A (diborole)cobalt complex with a C-H···B Bridge, CpCo(1,3-C3B2Me5H), and its thallium derivative

• Verfasst von: Muratov, Dmitry V. [VerfasserIn]
• Verfasst von: Siebert, Walter [VerfasserIn]
• Titel: A (diborole)cobalt complex with a C-H···B Bridge, CpCo(1,3-C3B2Me5H), and its thallium derivative
• Titelzusatz: synthesis, structure, and bonding
• Verf.angabe: Dmitry V. Muratov, Alexander S. Romanov, Pavel V. Petrovskii, Mikhail Yu Antipin, Walter Siebert, and Alexander R. Kudinov
• E-Jahr: 2012
• Jahr: 01 August 2012
• Umfang: 9 S.
• Fussnoten: Gesehen am 29.08.2018 ; Im Titel sind die Zahlen in C3B2Me5H tiefgestellt
• Titel Quelle: Enthalten in: European journal of inorganic chemistry
• Ort Quelle: Weinheim : Wiley-VCH, 1998
• Jahr Quelle: 2012
• Band/Heft Quelle: (2012), 26, Seite 4174-4182
• ISSN Quelle: 1099-0682
• DOI: doi:10.1002/ejic.201200215
• Datenträger: Online-Ressource
• Sprache: eng
• Sach-SW: Boron heterocycles
• Sach-SW: Cobalt
• Sach-SW: Sandwich complexes
• Sach-SW: Thallium
• K10plus-PPN: 1580484581

Abstract

The reaction of CpCo(1,3-C3B2Me5H) (1) with CpTl affords the thallium derivative CpCo(1,3-C3B2Me5)Tl (2). The structures of 1 and 2 were determined by X-ray diffraction at 100 K. An “extra” hydrogen atom in 1 occupies a C-H···B bridging position. According to DFT calculations, 1 exists as a mixture of two enantiomers with an enantiomerization barrier of only 0.5 kcal mol-1. The transition state has Cs symmetry with an endo-CH hydrogen atom. The isomeric iso-1with the Co-H···B bridge is less stable than 1 by 10 kcal mol-1.The formation of 1 and iso-1 from C3B2Me5H and CpCo(C2H4)2 have almost equal activation energies. The isomerization of iso-1 to 1 was shown to proceed as a two-step hydrogen transfer. The bonding of the “extra” hydrogen atom in the related CHB-bridged carborane nido-2,3,5-C3B3R5H2 and metallacarboranes M(C5R5)(C3B2R′5H) (R, R′ = H, Me; M = Co, Rh, Ir) as well as their hydridic isomers MH(C5R5)(C3B2R′5) was compared. According to energy decomposition analysis, the bonding of the parent anion [CpCo(1,3-C3B2H5)]- with metal cations becomes stronger in the following order: K+ < Na+ < Tl+ < Li+ < [RuCp]+. The attractive interactions between the [CpCo(1,3-C3B2H5)]- and Tl+ fragments are 68 % electrostatic and 32 % covalent.