Synthetic and structural aspects of perchlorato complexes of tellurium(IV) with different dithiocarbamates (dtc) [(R1R2NCS2) where R1 = R2 = methyl, ethyl, n-propyl, i-propyl; R1R2 = (CH2)5(piperidine), C2H4OC2H4 (morpholine)] are reported. The crystal structure of TeL3ClO4 (where L = diethyl dtc) has been determined. The crystals of the complex are monoclinic, space group P21/n, a = 11.379(3), b = 17.745(7), c = 14.016(8) Å, γ = 103.30(2)°, V = 2754.2 Å3, F(000) = 1352, DX = 1.61 mg M-3. The final R and Rw values are 0.047 and 0.058, respectively for 5224 unique reflections. Tellurium displays a distorted dodecahedral stereochemistry formed by two interposing trapezoids, one resulting from the four sulphurs of two L groups and the other from the two sulphurs of the third L and the two oxygens of the perchlorate ion. The average TeS distance 2.648(2) Å is close to that reported in other tris(dithiocarbamato)tellurium(IV) complexes. The perchlorate is weakly coordinated to tellurium(IV), with the average TeO distance being 2.994(8) Å. The unusual coordination of perchlorate (as a bidentate ligand) to tellurium(IV) dithiocarbamate is reported for the first time. © 1989.

S. P. Chidambaram

Gopalaswamiengar Aravamudan

Maha Seshasayee

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

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IIT Madras

Synthesis of unusual mixed ligand tellurium(IV) dithiocarbamates with perchlorate. Crystal and molecular structure of perchloratotris(diethyldithiocarbamato)tellurium(IV)

Polyhedron

The reactions of (diethyldithiocarbamato)halogenotellurium(II) with thiourea, benzimidazole-2-thiol, halides (Cl-, Br-, I-) and 1,10-phenanthroline (phen) have been studied. The products were principally characterized by elemental analyses, IR and 1H NMR spectroscopies. Novel anionic (diethyldithiocarbamato)dihalogenotellurate(II) complexes resulted from the reactions of Te(S2CNEt2)X (X = Br or I) with NEt4X (X = Br or I) and phen. The crystal structures of the complexes [NEt4][Te(S2CNEt2)I2], [H(phen)2][Te(S2CNEt2)I2] and [H(phen)2][Te(S2CNEt2)Br2] have been determined. In the anions tellurium is co-ordinated to two sulfur atoms of the dithiocarbamate in an almost isobidentate manner and to two halides in an overall planar trapezoidal geometry. In [NEt4][Te(S2CNEt2)I2] the two iodides are almost equidistant to tellurium with distances of 3.079(1) and 3.072(1) Å, whereas in [H(phen)2][Te(S2CNEt2)I2] the two Te-I distances are 3.151(1) and 3.038(1) Å and in [H(phen)2][Te(S2CNEt2)Br2] the two Te-Br distances are 2.911(1) and 2.986(1) Å. In [H(phen)2]+ the proton is bound to one of the nitrogen atoms of a phenanthroline group and the two phen groups are held together by three hydrogen bonds, of which two are of the interesting type C-H ⋯ N.

Journal of the Chemical Society - Dalton Transactions

Reactions of (diethyldithiocarbamato)halogenotellurium(II); crystal structures of R[Te{S2CNEt2}X2] [R = NEt4, X = I; R = H(phen)2 (phen = 1,10-phenanthroline), X = I or Br]

Reaction of tellurium(IV) with excess phenylenethiourea(2-mercaptobenzimidazole) in aqueous methanolic hydrochloric acid leads to the formation of Te(II) complex, tetrakis(phenylenethiourea)tellurium(II) chloride dihydrochloride. The characterisation and crystal structure of the complex are reported. The crystals are monoclinic, space group P21/c, a = 13.939(5), b = 26.523(9), c = 4.873(2) Å, β = 100.29(4)°, V = 1772.6 Å3, M = 872.4, Dc = 1.651 g cm-3, Z = 2, F(000) = 868, μ(MoKα) = 1.298 mm-1. Final R = 0.055 and RW = 0.056 for 918 independent reflections. The tellurium atom in the molecule lies at the crystallographic centre of symmetry and is bonded to four phenylenethiourea sulphur atoms in a square planar arrangement with TeS(1) = 2.678(6), TeS(2) = 2.674(5) Å and S(1)TeS(2) is 90.5(3)°. The ligand behaves as a thione. Chlorine atoms remain outside the coordination sphere of the Te and stabilise the packing arrangement in the unit cell through hydrogen bondings to nitrogen atoms. © 1984.

Synthesis and structure of tetrakis(phenylenethiourea)tellurium(II) chloride dihydrochloride, C28H26N8S4Cl4Te

The synthesis, properties, and crystal structure of the unusual mixed-ligand complex TeCl [(HOC2H4)2NCSS] 3-2H2O are described. The complex is monomeric in the crystalline state. The molecular structure shows a highly distorted pen-tagonal-bipyramidal coordination around tellurium featuring both strong and weak Te-S bonds in the equatorial plane and a strong Te-S bond and a rather weak Te-Cl bond in the axial positions. The complex is less stable than tetrakis-(diethyldithiocarbamato)tellurium(IV). The chlorine atom and all the oxygen atoms participate in hydrogen bonding, and the packing arrangement in the unit cell seems to be mainly dictated by the hydrogen-bonding network. © 1983, American Chemical Society. All rights reserved.

Journal	Polyhedron
ISSN	02775387
Open Access	No