Structure and electrical properties of a one-dimensional polymeric silver thiosaccharinate complex with argentophilic interactions.

Among the potential applications of coordination polymers, electrical conductivity ranks high in technological interest. We report the synthesis, crystal structure and spectroscopic analysis of an AgI-thiosaccharinate one-dimensional coordination polymer {systematic name: catena-poly[[[aquatetrakis(µ3-1,1-dioxo-1,2-benzisothiazole-3-thiolato-κ3N:S3:S3)tetrasilver(I)]-µ2-4,4'-(propane-1,3-diyl)dipyridine-κ2N:N'] dimethyl sulfoxide hemisolvate]}, {[Ag4(C7H4NO2S2)4(C13H14N2)(H2O)]·0.5C2H6OS}n, with the 4,4'-(propane-1,3-diyl)dipyridine ligand acting as a spacer. A relevant feature of the structure is the presence of an unusually short Ag...Ag distance of 2.8306 (9) Å, well within the range of argentophilic interactions, confirmed experimentally as such by a Raman study on the low-frequency spectrum, and corroborated theoretically by an Atoms in Molecules (AIM) analysis of the calculated electron density. Electrical conductivity measurements show that this complex can act as a semiconductor with moderate conductivity.

A polymeric silver thiosaccarinate complex with a two-dimensional triply entangled mesh and argentophilic interactions.

Silver(I) complexes with sulfur-donor ligands have a broad range of pharmacological applications. One of the most important factors for tuning the biological activity is the type of donor atom and the ease of ligand replacement. Silver thiosaccharinates display a wide range of structures from mono- to polynuclear complexes. We report the synthesis, crystal structure and vibrational spectroscopic analysis of a two-dimensional Ag(I)-thiosaccharinate coordination polymer, namely poly[tris(µ2-4,4'-bipyridine-κ(2)N:N')bis(µ3-1,1-dioxo-1,2-benzisothiazole-3-thiolato-κ(3)N:S(3):S(3))bis(µ2-1,1-dioxo-1,2-benzisothiazole-3-thiolato-κ(2)S(3):S(3))tetrasilver(I)], [Ag2(C7H4NO2S2)2(C10H8N2)1.5]n, with 4,4'-bipyridine acting as a spacer. A relevant feature of the structure is the presence of an unusually short Ag...Ag separation of 2.8859 (10) Å, well within the range of argentophilic interactions and confirmed as such by Raman analysis of the low-frequency spectrum. From a topological point of view, the structure presents interpenetration in the form of a threefold entangled 2D→2D mesh (2D is two-dimensional).

An ethanol-solvated centrosymmetric dimer of bismuth(III) and thiosaccharinate resulting from `semicoordination' contacts.

In the title compound, bis(µ-1,1-dioxo-1,2-benzothiazole-3-thiolato)-κ(3)N,S:S;κ(3)S:N,S-bis[(1,1-dioxo-1,2-benzothiazole-3-thiolato-κ(2)N,S)(ethanol-κO)bismuth(III)] ethanol hemisolvate, [Bi2(C7H4NO2S2)6(C2H5OH)2]·0.5C2H5OH, three independent thiosaccharinate (tsac) anions chelate the metal centre through the endocyclic N and exocyclic S atoms. The complex also presnts two `semicoordination' contacts, one from a pendant ethanol solvent molecule and a second one from an S atom of a centrosymmetrically related molecule. This latter interaction complements two π-π interactions between tsac rings to form a dimeric entity which is the elemental unit that builds up the crystal structure. These dinuclear units are connected to each other via a second type of π-π interaction, generating chains along [111]. Two ethanol molecules, one of them of full occupancy at a general position and semicoordinated to the central cation, and a second one depleted and disordered around a symmetry centre, stabilize the structure. The complex was studied theoretically and the vibrational assignations were confirmed by employing theoretical density functional theory (DFT) methods.

The conformations of two copper(I) complexes of 1H-benzimidazole-2(3H)-thione and thiosaccharinate.

(Acetonitrile-1κN)[µ-1H-benzimidazole-2(3H)-thione-1:2κ(2)S:S][1H-benzimidazole-2(3H)-thione-2κS]bis(µ-1,1-dioxo-1λ(6),2-benzothiazole-3-thiolato)-1:2κ(2)S(3):N;1:2κ(2)S(3):S(3)-dicopper(I)(Cu-Cu), [Cu(2)(C(7)H(4)NO(2)S(2))(2)(C(7)H(6)N(2)S)(2)(CH(3)CN)] or [Cu(2)(tsac)(2)(Sbim)(2)(CH(3)CN)] [tsac is thiosaccharinate and Sbim is 1H-benzimidazole-2(3H)-thione], (I), is a new copper(I) compound that consists of a triply bridged dinuclear Cu-Cu unit. In the complex molecule, two tsac anions and one neutral Sbim ligand bind the metals. One anion bridges via the endocyclic N and exocyclic S atoms (µ-S:N). The other anion and one of the mercaptobenzimidazole molecules bridge the metals through their exocyclic S atoms (µ-S:S). The second Sbim ligand coordinates in a monodentate fashion (κS) to one Cu atom, while an acetonitrile molecule coordinates to the other Cu atom. The Cu(I)-Cu(I) distance [2.6286 (6) Å] can be considered a strong 'cuprophilic' interaction. In the case of [µ-1H-benzimidazole-2(3H)-thione-1:2κ(2)S:S]bis[1H-benzimidazole-2(3H)-thione]-1κS;2κS-bis(µ-1,1-dioxo-1λ(6),2-benzothiazole-3-thiolato)-1:2κ(2)S(3):N;1:2κ(2)S(3):S(3)-dicopper(I)(Cu-Cu), [Cu(2)(C(7)H(4)NO(2)S(2))(2)(C(7)H(6)N(2)S)(3)] or [Cu(2)(tsac)(2)(Sbim)(3)], (II), the acetonitrile molecule is substituted by an additional Sbim ligand, which binds one Cu atom via the exocylic S atom. In this case, the Cu(I)-Cu(I) distance is 2.6068 (11) Å.

A triclinic polymorph of cyclo-tetra-µ-thiosaccharinato-κ8S:S-tetrakis[(triphenylphosphane-κP)silver(I)].

The triclinic structure of the title compound, cyclo-tetrakis(µ-1,1-dioxo-1λ(6),2-benzothiazole-3-thiolato-κ(2)S:S)tetrakis[(triphenylphosphane-κP)silver(I)], [Ag(4)(C(7)H(4)NO(2)S(2))(4)(C(18)H(15)P)(4)], is a polymorph of the previously reported monoclinic structure [Dennehy, Mandolesi, Quinzani & Jennings (2007). Z. Anorg. Allg. Chem. 633, 2746-2752]. In both polymorphs, the complex lies on a crystallographic inversion centre and the bond distances are closely comparable. Some differences can be found in the interatomic angles and torsion angles involving the inner Ag(4)S(4) skeleton. The polymorphs contain essentially identical two-dimensional layers, but with different layer stacking arrangements. In the triclinic form, all layers are related by lattice translation, while in the monoclinic form they are arranged around glide planes so that adjacent layers are mirrored with respect to each other.

Reactive dyes remotion by porous TiO2-chitosan materials.

In this work, the aim was to evaluate the remotion (adsorption plus degradation) of two reactive dyes, Methylene Blue (MB) and Benzopurpurin (BP), from aqueous solutions by the utilization of TiO2-chitosan microporous materials. Two different TiO2-chitosan hybrid materials were synthesized: TiO2-Chit A with 280 mg chitosan/gTiO2 and TiO2-Chit B with 46.76 mg chitosan/g TiO2. Adsorption data obtained at different solution temperatures (25, 35, and 45 degrees C) revealed an irreversible adsorption that decrease with the increment of T. Langmuir, Freundlich and Sips isotherm equation were applied to the experimental data. The obtained parameters and correlation coefficient showed that the adsorption of both dyes on TiO2-Chit A at the three work temperatures was best predicted by the Langmuir isotherm, while Sips equation adjusted better to adsorption data on TiO2-Chit B. The adsorption enthalpy was relatively high and varied with T, indicating that interaction between adsorbent and adsorbate molecules was not only physical but chemical. There is a change in the adsorption heat capacity, (Delta(ads)C(p)<0), related with intense hydrophobic interactions. The kinetic adsorption data were processed by the application of Lagergren and Avrami models. It was found that adsorption of both dyes on both adsorbents under the operating conditions was best predicted by Avrami model. The variation of kinetic order, n, and k(av) with T are related to a pore followed by intra particle diffusion control of the adsorption rate. MB photodegradation on both TiO2-chitosan hybrid materials was of 91 (in A) and 41% (in B) and augmented with the chitosan content. For BP can be seen that the process in darkness resulted in a high remotion capacity than in UV light presence.

Poly[(mu3-1,1-dioxo-1,2-benzoisothiazole-3-thiolato-kappa3N:S3:S3)silver(I)].

The centrosymmetric title compound, [Ag(C(7)H(4)NO(2)S(2))]n, consists of dinuclear units in which two thiosaccharinate anions each bridge two Ag atoms via an endocyclic N atom and an exocyclic S atom across a crystallographic centre of inversion midway between the Ag atoms. The dimeric units are connected via Ag-S(exo) interactions to create two-dimensional networks. The thiosaccharinate anions bridge in a mu3-S:S:N manner. The Ag...Ag distance can be considered a strong argentophilic interaction.