Thiocyanate Moiety Research Articles

X-ray diffraction, spectral and magnetic studies of the nickel(II) thiocyanate complexes with tridentate 2,6-dithiocarboxamidopyridine SNS and 2,6-dicarboxamidopyridine ONO ligands: Influence of donor atoms on the coordination geometry of nickel

The systematic investigation of electronic effects on the coordination geometry of nickel(II) thiocyanate complexes with the tridentate N, N, N′, N′-tetraethylpyridine-2,6-dithiocarboxamide (S-dept) and N, N, N′, N′-tetraethylpyridine-2,6-dicarboxamide (O-deap) ligands shows a significant change in the geometry of the metallic site. Their complexes conform to composition [Ni 2(μ-NCS) 2(S-dept) 2(NCS) 2] ( 1), [Ni(NCS) 2(O-deap)(CH 3CN)] · CH 3CN ( 2) and [Ni(NCS) 2(O-deap)(C 2H 5OH)] ( 3), respectively. X-ray crystallographic studies were done for 1– 3. In the crystal lattice, complex 1 exists as a centrosymmetric dimer in which the dinuclear core is bridged by two N-bonded thiocyanate groups. The near octahedral geometry of the nickel atom is achieved through the two bridging N atoms of the thiocyanate groups, three SNS donor atoms of the ligand S-dept and through the terminal nitrogen atom of a non-bridging thiocyanate moiety. To the best of our knowledge, complex 1 presents the first example in literature with the highest asymmetry in N-bridging thiocyanato ligands. Ni ion is coordinated to ONO donor set of atoms of O-deap and two N-bonded NCS terminal groups. The sixth coordination site is completed by the N atom of an acetonitrile molecule. The coordination around Ni atom in 3 is also distorted octahedral. The change in the sixth coordination position from acetonitrile in 2 to ethanol in 3 has a profound influence in the overall topology of the metal–ligand complex. The complex interplay of weak interactions in stabilizing the 3-dimensional lattice of these molecules is well demonstrated.

Surface thiocyanation of plasticized poly(vinyl chloride) and its effect on bacterial adhesion

Thiocyanates, especially bis-alkylthiocyanates are highly effective in killing a number of bacterial strains and are reported to be potent biocides at ppm concentrations. In order to examine whether a covalently bound and immobilized thiocyanate group on a biomaterial surface is still effective as a bactericide, plasticized poly(vinyl chloride) (PVC) was thiocyanated using sodium thiocyanate in the presence of a phase transfer catalyst in aqueous media leading to the nucleophilic substitution of chlorine by thiocyanate on the PVC surface. Thiocyanation imparted hydrophilicity to the surface in comparison with bare PVC. Control and thiocyanated PVC surfaces were exposed to two strains of bacteria commonly implicated in device-associated infections, such as Staphylococcus aureus and Staphylococcus epidermidis. Bacterial adhesion and colonization was quantitated by counting the viable organisms on the adhered surface as well as by optical and scanning electron microscopy. Significantly reduced retention of S. epidermidis and S. aureus was seen on the thiocyanated PVC surface. Immobilized thiocyanate was non-cytotoxic in a preliminary cell culture assay. The study thus showed that even though an immobilized thiocyanate moiety on the polymer surface was not as effective as a bactericide unlike soluble thiocyanates, it prevented the retention and colonization of the bacteria to a considerable extent.

Design and synthesis of aryloxyethyl thiocyanate derivatives as potent inhibitors of Trypanosoma cruzi proliferation.

As a part of our project directed at the search of new chemotherapeutic agents against American trypanosomiasis (Chagas' disease), several drugs possessing the 4-phenoxyphenoxy skeleton and other closely related structures employing the thiocyanate moiety as polar end group were designed, synthesized, and evaluated as antiproliferative agents against Trypanosoma cruzi, the parasite responsible for this disease. These thiocyanate analogues were envisioned bearing in mind the potent activity shown by 4-phenoxyphenoxyethyl thiocyanate (compound 8) taken as lead drug. This compound had previously proved to be an extremely active growth inhibitor against T. cruzi with IC(50) values ranging from the very low micromolar level in epimastigotes to the low nanomolar level in the intracellular form of the parasite. Of the designed compounds, the ethyl thiocyanate drugs connected to nonpolar skeletons, namely, arylthio, 2,4-dichlorophenoxy, ortho-substituted aryloxy, and 2-methyl-4-phenoxyphenoxy (compounds 15, 34, 47, 52, 72, respectively), were shown to be very potent antireplicative agents against T. cruzi. On the other hand, conformationally restricted analogues as well as branched derivatives at the aliphatic side chain were shown to be moderately active against T. cruzi growth. The biological activity of drugs bearing the thiocyanate group correlated quite well with the activity exhibited by their normal precursors, the tetrahydropyranyl ether derivatives, when bonded to the same nonpolar skeleton. Compounds having the tetrahydropyranyl moeity as polar end were proportionally much less active than sulfur-containing derivatives in all cases. Drugs 47 and 72 also resulted to be very active against the amastigote form of the parasite growing in myoblasts; however, they were slightly less active than the lead drug 8. On the other hand, compounds 34 and 52 were almost devoid of activity against myoblasts. Surprisingly, the dithio derivative 15 was toxic for myoblasts.

Syntheses of [Ni 2(dien) 2(NCS) 4(H 2O)] and [Ni(aepn)(NCS) 2] n ((dien = bis(2-aminoethyl)amine and aepn = N-(2-aminoethyl)-1,3-propanediamine): single crystal structure analysis and thermal behaviour in the solid state

[Ni 2(dien) 2(NCS) 4(H 2O)] ( 1) and [Ni(aepn)(NCS) 2] n ( 2) (where dien = bis(2-aminoethyl)amine and aepn = N-(2-aminoethyl)-1,3-propanediamine) have been synthesised from solution. Single crystal X-ray structure analyses of 1 and 2 reveal that the metal atoms in both the complexes display distorted octahedral geometry with the triamine coordinating facially in 1 and meridionally in 2. The dinuclear [Ni 2(dien) 2(NCS) 4(H 2O)] unit in 1 is bridged via a thiocyanate moiety while in 2 the nickel(II) octahedra form a polymeric chain. The species 1 on deaquation at ∼ 165°C followed by cooling yields a conglomerated mass ( 1a). The species 2 melts at ∼ 230°C which on cooling yields conglomerated mass ( 2a). Both 1a and 2a are amorphous; the former reverts to 1 in a humid atmosphere.

Cis-Chloro(isothiocyanato)bis(1,10-phenanthroline)copper(II), cis-[CuCl(NCS)(phen)2

The crystal structure of green [CuCl(NCS)(C 12 H 8 N 2 ) 2 ], containing six-coordinate copper(II) with a tetragonal [CU II N 5 Cl] core, is reported. The copper to isothiocyanate distance is 1.960(6) A, with Cu bonded to the N-atom end of the thiocyanate moiety. The three remaining short distances for the tetragonal core are Cu-N distances to the 1,10-phenanthrolines which are 2.043(5), 2.060(4) and 2.064(4) A. One of the long distances to the Cu-atom center is occupied by an N atom of a 1,10-phenanthroline with a Cu-N distance of 2.370 (5) A, and the other long interaction has a Cu-Cl distance of 2.679 (2) A.

2,4-Dichlorobenzyl thiocyanate, an antimitotic agent that alters microtubule morphology.

A compound of simple structure, 2,4-dichlorobenzyl thiocyanate (DCBT), is an antimitotic agent with a number of unusual properties. The drug causes an extreme reorganization of microtubules in cells in culture. Most normal microtubules disappear, and remaining tubulin-containing structures appear to be bundled or aggregated. DCBT irreversibly inhibits in vitro polymerization of purified tubulin, but only after a prolonged preincubation of the protein with the drug. Binding of radiolabeled DCBT to tubulin similarly requires a long incubation time, with the reaction not being complete even after 6 hr at 37 degrees C. A specific interaction with tubulin is also shown by the crossresistance to DCBT of Colcemid-resistant cells with an altered beta-tubulin. A human KB carcinoma cell line and a Chinese hamster ovary cell line selected for crossresistance to multiple chemotherapeutic agents, including most antimitotic drugs, are sensitive to DCBT. Initial structure-function studies have demonstrated weak antimitotic and antitubulin activity with the parent compound benzyl thiocyanate. Chlorination at either position 2 or position 4 of the phenyl ring produces compounds of intermediate activity (4-chlorobenzyl thiocyanate is more active than 2-chlorobenzyl thiocyanate). The thiocyanate moiety appears to be essential for activity.

The geminal molecular structure of the compound N 3P 3Cl 4(NCS) 2

The compound, N 3P 3Cl 4(NCS) 2, was prepared and characterized by i.r., mass and 31P NMR spectroscopy. I.R. data indicated that each thiocyanate moiety is nitrogen-bonded to a phosphorus atom in the ring. A geminal molecular structure was assigned on the basis of 31P NMR data. Several alcohol and amine addition derivatives of the compound gem-N 3P 3Cl 4(NCS) 2 were also prepared. The addition compounds were characterized by infrared and 31P NMR spectroscopy. Geminal molecular structures were assigned to these adducts on the basis of their 31P NMR spectra.

The crystal and molecular structure of μDithiocyanatotetrakis(methyldiphenylphosphine)dicopper(I)

The crystal and molecular structure of Dithiocyanatotetrakis (methyldiphenylphosphine)dicopper(I) [CuNCS(PCH3(C6H5)2)2]2 has been determined from three-dimensional X-ray data collected from a single crystal. The material crystallizes in the space group P1 of the triclinic system with two molecules in a cell of dimensions a=10.32 0.02, b=11.24 0.02, c = 12.00 0.02 Å, a=90.4 0.1°, The observed density of 1.36 0.02 g/cm3 agrees well with the calculated density of 1.36 g/cm3. Intensity data were collected on multiple films by the integrated equi-inclination Weissenberg technique The structure was refined by full-matrix least-squares methods to a final R Factor of 8.7 percent for 1195 non-zero independent reflections. The complex exists as a dimer in the solid state in which the thiocyanates bridge the two copper atoms. The two thiocyanate moieties and the copper atoms form an eight membered ring which is only approximately planar. The geometry around the copper atom can be described as a higly distorted tetrahedron.