4-(Dimethyl-amino)phenyl ethynyl telluride

The title compound, C(10)H(11)NTe, is the first organyl ethynyl telluride, R-Te-C C-H, to be structurally characterized. In the L-shaped mol-ecule, the aryl moiety, viz. Me(2)NC(6)H(4)Te, is almost perpendicular to the Te-C C-H fragment. The Te-Csp(2) bond [2.115 (3) Å] is significantly longer than the Te-Csp bond [2.041 (4) Å]. The Te-C C group is approximately linear [Te-C-C = 178.5 (4)° and C C = 1.161 (5) Å], while the coordination at the Te atom is angular [C-Te-C = 95.92 (14)°]. In the crystal structure, there are Csp-H⋯N hydrogen bonds which are perpendicular to the CNMe(2) group; the N atom displays some degree of pyramidalization. Centrosymmetrically related pairs of mol-ecules are linked by Te⋯π(ar-yl) inter-actions, with Te⋯Cg = 3.683 (4) Å and Csp-Te⋯Cg = 159.1 (2)° (Cg is the centroid of the benzene ring). These inter-actions lead to the formation of zigzag ribbons which run along c and are approximately parallel to (110

Twinning by merohedry in bis(4-methoxyphenyl)tellurium(IV) diiodide dimethyl sulfoxide hemisolvate

Green crystals of the title compound, C14H14I2O2Te.0.5C2H6OS, space group P32, show twinning by merohedry (class II). The asymmetric unit contains two organotellurium molecules and one dimethyl sulfoxide (DMSO) molecule. The crystal structure displays secondary Te I and Te O(DMSO) bonds that lead to [(4-MeOC6H4)2TeI2]2.DMSO supramolecular units in which the two independent organotellurium molecules are bridged by the DMSO O atom. In addition to these secondary bonds, I I interactions link translationally equivalent organotellurium molecules to form nearly linear I-Te-I I-Te-I chains. These chains are crosslinked, forming two-dimensional arrays parallel to (001). The crystal packing consists of a stacking of these sheets, which are related by the 32 axis. This study describes an unusual dimeric arrangement of X-Te-X groups

Dibromobis(4-methoxyphenyl)tellurium(IV)

The structur analysis shows that the title compound, [TeBr2(C7H7O)2], is isostructural with the corresponding dichloro compound. There are two molecules in the asymmetric unit in which the Te atom has pseudotrigonal bipyramidal coordination geometry. The two independent molecules, along with their centrosymmetric equivalents, form isolated tetramers by means of Te…Br contacts ranging from 3.535 (1) to 3.741(1) A

Bis(p-methoxyphenyl) Telluride

The title compound, C14H14O2Te, displays an angular geometry at tellurium, with a C-Te-C angle of 99.5(1)º and Te-C distances of 2.110(3) and 2.112(3)A. The Te atom is displaced by 0.1963(3) and 0.0044(3)A out of the planes of the aromatic rings. These rings are approximately perpendicular to one another [dihedral angle 70.4(1)º], while each methoxy group is almost coplanar with the phenyl ring to which it is bonded [dihedral angles 3.3(2) and 1.5(3)º]

Two Polymorphs of Bis(4-methoxyphenyl)tellurium(IV) Diiodide

The title compound, (C7H7O)2Tel2 (orC14H14I2O2Te), crystallizes in space group P1, either with Z = 8, (Ia), or Z = 4, (Ib). The six independent molecules [four in (Ia) and tow in (Ib)] have very similar structures. The geometry at the Te atoms is pseudo-trigonal bipyramidal, with the I atoms in the axial positions and the anisyl groups and the lone pair of electrons in the equatiorial plane. The Te-C and Te-I distances are in the ranges 2.107(4)-2.128(6) and 2.8549 (10)-3.0071(10) A, respectively. In both polymorphs, the molecules are associated via Te...I secondary bonds [3.6922(6)-3.9017(7)A] to form centrosymmetric tetramers in which the Te4I8 cores display step-like geometries. Including the secondary interactions, the coordination about each Te atom is distorted octahedral

New bioconjugated rhenium carbonyls by transmetalation reaction with zinc derivatives

The transmetallation reaction between zinc dithiocarbamates and rhenium carbonyls has been used as a new strategy to link biomolecules to transition metals. The zinc(II) dithiocarbamate of isonipecotic acid (1) and the succinimidyl ester derivative (2) were prepared by straight forward procedures and were fully characterized by spectroscopic and X-ray diffraction methods, showing in both cases the presence of dinuclear complexes. Complex 2 reacted with all the primary and secondary amines studied (glycine methyl ester, β-alanine methyl ester, 1-(2-methoxyphenyl)piperazine and D-(+)-glucosamine) through the activated succinimidyl ester group, linking the metallic fragment with the biomolecule by the formation of a peptidic bond, and leading to the respective bioconjugated zinc complexes 3-6. In all cases, these zinc complexes could be isolated from the reaction medium by simple precipitation. These results evidence the potential of complex 2 to be used as a synthon to link the zinc dithiocarbamate fragment to biomolecules that contain an amine group. Complexes 3-6 were characterized by the usual spectroscopic methods and all data agree with the proposed structures, which do not contain significant interactions between the zinc fragment and the functional groups of these biomolecules. The transmetallation reaction between the zinc complexes 3-6 and the rhenium carbonyl [ReBr₃(CO)₃]²⁻ led to the expected rhenium dithiocarbamates 7-10 with no change in the organic dithiocarbamate fragments, confirming the viability of this reaction as a tool for linking biomolecules to transition elements. All complexes were characterized by spectroscopic methods and the crystal structure of 8 was studied by X-ray diffraction analysis. All data demonstrated that the biomolecule is positioned far away from the fac-{Re(CO)₃} fragment and the octahedral coordination around the metal is completed by the functionalized dithiocarbamate and a phosphine ligand. Finally, the analysis by ESI-MS spectrometry of the reaction between the zinc complex 4 and a water solution of [Re(H₂O)₃(CO)₃]+ at a very low concentration (10 ppm) showed that the transmetallation reaction took place even though the solubility of the zinc complex in water medium was as low as 0.66 ppm. This preliminary result supports the viability of this approach for the preparation of rhenium and technetium target specific radiopharmaceuticals since the preparation of these compounds are always performed in water medium

(2-{[2-(diphenyl-phosphino)phen-yl]thio}-phen-yl)diphenyl-phosphine sulfide

In the title compound, CHPS, the dihedral angle between the central benzene rings is 66.95 (13)°. In the crystal, molecules are linked via C-H⋯π and π-π inter­actions [shortest centroid-centroid distance between benzene rings = 3.897 (2) Å]