CROWN THIOETHER CHEMISTRY OF TIN(IV) - FORMATION AND CRYSTAL AND MOLECULAR-STRUCTURES OF 3SNCL(4)CENTER-DOT-2[9]ANES(3) AND 2SNCL(4)CENTER-DOT[18]ANES(6)CENTER-DOT-MECN ([9]ANES(3)=1,4,7-TRITHIACYCLONONANE [18]ANES(6)=1,4,7,10,13,16-HEXATHIACYCLOOTADECANE)

Reactions of tin(lv) chloride-with selected thiacrown ligands in aceto nitrile have been studied. With [9]aneS(3) (1,4,7-trithiacyclononane) the yellow compound 3SnCl(4) . 2[9]aneS(3) has been isolated and struc turally characterised by X-ray diffraction: orthorhombic, space group Pbca, a = 11.245(5) Angstrom, b = 12.927(6) Angstrom, c = 23.779(10) A ngstrom, Z = 4, at 230(2) K. The structure consists of six-co-ordinate [SnCl3([9]aneS(3))](+) cations and [SnCl6](2-) anions in the ratio 2: 1. In the cation the thiacrown is chelated facially to a SnCl3 unit wi th Sn-Cl 2.369(4) (mean), Sn-S 2.637(4) Angstrom (mean). The [SnCl6](2 -) counter anions exhibits a regular octahedral geometry with Sn-Cl2.4 48(4) (mean) Angstrom. The reaction with [18]aneS(6) (1,4,7;10,13,16-h exathiacyclooctadecane) provides yellow crystals of the adduct 2SnCl(4 ) .[18]aneS(6) . MeCN the structure of which has also been determined by X-ray diffraction; monoclinic, space group C2, a = 16.901 (5). b = 1 2.968(5), c = 7.284(3) Angstrom. beta = 100.50(3)degrees. Z = 2, at 244(2) K. The structure consists of two SnCl4 units located at opposit e enas of the ring cavity with one above andthe other below the ring p lane. Each tin atom is six-co-ordinate and is attached to the ring via cis chelation of two sulfur atoms.