Structural and spectroscopic elucidation of imidazolium and pyridinium based hexachloridophosphates and niobates

1-Ethyl-3-methylimidazolium hexachloridophosphate, [EMIm][PCl6] (1), 1-ethyl-3-methylimidazolium hexachloridoniobate, [EMIm][NbCl6] (2), 1-butyl-4-methylpyridinium hexachloridophosphate, [1,4-BMPy][PCl6] (3), 1-butyl-4-methylpyridinium hexachloridoniobate, [1,4-BMPy][NbCl6] (4), and 1-butyl-3-methylpyridinium hexachloridoniobate, [1,3-BMPy] [NbCl6] (5) have been synthesized and characterized by single-crystal X-ray diffraction and Raman spectroscopy. All the saltlike compounds crystallize in the monoclinic space group: [EMIm][PCl6] (1): P2(1)/c (no. 14), a = 7.698(1), b = 12.266(2), c = 15.019(2) angstrom, beta = 101.45(1)degrees, V = 1389.9(3)angstrom(3) and Z = 4; [EMIm][NbCl6] (2): P2(1)/n (no. 14), a = 20.186(1), b = 7.084(1), c = 20.549(1)angstrom, beta = 98.46(1)degrees, V = 2906.6(4) angstrom(3) and Z = 8; [1,4-BMPy][PCl6] (3): P2(1)/c (no. 14), a = 14.681(2), b = 7.242(1), c = 16.157(2)angstrom, beta = 101.55(1)degrees, V = 1683.0(3) angstrom(3) and Z = 4; [1,4-BMPy][NbCl6] (4): P2(1)/c (no. 14), a = 15.163(2), b = 7.323(1), c = 16.205(2)angstrom, beta = 101.92(1)degrees, V = 1760.5(4)angstrom(3) and Z = 4; [1,3-BMPy][NbCl6] (5): P2(1)/c (no. 14), a = 10.396(1), b = 23.050(2), c = 14.974(2)angstrom, beta = 102.28(1)degrees, V = 3505.9(6)angstrom(3) and Z = 8. Title compounds are built up by the mentioned bulky organic cations and octahedral [PCl6](-) respective [NbCl6](-) anions. No significant hydrogen bonding is observed between the organic cations and respective inorganic anions. FT-Raman spectra of the title compounds have been recorded and interpreted, especially with respect to the inorganic parts [PCl6]- and [NbCl6](-). NMR spectra and the melting temperatures of 1-5 are given.