266ChemInform Abstract The reaction of ortho-lithiobenzylamine with elemental Te followed by air oxidation did not afford an expected ditelluride but an ill defined "tellurinic anhydride" which undergoes facile halogenolysis to give (IV) or a corresponding chloride, when SO2Cl2 is used. (IV) crystallizes in P21/n with Z=4 in an octahedral geometry where the lone pair of electrons occupies one equatorial position. Metathetical reactions of the Cl-analogues of (IV) and (V) with excess sodium diethyldithiocarbamate afford the corresponding dithiocarbamato derivatives in 71 and 80% yield. The structure of the alkyl-telluro-substituted compounds (IX) is confirmed by an X-ray analysis of (IXb) ( P21/n, Z=4).

The syntheses and spectroscopic data (13C n.m.r.) for some new organyltellurium ligands are described. Thus trans metallation of 2-(2-pyridy1)phenyl-(R) or 2-(quinolin-2-yl)phenyI-(R') mercury( it) chloride with TeBr, gives the organyltellurium tribromides RTeBr, and R' TeBr,, which may be reduced to the organyltellurium bromides RTeBr and R'TeBr, some metathesis reactions of which are described; or, in the presence of excess hydrazine, to diorganyl ditellurides, R, Te, and R' ,Te,. Reduction of RTeBr,X with NaBH, gave a novel tritelluride, R, Te, ; a method of preparation for R' ,Te, was also devised. Syntheses of the tellurides R,Te, R' ,Te, and RTe(C,H,OEt-p) were developed and the intermediacy of ionic compounds [ R,TeBr] [HgCIBr,] and [ R,TeCI] [HgCI,] noted. The crystal structures of 2-(2-pyridyl)phenyltellurium(iv) tribromide, (1 ), dimethyldithiocarbamato [2-(2-pyridyl) phenyl] tellurium ( II), (2), and p-ethoxyphenyl2-(2-pyridy1)phenyltelluride, (3), have been determined from three-dimensional X-ray counter data. Complex (1 ) is triclinic, space group PT with a = 6.953(6), b = 8.382(1), c = 12.133(2) A, cx = 78.68(1), p = 82.87(4), y = 87.14(4)", and Z = 2; R = 0.0735 for 1 963 observed reflections. The co-ordination about Te is octahedral with a vacant equatorial position, two Br atoms apical, the third Brand the organic group equatorial [Te-C, 2.1 lO(19); Te-N, 2.244(14) A]. The compound is essentially monomeric, with a weak association between Te and Br [3.596(3) A] in a neighbouring molecule. Complex (2) is triclinic, space group Pf with a = 8.809(3), b = 9.032(5), c = 10.727(4) A, u = 83.06(4), p = 86.49(3), y = 63.68(4), and Z = 2; R = 0.041 7 for 2 502 observed reflections. The co-ordination about Te is trigonal bipyramidal, C ( l ) and two lone pairs of Te comprising the equatorial co-ordination and the S ( l ) atom together with the pyridyl-N atom axial [Te-C, 2.1 1 l ( 5 ) ; Te-N, 2.354(4) A]. No significant intermolecular contacts occur. Complex (3) is monoclinic, space group P2,lc with a = 13.422(2), b = 16.469(3), c = 7.71 l ( 3 ) A, B = 91.01 (2)", and Z = 4; R = 0.041 5 for 2 01 4 observed reflections. The Te atom is bonded to two C atoms. The N atom of the pyridyl ring is twisted away from Te [Te-N, 2.695(4) A] by rotation of the pyridyl ring about the pyridyl-phenyl bond by 23.2(3)", a manifestation of the trans effect of the TeC(ethoxypheny1) covalent bond.

The Lewis Acidity of Organylbismuth(iii) Compounds. New Organylbismuth(iii) Dithiocarbamate Chemistry. The Crystal and Molecular Structure of Bis-(diethyldithiocarbamato)phenylbismuth(iii) and Bis(diethy1dithiocarbamato)-[2-(2'-pyridyl)phenyl] bismuth( 1 1 1 ) *

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The title compound (VI) is prepared as shown.