed to the [{Cp*5Bi5Cl9}](+) fragment of the latter. 2 and 4 are zigzag polymers with different types of intermolecular interaction in the crystals. More ionic Cp*-Bi bonding results in higher hapticity and appears to favor cage formation, while more covalent bonding favors lower hapticity. According to quantum chemical calculations on the simplified gas phase models Cp*BiX2 (X = F, Cl, Br, I), the Cp* ring is attached via a eta(1)(pi)-bonding mode. The structural diversity of the observed assemblies is driven by the nature of Cp*-Bi bonding, which was examined by NBO analysis.

• 出版日期2011-5-23