Research Article: A second monoclinic polymorph of {bis­[5-methyl-3-(trifluoro­meth­yl)pyrazol-1-yl]borato}{tris­[5-methyl-3-(trifluoro­meth­yl)pyrazol-1-yl]borato}cobalt(II): a structure containing a B—H⋯Co agostic inter­action

Date Published: July 01, 2011

Publisher: International Union of Crystallography

Author(s): Robert T. Stibrany, Joseph A. Potenza.


The title compound, [Co(C10H10BF6N4)(C15H13BF9N6)], is a polymorph of the previously reported neutral cobalt(II) complex [Stibrany & Potenza (2010 ▶). Acta Cryst. E66, m506–m507], which contains one each of the monoanionic ligands, bis­[5-methyl-3-(trifluoro­meth­yl)pyrazol-1-yl]borate (Bp) and tris­[5-methyl-3-(trifluoro­meth­yl)pyrazol-1-yl]borate (Tp). A distorted octahedral coordination geometry of the CoII atom results from ligation of an H atom, which is part of an agostic B—H⋯Co inter­action [H⋯Co = 2.12 (3) Å], and by five imine N atoms, two from a Bp ligand and three from a Tp ligand. Weak intra- and inter­molecular C—F⋯π inter­actions with F⋯centroid distances ranging from 3.025 (4) to 3.605 (4) Å are observed.

Partial Text

For our study of nitro­gen-containing heterocyles and their complexes with metal ions, see: Stibrany & Potenza (2006 ▶, 2009a ▶,b ▶); Stibrany et al. (1999 ▶, 2005 ▶, 2006 ▶). For a polymorph of the title compound, see: Stibrany & Potenza (2010 ▶). For oxidation studies of copper and cobalt complexes utilizing the title ligand, see: Gorun et al. (2000 ▶). For agostic inter­actions, see: Ruman et al. (2001 ▶, 2002 ▶); Siemer et al. (2001 ▶); Ghosh et al. (1998 ▶).




0 0 vote
Article Rating
Notify of
Inline Feedbacks
View all comments