Three novel Cu(II), Cd(II) and Cr(III) complexes of 6−Methylpyridine−2−carboxylic acid with thiocyanate: Synthesis,crystal structures,DFT calculations,molecular docking and α-Glucosidase inhibition studies

Novel complexes of 6?methylpyridine?2?carboxylic acid and thiocyanate {[Cu(NCS)(6-mpa)₂], (1); [Cd(NCS)(6-mpa)]_n, (2); [Cr(NCS)(6-mpa)₂·H₂O], (3)} were synthesized, and their structures were characterized by XRD analysis, FT–IR and UV–Vis spectroscopic techniques. The inhibitory activities of the synthesized complexes (1–3) on α-glucosidase were determined by using genistein reference compound. Furthermore, the optimized geometry and vibrational harmonic frequencies for the complexes 1–3 were obtained by DFT/HSEh1PBE/6–311G(d,p)/LanL2DZ level. Electronic spectral properties were examined by using TD-DFT/HSEh1PBE/6–311G(d,p)/LanL2DZ level with CPCM model. Additionally, major contributions to the electronic transitions were determined via Swizard program. The refractive index, linear optical and non?nonlinear optical parameters of the complexes 1–3 were investigated at HSEh1PBE/6–311G(d,p) level. The docking studies of the complexes 1–3 to the binding site of the target protein (the template structure S. cerevisiae isomaltase are fulfilled. Lastly, natural bond orbital analysis was used to investigate inter- and intra-molecular bonding and interaction among bonds.     

Separation of Mercury with an Ammonium Sulfate‐Ammonium Thiocyanate‐Ethyl Violet Flotation System

The separation behavior of mercury by a flotation system consisting of ammonium sulfate, ammonium thiocyanate and ethyl violet, and the conditions for the separation of Hg(II) with other common metal ions have been studied. The studies show that in aqueous solutions, Hg(II) combines with NH₄SCN and ethyl violet(EV) into dissoluble ternary ion‐association complex [Hg(SCN)4^2?]?(EV)₂. In the presence of ammonium sulfate, the precipitate is floats well on the surface of the water phase and separates from water thoroughly. It shows that Hg(II) can be separated completely from Cd(II), Fe(II), Co(II), Ni(II), Mn(II) and Al(III) by flotation at pH1.0. The flotation mechanism of Hg(II) is described in this paper.     

牛磺酸双核铜络合物为载体的高选择性硫氰酸根离子电极的研究

本文报道了一种以牛磺酸双核铜络合物为中性载体的硫氰酸根PVC膜电极。该电极对硫氰酸根有良好的电位响应并呈现出anti-Hofmeister行为,其选择性顺序SCN^->I^->ClO₄^->Sal^->NO₃^-> NO₂^-> Br^- > Cl^- > SO₃^-> SO₄ ^2-。在20℃ pH 5.0的磷酸缓冲溶液中,其线性范围为1.0´10 ^-1~ 1.0´10^-6mol×L-1,检测线为8.0×10 ^-7mol•L^-1,斜率为 -56.5 mV/pcSCN^-。紫外、红外和交流阻抗研究表明电极的高选择性与载体的立体结构和分析物与中心金属离子的作用相关。将该电极用于废水和人体尿液中硫氰酸根的测定,获得了较满意的结果。     

Synthesis of Snake-cage Resins and Study of Their Separation Ability

IntroductionSnake-cageresin,alsoca1ledsnake-cagepolyelectrolyte['],isaspecialkindofamphotericresin.ItwasfirstinvestigatedbyHatchM.J.etal.in1957[z].Thetypicalandusefulsnake-cageresinisRetardation11A-8(l1A-8inthecon-text)manufacturedbyDowChemicalCoI,TD.Itissynthesizedbypolymerizingacrylicacidinsidethenetworkofastrongbasicanionexchangeresinwith8%crosslinking.Thus,theresinconsistsofacrosslinkedpolymermatrix,cage,andalinearpolymer,socalledsnake,whichisphysicallytrappedinsidethecage.Thecagepol…     

水热法制备ZnS纳米线

以十六烷基三甲基溴化铵(CTAB)为表面活性剂，利用水热法通过二吡啶硫氰酸锌分解制备了ZnS纳米线，并用SEM、XRD、EDX和HR-TEM等方法对其纳米结构进行了表征。实验结果表明，反应时间和表面活性剂浓度是决定纳米ZnS最终形貌的关键因素，CTAB起到了纳米线生长的分子-诱导模板作用。     

Binary and ternary complexes involving manganese(II), 2,2’-bipyridine and halide or thiocyanate ions inN,N-dimethylformamide

Ternary complexation involving the manganese(II) ion, 2,2’-bipyridine (bipy), and halide (chloride, bromide) or pseudohalide (thiocyanate) ions has been studied by precise titration calorimetry inN,N -dimethylformamide (DMF) at 298K. All the titration curves are explained well in terms of formation of mononuclear complexes of the type [MnX_m(bipy)_n](^2-m) + (X = CI, Br or SCN), and the formation of [MnCl(bipy)]⁺, [MnCl₂(bipy)], [MnCl(bipy)₂]⁺ and [MnCl₂(bipy)₂] has been established in the chloride system, [MnBr(bipy)]⁺, [MnBr₂(bipy)], [MnBr(bipy)₂]⁺ in the bromide system, and [Mn(NCS)(bipy)]⁺, [Mn(NCS)₂(bipy)], [Mn(NCS)₃(bipy)]^-, [Mn(NCS)(bipy)₂]⁺, and [Mn(NCS)₂(bipy)₂] in the thiocyanate system. The data were analyzed on the basis of the thermodynamic parameters for the binary Mn^lIbipy and Mn^II-X (X = Cl, Br and SCN) systems, the latter being determined in previous work. The formation constants, reaction enthalpies, and entropies of the ternary complexes were extracted. The thermodynamic parameters thus obtained are discussed in comparison with those of the corresponding systems of other transition metal(II) ions.     

Separation of Iron(III) with Ammonium Thiocyanate‐H2O‐n‐Propyl Alcohol Extraction System in the Presence of Sodium Chloride

The behavior and conditions of liquid‐liquid extraction‐separation of Fe(III) by ammonium thiocyanate‐H₂O‐n‐propyl alcohol system in the presence of NaCl were studied, and the possible reactive mechanism of extraction of Fe(III) was deduced. The study showed that, in the presence of a given amount of NaCl, phases were separated thoroughly between n‐propyl alcohol and water. In the process of phase separation, the complex [Fe(SCN)_n]^(3‐n) formed by NH₄SCN and Fe(III) was quantitatively extracted into the n‐propyl alcohol phase. The extracted Fe(III) exists in the n‐propyl alcohol phase mainly as the forms of Fe(SCN)₂⁺ and Fe(SCN)₃. Also, the relationship between extraction yield of Fe(III) and the amount of NH₄SCN agreed well with the quadratic equation E = 0.54 + 58.14x ? 8.39x² (E and x represent the recovery rate of Fe(III) and the volume (mL) of 0.1 M NH₄SCN respectively). The quadratic R‐Square is 0.9990. With this method, Fe(III) can be completely separated from Co(II), Ni(II), Mn(II), Al(III), Bi(III) and Cd(II) at pH 1.0?2.0. The present method was applied in determining Fe(III) in samples with satisfactory results such as relative standard deviation from 2.06% to 2.89% and recovery rate in the range of 98.4?101.4%.     

Determination of Iodide and Thiocyanate in Seawater by Liquid Chromatography with Poly(ethylene glycol) Stationary Phase

Novel, simple, rapid, highly sensitive, and direct determination of iodide and thiocyanate ions in seawater has been performed by liquid chromatography (LC) with UV detection at 220 nm. The separation was achieved on a C₃₀ column of conventional size (150 mm × 4.6 mm i.d.) modified with poly(ethylene glycol); an aqueous solution of 300 mM sodium sulfate and 50 mM sodium chloride was used as mobile phase. Detection limits (S/N=3) obtained by injecting a 20-L sample were 0.5 and 6 ng mL^–1 for iodide and thiocyanate, respectively. The method was successfully used for rapid and direct determination of iodide and thiocyanate in seawater samples, collected from the coasts of Japan, without any extra pretreatment.Dedicated to Professor K. Jinno on the occasion of his 60^th birthday     

Temperature dependence of apparent molar volumes and viscosity B-coefficients of amino acids in aqueous potassium thiocyanate solutions from 15 to 35°C

Precise density and viscosity data at 15, 25 and 35°C for solutions of glycine, DL-alanine, L-threonine, -alanine, -aminobutyric acid and -aminocaproic acid in water and in (1m, 3m, 5m) aqueous potassium thiocyanate were measured and the limiting apparent molar volumes V ^o and the B-coefficients calculated. The V ^o and B values were split into the contributions from the NH ₃ ⁺ ,COO^– and CH₂ groups. These data are rationalized on the basis of hydrophillic and hydrophobic interactions between the various groups present in these solutions.Abstracted from the Ph.D Thesis of R. K. Goyal, University of Delhi, 1990.     

Osmotic and activity coefficients of ammonium thiocyanate in aqueous solutions at 25°C

Osmotic and activity coefficients of ammonium thiocyanate determined by the isopiestic vapor pressure method are compared with the data recently reported by Covington and Matheson. Activity coefficients calculated using the Pitzer equation are now in much better agreement although a systematic difference is evident in the two sets of data.Comment to the paper by Covingtonet al. (see ref. 2).We thank Mr. P. Kordes for programming.