Investigations on a Series of Ionic Liquids Containing the [CoIIBr3quin]- Anion (quin = quinoline)

A series of eight new 1-alkyl-3-methylimidazolium derived salts with the pseudotetrahedral Co-II-based complex anion, [Co(II)Br(3)quin](-), quin = quinoline, and 1-alkyl-3-methylimidazolium cations, AlkMIm, Alk = ethyl, n-butyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, allyl, and propargyl; M = methyl, was synthesized. The melting point of each compound was measured to see if they are designated as metal-containing ionic liquids (magnetic ionic liquids). Each compound was further characterized by elemental analysis, NMR, IR, and UV/vis spectroscopy. From NMR investigations, information about the magnetic behavior was derived using the EVANS method. It has been found that every compound is paramagnetic with effective magnetic moments of spin-only Con. The solid state structures of the compounds (AlkMIm)[Co(II)Br(3)quin] with Alk = ethyl, n-butyl, n-hexyl, and n-nonyl were established by single-crystal X-ray diffraction techniques with regard to finding correlations between thermal and structural properties: (EMIm)[CoBr(3)quin]: triclinic, P (1) over bar (No. 2), a = 7.4889(3) angstrom, b = 8.2056(3) angstrom, c = 15.2471(6) angstrom, alpha = 88.453(2)degrees, beta = 85.457(2)degrees, gamma = 79.531(2)degrees, Z = 2, r(1)(F)/wR(2)(F-2) = 0.0248/0.0569; (BMIm)[CoBr(3)quin]: triclinic, P (1) over bar (No. 2), a = 8.2915(4) angstrom, b = 10.2560(4) angstrom, c = 12.3943(5) angstrom, alpha = 91.877(2)degrees, beta = 95.427(2)degrees, gamma = 101.826(2)degrees, Z = 2, R-1(F)/wR(2)(F-2) = 0.028057/0.0592; (HexMIm)[CoBr(3)quin]; monoclinic, P2(1)/c (No. 14), a = 8.0375(2) angstrom, b = 25.7514(5) angstrom, c = 11.3451(3) angstrom, beta = 105.449(1)degrees, Z = 4, R-1(F)/wR(2)(F-2) = 0.0263/0.0554; (NonMIm)[CoBr(3)quin]: monodinic, P2(1)/c (No. 14), a = 13.1727(5) angstrom, b = 12.1438(5) angstrom, c = 17.2612(6) angstrom, beta = 111.321(2)degrees, Z = 4, R-1(F)/wR(2)(F-2) = 0.0288/0.0588.