Chelating Dithiocarbamate Ligands Research Articles

A new structural motif for cadmium dithiocarbamates: crystal structures and Hirshfeld surface analyses of homoleptic zinc and cadmium morpholine dithiocarbamates

Abstract The crystal and molecular structures of two homoleptic morpholine-derived dithiocarbamates of zinc, binuclear {Zn[S2CN(CH2CH2)2O)2]2}2 (1), and cadmium, one-dimensional coordination polymer {Cd[S2CN(CH2CH2)2O)2]2}2 (2), are described. In 1, a centrosymmetric binuclear molecule is found as there are equal numbers of chelating and bidentate bridging dithiocarbamate ligands; weak transannular Zn···S interactions are found within the resultant eight-membered {···SCSZn}2 ring which has the form of a chair. The resultant 4+1 S5 donor set is highly distorted with the geometry tending towards a square-pyramid. By contrast, a square-planar geometry is found in centrosymmetric 2 defined by symmetrically chelating dithiocarbamate ligands. The presence of Cd···S secondary bonding in the crystal of 2 leads to a distorted 4+2 S6 octahedron and a linear coordination polymer, which is unprecedented in the structural chemistry of cadmium dithiocarbamates. The analyses of the Hirshfeld surfaces for 1 and 2 show the dominance of H···H, S···H/H···S and O···H/H···O contacts to the surface, i.e. contributing around 90 and 80%, respectively.

Structural variations in zinc(II) complexes with N,N-di(4-fluorobenzyl)dithiocarbamate and imines: New precursor for zinc sulfide nanoparticles

Bis(N,N-di(4-fluorobenzyl)dithiocarbamato-κ2S,S′)zinc(II) (1), bis(N,N-di(4-fluorobenzyl)dithiocarbamato-κ2S,S′)(pyridine-κN)zinc(II) (2), (μ-4,4′-bipyridine-κ2N,N′)bis[bis(N,N-di(4-fluorobenzyl)dithiocarbamato-κ2S,S′)zinc(II)] (3) and (2,2′-bipyridine-κ2N,N′)bis(N,N-di(4-fluorobenzyl)dithiocarbamato-κS,S′)zinc(II) (4) were prepared and characterized by elemental analysis, spectroscopy (IR, 1H and 13C NMR) and their structures were elucidated by X-ray crystallography. The centrosymmetric dinuclear structure of 1 features both bridging and chelating dithiocarbamate ligands to that a distorted trigonal bipyramidal S5 coordination geometry results. The coordination geometry of zinc(II) in 2 and both zinc(II) in the dinuclear complex 3 is an intermediate between tetragonal pyramidal and trigonal bipyramidal. In complex 4, the resulting N2S4 donor set defines a distorted octahedral geometry. Addition of imines (pyridine, 4,4′-bipyridine and 2,2′-bipyridine) to the complex 1 affects the ZnS distances and SZnS angles. The optimized geometry, HOMO-LUMO in the ground state and MEP have been calculated for 1 and 2. MEP analysis support the substantial contribution of the resonance structure RR′-N+CS22− to the description of their structures on the complexes 1 and 2. Quantification of the intermolecular interactions present in 1–4 was realized by Hirshfeld surface analysis. Zinc sulfide nanoparticles were prepared from 1 and characterized by PXRD, SEM, TEM, EDAX and DRS. The PXRD study showed that the nanoparticles is composed of cubic phase of zinc sulfide. Photocatalytic activity of as-prepared ZnS was tested by examining the degradation of rhodamine-B in aqueous solution under UV light illumination.

Bis[N-2-hy-droxy-ethyl,N-methyl-dithio-carbamato-κ2S,S)'-4-{[(pyridin-4-yl-methyl-idene)hydrazinyl-idene}meth-yl]pyridine-κN1)zinc(II): crystal structure and Hirshfeld surface analysis.

In the title compound, [Zn(C4H8NOS2)2(C12H10N4)], the ZnII atom exists within a NS4 donor set defined by two chelating di-thio-carbamate ligands and a pyridyl-N atom derived from a terminally bound 4-pyridine-aldazine ligand. The distorted coordination geometry tends towards square-pyramidal with the pyridyl-N atom occupying the apical position. In the crystal, hydroxyl-O-H⋯O(hydrox-yl) and hydroxyl-O-H⋯N(pyrid-yl) hydrogen-bonding give rise to a supra-molecular double-chain along [1-10]; methyl-C-H⋯π(chelate ring) inter-actions help to consolidate the chain. The chains are connected into a three-dimensional architecture via pyridyl-C-H⋯O(hydrox-yl) inter-actions. In addition to the contacts mentioned above, the Hirshfeld surface analysis points to the significance of relatively weak π-π inter-actions between pyridyl rings [inter-centroid distance = 3.901 (3) Å].

Crystal structure of bis-[N-(2-hy-droxy-eth-yl)-N-methyl-dithio-carbamato-κ2S,S'](pyridine)-zinc(II) pyridine monosolvate and its N-ethyl analogue.

The common structural feature of the title compounds, [Zn(C4H8NOS2)2(C5H5N)]·C5H5N (I) and [Zn(C5H10NOS2)2(C5H5N)]·C5H5N (II), which differ by having di-thio-carbamate N-bound methyl (I) and ethyl (II) groups, is the coordination of each ZnII atom by two non-symmetrically chelating di-thio-carbamate ligands and by a pyridine ligand; in each case, the non-coordinating pyridine mol-ecule is connected to the Zn-containing mol-ecule via a (hy-droxy)O-H⋯N(pyridine) hydrogen bond. The resulting NS4 coordination geometry is closer to a square-pyramid than a trigonal bipyramid in the case of (I), but almost inter-mediate between the two extremes in (II). The mol-ecular packing features (hy-droxy)O-H⋯O(hy-droxy) hydrogen bonds, leading to supra-molecular chains with a zigzag arrangement along [10-1] (I) or a helical arrangement along [010] (II). In (I), π-π [inter-centroid distances = 3.4738 (10) and 3.4848 (10) Å] between coordinating and non-coordinating pyridine mol-ecules lead to stacks comprising alternating rings along the a axis. In (II), weaker π-π contacts occur between centrosymmetrically related pairs of coordinating pyridine mol-ecules [inter-centroid separation = 3.9815 (14) Å]. Further inter-actions, including C-H⋯π(chelate) inter-actions in (I), lead to a three-dimensional architecture in each case.

Bis(N,N-di-ethyl-dithio-carbamato-κ2S,S')(3-hy-droxy-pyridine-κN)zinc and bis-[N-(2-hy-droxy-eth-yl)-N-methyldithio-carbamato-κ2S,S'](3-hy-droxy-pyridine-κN)zinc: crystal structures and Hirshfeld surface analysis.

The common feature of the mol-ecular structures of the title compounds, [Zn(C5H10NS2)2(C5H5NO)], (I), and [Zn(C4H8NOS2)2(C5H5NO)], (II), are NS4 donor sets derived from N-bound hy-droxy-pyridyl ligands and asymmetrically chelating di-thio-carbamate ligands. The resulting coordination geometries are highly distorted, being inter-mediate between square pyramidal and trigonal bipyramidal for both independent mol-ecules comprising the asymmetric unit of (I), and significantly closer towards square pyramidal in (II). The key feature of the mol-ecular packing in (I) is the formation of centrosymmetric, dimeric aggregates sustained by pairs of hy-droxy-O-H⋯S(di-thio-carbamate) hydrogen bonds. The aggregates are connected into a three-dimensional architecture by methyl-ene-C-H⋯O(hy-droxy) and methyl-C-H⋯π(chelate) inter-actions. With greater hydrogen-bonding potential, supra-molecular chains along the c axis are formed in the crystal of (II), sustained by hy-droxy-O-H⋯O(hy-droxy) hydrogen bonds, with ethyl-hydroxy and pyridyl-hydroxy groups as the donors, along with ethyl-hydroxy-O-H⋯S(di-thio-carbamate) hydrogen bonds. Chains are connected into layers in the ac plane by methyl-ene-C-H⋯π(chelate) inter-actions and these stack along the b axis, with no directional inter-actions between them. An analysis of the Hirshfeld surfaces clearly distinguished the independent mol-ecules of (I) and reveals the importance of the C-H⋯π(chelate) inter-actions in the packing of both (I) and (II).

Bis(phosphane)copper(I) and silver(I) dithiocarbamates: crystallography and anti-microbial assay

Abstract The crystal and molecular structures of (Ph3P)2M[S2CN(Me)CH2CH2OH], M=Cu, isolated as a 1:1 dichloromethane solvate (1·CH2Cl2), and M=Ag (4) show the central metal atom to be coordinated by a symmetrically (1·CH2Cl2) and asymmetrically chelating (4) dithiocarbamate ligand. The distorted tetrahedral geometries are completed by two PPh3 ligands. The presence of hydroxyl-O–H···S(dithiocarbamate) hydrogen bonds leads to centrosymmetric dimeric aggregates in each crystal structure. In the molecular packing of 1·CH2Cl2, channels comprising 1 are formed via aryl-C–H···O interactions with the solvent molecules associated with the walls of the channels via methylene-C–H···S, π(aryl) interactions. For 4, the dimeric aggregates are connected via a network of aryl-C–H···π(aryl) interactions. Preliminary screening for anti-microbial activity was conducted. The compounds were only potent against Gram-positive bacteria. Some further selectivity in activity was noted. Most notably, all compounds were active against methicillin resistant Staphylococcus aureus.

Bis(N-benzyl-N-methyldithiocarbamato-κ2S,S′)(pyridine-κN)cadmium(II)

The title compound, [Cd(C9H10NS2)2(C5H5N)], features a five-coordinate CdIIatom, being coordinated by two nearly symmetrically chelating dithiocarbamate ligands and a pyridine N atom. The resulting NS4donor set defines a distorted coordination geometry tending toward square pyramidal. In the molecular packing, centrosymmetric ten-membered {...HCNCS}2synthons arise as a result of methylene-C—H...S interactions. These are connected into layers parallel to (10-2)viaweak methyl-C—H...π(phenyl) interactions.

Cadmium complex possessing simultaneously silanethiolato- and dithiocarbamato-ligands. A novel single-source precursor of cadmium sulfide

Thermal decomposition of suitable coordination compounds may be used as efficient route for fabrication of semiconducting layers. A new potential CdS precursor—a cadmium complex with all-sulfur Cd-coordination sphere [Cd{μ-SSi(OBu t )3}(S2CNC4H8)]2 1—has been prepared, and its properties are investigated. The complex was obtained in the reaction between dimeric bis(tri-tert-butoxysilanethiolato)cadmium(II) [Cd{SSi(OBu t )3}2]2 and ammonium N,N-tetrametylene-dithiocarbamate and characterized by spectral methods (IR, UV–Vis, MS, and NMR). X-ray structure analysis revealed the complex as molecular and dimeric in solid state with each of chelating dithiocarbamate ligands bonded to one Cd center and sulfur atoms from two tri-tert-butoxysilanethiolato ligands bridging metallic centers and thus completing the CdS4 coordination sphere. Thin film of the precursor prepared on SiO2 substrates via spin-coating technique was analyzed by AFM. Its decomposition was studied by thermal analysis methods (TG, DSC, and TG-FTIR). After melting at 227 °C, [Cd{μ-SSi(OBu t )3}(S2CNC4H8)]2 undergoes endothermic decomposition leading to CdS as the only solid product further identified by XRD, EDS, FIR as hexagonal CdS form. Its morphology is characteristic and may be described as “micro-noodles”.

Structural systematics of RSn(S 2CN R′ R″) 2Cl compounds

Abstract Three new organotin(IV) structures of general formula RSn(S 2CN R′ R″) 2Cl, where R′ ≠ R″, namely MeSn · [S 2CN(Me)(Cy)] 2Cl ( 1), MeSn[S 2CN( i-Pr)(CH 2Ph)] 2Cl ( 2) and PhSn[S 2CN(Et)( i-Pr)] 2Cl ( 3) are described. Each structure features tin in a distorted octahedral geometry defined by a C ClS 4donor set as a result of two chelating dithiocarbamate ligands. In all cases the tin-bound carbon and chloride atoms are cis. The shorter Sn–S bond lengths in 3are correlated with the presence of the relatively more electronegative Sn-bound phenyl substituent. The new structures conform to the structural motif adopted by all other compounds with the formula RSn(S 2CN R′ R″) 2Cl, where R′ = R″, suggesting the unsymmetrical substitution pattern of the dithiocarbamate ligands in the present study does not influence the adoption of this structural motif. The homogeneity in the structural motif notwithstanding, non-systematic variations in geometric parameters are found in these structures indicating an overall influence of crystal packing upon molecular geometry.

Crystal Structure of Bis(<i>μ</i>-4-methylpiperidine-1-carbodithioato-1:2<i>κ</i><sup>3</sup><i>S</i>,<i>S</i>′:<i>S</i>′;2:1<i>κ</i><sup>3</sup><i>S</i>,<i>S</i>′:<i>S</i>′)bis[(4-methylpiperidine-1-carbodithioato-<i>k</i><sup>2</sup><i>S</i>,<i>S</i>′)cadmium(II)

The structure of the title compound features both bridging and chelating dithiocarbamate ligands, so that a tetragonal pyramidal S5 coordination geometry results. Each of the chelating ligands is bidentately coordinated to a cadmium atom, and forms a planar four-membered chelate ring [CdS2C]; However, a pair of tridentate bridging ligands combine two neigbouring cadmium atoms, forming extended eight-membered tricyclic moieties [Cd2S4C2], whose geometry can be approximated by a ‘chair’ conformation. The compound crystallizes in the triclinic space group P1 with the following unit-cell parameters: a = 8.5286(6), b = 11.4221(6), c = 11.4561(6)A, α = 112.632(2), β = 97.216(2), γ = 106.241(2)°, Z = 1. The crystal structure was solved by direct methods using single-crystal X-ray diffraction data collected at room temperature, and refined by full-matrix least-squares procedures to a final R-value of 0.0297 for 5115 observed reflections. Both of the piperidine rings exhibit a chair conformation. The structure has an intermolecular hydrogen bond of the type C-H…S, which helps to stabilize the crystal structure.

Synthesis and Crystal Structure of Bis(N-alkyl-N-phenyl dithiocarbamato)mercury(II)

The mixed ligand dithiocarbamate complex was synthesized by the reaction between the ammonium salt of the dithiocarbamate ligands with mercury salt. There are two mercury complexes in the asymmetric unit with a compositional disorder between an ethyl group and a methyl group. A distorted tetrahedral geometry is found for each mercury atom defined by four sulphur atoms derived from two asymmetrically chelating dithiocarbamate ligands. IR spectra show thioureide υ(C–N) bands at 1491 cm−1 which is higher than observed in the simple complexes of the same ligands. The effect of alkyl substituents were observed in the magnetic unequivalence of the thioureide and phenyl units in the NMR spectroscopy. The molecules are related to each other by virtue of the compositional disorder which exists at three positions in the alkyl group across the unit. The compound crystallizes in the triclinic space group P-1 with a = 10.4764(10) A, b = 11.0433(10) A, c = 18.5566(17) A, α = 97.8980(10)°, β = 95.3340(10)°, γ = 110.3010(10)°, and Z = 2. In the molecular structure, there are two tetrahedrally coordinated mercury complexes in the asymmetric unit with compositional disorder at the positions of C17, C26, and C35 between an ethyl group and a methyl group. The molecules are related to each other by virtue of the compositional disorder.

(2,2′-Bipyridyl)bis[N,N-bis(2-hydroxyethyl)dithiocarbamato-κ2S,S′]cadmium(II)

The title compound, [Cd(C5H10NO2S2)2(C10H8N2)], features a trigonal-prismatic coordination geometry for the CdII ion, based on an N2S4 donor set defined by two chelating dithio­carbamate ligands and a 2,2′-bipyridyl ligand. In the crystal, extensive O—H⋯O hydrogen bonding results in the formation of 12-membered {⋯HO}6 synthons and one-dimensional supra­molecular chains with further O—H⋯S inter­actions providing additional stability to the linear chain with base vector [01].

Tetra-n-butylammonium iodido(pyrrolidine-1-carbodithioato-κ2S,S′)(tris-tert-butoxysilanethiolato-κS)cadmate(II)

In the anion of the title compound, (C16H36N)[Cd(C5H8NS2)(C12H27O3SSi)I], the Cd atom is four-coordinated by S,S′-chelating dithio­carbamate, S–donating silanethiol­ate and iodide ligands in a distorted tetrahedral environment . Inter­molecular C—H⋯ S and C—H⋯I inter­actions between cations and anions are present. Two C atoms of a tert-butyl group are disordered over two positions; the site occupancies are ca 0.65 and 0.35.

Hydrogen-Bonding Interactions in the Crystal Structure of Bis(N-propyl-N-(2-hydroxyethyl)dithiocarbamato-S,S′)nickel(II): Ni[S2CN(nPr)(CH2CH2OH)

Two independent molecules of Ni(S2CN(Pr)CH2CH2OH)2, each located about a center of inversion, comprise the asymmetric unit. The molecules differ from each other in terms of the relative orientation of the terminal hydroxyl groups. A square planar geometry is found for each nickel atom defined by four sulfur atoms derived from two symmetrically chelating dithiocarbamate ligands. The crystal packing is dominated by O–H···O interactions that lead to extensive cross linking in all directions. The compound crystallizes in the triclinic space group P-1 with a = 6.4008(11) A, b = 11.480(2) A, c = 12.517(2) A, α = 88.021(2)°, β = 82.491(2)°, γ = 89.986(2)°, and Z = 2.

Chlorobis(2-chlorobenzyl)(4-ethylpiperazine-1-dithiocarbamato-κ2 S,S′)tin(IV)

In the title complex, [Sn(C7H6Cl)2(C7H13N2S2)Cl], the Sn atom is five-coordinate in a trigonal–bipyramidal geometry. One Sn—S bond is markedly longer than the other for the chelating dithiocarbamate ligand.

Tetraethylammonium bis(N,N-diethyldithiocarbamato-κ2S,S′)iodocadmate(II)

The title compound, (C8H20N)[Cd(C5H10NS2)2I], containing a heteroleptic five-coordinate mononuclear anionic cadmium complex, crystallizes in orthorhombic form in the space group Pnma. Both anion and cation lie about mirror planes. Unlike other known [Cd(dtc)2X]-type complexes (where dtc is dithiocarbamate and X is a halogen or pseudohalogen), the central CdS4I core shows a square-pyramidal configuration, with a basal plane defined by four S atoms from two chelating dithiocarbamate ligands related by a symmetry plane. The central Cd atom is displaced from the basal S4 plane towards the apical I atom of the square pyramid.

(η5-Cyclopentadienyl)(N,N-dimethyldithiocarbamato-κ2S,S′)[η4-tetrakis(trifluoromethyl)cyclobutadienyl]molybdenum(IV)

The title complex, [Mo(C8F12)(C5H5)(C3H6NS2)], contains both a eta4-C4(CF3)4 cyclobutadienyl ligand with approximate C4v local symmetry and a eta5-C5H5 cyclopentadienyl ring. The centroids of the rings and the S atoms of a chelating dithiocarbamate ligand define the pseudo-tetrahedral coordination of the Mo atom. The Mo-C(cyclobutadienyl) bond lengths [2.189 (2)-2.211 (2) A] are unusually short, probably reflecting strong electron withdrawal by the trifluoromethyl groups. The molecules straddle crystallographic mirror planes.

Crystallographic report: Bis[(nitro)bis(dithiotetrahydropyrrolocarbamato) bismuth(III)

AbstractThe loosely associated centrosymmetric structure of [Bi(S2CNC4H8)2(NO3)]2 features chelating dithiocarbamate and nitrate ligands, as well as weak intermolecular BiS interactions, so that a distorted pentagonal bipyramidal S5O2 coordination geometry results. Copyright © 2005 John Wiley & Sons, Ltd.

Crystallographic report: Bis[tris(morpholindithiocarbamato)bismuth(III)

AbstractThe dimeric and centrosymmetric structure of {Bi[S2CN(CH2CH2)2O]3}2 features chelating dithiocarbamate ligands and intermolecular BiS interactions, so that a distorted pentagonal bipyramidal S7 coordination geometry results. Copyright © 2004 John Wiley & Sons, Ltd.

Crystallographic report: Bis(N‐cyclohexyl,N‐methyldithiocarbamato)zinc(II)

AbstractThe mononuclear structure of Zn[S2CN(Me)Cy)]2 features a tetrahedral zinc center defined by two chelating dithiocarbamate ligands. Copyright © 2004 John Wiley & Sons, Ltd.