The extremely moisture-sensitive [SnX 4 (Me 2 Te) 2 ] and [SnX 4 (ditelluroether)] [X = Cl or Br;

Homoleptic silver(i) complexes [Ag(L-L),]BF, {L-L = RE(CH,),ER [R = Ph or Me, n = 2 or 3 ( E = S or Se), n = 3 ( E = Te)]} have been prepared and characterised by analysis, FAB mass spectrometry, and multinuclear N M R spectroscopy ('H, "Se, lZ5Te and lo9Ag). Variable-temperature N M R studies c = 10.339(3) 1 , U = 2075.7(7) A3 [from 28 values of

The reaction of Pb[BF(4)](2) in H(2)O/MeCN solution with the macrocycle 18-crown-6 gave the dinuclear complex [{Pb(18-crown-6)(H(2)O)(μ(2)-BF(4))}(2)][BF(4)](2), containing two nine-coordinate lead centres, each bound to all six oxygens of a crown ligand, one water molecule and bridged by two μ(2)-BF(4) groups. In contrast, the oxa-thia crown [18]aneO(4)S(2) gave the mononuclear [Pb([18]aneO(4)S(2))(H(2)O)(2)(BF(4))][BF(4)] in which the lead is coordinated O(4)S(2) within the puckered ring of the macrocycle, and with two water molecules on one side of the plane and a chelating (κ(2)) BF(4)(-) on the other. The [Pb([18]aneO(4)Se(2))(BF(4))2] has the two BF(4)(-) groups arranged mutually cis and with the macrocycle folded; within each BF(4)(-) group the Pb-F distances differ by ~0.5 Å, producing a very unsymmetrical chelate. The 15-membered ring macrocycles 15-crown-5 and [15]aneO(3)S(2) produce sandwich complexes [Pb(macrocycle)(2)][BF(4)](2) which contain 10-coordinate lead centres. Pb[PF(6)](2) in H(2)O/MeCN solution formed [Pb(18-crown-6)(H(2)O)(2)(PF(6))][PF(6)] and [Pb([18]aneO(4)S(2))(H(2)O)(2)(PF(6))][PF(6)] which contain weak κ(2)-coordination of the PF(6)(-) group on the opposite side of the macrocyclic ring to two coordinated water molecules, giving 10-coordinate lead. In contrast, [Pb([18]aneO(4)Se(2))(PF(6))(2)] has two κ(2)-coordinated PF(6)(-) groups disposed cis, with a very folded macrocycle conformation. In [Pb(18-crown-6)(NO(3))(PF(6))] a chelating nitrate group occupies the coordination sites at Pb(II) instead of the two water molecules, and the weakly coordinating PF(6)(-) group is tridentate. The crystal structures of the lead nitrate complexes, [Pb(15-crown-5)(NO(3))(2)] and [Pb([18]aneO(4)Se(2))(NO(3))(2)], containing nine- and 10-coordinate lead respectively, are also reported. In solution the complexes are labile, and both conductivity and (19)F NMR spectroscopic studies show the BF(4)(-) and PF(6)(-) groups are dissociated, whereas in the nitrate complexes the anion coordination is retained in solution. The identification of the coordination modes of the NO(3)(-) and BF(4)(-) groups in the solid complexes by IR spectroscopy is discussed.

Homoleptic copper(I) and silver(I) complexes [M(n)(L-L)(2)(n)()](BF(4))(n)() (M = Cu or Ag; L-L = MeECH(2)EMe; E = S, Se or Te) have been prepared and characterized by analysis, FAB mass spectrometry, and IR and multinuclear NMR spectroscopy ((1)H, (77)Se, (125)Te, (63)Cu and (109)Ag). The single-crystal X-ray structures of [Cu(n)()(MeSeCH(2)SeMe)(2)(n)()](PF(6))(n)() (orthorhombic, P2(1)2(1)2(1), a = 10.879(7) Å, b = 16.073(7) Å, c = 9.19(1) Å, Z = 4) and [Ag(n)()(MeSeCH(2)SeMe)(2)(n)()](BF(4))(n)() (monoclinic, P2(1)/c, a = 14.546(9) Å, b = 14.65(1) Å, c = 30.203(9) Å, Z = 4) reveal extended three-dimensional cationic frameworks in the solid state which contain large cylindrical or rectangular channels accommodating the PF(6)(-) or BF(4)(-) counterions. In contrast, a single-crystal X-ray structure of [Cu(n)()(MeSCH(2)SMe)(2)(n)()](PF(6))(n)().nMeNO(2) (orthorhombic, Pbcn, a = 15.506(3) Å, b = 8.934(2) Å, c = 25.859(3) Å, Z = 8) shows tetrahedral Cu(I) ions coordinated to bridging dithioethers forming an cationic ribbon-like arrangement of 8-membered rings. Adjacent rings are linked by the Cu atoms. Variable temperature NMR studies have been used to probe various exchange processes occurring in solution in these systems.

Reaction of TiCl(4) or ZrI(4) with the soft, neutral o-C(6)H(4)(CH(2)EMe)(2) (E = S or Se) in anhydrous CH(2)Cl(2) (or toluene) yields the distorted octahedral chelate complexes [MX(4){o-C(6)H(4)(CH(2)EMe)(2)}]. Using Et(2)Se gives [MX(4)(Et(2)Se)(2)] (M = Zr, X = Cl or I; M = Hf, X = I). The Sn(IV) analogues, [SnCl(4){o-C(6)H(4)(CH(2)EMe)(2)}] and [SnCl(4)(Et(2)Se)(2)] were obtained similarly. These complexes have been characterised spectroscopically and analytically, and crystal structures of trans-[SnCl(4)(Et(2)Se)(2)] and some selenonium salts derived as minor by-products from the parent Group 4 complexes are described. The neutral chalcogenoether complexes have been evaluated as single source precursors to ME(2)/ME thin films via LPCVD. [TiCl(4){o-C(6)H(4)(CH(2)EMe)(2)}] leads to the deposition of air and moisture stable TiE(2) films (with no residual Cl). Coverage of the substrate is uniform with platelet growth perpendicular to the surface. The heavier Zr(IV) species do not lead to significant ZrE(2) deposition. On the other hand, LPCVD of [SnCl(4){o-C(6)H(4)(CH(2)SMe)(2)}] leads to deposition of SnS(2) at lower temperatures and SnS at higher temperatures, while [SnCl(4){o-C(6)H(4)(CH(2)SeMe)(2)}] gives rather uneven coatings of SnSe(2). The Et(2)Se derivative, [SnCl(4)(Et(2)Se)(2)] leads to uniform deposition of SnSe(2) with growth perpendicular to the substrate surface. The SnE(2)/SnE films are stable indefinitely to air and moisture. The generation of TiS(2), SnS(2) and SnS in this way are very rare examples of metal sulfide deposition from C-S bond fission within a thioether complex.