Date Published: June 01, 2012
Publisher: International Union of Crystallography
Author(s): Christian Holzhacker, Karl Kirchner, Kurt Mereiter.
The title compound, C11H20N2PS+·BF4−, is a salt of 2-(diisopropylthiophosphorylamino)pyridine, a chelating bidentate ligand that furnishes an S atom as a soft donor and a pyridine N atom as a hard atom for transition-metal complexation. The title salt crystallizes with two formula units in the asymmetric unit. The two independent cations are protonated at the pyridine N atoms and have the S atoms syn-oriented to them so as to form bent intramolecular N—H⋯S hydrogen bonds, one of which one is bifurcated by involving also an N—H⋯F interaction. The phosphorylamino NH groups form near linear hydrogen bonds to proximal tetrafluoroborate anions. Five weak C—H⋯F and three weak C—H⋯S interactions link the constituents into a three-dimensional framework. As a result of the crystal packing, the two cations differ notably in conformation, as can be seen from the S—P—N—C torsion angles of −18.7 (1)° in the first and −35.1 (1)° in the second cation.
For the synthesis of 2-(diisopropylthiophosphorylamino)pyridine, see: Smith & Sisler (1961 ▶); Bichler et al. (2011 ▶). For Cu, Pd, and Fe complexes of 2-(diisopropylthiophosphorylamino)pyridine, see: Öztopcu et al. (2011 ▶); Bichler et al. (2011 ▶); Holzhacker et al. (2011 ▶). For an review on S-bearing transition-metal catalysts, see: Bayón et al. (1999 ▶).