共查询到20条相似文献,搜索用时 187 毫秒
1.
《中国化学快报》2023,34(3):107291
Herein, we report a new metal-organic framework with an AIE ligand (H4TCPP = 2,3,5,6-tetra-(4-carboxyphenyl)pyrazine) and Mg2+ ions, that is, [Mg2(H2O)4TCPP]·DMF·5CH3CN (Mg-TCPP, TCPP = tetra-(4-carboxyphenyl)pyrazine) for detection of nitroaromatic explosives. Due to the coordination effect and restricted intramolecular rotation, Mg-TCPP exhibits bright blue light. As a fluorescent sensor, Mg-TCPP exhibits high selectivity and sensitivity for sensing 2,4,6-trinitrophenol (TNP) by quenching behaviors with the Stern-Volmer quenching constant (KSV) of 3.63×105 L/mol and achieves the low limit of detection of 25.6 ppb, which is beyond most of the previously reported fluorescent materials. Notably, the portable Mg-TCPP films are prepared and it can be used for rapid and sensitive TNP detection in a variety of environments including organic solvent and aqueous solution. Moreover, TNP vapor can be detected within 3 min by naked eye and the film could be regenerated under simple solvent cleaning. 相似文献
2.
The detection of nitroaromatic compounds, best known as raw materials in explosives preparations, is important in many fields including environmental science, public security and forensics. CdSe quantum dots capped with PAMAM-G4 dendrimer were synthetized in water and used for the detection of trace amounts of three nitroaromatic compounds: 4-methoxy-2-nitrophenol (MNP), 2-amine-5-chloro-1,3-dinitrobenzene (ACNB) and 3-methoxy-4-nitrobenzoic acid (MNB). To increase the apparent water solubility of these compounds α-cyclodextrin (α-CD) was used to promote the formation of inclusion complexes. The studied nitroaromatic compounds (plus α-CD) significantly quenched the fluorescence intensity of the nanocomposite with linear Stern-Volmer plots. The Stern-Volmer constants (standard deviation in parenthesis) were: MNB, KSV = 65(5) × 104 M−1; ACNB, KSV = 19(2) × 104 M−1; and, MNP, KSV = 33(1) × 102 M−1. These constants suggest the formation of a ground state complex between the nitroaromatric compounds and the sensor which confers a relatively high analytical sensitivity. The detection sensibilities are about 0.01 mg L−1 for MNB and ACNB and about 0.1 mg L−1 for MNP. No interferences or small interferences are observed for trinitrotoluene [KSV = 10(2) × 102 × M−1], 2,4-dinitrotoluene [KSV = 20(3) × 10 M−1], 2,6-dinitrotoluene [KSV = 11(4) × 10 M−1] and nitrobenzene [KSV = 2(1) × 103 × M−1]. 相似文献
3.
3D nanographene 1, with three HBC units arraying in the 3D triptycene scaffold, displayed strong intrinsic fluorescence properties and could be used as a detector for nitroaromatic explosives such as TNP with quenching efficiency Ksv of 1.8 × 104 M−1 and sensitivity of 2.4 ng/mm2, respectively. 相似文献
4.
Santanu Chowdhury Palash Mal Chandrama Basu Helen Stoeckli–Evans Soma Mukherjee 《Polyhedron》2009,28(17):3863-3871
New luminescent mononuclear and dinuclear copper(II) (S = 1/2) complexes [Cu(HL)(H2O)2](ClO4)2 (1a) and [Cu2(HL)2(μ-SO4)2]·2H2O (1b) were synthesized with the acyclic tridentate pyridine-2-carboxaldehyde-2-pyridylhydrazone ligand, HL (1). Interestingly, the mononuclear complex 1a can be converted into the disulfate bridged dimeric copper(II) complex 1b by passing freshly prepared SO2 through the basic medium. On excitation at 290 nm, the ligand fluoresces at 364 nm due to an intraligand 1(π–π1) transition. Upon complexation with copper(II), the emission peak is slightly blue shifted (356 nm, F/F0 0.76 for 1a and 354 nm, F/F0 0.89 for 1b) with a little quenching in the emission intensity. The association constants (Kass (5.06 ± 0.004) × 104 for 1a and Kass (5.46 ± 0.006) × 104 for 1b at 298 K) and the thermodynamic parameters have been determined by UV–Vis spectroscopy. The molecular structure of the complex 1b (Cu?Cu 4.456 Å) has been determined by single crystal X-ray diffraction studies. The complex 1b exhibits a strong interaction towards DNA as revealed from the Kb (intrinsic binding constant) 6.3 × 104 M?1 and Ksv (Stern–Volmer quenching constant) 2.93 values. 相似文献
5.
A new Zr-substituted sandwich-type polyoxometalate, H8K3[Zr3K2(μ3-O)2(μ2-OH)(H2O)2(A-α-PW9O34)2]·2Cl?·7H2O (1), has been made under hydrothermal conditions. 1 was characterized by IR spectrum, thermogravimetric analysis, powder X-ray diffraction and single-crystal X-ray diffraction, respectively. Crystal data for 1: tetragonal space group P42212, a = 24.0096(3), b = 24.0096(3), c = 14.7416(3) Å, V = 8498.0(2) Å3 and Z = 4. Single crystal X-ray structure analysis reveals that 1 exhibits a three-dimensional framework structure based on Zr3K2-substituted sandwich-type polyanions [Zr3K2(μ3-O)2(μ2-OH)(H2O)2(PW9O34)2]9? linked by K–O chains. UV–Vis spectrum indicates that 1 is a wide-gap semiconductor. In addition, the SHG of 1 was also investigated. 相似文献
6.
Mercedes Alvarez Alcalde Alvaro Antelo Aida Jover Francisco Meijide José Vázquez Tato 《Journal of inclusion phenomena and macrocyclic chemistry》2009,63(3-4):309-317
Two βCD dimers (linked by succinic acid, 2, or ethylenediaminetetraacetic acid, EDTA, 3, bridges) and a negatively charged monomer derivative of βCD, 1, have been synthesized and their ability to solubilize cholesterol in aqueous solution was studied. The three compounds exhibit a great capacity in solubilizing cholesterol as, for instance, concentrations up to 6 mM of cholesterol were measured in the presence of 25 mM of 3. The phase-solubility diagrams of the two dimers exhibit A L type profiles while the monomer 1 follows an A P isotherm. The cholesterol/dimer complexes have 1:1 stoicheiometries while monomer 1 forms two complexes with molar ratios of 1:1 and 1:2 (cholesterol/1). The equilibrium constants are K 1:1 = (5.9 ± 0.3) × 104 M?1 and K 1:1 = (8.8 ± 0.2) × 104 M?1 for 2 and 3, respectively, and K 1:1 = 73 ± 19 M?1 and K 1:2 = 204 ± 65 M?1 for 1. The comparison of K 1:1(3) with the product K 1:1 × K 1:2 (1) reveals that a chelate effect in binding the cholesterol by 3 exists. The structure of the cholesterol/3 complex was studied by ROESY experiments and by molecular dynamics simulations. 相似文献
7.
Xiong Gan Zhiming Zhang Shuang Yao Weilin Chen Enbo Wang Hong Zhang 《Journal of Cluster Science》2008,19(2):401-410
Two new one-dimensional chain-like compounds, K4Na4[Mn2(H2O)8Mn4(H2O)2(GeW9O34)2] · 20.5H2O (1) and K2Na4Cu2(H2O)12[Cu(H2O)2Cu4(H2O)2(SiW9O34)2] · 15H2O (2), constructed from the sandwich-type clusters, have been obtained by the routine synthetic reactions in aqueous solutions, and their structures were determined by X-ray single crystal diffraction analysis. The crystal data is following: for 1, space group, monoclinic, P 21/n, a = 16.693(3) Å, b = 14.935(3) Å, c = 20.090(4) Å, β = 92.23(3)°, V = 5004.7(17) Å3, Z = 2; For 2, space group, triclinic, P ?1, a = 11.744(2) Å, b = 13.415(3) Å, c = 17.609(4) Å, α = 73.08(3)°, β = 82.68(3)°, γ = 65.18(3)°, V = 2409.1(8) Å3, Z = 1. The crystal structure of 1 shows a 1D ladder-like chain, built up of the sandwich anions [Mn4(H2O)2(GeW9O34)2]12? and the Mn2+ ions. Compound 2 is a polymeric chain, composed of the Cu-substituted sandwich-type anions [Cu4(H2O)2(SiW9O34)2]12? linked by the Cu(H2O)4 clusters. These extended materials based on the sandwich-type polyoxoanions are rarely reported in the POM chemistry. 相似文献
8.
Prasant Kumar Nanda Manindranath Bera Ana Maria da Costa Ferreira Armando Paduan-Filho Debashis Ray 《Polyhedron》2009,28(18):4065-4071
The reaction of Cu(ClO4)2·6H2O with dimethylglyoxime (H2dmg) in a 1:1 mole ratio in aqueous methanol at room temperature affords the dinuclear complex [Cu2(μ-Hdmg)4] (1). Reaction of 1 with [Cu(bpy)(H2O)2](ClO4)2 (bpy = 2,2′-bipyridine) in a 1:1 mole ratio in aqueous methanol at room temperature yields the tetranuclear complex [Cu4(μ-Hdmg)2(μ-dmg)2(bpy)2(H2O)2](ClO4)2 (2). The direct reaction of Cu(ClO4)2·6H2O with H2dmg and bpy in a 2:2:1 mole ratio in aqueous methanol at room temperature also yields 2 quantitatively. The complexes 1 and 2 were structurally characterized by X-ray crystallography. Unlike the binding in Ni/Co-dmg, two different types of N?O bridging modes during the oxime based metallacycle formation and stacking of square planar units have been identified in these complexes. The neutral dinuclear complex 1 has CuN4O coordination spheres and complex 2 consists of a dicationic [Cu4(μ-Hdmg)2(μ-dmg)2(bpy)2(H2O)2]2+ unit and two uncoordinated ClO4? anions having CuN4O and CuN2O3 coordination spheres. The two copper(II) ions are at a distance of 3.846(8) Å in 1 for the trans out of plane link and at 3.419(10) and 3.684(10) Å in 2 for the trans out of plane and cis in plane arrangements, respectively. The average Cu–Noxime distances are 1.953 and 1.935 Å, respectively. The average basal and apical Cu?Ooxime distances are 1.945, 2.295 and 2.429 Å. The UV–Vis spectra of 2 is similar to the spectrum of the reaction mixture of 1 and [Cu(bpy)(H2O)2]2+. Variable temperature magnetic properties measurement shows that the interaction between the paramagnetic copper centers in complex 1 is antiferromagnetic in nature. The EPR spectra of frozen solution of the complexes at 77 K consist of axially symmetric fine-structure transitions (ΔMS = 1) and half-field signals (ΔMS = 2) at ca. 1600 G, suggesting the presence of appreciable Cu–Cu interactions. 相似文献
9.
Reactions of CuCl2, m-nitrobenzoic acid (HNBA) and NaOH with 2,2′-bipyridine (bpy) or 1,10-phenanthroline (phen) in aqueous ethanol afforded two Cu(II) complexes Cu(bpy)(NBA)2, 1, and [Cu(phen)(H2O)2(NBA)](NBA), 2. The monomolecular Cu(bpy)(NBA)2 moieties are both bridged by hydrogen bonding interactions and interlayer π *–π *stacking interactions to form a 3D (3,4,6)-connected supramolecular architecture with the Schäfli symbol of (44·62)(44·66·85)(63)2. Complex 2 crystallizes in a noncentrosymmetric space group P21 where all molecules show the same orientation along the polar b axis. Preliminary investigations suggest that 2 exhibits ferroelectric hysteresis loops at room temperature with remanent polarization (P r) of ca. 0.09 μC cm?2 and coercive electric fields of 2.53 kV cm?1, respectively. It may be a potential ferroelectric with a relatively large spontaneous polarization (P s) of 0.22 μC cm?2. Furthermore, permittivity property measurements reveal a dielectric constant (ε r) of 6.36. Variable-temperature (2–300 K) magnetic susceptibility measurements showed the presence of weak ferromagnetic interactions between the Cu(II) ions for both 1 and 2. 相似文献
10.
The reactions of [MIII(CN)6]3? (M = Cr or Co) with CuII complexes of a tridentate schiff base [Cu(aemp)Cl] or [Cu(aemp)Ac]2 (Haemp = 2-[(2-amino-ethylimino)-methyl]-phenol) give rise to 1D cyanide-bridged bimetallic coordination polymers [Cu4(aemp)4(H2O)2][Cr(CN)6]Cl (1) and [Cu3(aemp)3(H2O)][Co(CN)6]·2H2O·MeOH (2). In complex 1, the six cyanide ligands of the [Cr(CN)6]3? moiety are involved in bridging, while in complex 2 only five cyanide ligands act as bridges to give a neutral chain. Magnetic studies reveal that complex 1 exhibits intermetallic ferromagnetic coupling, with J = 8.2 cm?1. 相似文献
11.
An aggregation enhanced emission (AEE) polyurethane named STMPU-211 containing 0.13% mole concentration of 4,4′-((1Z,3Z)-1,4-diphenylbuta-1,3-diene-1,4-diyl) dibenzaldehyde (TABDAA) in the soft segments was synthesized and proved to be sensitive to Fe3+ and nitroaromatic explosives. The fluorescence of the AEE polyurethane was reduced in the presence of Fe3+, and almost quenched when 5000?μM Fe3+ was added. Meanwhile, the fluorescence intensity of STMPU-211 solution in DMF/water mixture was decreased when explosives like 2,4,6-trinitrophenol (PA) and 3-nitro-1,2,4-triazol-5-one (NTO) were applied. Especially, the quenching coefficient KSV value of PA was 5.7?×?106?M?1, confirming that the polyurethane STMPU-211 could be a highly sensitive sensor for the detection of PA. Therefore, AEE polyurethanes with low concentration of TABDAA have promising applications in biological probe, environment monitoring and antiterrorism fields. 相似文献
12.
《Journal of Coordination Chemistry》2012,65(8):1387-1401
A new copper(II) complex [Cu(adefovir)2Cl2], where adefovir = adefovir dipivoxil drug, was synthesized and characterized by using different physicochemical methods. Binding interaction of this complex with calf thymus DNA (ct-DNA) has been investigated by multi-spectroscopic techniques and molecular modeling study. The complex displays significant binding properties of ct-DNA. The results of fluorescence and UV–vis absorption spectroscopy indicated that, this complex interacted with ct-DNA in a groove-binding mode, and the binding constant was 4.3(±0.2) × 104 M?1. The fluorimeteric studies showed that the reaction between the complex and ct-DNA is exothermic (ΔH = 73.91 kJ M?1; ΔS = 357.83 J M?1 K?1). Furthermore, the complex induces detectable changes in the CD spectrum of ct-DNA and slightly increases its viscosity which verified the groove-binding mode. The molecular modeling results illustrated that the complex strongly binds to the groove of DNA by relative binding energy of the docked structure ?5.74 kcal M?1. All experimental and molecular modeling results showed that the Cu(II) complex binds to DNA by a groove-binding mode. 相似文献
13.
Yang Wang Jia-Wei Mao Chao Ding Zhi-Quan Pan Jian-Fen Li Hong Zhou 《Transition Metal Chemistry》2014,39(1):111-118
Two unsymmetrical complexes, [NiL1]ClO4 (1) and [NiL2]ClO4 (2) have been synthesized and characterized by IR, UV, ES-MS and single crystal X-ray diffraction, where HL1 and HL2 are, respectively, the [1+1] condensation products of 2,6-diformyl-4-X-phenol (X = F or CH3) with N 1-(2-aminoethyl)-N 2-(4-nitrobenzyl) ethane-1,2-diamine. The coordination geometry of the metal in both complexes can be approximately described as square planar with a mean plane deviation of 0.032 Å in complex 1 and 0.027 Å in complex 2, respectively. The binding activities of the complexes toward calf-thymus DNA have been analyzed by spectroscopy and viscosity methods. The binding constants of 1 and 2 obtained from UV spectroscopic studies are 5.43 × 105 and 1.83 × 105 M?1, respectively, while the linear Stern–Volmer quenching constants obtained from fluorescence spectroscopic studies are 0.83 × 103 and 0.71 × 103 M?1, respectively. The cyclic voltammograms of the complexes show a pseudo-reversible electrochemical process. 相似文献
14.
Four azido-bridged dinuclear Mn(II) complexes, [Mn2(phen)4 μ-1,1-N3)2][FeIII(bpmb)(CN)2]2·H2O (1), [Mn2(phen)4(μ-1,1-N3)2][FeIII(bpClb)(CN)2]2·H2O (2), and [Mn2(phen)4(μ-1,1-N3)2][MIII(bpdmb)(CN)2]2·3H2O [M = Fe (3) or Cr (4); phen = 1,10-phenanthroline, bpmb2– = 1,2-bis(pyridine-2-carboxamido)-4-methyl-benzenate, bpClb2– = 1,2-bis(pyridine-2-carboxamido) 4-chloro-benzenate, bpdmb2– = 1,2-bis(pyridine-2-carboxamido)-4,5-dimethyl-benzenate], have been synthesized using the synthetic strategy of large anion inducement. Single-crystal X-ray diffraction analysis reveals that all four complexes are doubly end-on (EO) azido-bridged binuclear Mn(II) complexes with two large [M(L)(CN)2]– (L = bpmb2?, bpClb2?, or bpdmb2?) building blocks acting as charge-compensating anions. The magnetic properties of the complexes have been investigated, and the results indicate that the magnetic coupling between two Mn(II) centers through the EO azide bridges is ferromagnetic, with J = 0.64(1) cm?1 for 1, 0.43(1) cm?1 for 2, 0.50(1) cm?1 for 3, and 0.66(2) cm?1 for 4. The magneto-structural relationships of EO azido-bridged Mn(II) systems are discussed. 相似文献
15.
Two novel heterotrimetallic tetranuclear complexes [Cu(H2L)(CH3OH)]2Gd(DMF)Fe(CN)6·2H2O·DMF (1) and [Cu(H2L)(CH3OH)]2Tb(H2O)0.57(DMF)0.43Fe(CN)6·5.5H2O (2) are reported (H4L = N,N′-ethylenebis(3-hydroxysalicylidene)). The central Ln(III) ion is surrounded by two neutral [Cu(H2L)(CH3OH)] moieties, forming a Cu2Ln trinuclear unit. The [Fe(CN)6]3? anion is weakly coordinated to one Cu(II) ion of [Cu(H2L)(CH3OH)] through a cyanide nitrogen atom with the N–Cu distance of ca. 3.2 Å. Magnetic susceptibility measurements indicate the presence of overall ferromagnetic interactions in complexes 1 and 2. The magnetic coupling constant in complex 1 is J Cu1Gd1 = 4.54 cm?1 and J Cu2Gd1 = 7.97 cm?1 based on \( \hat{H} = - 2J_{\text{Cu1Gd1}} \hat{S}_{\text{Cu1Gd1}} - 2J_{\text{Cu2Gd1}} \hat{S}_{\text{Cu2Gd1}} \) . Dynamic AC magnetic susceptibility studies reveal that complex 2 shows frequency-dependent out-of-phase signals, typical of single molecule magnet behavior. The energy barrier for complex 2 under a 2 kOe applied DC magnetic field is 13 K. 相似文献
16.
From extraction experiments and γ-activity measurements, the exchange extraction constants corresponding to the general equilibrium M+(aq) + 1·Cs+(nb) ? 1·M+(nb) + Cs+(aq) taking place in the two-phase water–nitrobenzene system (M+ = Li+, Na+, H+, NH4 +, Ag+, K+, Rb+, Tl+; 1 = dibenzo-30-crown-10; aq = aqueous phase, nb = nitrobenzene phase) were determined. Furthermore, the stability constants of the 1·M+ complexes in water-saturated nitrobenzene were calculated; they were found to increase in the series of Cs+ < H+, Ag+ < NH4 + < Na+ < Rb+ < Li+ < K+, Tl+. 相似文献
17.
Farukh Arjmand Mubashira Aziz Mala Chauhan 《Journal of inclusion phenomena and macrocyclic chemistry》2008,61(3-4):265-278
New water soluble Co(II) 1, Ni(II) 2 and Cu(II) 3 complexes of 4,15-bis(2-hydroxyethyl)-2,4,6,13,15,17-hexaazatricyclodocosane Co(II) were synthesized and characterized by various techniques, viz. elemental analysis, conductivity measurements, infrared, electronic, ESI-MS, 1H and 13C NMR spectroscopy. Molar conductance measurements in aqueous solution showed that complexes 1, 2 and 3 are ionic in nature. On the basis of spectroscopic data, a square planar geometry was assigned to the complexes involving four N-atoms of the two cyclohexane moieties. Interaction studies of 1 and 3 with CT-DNA were carried using UV/Visible absorption spectroscopy, fluorescence spectrophotometry, cyclic voltammetry and viscosity measurements. Absorption spectral traces reveal 27.7 and 23.3% hyperchromism for complexes 1 and 3, respectively indicative of strong binding to CT-DNA. These results were authenticated by fluorescence quenching experiments and viscosity measurements. The intrinsic binding constants K b of 1 and 3 are 2.94 × 104 and 2.71 × 104 M?1, respectively. Early transition metals show preference for O6 position while later ones copper and cobalt prefer N7 position of DNA base guanine. To validate this hypothesis, interaction studies of copper (II) and cobalt (II) complexes were carried out with 5′GMP, which revealed electrostatic interactions are more favored along with hydrogen bonding than coordinate covalent interaction to N7 position of guanine. 相似文献
18.
《Journal of Coordination Chemistry》2012,65(12):2054-2064
Two iron(II) complexes, [FeII(pytBuN3)2](FeCl4) (1) and [FeII(pytBuMe2N3)Cl2] (2), with sterically constrained pytBuN3 and pytBuMe2N3 chelate ligands (pytBuN3 = 2,6-bis-(aldiimino)pyridyl; pytBuMe2N3 = 2,6-bis-(ketimino)pyridyl), have been synthesized and characterized by elemental analysis, IR, UV–vis spectra, and preliminary X-ray single-crystal diffraction. The latter revealed that Fe(II) in 1 is six-coordinate by six nitrogen donors from two bisiminopyridines in a distorted octahedron. Complex 2 reacts with thiourea with a second-order rate constant k2 = (2.50 ± 0.05) × 10?3 M?1 s?1 at 296 K, and the reaction seemed to be slow. In a similar way, the interaction of 2 and DNA was studied by fluorescence and absorption spectroscopy. The results revealed that 2 caused fluorescence quenching of DNA through a dynamic quenching procedure. The binding constants KA, Kapp, and KSV as well as the number of binding sites between 2 and DNA were determined. 相似文献
19.
《印度化学会志》2021,98(9):100125
A new Cu(II) coordination framework {[Cu(4-abpt)(μ3-SO42-)(H2O)]·3H2O}∞ (1) based on the Cu–SO42- inorganic layer and the bent dipyridyl ligand was obtained under solvothermal conditions (4-abpt = 4-amino-3,5-bis(4-pyridyl)-1,2,4-triazole). The compound displays a three-dimensional (3D) “pillar-layer” framework, which can be simplified into a 3,5-connected gra topology. Furthermore, the magnetic properties of 1 have been investigated. As a result, compound 1 displays a weak antiferromagnetic interaction among the Cu(II) centers. 相似文献
20.
Romrawee Pratumwieng Atittaya Meenongwa Rosa F. Brissos Patrick Gamez Yanee Trongpanich Unchulee Chaveerach 《Transition Metal Chemistry》2017,42(4):311-322
Cu(II) complexes of the tridentate ligand N-(methylpyridin-2-yl)-amidino-O-methylurea (L), namely [Cu(L)Cl2] and [Cu(L)ClO4]ClO4, have been investigated for interactions with DNA by spectroscopic methods and viscosity measurements. Both complexes bind to DNA through non-intercalative interactions. [Cu(L)Cl2] (K b = 2.81 × 105 M?1) shows similar DNA-binding potential to [Cu(L)ClO4]ClO4 (K b = 1.57 × 105 M?1). Investigation of the chemical nuclease properties toward plasmid pBR322 DNA by gel electrophoresis and atomic force microscopy (AFM) suggests that both complexes are able to cleave the supercoiled form (Form I) to the nicked (Form II) and linear forms (Form III) through an oxidative pathway. The possible reactive oxygen species have been investigated by the use of scavengers, indicating that hydroxyl radicals may be involved in the DNA cleavage mechanism. Both of these complexes show similar activities against selected human cancer cell lines. 相似文献