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Updated: Jun 5, 2026

Palladium N-Heterocyclic Carbene Complexes: Synthesis from Benzimidazolium Salts and Catalytic Activity in Carbon-carbon Bond-forming Reactions
Published on: July 30, 2017
4-(Dimethyl-amino)pyridinium 4-toluene-sulfonate
1Department of Chemistry, University of Otago, PO Box 56, Dunedin, New Zealand.
Abstract:
In the title compound, C(7)H(11)N(2) (+)·C(7)H(7)O(3)S(-), the cation is protonated at the N atom of the heterocyclic ring. The dimethyl-amino group lies close to the pyridinium ring plane with a dihedral angle between the pyridinium and the dimethyl-amine CNC planes of 3.82 (17)°. The N-C bond linking the dimethyl-amino substituent to the pyridinium ring is characteristically short [1.3360 (19) Å], suggesting some delocalization in the cation. In the crystal structure, N-H⋯O hydrogen bonds link individual pairs of cations and anions. The structure is further stabilized by an extensive series of C-H⋯O hydrogen bonds, augmented by π-π [centroid-centroid distance between adjacent pyridinium rings = 3.5807 (10) Å] and C-H⋯π inter-actions, giving a network structure.
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