A Novel Gd Coordination Polymer Based on 2-(Pyridin-3-yl)-1H-imidazole-4,5-dicarboxylate: Synthesis, Structure and Dielectric Properties

A new Gd coordination polymer based on 2-（pyridin-3-yl）-lH-imidazole-4,5-dicar- boxylate, formulated as {[Gd2（HPyIDC）2（H2O）5]·（bpy）·（NO3）2·3H2O}n （1, bpy = 4,4＇-bipyridine） has been synthesized under hydrothermal conditions. The compound crystallizes in triclinic, space group Pi with a = 11.451（2）, b = 11.596（2）, c = 15.7333（3） A, β = 79.47（3）°, Z = 2, V= 1948.6（7） A^3, C30H34Gd2N10O22, Dc = 2.047 g/cm^3, Mr= 1201.17, 2（MoKa） = 0.71073 A,μ = 3.477 mml, F（000） = 1176, the final R = 0.0554 and wR = 0.1181. Polymer 1 is a 2D network built up from 4-connected HPylDC2- anion and 4-connected Gd ions. Dielectric constant of complex 1 was measured at different frequencies with temperature variation.

4-(7-Methoxy-2,2-dimethyl-2,3-dihydrobenzo-furan-5-yl)-N-(pyridin-2-yl)thiazol-2-amine: Chiral Crystal from Achiral Molecule

The title compound 4-（7-methoxy-2,2-dimethyl-2,3-dihydrobenzofuran-5-yl）-N- （pyridin-2-yl） thiazol-2-amine was synthesized by reacting 2-bromo-1-（7-methoxy-2,2-dime- thyl-2,3-dihydrobenzofuran-5-yl）ethanone with 1-（pyridine-2-yl）thiourea, and its crystal was determined by single-crystal X-ray diffraction. The crystal belongs to the monoclinic system, chiral space group C2 with a = 18.1328（14）, b = 5.5969（5）, c = 19.2195（15） A, β= 115.5420（10）°, V= 1759.9（2）A3, Z = 4, F（000） = 744, C19H19N3O2S, Mr= 353.43, Dc= 1.334 g/cm3, S = 1.15, μ = 0.201 mm-1, the final R = 0.035 and wR = 0.111 for 2307 observed reflections （I 〉 2σ（I））. The Flack parameter is -0.03（10）. The preliminary bioassay result indicated that the title compound exhibits strong insecticidal activity （93.75% mortality） against Mythimna separate at the concentration of 1.000 g/L.

A One-dimensional Cd(Ⅱ)Coordination Polymer Constructed from 1,4-Benzene-dicarboxylic Acid and 3-(2,6-Di(pyrazin-2-yl)pyridin-4-yl)-1H-indole:Synthesis,Structure and Photoluminescence

A new coordination polymer {[Cd（C_（21）H_（14）N_6）（C_8H_4O_4）]·H_2O}_n（1） was synthesized by an elaborate design via the reaction of 3-（2,6-di（pyrazin-2-yl）pyridin-4-yl）-1H-indole（bppi）,1,4-benzene-dicarboxylic acid（H2bdc） and cadmium（Ⅱ） nitrate in CH_3OH/H_2O mixed solvents. Complex 1 crystallizes in orthorhombic,space group Ccca with a = 20.012（4）,b = 31.881（6）,c = 19.808（4） ？,V = 12638（4） ？~3,Z = 16,C_（29）H_（20）CdN_6O_5,M_r = 644.91,D_c = 1.356 g·cm^（-3）,μ = 0.735 mm^（-1）,F（000） = 5184,GOOF = 1.046,the final R = 0.0405 and wR = 0.1063 for 6870 observed reflections（I 〉 2σ（I））. The Cd（Ⅱ） centre is hepta-coordinated by three N and four O atoms from one bppi terminal ligand and two bdc2– ligands,respectively,displaying a capped trigonal prism geometry. Structure extension gives coordination polymeric chains,in which the bdc2– linkers connect Cd（Ⅱ） cations into a one-dimensional（1D） coordination polymer along the c axis,giving zigzag chains with the Cd···Cd separation of 11.178（1） ？. The adjacent bppi terminal ligands in the chains are anti-periplanar conformation. The three-dimensional（3D） structure is stabilized by π···π stacking and hydrogen-bonding interactions to form a supramolecular self-penetrating network with 1D channels. In 1,there are voids 2999.7 ？~3 with 23.7% of per unit cell volume. Thermal analysis indicates that the framework of 1 is stable until 651 K and the photoluminescence of 1 in the solid shows very weak fluorescence at 382 and 560 nm upon excitation at 310 nm.

A Y(Ⅲ)-organic Coordination Polymer Constructed from 2-(Pyridine-4-yl)-1H-imidazole-4,5-dicarboxylate and Oxalate Ligands: Structure and Luminescent Property

A novel compound, {[Y（HPIDC）（OX）1/2（H2O）]·2H2O}n （1, H3PIDC = 2-（pyridin-4- yl）-1H-imidazole-4,5-dicarboxylic acid, H2OX = oxalic acid）, has been synthesized under hydrothermal conditions and characterized by thermal analysis （TGA）, powder X-ray diffraction （PXRD）, and single-crystal X-ray diffraction. Complex 1 crystallizes in monoclinic space group P21/c with a = 8.342（8）, b = 14.61（1）, c = 11.487（1）, β = 90.78（9）°, V = 1400.4（2）3, Z = 4, C11H11N3O9Y, Mr = 418.14, Dc = 1.983 g/cm3, F（000） = 836, Rint = 0.0509, T = 293（2） K, μ = 4.240 mm-1, the final R = 0.0477 and wR = 0.1125 for 2770 observed reflections with I 2σ（I）. Compound 1 exhibits a 3D framework and generates the 1D open channels filled with free water molecules. The structure of 1 can be rationalized as a diamondoid network when the atom yttrium is regarded as a 4-connected node linking four surrounding yttrium atoms. The luminescent property of compound 1 is also investigated.

Synthesis, Structure and Photocatalytic Activity of Two 4-(2,6-Di(pyrazin-2-yl)pyridin-4-yl)benzoate-Based Chain Complexes

Two new one-dimensional chains extended by alternate benzenedicarboxylate（BDC） and 4-（2,6-di（pyrazin-2-yl）pyridin-4-yl）benzoate（L-） connectors, {[Cu（L）（BDC）（0.5）]·3.5 H2 O}n （1） and {[Zn（L）（BDC）（0.5）] ·H2 O}n （2）, were solvothermally synthesized. Complex 1 is in triclinic system, space group P1 with a = 9.6456（14）, b = 11.1160（16）, c = 12.0414（18） A, α = 106.266（3）, β = 92.277（3）, γ =108.104（3）°, V = 1166.6（3） A3, Dc = 1.603 g·cm（-3）, Mr = 563.00, Z = 2, F（000） = 578, μ = 0.996 mm（-1）, the final R = 0.0575 and wR = 0.1386 for 3704 observed reflections with I ＆gt; 2σ（I）. Complex 2 crystallizes in monoclinic, space group C2/c with a = 28.607（5）, b = 8.9767（16）, c = 19.705（4） ？, β = 125.396（3）°, V = 4125.0（13） ？3, Dc = 1.674 g·cm（-3）, Mr = 519.79, Z = 8, F（000） = 2120, μ = 1.242 mm（-1）, the final R = 0.0487 and w R = 0.0907 for 2944 observed reflections with I ＆gt; 2σ（I）. Resulting from the narrower band gap and broader response to visible light, the CuII-chain exhibits better photocatalytic performance towards the degradation of rhodamine B and methylene blue than those of ZnII-chain.

2-羟基-4-(5,6-二硝基-1H-苯并[2,3-d]咪唑-2-基)苯甲酸甲酯的合成探索

以4,5-二硝基邻苯二胺和2-羟基对苯二甲酸单甲酯为起始原料,设计并成功采用一锅法合成出2-羟基-4-(5,6-二硝基-1H-苯并[2,3-d]咪唑-2-基)苯甲酸甲酯(MHDIB)。以50 mL二乙二醇二甲醚为溶剂,1.5 g的2-羟基对苯二甲酸单甲酯和2.5 g SOCl2在80℃反应2 h制2-羟基-4-氯羰基苯甲酸甲酯。室温下快速向反应体系中加入1.56 g 4,5-二硝基邻苯二胺,并于85℃反应1 h后加入3.52 g多聚磷酸,回流反应1 h后水析出粗产品,经乙醇重结晶得到纯度为93.67%的黄色针状产物,产率为17.82%。产物经IR、MS、1H NMR的准确定性和表征,作为AB型新单体的前体可应用于羟基改性PBI纤维即聚2-羟基-1,4-亚苯基-2,6-苯并[2,3-d:5',6'-d']二咪唑(H-PBI)的创新研究。

Synthesis,structure and dielectric properties of a novel Gd coordination polymer based on 2-(pyridin-4-yl)-1H-imidazole-4,5-dicarboxylate

A new Gd coordination polymer based on 2-（pyridin-4-yl）-I H-imidazole-4,5-dicarboxylate （H3PIDC） has been synthesized under hydrothermal conditions, formulated as {[Gd3（HPIDC）3（PIDC）（H2O）4].3H2O}n （1）. The compound crystallizes in the monoclinic system, space group C2/c with a=20.951（7）, b = 9.515（3）, c = 27.483（10） A,β= 106.176（6）°, Z = 4, V= 5262（3） A3, C40 H45 Gd3 N12 O30, Dc = 2.071 g/cm3, Mr=1645.63, λ （MoKa）=0.71073A, μ=3.846mm-1, F（000）=3204, the final R=0.0390 and wR= 0.1332. Complex 1 is a two-dimensional MOF built up from T-shaped 3-connected HPIDC2 , PIDC3 and 4-connected metal nodes. Dielectric constant of complex 1 was measured at different frequencies with temperature variation.

Crystal Structure,Thermal Behavior and Luminescence of a New Dimeric Manganese(Ⅱ) Complex Constructed with 3-Carboxy-1-carboxymethyl-2-oxidopyridinium

A new dimeric Mn（Ⅱ） complex,namely,[Mn（L）（PIP）]_2·H_2O（1）,was synthesized under hydrothermal condition（H_2L = 3-carboxy-1-carboxymethyl-2-oxidopyridinium and PIP = 2-（pyridin-3-yl）-1H-imidazo[4,5-f][1,10]phenanthroline）.It crystallizes in triclinic,space group P1 with a = 9.2037（13）,b = 9.6794（13）,c = 14.649（3） A,α = 94.858（3）,β = 94.928（3）,γ = 114.468（2）o,V = 1172.9（3） A^3,Z = 1,C_（52）H_（34）Mn_2N_（12）O_（11）,Mr = 1112.79,Dc = 1.575 g/cm^3,F（000） = 568,μ（Mo Ka） = 0.618 mm^-1,R = 0.0432 and w R = 0.1151.In 1,two L anions bridge two Mn（Ⅱ） atoms to give a dimeric [Mn（L）（PIP）] unit with the Mn···Mn distance of 3.009（2） A.The two PIP ligands are located on both sides of the dimer,which provides suitable π-π stacking interactions between PIP ligands.By these π-π stacking interactions,adjacent dimers are extended into a two-dimensional supramolecular layer.Further,the strong N–H···O hydrogen bond stabilizes the supramolecular layer structure of 1.Moreover,the thermal behavior and luminescent property of 1 have been studied.

A New Two-dimensional Coordination Polymer Based on Trinuclear Manganese Clusters

A novel two-dimensional Mn（II） coordination polymer, [Mn3（L）R（cis-chdc）fftrans- chdc）]n （L = 2-amino-4-（1H-imidazo[4,5-J][1,10]phenanthrolin-2-yl）phenol and chdc = 1,4-cyclo- hexanedicarboxylate）, has been hydrothermally synthesized and characterized by elemental analysis, IR, TG PL and single-crystal X-ray diffraction. Crystallographic data for this compound： monoclinic space group P2/n with a = 11.0058（13）, b = 9.0179（11）, c = 28.431（3） A, β = 92.850（2）°, V = 2818.3（6） A3, Z = 2, C62Hs6Mn3N10O14, Mr = 1329.99, Dc = 1.567 g/cm3, F（000） = 1370, p（MoKa） = 0.742 mm-1, R = 0.0553 and wR = 0.1421. The chdc carboxylates bridge the Mn（II） atoms to form a trinuclear Mn（lI） cluster. The cis-chdc ligands are held together by the trinuclear Mn（II） clusters to result in a chain structure. Further, the trans-chdc ligands link adjacent chains to furnish a two-dimensional network. The π-π interactions between neighboring layers link the adjacent layers into a three-dimensional supramolecular architecture. Moreover, the N-H...O and O-H...O hydrogen bonds further stabilize the 3D supramolecular architecture.

On the road towards the global analysis of human synapses

Synapses are essential units for the flow of information in the brain.Over the last 70 years,synapses have been widely studied in multiple animal models including worms,fruit flies,and rodents.In comparison,the study of human synapses has evolved significantly slower,mainly because of technical limitations.However,three novel methods allowing the analysis of molecular,morphological,and functional properties of human synapses may expand our knowledge of the human brain.Here,we briefly describe these methods,and evaluate how the information provided by each unique approach may contribute to the functional and anatomical analysis of the synaptic component of human brain circuitries.In particular,using tissue from cryopreserved human brains,synaptic plasticity can be studied in isolated synaptosomes by fluorescence analysis of single-synapse long-term potentiation（FASS-LTP）,and subpopulations of synapses can be thoroughly assessed in the ribbons of brain tissue by array tomography（AT）.Currently,it is also possible to quantify synaptic density in the living human brain by positron emission tomography（PET）,using a novel synaptic radio-ligand.Overall,data provided by FASS-LTP,AT,and PET may significantly contribute to the global understanding of synaptic structure and function in both healthy and diseased human brains,thus directly impacting translational research.