The divalent tellurium title complex (II) has been synthesized by addition of Ph2Te2 and Br-2 to the ligand 1-phenyl-3-(2-thiazolyl)-2-thiourea (I). The molecular structures of I and II were subsequently determined by X-ray crystallographic methods. As a result, it was found that upon complexation, the ligand had undergone a transition from a thiourea to to an isomeric isothiourea, involving a transfer of a thiourea proton to the thiazolyl ring. This does not seem to influence the bonding properties of the ligand, and the reasons for this are discussed. The central tellurium atom is three-coordinate and its coordination sphere is T-shaped with a linear S-Te-Br sequence with bond lengths Te(1)-S(1) and Te(1)-Br(1) equal to 2.548(1) and 2.883(1) Angstrom, respectively, and angle S(1)-Te(1)-Br(1)=174.49(2)degrees. At nearly right angles to this sequence, there is a Te(1)-C(11)(phenyl) bond of 2.127(3) Angstrom.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Six novel tellurium(II) complex salts [Te(etu)4][SiF6] (1), [Te(etu)4][SiF6]·H2O (2), [Te(trtu)4][SiF6] (3), [Te(etu)4][GeF6]·H2O (4), [Te(trtu)4][GeF6] (5) and [Te(etu)4][SnF6] (6) (etu=ethylenethiourea, trtu=trimethylenethiourea) have been prepared and characterized, mainly by X-ray crystallographic methods. All the Te(II) complex cations are square planar, but 1–5 have an unusual conformation as all four thiourea ligands are extending to the same side of the coordination plane. This conformation is probably stabilized by the supramolecular interactions shown in the figure. The red colour of 1–5 is also surprising and is explained on the basis of the cis-S–Te–S–C torsion angles near to 180°, which results in a red shift in the UV–Vis spectrum. In 6 this torsion angle is close to 90° and the colour is yellow.

The complexes were synthesised by adding a hot solution of the appropriate substituted thiourea in MeOH (Br- complexes) or DMF (I- complexes) to a solution of TeO2 dissolved in hot conc. HCl. The structures of the resulting four-coordinate square planar complexes, cis-[TeBr2{((PrNH)-Pr-i)(2)CS}(2)] (1), cis-[TeBr2{((BuNH)-Bu-i)(2)CS}(2)] (2), trans[Tel(2){((PrNH)-Pr-i)(2)CS}(2)](3), and trans-[Tel(2){((BuNH)-Bu-i)(2)CS}(2)](4), were studied by means of X-ray crystallographic methods. The average Te-S bond length in 1 and 2 is 2.5364 Angstrom. The corresponding average Te-Br bond length is 2.9639 Angstrom, reflecting the stronger trans influences of the two thioureas as compared to that of bromide. In 3 and 4 where there is no trans influence affecting the Te-ligand bonds, the average Te-S and Te-I bond lengths are 2.6926 and 2.9761 Angstrom respectively. Tetraalkyl- or aryl-substituted thioureas alone as well as bulky disubstituted thioureas together with I- ligands seem to favor formation of trans complexes.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

During the synthesis of a series of square-planar [TeCl2(stu)2] complexes, where stu represents bulky di- or tetrasubstituted thioureas, the title compound, [TeCl[(C6H11NH)2CS]3]Cl or C39H72ClN6S3Te+*Cl-, was the unexpected result when stu was N,N'-dicyclohexylthiourea. The complex is square planar, with Te-S distances of 2.5803 (4), 2.6211 (4) and 2.8214 (4) A, and a Te-Cl distance of 2.6485 (4) A, indicating a small trans influence of the thiourea ligand.

The four Te-II complexes, cis-[TeCl2{((PrNH)-Pr-i)(2)CS}(2)] (1), cis-[TeCl2{((BuNH)-Bu-i)(2)CS}(2)] (2), trans-[TeCl2{(PhNMe)(2)CS}(2)] (3), and trans- [TeCl2{(Et2N)(2)CS}(2)] (4), have been synthesised and their molecular structures solved by means of X-ray crystallography. All four complexes are square planar, those with disubstituted thiourea ligands have a cis configuration, those with tetrasubstituted thioureas have a trans configuration. The Te-S bond lengths in 1 and 2 average 2.4994 and 2.5213 Angstrom, respectively. The Te-Cl bonds trans to the Te-S bonds have average lengths of 2.8754 and 2.8334 Angstrom, reflecting the trans influence of the two disubstituted thioureas. In 3 and 4 with identical ligands trans to each other, the average Te-S and Te-Cl bond lengths are 2.6834 and 2.5964 Angstrom, respectively.

Reaction of the protonated large-bite bidentate ligand Ph2P(S)NHP(S)(OPh)2 with [Te{NH2)2CS}4]Cl2 resulted in the complex [Te(LL)2], (1a), where (LL)−=Ph2P(S)NP(S)(OPh)2. When (LL)− reacted with 4-MeOC6H4TeCl3, an isomeric complex, 1b, resulted. Reaction between the less basic ligand iPr2P(S)FcP(S)iPr2 (Fc=ferrocene) and 4-MeOC6H4TeCl3 yielded the complex [(4-MeOC6H4TeCl3)2 {μ-iPr2P(S)FcP(S)iPr2}], (2). X-ray crystallographic studies show that 1a and 1b both are square planar complexes of Te(II), 1a being asymmetric and ‘cis’ with two short TeS bonds trans to two long TeS bonds (average bond lengths being 2.5415 and 2.9050 Å). Isomer 1b is centrosymmetric, ‘trans’, with nearly equal TeS bond lengths averaging 2.6805 Å. Complex 2 is an addition compound where the large dithio ligand bridges two 4-MeOC6H4TeCl3 units through weak TeS bonds. The resulting coordination around each Te(IV) atom is ψ-octahedral with the lone pair of electrons and aryl in axial positions relative to the TeCl3S equatorial plane. Here the TeS bond lengths are 2.7560(16) and 2.6910(12) Å. The trans influence of the dithio ligand in 2 is smaller than that of Cl−, resulting in an average TeCl bond length trans to sulfur of only 2.4196 Å, while the other TeCl bond lengths average 2.4959 Å. The reason for the lower basic nature of the ligand with a PFcP backbone compared to those with PNP backbones, is that it lacks a central charge donating group like N̈−.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

A series of E-2-ferrocenemethylene-1-benzocyclanones (3a–e) were synthesized by base-catalysed condensation of ferrocenecarboxaldehyde (2) with benzocyclanones 1a–e. The stereostructure (configuration and conformation) and the electronic properties (conjugation of the enone moiety with the aromatic rings) of the compounds were studied by IR, 1H and 13C NMR and Mössbauer spectroscopy. The structure of E-2-ferrocenemethylene-1-benzosuberone (3c) was also investigated by X-ray spectroscopy.

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The reactions of 4-(2-chloroethyl)morpholine hydrochloride with ArTe− and Te2−, generated in situ (under N2 atmosphere) have resulted in N-{2-(4-methoxyphenyltelluro)ethyl}morpholine (L1) and bis{2-(N-morpholino)ethyl}telluride (L2), respectively, which are first tellurated derivatives of morpholine. 1H- and 13C{1H}-NMR spectra of L1 are as expected but HETCOR experiments are used to assign the overlapping signals of CH2Te and CH2N in 1H-NMR spectrum of L2. The complexes of stoichiometries [PdCl2(L1/L2)2] (1/3) and [HgBr2(L1/L2)]2 (2/4) are synthesized. The NMR (1H and 13C{1H}) spectra of all the four complexes have CH2Te and ArCTe signals deshielded with respect to those of free L1/L2, indicating that the two ligands coordinate through Te only. The trans Pd-complexes 1 and 3 are characterized structurally and their PdTe bond lengths (average) are 2.596 and 2.600 Å, respectively. The Pd-Cl bonds in 1 are marginally shorter (average 2.312 Å) in comparison to those of 3 (average 2.325 Å). The geometry of palladium is square planar. The TeC(aryl) is shorter than TeC(alkyl). The dimeric mercury complexes 2 and 4 appear to be formed through the formation two bromo bridges between Hg atoms.

The palladium(II) and platinum(II) complexes of 1,4-oxatellurane (L), having the composition [MCl2L2], are synthesized and characterized spectroscopically and structurally (Pt complex only; Pt-CI 2.3169(9) Angstrom; Pt-Te 2.5945(3) Angstrom) for the first time.

A series of cyclic ketones is condensed with ferrocenecarboxaldehyde to yield cross-conjugated diferrocenal (diferrocenylidene) ketones [in this work, from cyclobutanone (C up to and including cycloöctanone C 8)]. Placement of the vinyl protons as transoid is done via X-Ray Crystallography. Moreover, there appears to be maximal deshielding of these protons at the C ring while the carbonyl stretching frequency decreases regularly with increasing ring size.

The three title compounds have been synthesized and their structures determined by X-ray crystallography. [Te-2(mu-Cl)(2){(SPPh2)(2)N}(2)], 1, is a dinuclear square planar Te(II) complex where each Te atom is coordinated to the two sulfur atoms of the bidentate dithiolate ligand and to the two bridging chloride ligands. The Te-S bond lengths are 2.4980(8) and 2.5054(8) Angstrom, while the Te-Cl bond lengths are 2.9065(9) and 2.9230(9) Angstrom. In [(4-MeOC6H4TeCl3)(2){mu-Ph2P(S)CH2CH2P(S)Ph-2}], 2, the dithio ligand is neutral and adds a molecule of [4-MeOC6H4TeCl3] at each sulfur atom, thus bridging the two Te(IV) atoms. The coordination of both tellurium atoms is psi-octahedral with the anisyl group and a lone pair of electrons in axial positions. The Te-S bonds, 2.7747(6) and 2.8198(5) Angstrom, are surprisingly weak while the Te-Cl bonds lie in the range 2.4247(5) to 2.5343(6) Angstrom, those trans to Te-S being shortest. [Te-2(mu-Ph2PS2)(2)], 3, is a binuclear Te(I) complex, mainly held together by a Te-Te bond of 2.7298(5) Angstrom. Both anisobidentate diphenyldithiophosphinate ligands bridge the two tellurium atoms. The resulting coordination around each tellurium is best described as T-shaped with the Te-Te bond along the stem. In the asymmetric near linear S-Te-S system, the short Te-S bonds are 2.487(2) and 2.495(2) Angstrom while the long bonds are 2.947(2) and 3.033(2) Angstrom, respectively. The strongly different trans influences of the dithio ligands of 1 and 2 are discussed and it is suggested that they are dependent upon the basicity of the sulfur atoms. (C) 1999 Elsevier Science Ltd. All rights reserved.

The three title compounds have been synthesized and their structures determined by X-ray crystallography. [Te2(μ-Cl)2{(SPPh2)2N}2], 1, is a dinuclear square planar Te(II) complex where each Te atom is coordinated to the two sulfur atoms of the bidentate dithiolate ligand and to the two bridging chloride ligands. The Te–S bond lengths are 2.4980(8) and 2.5054(8) Å, while the Te–Cl bond lengths are 2.9065(9) and 2.9230(9) Å. In [(4-MeOC6H4TeCl3)2{μ-Ph2P(S)CH2CH2P(S)Ph2}], 2, the dithio ligand is neutral and adds a molecule of [4-MeOC6H4TeCl3] at each sulfur atom, thus bridging the two Te(IV) atoms. The coordination of both tellurium atoms is ψ-octahedral with the anisyl group and a lone pair of electrons in axial positions. The Te–S bonds, 2.7747(6) and 2.8198(5) Å, are surprisingly weak while the Te–Cl bonds lie in the range 2.4247(5) to 2.5343(6) Å, those trans to Te–S being shortest. [Te2(μ-Ph2PS2)2], 3, is a binuclear Te(I) complex, mainly held together by a Te–Te bond of 2.7298(5) Å. Both anisobidentate diphenyldithiophosphinate ligands bridge the two tellurium atoms. The resulting coordination around each tellurium is best described as T-shaped with the Te–Te bond along the stem. In the asymmetric near linear S–Te–S system, the short Te–S bonds are 2.487(2) and 2.495(2) Å while the long bonds are 2.947(2) and 3.033(2) Å, respectively. The strongly different trans influences of the dithio ligands of 1 and 2 are discussed and it is suggested that they are dependent upon the basicity of the sulfur atoms.

The three title compounds have been synthesized and their structures determined by X-ray crystallography. [Te-2(mu-Cl)(2){(SPPh2)(2)N}(2)], 1, is a dinuclear square planar Te(II) complex where each Te atom is coordinated to the two sulfur atoms of the bidentate dithiolate ligand and to the two bridging chloride ligands. The Te-S bond lengths are 2.4980(8) and 2.5054(8) Angstrom, while the Te-Cl bond lengths are 2.9065(9) and 2.9230(9) Angstrom. In [(4-MeOC6H4TeCl3)(2){mu-Ph2P(S)CH2CH2P(S)Ph-2}], 2, the dithio ligand is neutral and adds a molecule of [4-MeOC6H4TeCl3] at each sulfur atom, thus bridging the two Te(IV) atoms. The coordination of both tellurium atoms is psi-octahedral with the anisyl group and a lone pair of electrons in axial positions. The Te-S bonds, 2.7747(6) and 2.8198(5) Angstrom, are surprisingly weak while the Te-Cl bonds lie in the range 2.4247(5) to 2.5343(6) Angstrom, those trans to Te-S being shortest. [Te-2(mu-Ph2PS2)(2)], 3, is a binuclear Te(I) complex, mainly held together by a Te-Te bond of 2.7298(5) Angstrom. Both anisobidentate diphenyldithiophosphinate ligands bridge the two tellurium atoms. The resulting coordination around each tellurium is best described as T-shaped with the Te-Te bond along the stem. In the asymmetric near linear S-Te-S system, the short Te-S bonds are 2.487(2) and 2.495(2) Angstrom while the long bonds are 2.947(2) and 3.033(2) Angstrom, respectively. The strongly different trans influences of the dithio ligands of 1 and 2 are discussed and it is suggested that they are dependent upon the basicity of the sulfur atoms.