Tetrachlorocobaltates(II) of diprotonated α,ω-diaminoalkanes with the formula [NH3(CH2)
n
NH3]CoCl4, where n = 5 (cadaverine; 1,5-pentanediammonium tetrachlorocobaltate), 8 (1,8-octanediammonium tetrachlorocobaltate) and 10 (1,10-decanediammonium tetrachlorocobaltate), were prepared. The compounds were studied by mass spectrometry, FT-IR and visible spectroscopy, magnetic susceptibility techniques and thermal analysis. The compounds contain the tetrahedral tetrachlorocobaltate(II) ion and the corresponding diprotonated diamine (cadaverine, 1,8-octamethylenediamine and 1,10-decamethylenediamine). The compound corresponding to cadaverine crystallizes in the monoclinic space group P21/c, with lattice parameters a = 7.1633 (7), b = 15.940 (3), c = 11.137 (2) Å, β = 98.44 (1)° and Z = 4. Its crystal structure contains slightly distorted tetrahedral CoCl_4^{2-} ions: the largest difference in Co—Cl bond lengths is 0.029 Å and the largest difference in Cl—Co—Cl angles is 7.76°. The compound also contains diprotonated cadaverine ions. An extensive hydrogen-bonding network connects these ions. The slightly positive deviations of the magnetic susceptibility from the Curie–Weiss law are in agreement with the 4
A
2 ground state for the tetrachlorocobaltate anion. The compounds with eight and ten C atoms show phase transitions in the solid state and a greater complexity is observed in their differential scanning calorimetry curves. Unfortunately, no suitable single crystals of these could be obtained.
Characterization of polycyclic aromatic hydrocarbons and their phenanthroperylene quinone precursors in fossil crinoids using liquid chromatography–atmospheric pressure photoionization mass spectrometry
