Volume 41, Issue 5-6

The reaction of the H 2 salophen ligand, 2,2′-((1E,1′E)-(1,2-phenylenebis(azanylylidene))bis (methanylylidene))diphenol, with one molar equivalent of Si(NCS) 4 , MeSi(NCS) 3 ( 13 ), or HMeSi(NCS) 2 afforded neutral hexacoordinate silicon complexes, which have an-NCS bi-functionality (complex 1 ) and mono-functionality (complex 14 ). The reaction of Si(NCS) 4 with the H 2 salophen-type ligand1,1′-((1E,1′E)-(1,2-phenylenebis(azanylylidene))bis(methanylylidene)) bis(naphthalen-2-ol) (H 2 Noph), afforded the hexacoordinate silicon complex 15 , which has an-NCS bi-functionality. Single-crystal X-ray structural and elemental analyses were used to characterize and confirm the structure of the starting material 13 and complexes 1 , 14 , and 15 . The complexes were characterized in solution by 1 H, 13 C, and silicon-29 nuclear magnetic resonance ( 29 Si NMR) and in the solid state by 29 Si cross-polarization/magic angle spinning (CP/MAS) NMR. Because of the poor solubility of complex 1 , it was only possible to characterize it in the solid state by 13 C and 29 Si CP/MAS NMR and in solution by 1 H NMR.

New bismuth(III) bromine compounds of the heterocyclic thioamides were prepared and structurally characterized. The reaction of heterocyclic thioamides with bismuth(III) bromide resulted in the formation of the {[BiBr 2 (μ 2 -Br)(MMI) 2 ] 2 ·CH 3 COCH 3 ·H 2 O} ( 1 ), {[BiBr 2 (MBZIM) 4 ]·Br·2H 2 O} ( 2 ), {[BiBr 2 (μ 2 -Br)(tHPMT) 2 ] 2 ·CH 3 CN} ( 3 ), {[BiBr 2 (μ 2 -Br)(PYT) 2 ] 2 ·CH 3 CN} ( 4 ) and {[BiBr 2 (μ 2 -Br)(MBZT) 2 ] 2 2CH 3 OH} ( 5 ) complexes (MMI: 2-mercapto-1-methylimidazole, MBZIM: 2-mercaptobenzimidazole, tHPMT: 2-mercapto-3,4,5,6-tetrahydro-pyrimidine, PYT: 2-mercaptopyridine and MBZT: 2-mercaptobenzothiazole). The complexes 1–5 were characterized by melting point (m.p.), elemental analysis (e.a.), molar conductivity, Fourier-transform infrared (FT-IR), Fourier-transform Raman (FT-Raman), nuclear magnetic resonance ( 1 H and 13 CNMR) spectroscopy, UV-Vis spectroscopy and thermogravimetric-differential thermal analysis (TG-DTA). The molecular structures of 1–5 were determined by single-crystal X-ray diffraction. Complex 2 is a first ionic monomuclear octahedral bismuth(III) bromide, while the complexes 1 , 3–5 are the first examples of dinuclear bismuth(III) bromide derivatives. Complexes 1–5 were evaluated in terms of their in vitro cytotoxic activity against human adenocarcinoma breast (MCF-7) and cervix (HeLa) cells. The toxicity on normal human fetal lung fibroblast cells (MRC-5) was also evaluated. Moreover, the complexes 1–5 and free heterocyclic thioamide ligands were studied upon the catalytic peroxidation of the linoleic acid by the enzyme lipoxygenase (LOX).

Three bis(triorganotin) benzenedicarboxylates, 1, n -C 6 H 4 (COOSnR 3 ) 2 ( n , R=3, C 6 H 5 C(CH 3 ) 2 CH 2 , 1 ; 4, C 6 H 5 C(CH 3 ) 2 CH 2 , 2 ; 4, C 6 H 11 - c , 3 ), were synthesized by the reaction of 1,3 or 1,4-benzenedicarboxylic acid with triorganotin chlorides in the solution of CH 3 ONa-CH 3 OH and characterized by means of elemental analysis, Fourier-transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR) ( 1 H, 13 C, and 119 Sn) spectra, and X-ray single-crystal diffraction. Compounds 1–3 are all di-nuclear tin complexes in which the carboxylate is monodentate and each tin atom possesses a distorted SnC 3 O tetrahedral geometry.

In this study, two new Mg 3 -cluster-based coordination polymers are obtained via a one-pot solvothermal reaction of Mg(NO 3 ) 2 ·6H 2 O with two C 3 -symmetrical N-rich polycarboxylic acid organic ligands with different ligand flexibilities, which show interesting structural diversity. The complex 1 with the formula of [Mg 3 (tatb) 2 (MeOH) 2 (DMA) 2 ](DMA) 2 (H 3 tatb=4,4′,4″-s-triazine-2,4,6-triyl-tribenzoic acid, DMA=N,N-dimethylacetamide) is constructed from the linear Mg 3 cluster, which is further extended via the rigid tatb 3− ligand to afford a 2D layered framework. In comparison, the complex 2 with the formula of [Mg 3 (tatab) 2 (H 2 O) 6 ](DMA) 2 (H 3 tatab=4,4′,4″-s-triazine-1,3,5-triyltri-p-aminobenzoic acid) is built from the similar Mg 3 cluster but shows a 3D framework due to the flexibility of the tatab 3− ligand. Furthermore, the in vitro anticancer activity is evaluated against human spinal tumor lines U-266 via the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.

A three-level Box–Behnken model (BBM) under response surface methodology (RSM) was used to optimize the removal of cadmium (Cd) ion by pistachio residues biochar (PRB) and PRB supported by nanoscale zero-valent iron (PRB-nZVI) from aqueous solutions. Optimization experiments were carried out by evaluation of the effect of four variables (initial Cd concentration, initial solution pH, adsorbent dosage, and contact time) at three levels (high, medium, and low), and one category contained two variables (PRB and PRB-nZVI). For this purpose, a total of 58 experimental runs were set and the experimental data were fitted to the empirical second-order polynomial model of a suitable degree. The physical and chemical structure results of the adsorbents confirmed the formation of nZVI (with diameters ~35 nm) on the PRB surface. The results showed that the new composite of biochar (PRB-nZVI) exhibited higher Cd removal efficiency compared with PRB from aqueous solutions. The existence of functional groups and nZVI on the surface of PRB-nZVI could be better than PRB for Cd removal in aqueous solutions by the processes of sorption, precipitation, and co-precipitation. Numerical optimization revealed that the optimum removal (96.58%) was obtained at an initial Cd concentration of 25.99 mg L −1 (pH 6.58), adsorbent dose (PRB-nZVI) of 0.55 g L −1 , and contact time of 34.11 min, with desirability of 1. Based on the results, it is recommended that PRB-nZVI can be effectively used for the removal of Cd from a contaminated aqueous solution with varying chemical and physical conditions.

The polymeric organotin(IV) selenate complex [(Me 3 Sn) 3 (SeO 4 )(OH)] n ( 1 ) has been isolated as single crystals from the reaction of [(Me 2 NH 2 ) 2 SeO 4 ] and Me 3 SnCl in methanol. In the solid state, compound 1 was characterized by X-ray diffraction analysis, Fourier transform-infrared spectroscopy, and elemental analysis. 1 crystallizes in the orthorhombic system space group Pbca with a =11.0231(2) Å, b =16.3461(3) Å, c =20.9945(4) Å, α = β = γ =90°, V =3782.89(12) Å 3 , and Z =8. Its structure can be described as a polymeric zigzag chain based on Me 3 Sn moieties linked by tridentate selenate anions. Pendant (Me 3 Sn) 2 OH groups are also connected to the chain, according to a syndiotactic organization, and via Sn-O-Se bonds. Intermolecular OH···O hydrogen bonds and long Se-O···Sn distance interactions promote the association of chains together and lead to the propagation of a three-dimensional network. In addition, the behavior of 1 in solution (methanol) was also studied by multinuclear nuclear magnetic resonance spectroscopy and mass spectrometry.