2-[(Diisopropylthiophosphoryl)amino]-pyridinium tetrafluoroborate

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 synoriented 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)(degrees) in the first and -35.1 (1)(degrees) in the second cation.