SYNTHESIS, X-RAY AND SPECTROSCOPIC CHARACTERIZATION OF [SNI2(MBIT)(2)](I-3)(2)CENTER-DOT-2 3I(2) OBTAINED THROUGH THE ONE-STEP REACTION OF MBIT-CENTER-DOT-2I(2) WITH TIN METAL-POWDER 1,1'-BIS(3-METHYL-4-IMIDAZOLINE-2-THIONE)METHANE)/

The reaction of the adduct mbit.2I(2) =1,1'-bis(3-methyl-4-imidazoline -2-thione)methane) with tin metal powder produces Sn(mbit)(2)I-9.3 in mild conditions. An X-ray diffraction study on a crystal showed that t he compound consists of a cation [SnI2(mbit)(2)](2+) having two I-3(-) as counterions, interacting with two disordered diiodine molecules. I n the cation, the metal atom lying on a symmetry centre exhibits a sli ghtly distorted octahedral coordination with the two iodides at the ap ices in trans position, and with the two mbit molecules acting as bide ntate chelating ligands through the sulfur atoms and forming an eight- membered ring, the tin metal atom included. The counterions I-3(-) are slightly bent (I(2)-I(3)-I(4) 176.0(1)) and so asymmetric (I(2)-I(3) 2.841(6), I(3)-I(4) 3.016(5) Angstrom) that they can be better describ ed as I-. I-2 adducts. The presence of the two independent, centrosymm etric and disordered diiodine molecules as guests in the channel runni ng parallel to [111] brings about I-8(2-) units of the type I-2 . I-.. . I-2 ... I-. I-2, where two triiodide ions related by a symmetry cent re are linked only for one third to I(5)-I(5(ii)), that is one of the two disordered guest I-2 molecules (I(4)... I(5) 3.22(1) Angstrom). Tw o I-8(2-) units related by a symmetry centre are held together through a non-negligible interaction (I(4)... I(6) 3.55(1) Angstrom) involvin g the other disordered diiodine molecule (I(6)-I(6(iii))) giving rise to an octadecaiodide. Crystallographic data for C18H24N8S4I9.3Sn are a s follows: the crystal is trigonal, M = 1783.77, space group <R(3)over bar>, Z=3, V=3146(4) Angstrom(3), a=18.100(6) Angstrom, alpha=115.55( 2)degrees, R=0.0584. In accordance with a description of the counterio ns as a sequence of the type I-2 . I-... I-2 ... I-. I-2, FT-Raman spe ctra do not show the peaks generally found in conventional triiodides, but those related to perturbed diiodine molecules. (C) 1998 Elsevier Science S.A.