A survey of tellurium-centered secondary-bonding supramolecular synthons

Six tetranuclear cadmium(II) complexes, Na[Cd4(hmt)2(H2O)6(dpa)4(NO3)]·8H2O (1), Na[Cd4(hmt)2(CH3OH)2(H2O)4(dpa)4I]·8H2O (2), Na[Cd4(hmt)2(H2O)6(dpa)4Br]·8H2O (3), Na2[Cd4(hmt)2(H2O)6(dpa)4(SCN)2]·4H2O (4), {Na[Cd4(hmt)2(H2O)6(dpa)4Cl](H2O)4}n (5), and {[Cd4(hmt)3(H2O)5(dpa)4](H2O)10}n (6) (hmt = hexamethylenetetramine, H2dpa = diphenic acid), were synthesized by reactions of H2dpa, hmt, and CdX2 (X = NO3-, I-, Br-, Cl-, SCN-, and OAc-). All the complexes contain a basic unit [Cd4(dpa)4], in which four dpa ligands in a chelating bis-bidentate coordination mode link two six-coordinate and two seven-coordinate cadmium(II) centers. The research result demonstrates that the nature of the counterions has an important effect on the assembly process of neutral and anionic mixed ligands with metal ions. In 1−3, NO3-, I-, or Br- bridges the two seven-coordinate CdII centers of the unit to form a discrete tetranuclear molecule with a cis-conformation and hmt as a terminal ligand coordinated to each of the two six-c...

Anion Effect on the Structural Conformation of Tetranuclear Cadmium(II) Complexes

The treatment of MCl(2).nH(2)O (M = Ca, Sr, or Ba) with 2-mercaptobenzoic acid (H-2-MBA) in a 1:2 ratio in an EtOH/H(2)O/NH(3) mixture leads to the formation of extended polymeric solids [[Ca(OOCC(6)H(4)SSC(6)H(4)COO)(H(2)O)(2)].0.5(C(2)H(5)OH)](n)(1), [[Sr(OOCC(6)H(4)SSC(6)H(4)COO)(H(2)O)(2)].0.5(C(2)H(5)OH)](n)(2), and [[Ba(2)(OOCC(6)H(4)SSC(6)H(4)COO)(2)(H(2)O)(2)].0.5H(2)O](n)(3), respectively. In all of the cases, under the reaction conditions employed, the H-2-MBA ligand undergoes thiol oxidation to form 2,2'-dithiobis(benzoic acid) (H(2)-DTBB). While the DTBB forms a 1:1 complex with heavier alkaline earth metals (1-3), only an ammonium salt, [(HOOCC(6)H(4)SSC(6)H(4)COOH)(HOOCC(6)H(4)SSC(6)H(4)COONH(4))] (4), was obtained as the final product in the reaction of H-2-MBA with MgCl(2).6H(2)O. Compounds 1-4 have been characterized with the aid of elemental analysis, thermal analysis, and infrared spectroscopic studies. All of the products are found to be thermally stable and do not melt on heating to 250 degrees C. Thermogravimetry on complexes 1-3 indicates the loss of coordinated and lattice water/solvent molecules below 200 degrees C (for complex 2) or 350 degrees C (for complexes 1 and 3). The solid-state structures of all of the derivatives 1-4 have been established by single-crystal X-ray diffraction studies. The calcium and strontium coordination polymers 1 and 2 are isomorphous. The DTBB ligands in 1 and 2 are hexadentate, and the compounds have a channel structure in which solvent ethanol molecules are included. In compound 3, barium ion forms a complex 3-dimensional coordination polymer where both the carboxylate and the sulfur centers of the DTBB ligands (which are hepta- and octadentate) coordinate to the metal.

Reactions of 2-mercaptobenzoic acid with divalent alkaline earth metal ions: synthesis, spectral studies, and single-crystal X-ray structures of calcium, strontium, and barium complexes of 2,2'-dithiobis(benzoic acid)

Synthesis and characterisation of mercaptoimidazole, mercaptopyrimidine and mercaptopyridine complexes of platinum(II) and platinum(III). The crystal and molecular structures of tetra(2-mercaptobenzimidazole)- and tetra(2-mercaptoimidazole)platinum(II) chloride

This review summarizes the data for over nine hundred dimeric Cu(II) coordination compounds. There are several types of the bridges, from which doubly bridges by far prevail. The most common ligands are O− and N− donors. From the stereochemical point of view, a square-pyramidal arrangement with different degrees of distortion about Cu(II), is the most common. Several relationships were found between the Cu-Cu distances and the Cu-L-Cu bridge angle and the type of bridging, between the intra-ligand L-Cu-L ring angles and coordination numbers.

Copper(ii) coordination compounds: classification and analysis of crystallographic and structural data iii. dimeric compounds

Cristallisation dans P2 1 /c avec affinement respectivement jusqu'a 0,062 et 0,073. Les deux complexes ont une configuration pseudo plan carre. La piperidine adopte une conformation chaise

Structures of bis(piperidine-1-dithiocarbamato)nickel(II) and bis(piperidine-1-dithiocarbamato)copper(II)

C 14 H 28 N 2 S 4 cristallise dans P2 1 /n avec a=6,137, b=11,392, c=13,446 A, β=91,98 o , Z=2; affinement jusqu'a R=0,041. La molecule est centrosymetrique. Dans le centre de la molecule, la moitie C-S-S-C adopte une conformation trans plane. Pas de contacts intermoleculaires courts

A centric thiuram disulfide. Structure of tetraisopropylthiuram disulfide

http://journals.iucr.org/c/issues/1984/11/00/a23982/a23982.pdf

Structure of bis[N,N‐bis(2‐hydroxyethyl)dithiocarbamato]nickel(II), C10H20N2NiO4S4

Structure of bis[N,N‐bis(2‐hydroxyethyl)dithiocarbamato]copper(II), [Cu(C5H10NO2S2)2]

The synthesis, properties, and structural characterization of the title compound, C14H10O2S2Te, are reported. The crystals are monoclinic, space groupC2/c (No. 15) witha=24.369(6),b=4.333(2),c=14.569(3) A, andβ=109.56(2)°,V=1449.57 A3,M=402, andD

 x
 =1.843 g cm−3 forZ=4. The structure was solved by the heavy-atom method and refined by full-matrix least squares toR=0.029 andR

 w
 =0.027 for 772 diffractometer data. Crystal structure analysis and IR spectroscopic study indicate that the tellurium is covalently bonded to sulfur. There are weak secondary interactions between tellurium and oxygen which complete an S2O2 coordination around tellurium.

G. Aravamudan

Papers

Structures of bis(piperidine-1-dithiocarbamato)nickel(II) and bis(piperidine-1-dithiocarbamato)copper(II)

A centric thiuram disulfide. Structure of tetraisopropylthiuram disulfide

Structure of bis[N,N‐bis(2‐hydroxyethyl)dithiocarbamato]nickel(II), C10H20N2NiO4S4

Structure of bis[N,N‐bis(2‐hydroxyethyl)dithiocarbamato]copper(II), [Cu(C5H10NO2S2)2]

Synthesis, properties, and molecular structure of bis(thiobenzoato-S)tellurium(II), C14H10O2S2Te(II)