CONDUCTIVITY, FT-RAMAN SPECTRA, AND X-RAY CRYSTAL-STRUCTURES OF 2 NOVEL [D2I]IN (N = 3 AND D = N-METHYLBENZOTHIAZOLE-2(3H)-SELONE - N = 7 AND D = N-METHYLBENZOTHIAZOLE-2(3H)-THIONE) IODONIUM SALTS - 1ST EXAMPLE OF I-.3I2 HEPTAIODIDE

Solids of stoichiometry 1.2I2 (C8H7I4NS2; I) and 2.I2 (C8H7I2NSSe; II) are obtained respectively from mixtures of N-methylbenzothiazole-2(3H )-thione (1) and N-methylbenzothiazole-2(3H)-selone (2) with molecular diiodine in CH2Cl2 when the solutions were allowed to stand. The crys tals of I are monoclinic (a = 9.445(1) angstrom, b = 18.233(2) angstro m, c = 18.673(2) angstrom, beta = 98.62(1)-degrees, Z = 4, space group P2(1)/c; R = 0.030) and consist of the [(1)2I]+ cations and I7- anion s, formed by interaction of I- with three diiodine molecules (short di stances ranging between 2.746 and 2.771 angstrom, long distances betwe en 3.237 and 3.260 angstrom). The I7- anions interact weakly with each other (3.502 angstrom) to form parallel chains of anions; the cations are located between these chains. The crystals of II are triclinic (a = 12.147(10) angstrom, b = 9.681(4) angstrom, c = 10.950(4) angstrom, alpha = 71.03(2)-degrees, beta = 93.93(2)-degrees, gamma = 99.14(2)-d egrees, Z = 1, space group P1BAR; R =0.027) and consist of [(2)2I]+ ca tions and triiodide anions located on different crystallographic cente rs (d(I-I) = 2.899 and 2.919 angstrom for the two differently position ed triiodides). The FT-Raman spectra in the characteristic v(I-I) regi on show a very strong band for compound II at 121.2 cm-1, in accordanc e with the presence of a symmetrical triiodide anion, while for I the medium peak at 175.2 cm-1 and the strong one at 157.4 cm-1 are indicat ive of the presence of perturbed diiodine molecules, as generally foun d in donor-12 adducts of weak or medium-weak strength. Both compounds have very low electric conductivity.