1-Pyrenecarboxaldehyde thiosemicarbazone:A novel fluorescent molecular sensor towards mercury(Ⅱ) ion

A novel and simple fluorescent molecular sensor,1-pyrenecarboxaldehyde thiosemicarbazone（Hpytsc）,was synthesized.Its higher sensitivity and selectivity to mercury（Ⅱ） ion were studied through absorption and emission channels.The UV-vis spectra show that the increasing mercury（Ⅱ） ion concentrations result in the decreasing absorption intensity.The fluorescence monomer emission of Hpytsc is enhanced upon binding mercury（Ⅱ） ion,which should be due to the 1：1 complex formation between Hpytsc and metal ion.

High extraction ability of 1,3-dialkynyl calixarene towards mercury(Ⅱ) ion

The reaction of 1,3-dipropyn-2-yloxycalix[4]arene with mercury（U） acetate could give mercury-containing alkynyl calixarene polymer. The extraction behavior of 1,3-dipropyn-2-yl-oxycalix[4]arene towards mercury（Ⅱ） ion was examined. When the mole ratio of Hg^2＋/calixarene was 1：1, the extractive percent can reach to 99.1%, and the extraction capacity was up to 431 mg/g. It could also decrease the Hg^2＋ concentration from 5 to 0.85 mg/L, which was only 17% of the national standard of effluent and satisfied the national standard of drinking water. The extraction process included chemical reaction.

Syntheses and Crystal Structures of Two New Mercury(Ⅱ) Complexes with Double Betaine Ligands

Reaction of HgCl2 and double betaine ligands in water at about 80 ℃ yielded two new Hg（Ⅱ） complexes,[Hg（L1）Cl2]·H2O 1 and [Hg2（L2）Cl4]·3HgCl2 2（L1 = 1,3-bis（pyridinio-4-carboxylato）-propane,L2 = 1,4-bis（pyridinio-4-carboxylato）-1,4-dimenthylbenzene）.Their struc-tures have been characterized by single-crystal X-ray diffraction techniques.The structure of 1 contains 1-D chains,in which the adjacent Hg（Ⅱ） atoms are bridged by L1 ligands in a syn-syn bis-monodentate mode.The chains are further connected through face-to-face π-π stacking interactions between pyridine rings to generate an infinite double-chain network.In 2,two Hg（Ⅱ） atoms are joined by L2 ligands in the same coordination mode as 1 to form an isolated dinuclear structure.The thermal stabilities of both complexes have also been investigated.

Two-dimensional Supramolecular Structure of a Mercury(Ⅱ) Iodide Complex with Organosulfide

A mercury（Ⅱ） iodide complex with organosulfide [Hg（pymt）（pymtH）I] 1 （pymt = the anion of pyrimidine-2-thiolate） has been synthesized by slow evaporation of the solution at room temperature and structurally characterized by single-crystal X-ray diffraction. Basic ideas and data collected are given. X-ray diffraction analysis reveals that complex 1 is mononuclear. Crystallographic data： C8H7HgIN4S2, Mr = 550.79, monoclinic system, space group P21/c, a = 11.218（4）, b = 9.551（3）, c = 15.877（4） A^°, β = 129.697（15）°, V = 1308.9（7） A^°^3, Z = 4, Mr = 550.79, Dc = 2.795 g/cm^3, F（000） = 995, μ（MoKa） = 14.415 mm^-1, 2（MoKa） = 0.71073 A^°, T= 293（2） K, 2θmax = 54.9°, GOOF= 1.053, the final R = 0.0310 and wR = 0.0742 for 2547 observed reflections with I 〉 2σ（I） （refinement on F^2）. Complex 1 is connected through hydrogen bonds to give a one-dimensional supramolecular chain structure. Furthermore, π-π interactions are also found between the pyrimidine rings with the center-to-center distances of 3.439（4） and 3.603（4） A^°, so complex 1 expands the chains into a two-dimensional network.

Studies on the Crystal Structure and Photoluminescence of a Mercury(Ⅱ)Complex Based on a Novel Pyridine Ligand

A novel mercury（H） complex HgL2Br2 was prepared from HgBr2 and the organic ligand 2-（N-methyl-N-（4-（（E）-2-（pyridine-4-yl）vinyl）phenyl）amino）ethanol （L）. The ligand was synthesized and then characterized by FT-IR spectroscopy, tH NMR, mass spectrum and elemental analysis, while the single-crystal diffraction data of the complex were collected on a Siemens Smart CCD diffractometer. The complex crystallizes in triclinic space group PI with a = 5.367（5）, b = 12.466（5）, c = 23.945（5） A, α = 90.812（5）, β = 96.318（4）, γ = 96.093（5）°, Z = 2, Dc = 1.817 g.cm3,μ = 7.395 mm^-1, S = 0.825, and the final R= 0.0396. The Hg（Ⅱ） ion in the distorted tetrahedral mercury（Ⅱ） complex C32H36HgBr2N4O2 is coordinated by two N atoms from the two ligands together with two bromide ions. Solid-state emission of the ligand and its complex has been investigated at room temperature.

Structural Studies and Photoluminescence of a Novel Mercury(Ⅱ) Complex Based on a Tris[4-(1-pyrazolyl)-phenyl]amine

A novel iodine-bridged mercury（Ⅱ） complex [Hg（L）（μ-I）（I）]2 was isolated by a reaction between HgI2 and the organic ligand tris[4-（1-pyrazolyl）phenyl]amine L, and the complex and ligand were both characterized by FT-IR spectroscopy, ^1H NMR and elemental analysis. The complex crystallizes in monoclinic space group P21/c with a = 9.579（5）, b = 27.331 （5）, c = 11.268（5） А, β= 105.624（5）°, Z = 2, Dc = 2.099 g·cm^-3 and μ= 7.620 mm^-1. The title complex C54H42Hg2I4N14 is a diplex bridged dinuclear complex consisting of two Hg（Ⅱ） ions, two ligands, two bridging I-anions, and two terminal I-anions. Universal hydrogen bonds in the complex with the partners of neighboring molecule have generated a supramolecular arrangement. Solid-state emission of the ligand and its complex have been investigated at room temperature.

Two Novel Mercury(Ⅱ) and Copper(Ⅱ) Complexes Based on(5-Chloro-quinolin-8-yloxy)acetic Acid

Two novel mononuclear complexes with 5-chloro-8-（methoxycarbonylmethoxy）quinoline ligand（L）, namely, HgLBr2 1 and CuL2Cl2 2, have been prepared by solvothermal reaction of（5-chloro-quinolin-8-yloxy）acetic acid with HgBr2 and CuCl2, respectively. Their structures were characterized by IR, elemental analysis, UV-Vis-NIR spectra, TG and single-crystal X-ray diffraction analysis. Interestingly,（5-chloro-quinolin-8-yloxy）acetic acid is changed as 5-chloro-8-（methoxycarbonylmethoxy）quinoline ligand（L） in complexes 1 and 2. Crystal data for 1： C12H10Br2 Cl Hg NO3, Mr = 612.07, triclinic, space group P1 with a = 8.5983（7）, b = 9.7726（6）, c = 10.1549（6） A, α = 66.355（6）, β = 77.067（8）, γ = 78.803（8）°, V = 756.6（9）A^3, Z = 2, Dc = 2.687 g/cm^3, F（000） = 560, μ = 15.633 mm^-1, R = 0.0351 and w R = 0.0504. Crystal data for 2： C24H20Cl4 Cu N2O6, Mr = 637.76, triclinic, space group P1 with a = 10.5324（9）, b = 11.2377（16）, c = 12.0143（12） ？, α = 83.413（11）, β = 64.475（9）, γ = 83.144（11）°, V = 1270.9（2） ？3, Z = 2, Dc = 1.667 g/cm3, F（000） = 646, μ = 1.324 mm-1, R = 0.0408 and wR = 0.0922. In 1, the HgII centre is a distorted trigonal planar geometry comprised of two Br atoms and one quinoline N atom of L. Intermolecular π-π, C–H…π stacking interactions and intermolecular C–H…Br hydrogen bonds are observed in the molecular packing of 1. In complex 2, each CuII center has a distorted octahedral geometry comprised of two chloride ions, two quinoline N atoms and two O atoms of two L ligands. Intermolecular C–H…Cl hydrogen bonds exist in the molecular packing of 2. The fluorescence emission peak of complexes 1 and 2 appears near 406 and 410 nm, respectively. Optical diffuse-reflection spectral results suggest complex 1 has the property of semiconductor.

Coordination Modes of Polypyridyl Quinoxaline with Hg(Ⅱ),Pb(Ⅱ),Co(Ⅱ)and Mn(Ⅱ)

The interaction of metal ions（Hg^2＋,Pb^2＋,Co^2＋,Mn^2＋） with polypyridyl quinoxaline ligand 2,3,6,7,10,11-hexakis（2-pyridyl）dipyrazino[2,3-f：20,30-h]quinoxaline（HPDQ） was investigated,and four new complexes have been synthesized and characterized.Complex 1 exhibits a 0dimensional dual-core structure,2 is a one-dimensional chain structure based on a dual-core Pb unit,while 3 and 4 show a 0 dimensional single-core structural unit.Complex 1 is of monoclinic system,space group C2/c with a = 19.211（4）,b = 23.896（5）,c = 12.698（3） A°,β= 120.11（3）°,V= 5043.0（17）A°3,Z = 4,S = 1.053,F（000） = 2976,R^a = 0.0637 and wR^b = 0.1068（I 〉 2σ（I））.Complex 2 adopts triclinic system,space group P1 with a = 10.370（2）,b = 12.195（2）,c = 21.033（4） A°,α = 80.87（3）,β= 81.22（3）,γ = 82.38（3）°,V= 2579.3（8） A°3,Z = 2,S = 1.099,F（000） = 1328,R^a = 0.0609 and wR^b =0.1365（I 〉 2σ（I））.Complex 3 is of monoclinic system,space group Cllc with a = 14.166（3）,b =16.621（3）,c = 20.248（4） ？,β = 92.18（3）°,V= 4764.0（16） A°3,Z = 4,S = 1.005,F（000） = 2108,R^a =0.0589 and wR^b = 0.1332（I 〉 2σ（I））.Complex 4 belongs to the monoclinic system,space group C2/c with a = 14.404（3）,b = 16.626（3）,c = 20.346（4） ？,β = 92.43（3）°,V= 4868.2（17） A°3,Z = 4,S= 1.068,F（000） = 2108,R^a = 0.0833 and wR^b = 0.1591（I 〉 2σ（I））.Furthermore,the behavior of HPDQ with Hg^2＋,Pb^2＋,Co^2＋ and Mn^2＋ in the solution was also investigated,and the result shows after the metal ions were added respectively,the emission of all solutions shows fluorescence quenching and has a red shift compared with that of the HPDQ ligand.

基于光栅尺反馈的直线运动系统设计与实现

光栅尺位移传感器经常应用于闭环伺服系统中,用作直线位移的检测。为提高显微镜载物台定位精度,满足人们对显微镜自动成像以及自动化测量的要求,提出了一款基于高功率步进电机驱动器TMC5130,利用光栅尺测量平台位移反馈给处理器进行位移补偿的控制系统,实现直线运动平台的闭环控制。详细介绍了运动系统的硬件组成和软件设计,并且搭建了试验样机,开发了上位机测试工具。实验证明:所设计的直线运动平台位移精度达到1μm,具有精确定位功能,可应用于部分运动定位控制系统。

Selective Detection of Mercury（Ⅱ） and Copper（Ⅱ） Based on the Opposite Size-dependent Fluorescence Quenching of CdTe Quantum Dots

Three different size CdTe quantum dots （QDs） capped by 3-mercaptopropionic acid （MPA） have been prepared in aqueous solutions, and their interactions with Cu^2＋ and Hg^2＋ have been investigated. The opposite size-dependent fluorescence quenching of CdTe QDs by Hg^2＋ and Cu^2＋ was observed： Hg^2＋ quenched smaller particles more efficiently than larger ones while larger particles were more markedly quenched by Cu^2＋. Based on the different size responses, Hg^2＋ and Cu^2＋ were respectively detected with high sensitivity and selectivity, for the first time, using the QDs with different sizes but the same components and capping ligands.

One-dimensional Zigzag Chain Composed of HgI_2 Unit and 2,5-Bis(4-pyridyl)-1,3,4-thiadiazole:[HgI_2(C_(12)H_8N_4S)]

The title compound, [HgI2（C12H8N4S）], has been synthesized and characterized by single-crystal X-ray diffraction analysis. It crystallizes in monoclinic, space group P21/n with a = 14.086（2）, b = 6.0365（6）, c = 20.286（2）°A,β= 108.818（5）°, V = 1632.7（3）°A^3, Mr = 694.67, Z = 4, D, = 2.826 g/cm^3,μ= 13.331 mm^-1, F（000） = 1240, S = 1.108, the final R = 0.0438 and wR = 0.0934 for 3085 observed reflections （I〉 2σ（I））. The Hg（Ⅱ） atom is coordinated by two 2,5-bis（4-pyridyl）-1,3,4-thiadiazole （L） molecules and two iodine anions in a distorted tetrahedral coordination geometry. Mercury atoms are linked by the organic ligands to form a one-dimensional zigzag chain. It is noteworthy that such 1D zigzag chains are extended into a two-dimensional double layer framework through I…I interactions

MOF-derived Cu2O/Cu NPs on N-doped Porous Carbon as a Multifunctional Sensor for Mercury(Ⅱ) and Glucose with Wide Detection Range

Cu2O/Cu nanoparticles(NPs)in the nanoporous carbon matrix(designated as Cu2O/Cu@NPC)has been synthesized by in-situ calcination of a cupper-based metal-organic framework(Cu-MOF),and its morphology and composition were characterized by PXRD,SEM and Raman.Furthermore,elemental mapping and XPS analysis not only show Cu NPs is generated along with nitrogen(N)-doped carbon,but also indicate Cu2O NPs locates in the external layer of Cu@NPC.In addition,the adsorption of dye studies implies that Cu2O/Cu@NPC exhibits obvious interaction with Rhodamine B(Rh B)due to the feature of porous and N-doped structure.Cu2O/Cu@NPC has highly electrocatalytic performance for glucose and mercury(Ⅱ)with wide detection range and good stability,which can be used as a novel multifunctional sensor for glucose and mercury(Ⅱ).

Carboxymethyl cellulose thiol-imprinted polymers:Synthesis, characterization and selective Hg(Ⅱ) adsorption

Sulfur containing ion imprinted polymers(S-IIPs) were applied for the uptake of Hg(Ⅱ) from aqueous solution. Cysteamine which was used as the ligand for Hg(Ⅱ) complexation, was grafted along the epichlorohydrin crosslinked carboxylated carboxymethyl cellulose polymer chain through an amide reaction. The adsorption ability of S-IIPs towards Hg(Ⅱ)was investigated by kinetic and isotherm models, which, corresponding, showed that the adsorption process followed a pseudo-second-order, fitted well with the Langmuir isotherm with a maximum adsorption capacity of 80 mg/g. Moreover, thermodynamic studies indicated an endothermic and spontaneous reaction with the tendency of an enhanced randomness at the surface of the S-IIPs with temperature increases. S-IIPs indicated a high degree of selectivity towards Hg(Ⅱ) in the presence of Cu^(2+), Zn^(2+), Co^(2+), Pb^(2+)and Cd^(2+).Furthermore, the efficiency of S-IIPs was also evaluated against real samples showing86.78%, 91.88%, and 99.10% recovery for Hg(Ⅱ) wastewater, ground water and tap water,respectively. In this study, the adsorbent was successfully regenerated for five cycles, which allows for their reuse without significant loss of initial adsorption capability.

Development of a test strip based on DNA-functionalized gold nanoparticles for rapid detection of mercury(II) ions

A rapid,sensitive,selective and reliable strip assay based on DNA-functionalized gold nanoparticles for Hg^（2＋） detection has been developed,with a detection limit 5 nmol/L.The measurement principle was based on thymine-Hg^（2＋）-thymine（T-Hg^（2＋）-T） coordination chemistry and streptavidin-biotin interaction.The major advantages of this assay are that results can be read visually without any instrument in less than 10 min and that it does not require any sample pretreatment.

Synthesis and application of highly sensitive fluorescent probe for Hg2＋ regulated by sulfur

Rhodamine-based fluorescent probe is widely used in chemical analysis, environmental analysis and life sciences area due to their excellent optical properties. Based on the thiophilic property of Hg2＋, using C = S structural motif as the core segment, our group have designed and synthesized three novel probes containing cinnamyl aldehyde with different substituents, exhibiting high selectivity and excellent sensitivity. The structure-property relationships of these probes have been investigated that the optical change caused by electron withdrawing effect and heavy atom effect. Furthermore, these Hg2＋ probes could be applied in living mice imaging, which provide a promising tool for quantitative mercury（Ⅱ） ion imaging in living organism.