Synthesis and crystal structure of a thallium(I) hydrogen benzothiazolylcyanoximate complex with 18-crown-6: The thallium atom is in the center of the crown ether cavity

Complexes of composition [TI(18-crown-6){BTCO}] and [TI(18-crown-6){H(BTCO)(2)}] (BTCO = {ONC(CN)-(benzothiazolyl-2)}(-)) have been prepared. The crystal and molecular structure of the [TI(18-crown-6){H(BTCO)(2)}] complex has been determined from X-ray diffraction data (orthorhombic, space group Pbca, with a = 15.520(3), b = 11.668(2), c = 19.661(4) Angstrom, V = 3560.4(12) Angstrom(3), Z = 4). The structure was refined by least-squares methods to a final value of R = 0.029 based on 2525 independent reflections with I > 2 sigma(I). The metal atom occupies a center of symmetry. The lattice consists of centrosymmetric cations TI(18-crown-6)(+) and anions {H(BTCO)(2)}(-), which are bridges between neighboring cations to give a one-dimensional polymeric structure. The thallium atoms adopt the eight-fold coordination of a slightly distorted hexagonal-bipyramidal geometry with axial nitrile nitrogen atoms and reside exactly in the center of the crown ether (TI-O similar to 2.820-2.876 Angstrom, TI-N 2.987 Angstrom). No stereochemical activity of a lone pair electron density of TI was observed.