Synthesis and characterization of a tetranuclear copper(Ⅱ) complex with a chiral Schiff base ligand

The title complex l-[Cu^Ⅱ₄（Hvap）₂（vap）₂（MeOH）₂]（CIO₄）₂ 1 has been synthesized and characterized by EA. IR,TGA,solid-state CD spectra and X-ray single-crystal analyses（l-H₂vap’.a Schiff base ligand derived from the condensation of o-vanillin and l-2-amino-3-phenyl-l-propanol）.Complex 1 crystallizes in monoclinic system,chiral space group P2₁ with a =10.4257（18）.b = 21.695（4）,c = 15.721（3）A,β= 94.443（3）.V= 3545.1（11） ³,Z=2,Cu₄C₇₀H₇₈N₄O₂₂Cl₂.Mr= 1652.42,D_c= 1.548 g/cm³, F（000）= 1704 andμ（MoKα） = 1.338 mm^-1.The final R = 0.0682 and wR = 0.1420 for 6170 observed reflections with I > 2σ（I） and R = 0.1775 and wR = 0.1830 for all data.The structure of complex 1 contains a boat-shaped(Cu₄O₄} motif.The solid-state CD spectra confirm the chiral nature of complex 1.     

Two New Copper Complexes by H_4AQTC(Anthraquinone-1,4,5,8-tetracarboxylic Acid):Syntheses,Structures and Properties

Two new complexes[Cu(AQTC)_0.5(H₂O)₃]·3H₂O}_n (1,H₄AQTC=anthraquinone-1,4,5,8-tetracarboxylic acid) and Cu[(Py)₂C(OH)₂]₂(H₂AQTC)·2H₂O (2,(Py)₂CO=di-2-pyridyl ketone) have been prepared and characterized by elemental analyses and IR spectroscopy.X-ray crystallographic studies show that complex 1crystallizes in monoclinic space group C2/m and complex 2 in monoclinic space group P2_1/c.Complex 1 features a1D chain structure by carboxyl oxygen atoms.Complex 2 displays a mononuclear structure and anions and cations are separated.What's interesting is that the ligand of H₄AQTC with eight carboxyl oxygen atoms and two quinone oxygen atoms does not directly coordinate with metals,and only exist as a counter-anion in complex 2.Three-dimensional structures of two complexes are formed by intermolecular interactions.The thermogravimetric analyses of two complexes are investigated.The luminescent properties of complex 1 are investigated as well.     

Hydrothermal Synthesis,Crystal Structure and Properties of a New Binuclear Nickel(Ⅲ) Complex with 3-(Pyridin-2-yl)-1,2,4-triazole

A new binuclear nickel(II) complex Ni₂(HPT)_4(H₂O)₃ (1) has been hydrothermally synthesized with nickel hydroxide,3,4-pyridine dicarboxylic acid and 3-(pyridin-2-yl)-1,2,4-triazole (HPT) in the mixed solution (the volume ratio of methanol and water is 1:4).It crystallizes in tetragonal space group P4₂/n,with a=20.844(1),b=20.844(1),c=7.2463(7)A,V=3148.2(5)A³,D_c=1.587 g/cm³,Z=4,μ(Mo Ka)=1.257,F(000)=1544,the final GOOF=1.043,R=0.0437 and w R=0.1297.The crystal structure shows that the whole molecule consists of two nickel ions which are bridged by fourμ₂-η¹:η^0-3-(pyridin-2-yl)-1,2,4-triazole anions.The coordination environment of Ni(II) ion is Ni N₆,giving a distorted octahedral geometry.The thermal stability and fluorescent and magnetic properties of the complex were investigated.     

Synthesis,Structure and Fluorescence Property of New Cd-MOFs Based on a Tetraphenylethylene (TPE) Ligand

A very stable Cd^Ⅱ-organic framework,{[Cd₃(Tipe)_1.5(bpodc)₂Cl₂]·(H₂O)₂}_n(compound 1,Tipe=1,1,2,2-tetrakis(4-(imidazol-1-yl)phenyl)ethene,bpodc=benzophenone-4,4-dicarboxylic acid),has been successfully synthesized under hydrothermal conditions.Compound 1 crystallizes in the triclinic system,space group P1^-,with a=12.289(3),b=15.951(4),c=20.755(5)?,α=81.248(2)°,β=83.905(2)°,γ=89.452(2)°,V=3998.2(17)?³,Z=2,M_r=1839.59,D_c=1.528 g/cm³,μ=0.925 mm^-1,F(000)=1844,R=0.0508 and wR=0.1571 for 13998 observed reflections(I>2σ(I)).Its overall structure is a three-dimensional stacking with a porosity of 10.1%based on a calculation by PLATON.Compound 1 shows a blue fluorescence emission with the peak maximum of 501 nm(λ_ex=397 nm)by ligand-to-ligand charge transfer of TPE chromophore.And it exhibits excellent performance in detecting Fe³⁺and Cr₂O₇^2-ions in aqueous solutions as a multi-response sensor.     

One Novel Ag(Ⅰ) Compound Generated from Double Schiff-base Ligand with Quinoxaline-N-oxide as Terminal Binding Sites

One novel discrete coordination molecule with Ag^I centers,namely[Ag₃(L)₃(ClO₄)₃]·3CH₂Cl₂·6CH₃OH·1.5H₂O (1),has been synthesized based on the double Schiff-base ligand,3,6-bis[2-(4-oxidequinoxaline)-yl]-4,5-diaza-3,5-octadiene (L) and AgClO_4.The obtained Ag(I) compound was fully characterized by infrared spectroscopy,elemental analysis,and single-crystal X-ray diffraction.1 is of trigonal system space group P-31c with a=16.320(2),b=16.320(2),c=20.108(6)?,T=173(2) K,V=4638.2(16) A³,D_c=1.645 g/cm³,M_r=2297.33,Z=2,F(000)=2334,μ=0.970 mm~(–1),Goodness-of-fit=1.109,the final R=0.0776,wR=0.1813,Rindices (all data)=0.1196,wR=0.2011.The compound exhibits a triple-helical[Ag₃L₃]³⁺crown-like trimer,in which three Ag(I) atoms form an equilateral triangle with the Ag···Ag distance of 4.7 A.Uncoordinated counterions ClO₄^– and solvent molecules methanol generate the hydrogen-bonded frameworks based on discrete molecular complex building blocks.     

Synthesis,Structure and Characterization of a New Silicophosphate,K_2SiP_4O_(13), with a Six-fold Coordinated Si

A potassium silicophosphate,K2SiP4O13,has been synthesized in molten polyphosphoric acid.It crystalizes in the triclinic space group P1^-(No.2)with a=4.8327(10),b=7.7403(15),c=14.485(3)?,a=82.29(3)°,β=83.31(3)°,γ=81.95°,V=529.02(19)?³,Z=2.The crystallographic structure features 2D layers of[SiP₄O₁₃]_∞in the ab plane with counter cations K⁺residing among the layers,and the anionic framework of[SiP₄O₁₃]_∞is composed of six-fold coordinated Si atoms and tetraphosphate anions by sharing vertex O atoms.The title compound was characterized by powder X-ray diffraction,IR and Raman spectroscopies,UV-vis diffuse reflectance spectroscopy,thermogravimetry and differential scanning calorimetry.     

Synthesis,Structure and Highly Enhanced Phosphorescence of a Cadmium (Ⅱ) Coordination Polymer Assembled with 1,4-Naphthalenedicarboxylic Acid and 2-Propylimidazole

One cadmium(Ⅱ)coordination polymer[Cd(1,4-NDC)(PPIM)₂]_n(1,1,4-H₂NDC=1,4-na-phthalenedicarboxylic acid,PPIM=2-propylimidazole),has been synthesized under hydrothermal conditions and structurally characterized by elemental analysis,TGA and X-ray single-crystal diffraction.Complex 1 crystallizes in monoclinic with space group P2₁/n,a=8.8292(2),b=16.6936(4),c=16.7869(4)?,β=99.701(2)°,V=2438.86(10)?³,Z=4,Dc=1.489 Mg/m³,F(000)=1112,μ=0.932 mm^–1,S=1.076,the final R=0.0360 and wR=0.0850.In 1,the 1,4-NDC ligand bridges the Cd(Ⅱ)to form a 1D infinite chain,which are connected through N–H···O hydrogen bond to form a 2D layer then to an overall 3D supramolecular structure.The time-resolved measurements indicate that 1 shows highly prolonged phosphorescent lifetime about 452 times in comparison with that of pristine PPIM ligand.Single-crystal analysis and theory calculations indicate that strong coordination bonds and complete separation of HOMOs and LUMOs in the rigid matrix of 1 promote the long-last phosphorescence emission.     

A trinuclear {Fe2~ⅢFe~Ⅱ} complex involving both spin and non-spin transitions exhibits three-step and wide thermal hysteresis

The engineering of switchable molecules with magnetic multistability is lying on the cutting-edge research topics for integrating multi-switches and ternary memory devices.Here we presented a cyanide-bridged{Fe₂~ⅢFe~Ⅱ}desolvated complex{[(pzTp)Fe~Ⅲ-(CN)₃]₂[Fe~Ⅱ(L)]}(1),obtained through single-crystal-to-single-crystal (SCSC) transformation from its solvated phase{[(pzTp)-Fe~Ⅲ(CN)₃]₂[Fe~Ⅱ(L)]}·2CH₃OH·5H₂O (1·sol).Remarka...     

DMAO-activated Rare-earth Metal Catalysts for Styrene and Its Derivative Polymerization

The catalytic performance of rare-earth metal dialkyl complexes in combination with DMAO(dry methylaluminoxane) is explored.In the presence of 60 equivalents of DMAO,the half-sandwich complex(C₁₃H₈ CH₂ Ph)Sc(CH₂ SiMe₃)₂(THF)(1) is inert for styrene polymerization,but(C₅ Me₄ Ph)Sc(CH₂ C₆ H₄ NMe₂-o)₂(2) converts 18% styrene into syndiotactic polystyrene.Und...     

Metal complex with terpyrindine derivative ligand as highly selective colorimetric sensor for iron(Ⅲ)

A new metal complex[MnL₂]（NO₃）₂·CH₃CN（1） was synthesized by reaction of 4’-4-（l,2,4-triazol-l-yl）phenyl -2,2’:6’,2"-terpyridine（L） with manganese nitrate.The structure of the complex was determined by X-ray crystallography.The results of UV-vis studies showed that the complex exhibits colorimetric sensing ability for Fe³⁺,which can be observed by naked eye.     

High-temperature dielectric switch and second harmonic generation integrated in a stimulus responsive material

Stimulus re s ponsive materials can provide a variety of desirable properties in one equipment unit,such as optoelectronic devices,data communications,actuators,memories,sensors and capacitors.However,it remains a large challenge to design such stimulus responsive materials,especially functional materials having both dielectric switch and second harmonic generation(SHG).Here,a new stimuli-responsive switchable material [(CH₃)₃N(CH₂)₂Cl]₂]Mn(SCN)₄(H₂O)₂] was discovered as a potential secondharmonic generation(SHG) dielectric switch.It is worth noting that it has SHG characteristics before and after undergoing reversible high-temperature phase transitions.In this work,we successfully refined the tetramethylammonium cation to obtain a quasi-spherical cation,which is tetramethylchloroethylamine(TMCEM) cation.By substituting H with a halogen,the increased steric hindrance of the molecular makes energy barrier increased,resulting in the reversible high-temperature phase transition.At the same time,the interactions of quasi-spherical cations and [Mn(SCN)₄(H₂O)₂]^2- anions affect a noncentrosymmetric structure to induce the SHG effect.These findings provide a new approach to design novel functional switch materials.     

In-situ construction of a Mg-modified interface to guide uniform lithium deposition for stable all-solid-state batteries

Uniform lithium(Li)deposition in all-solid-state Li metal batteries is greatly influenced by the anode/electrolyte interface.Herein,a Mg-modified interface was constructed via the simple in-situ electrochemical reduction of Mg²⁺from Mg(TFSI)₂ in polyethylene oxide(PEO)and a Li bis(trifluoromethane)sulfoni mide(Li TFSI)formulae.As confirmed by cryogenic transmission electron microscopy,the anode/electrolyte interface exhibited hybrids consisting of crystalline Mg,Li₂O,and Li dots embedded in an amorphous polymer electrolyte.The crystalline Mg dots guided the uniform Li nucleation and growth,inducing a smoother anode/electrolyte interface compared with the pristine electrolyte.With 1 wt%Mg(TFSI)₂ in the PEO-Li TFSI electrolyte,the Mg-modified electrolyte enabled the Li/Li symmetric cells with cycling performance of over 1700 and 1400 h at current densities of 0.1 and 0.2 m A cm^-2,respectively.Moreover,the full LFP/Li cells using the novel Mg-modified electrolyte delivered a cycling lifespan of over 450 cycles with negligible capacity loss.     

The guest CH3CN molecule triggers solid-state photochromism in a Cu2I2-based MOF for advanced time-dependent encryption and inkless erasable printing

It remains a big challenge to develop solid-state stimuli-responsive materials for time-dependent information encryption and inkless erasable printing with long retention times. Herein, a 2D Cu₂I₂-based MOF with photoresponsive spiropyran(SP) groups orderly installed on its skeleton is developed. The structural isomerization from SP to colored merocyanine(MC) form can be triggered by removing the CH₃CN guests. Besides, the degree of structural isomerization and t...     

Electrochemical behavior of Ru(H_2bpp)_2(PF_6)_2 and its interaction with bovine serum albumin(BSA)

In this paper,it was found that Ru（H₂bpp）₂（PF₆）2（H₂bpp = 2,6-bis（pyrazol-3-yl）pyridine） complex had excellent electrochemical activity at the carbon paste electrode in the buffer solution of Tris-HCl（pH 7.0） with a couple reversible redox peaks at 0.296 V and 0.348 V,respectively.Voltammetry was used to investigate the electrochemical behavior of Ru（H₂bpp）₂（PF₆）₂ and the interaction between Ru（H₂bpp）₂（PF₆）₂ and bovine serum albumin（BSA）.In the present of BSA,the oxidation peak current of Ru（H₂bpp）₂（PF₆）₂ complex was decreased linearly and the decrease of oxidation peak current of Ru（H₂bpp）₂（PF₆）₂ is proportional to BSA concentration from 0.1 to 2.5 mg/L with a detection limit 0.02 mg/L.     

High-humidity Sensor of a New Trinuclear Ti3-Oxo Cluster

Crystalline polyoxo-titanium clusters （PTCs）,as a molecular model of TiO₂ nanomaterials,have attracted unprecedented attention due to their designable structure,tunable band gap,catalysis,and photochromic properties.A new trinuclear Ti₃-oxo cluster,[Ti₃（μ₂-O）(μ₃-O)（abz）₆（OⁱPr）₂]·CH₃CN·H₂O （Ti3）,was synthesized by solvothermal method with a yield of 60%by using 4-aminobenzoic acid as liga...     

Synthesis,Crystal Structure and DNA-Binding Property of a New Cu(Ⅱ) Complex Based on 4-(Trifluoro-methyl)nicotinic Acid

A new complex[Cu_1.5(tfc)₃(H₂O)₄]·3H₂O (1,Htfc=4-(trifluoro-methyl) nicotinic acid) has been synthesized and characterized by X-ray single-crystal diffraction,elemental analysis,IR spectra and thermogravimetric analysis.1 belongs to orthorhombic system,space group Pccn with a=44.507(2),b=10.7710(6),c=11.7544(7)?,V=5634.9(6)?³,Z=1,D_c=1.803 mg·cm^-3,F(000)=3068,μ=1.266 mm^-1,the final R=0.0488and w R=0....     

Synthesis,Crystal Structure and Antitumor Activity of a Ca(Ⅱ) Coordination Polymer Based on 4-Acetylphenoxyacetate Ligands

A novel Ca(Ⅱ) coordination polymer,[Ca L₂(H₂O)₂]_n (1,HL=4-acetylphenoxyacetic acid) has been synthesized with 4-acetylphenoxyacetic acid,Ca(ClO_4)₂·4H₂O and Na OH as raw materials.Complex 1 was characterized by elemental analysis and single-crystal X-ray diffraction analysis.The results show that the Ca(Ⅱ)ion is eight-coordinated in a distorted triangular dodecahedral geometric configuration with six carboxylate Oatoms of four L ligands and two O atoms of two coordinated water molecules.Complex 1 forms a one-dimensional chained structure by the bridging effect of carboxylate O atoms.The antitumor activity of HLligand and complex 1 has also been investigated.     

Synthesis, structure and characterization of the trinuclear copper (Ⅰ) complex [Cu_3(μ_3Br)_2(dppm)_3]Br

The novel trinuelear copper(I) complex [Cu3(μ3-Br)2(dppm)3]Br has been obtained by reaction of bis(diphenyl-phosphino)methane (dppm) with cupric bromide. The title complex was characterized by single-crystal X-ray analysis, elemental analysis, molecular weight determination, 31P NMR and its conductivity was also measured. The [Cu3(dppm)3Br2] cation consists of a triangular array of copper atoms, with dppm ligands (Ph2PCH2PPh2) bridging each edge of the triangle and two triply bridging Br groups bound to the two faces of the Cu3 unit. Crystallographic data: monoclinic, space group P21/c, a = 1.4739(4) , b = 1.7708(5), c = 2.8395(8) nm, β= 97.16(3)°, V = 7.353nm3, Z = 4,F(000)= 3296, Dcalc = 1.472 g/cm3, μ= 26.478 cm-1, R = 0.06, Rw = 0.08, 4654 reflections observed with I > 3σ(I).     

Synthesis,Crystal Structure,Theoretical Calculation,and Photophysical Property of a New Cd(Ⅱ) Complex Based on N-heterocyclic Ligand and Isophthalic Acid

A new metal-organic coordination complex[Cd(imp)(m-bdc)]_n (1,ipm=5-(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)-2-methoxyphenol,m-bdc=isophthalic acid) has been synthesized by hydrothermal reaction and characterized by elemental analysis,thermogravimetric (TG) analysis,infrared spectrum (IR) and single-crystal X-ray diffraction.Complex 1 crystallizes in monoclinic,space group C2/c with a=15.373(5),b=16.719(5),c=19.406(6)A,β=106.995(5)°,V=4770(2)A³,C₂₈H₁₈Cd N₄O₆,M_r=618.86,D_c=1.724 g/cm³,μ(Mo Kα)=0.971 mm^–1,F(000)=2480,Z=8,the final R=0.0391 and w R=0.1044 for 4701 observed reflections (I>2σ(I)).Single-crystal X-ray diffraction reveals that 1 exhibits a one-dimensional (1D) double-chain architecture,and the H-bond intersections link the 1D double-chain architecture into a 2D layer structure.TG analysis shows clear courses of weight loss,which corresponds to the decomposition of different ligands.We also study the luminescent properties of complex 1.In addition,to elucidate the essential electronic characters of this complex,theoretical calculation analysis was performed by the PBE0/LANL2DZ method in Gaussian 03 Program.     

High selectively oxidative bromination of toluene derivatives by the H_2O_2-HBr system

An aqueous solution of hydrogen peroxide and hydrogen bromide illuminated by a 60 W incandescent light bulb serves as a source of bromine radicals.Various substituted toluenes（NO₂,Cl,Br,H,CH₃） were high selectively brominated at the benzyl position for monobromination in CH₂C1₂ at ice water with catalyst free.This simple but effective bromination of toluene derivatives with an aqueous H₂O₂-HBr system is characterized with the use of inexpensive reagents and a lower impact on the environment, which make it a good alternative to the existing bromination methods.