共查询到20条相似文献,搜索用时 31 毫秒
1.
Abedien Zabardasti Sayed Asad Shangaie 《Journal of the Iranian Chemical Society》2016,13(10):1875-1886
Fifteen new complexes of transition metals were designed using three Schiff base ligands and aldol condensation of 2,3-diaminopyridine with 5-R-2-hydroxybenzaldehyde (R = F, Cl, Br) in the 1:2 molar ratio. The tetradentate ligands N,N′-bis(5-R-2-hydroxybenzaldehyde) pyridine were acquired with the common formula H2[(5-R-sal)2py] and characterized by IR, UV–Vis spectra, 1H-NMR and elemental analysis. These ligands produce 1:1 complexes M[(5-R-sal)2py] with Fe(III), Ni(II), Co(III), V(IV) and U(VI) metal ions. The electronic property and nature of complexes were identified by IR, UV–Vis spectra, elemental analysis, X-ray crystallography and cyclic voltammetric methods. The catalytic activity of complexes for epoxidation of styrene with UHP as primary oxidant at minimal temperature (10 °C) has been planned. The spectral data of the ligands and their complexes are deliberate in connection with the structural changes which happen due to complex preparation. The electrochemical outcome has good conformability with what suggested for electronic interaction among metal center and ligand by the UV–Vis and IR measurements. 相似文献
2.
Muhammed Bilaal Ismail Irvin Noel Booysen Matthew Piers Akerman 《Transition Metal Chemistry》2017,42(5):405-412
The respective coordination reactions of trans-[ReOCl3(PPh3)2] with N-[(4-oxo-4H-chromen-3-yl)methylidene]thiophene-2-carbohydrazide (Hchrtc) and N-[1,3-benzothiazol-2-ylmethylidene]thiophene-2-carbohydrazide (Hbztc) afforded two novel oxorhenium(V) complexes, cis-[ReOCl2(chrtc)(PPh3)] (1) and cis-[ReOCl2(bztc)(PPh3)] (2). These metal compounds were elucidated spectroscopically and their solid-state structures determined by single-crystal X-ray diffraction. The redox properties of the metal complexes were probed using cyclic and square wave voltammetry. The DNA interaction capabilities of 1 and 2 were gauged via UV/Vis spectroscopy DNA titrations and gel electrophoresis studies. A correlation is identified between the DNA cleavage observations and the redox potentials of the metal complexes. 相似文献
3.
Jia Zhang Chong-Chen Wang Peng Wang Xin-Xing Guo Shi-Jie Gao 《Transition Metal Chemistry》2016,41(6):637-645
The complexes [Ag4(dpe)4]·(btec) (1) and [Ag4(bpy)4]·(btec)·12H2O (2) (dpe = 1,2-di(4-pyridyl)ethylene, bpy = 4,4′-bipyridine, H4btec = 1,2,4,5-benzenetetracarboxylic acid) have been synthesized in aqueous alcohol/ammonia by slow evaporation at room temperature and characterized by elemental analysis, single-crystal X-ray diffraction, FTIR, UV–Vis and luminescence spectroscopies. Both complexes are composed of 1D infinite cationic [Ag/dpe(bpy)] n n+ chains and discrete btec4? anions. Their three-dimensional supramolecular structures are built up of cationic sheets formed from [Ag/dpe(bpy)] n n+ units via weak Ag…Ag and Ag…N interactions, plus anionic btec4? sheets featuring electrostatic, π–π and hydrogen bonding interactions. Both complexes exhibited photocatalytic activity for the decomposition of methyl orange under UV light irradiation. 相似文献
4.
Chenglong Shi Yan Jing Yongzhong Jia 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2017,91(4):692-696
Extraction of Li+ ions from salt lake brine into an ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C2mim][NTf2]) mixed with tri-n-butyl was investigated. The extraction mechanism was been studied using UV–Vis spectroscopy From the temperature dependence data, the thermodynamic functions values (ΔG°, ΔH°, and ΔS°) were calculated. Furthermore, stripping of metals from ionic liquid phase to an aqueous phase by hydrochloric acid was accomplished. 相似文献
5.
Abimbola Adebisi Irvin Noel Booysen Matthew Piers Akerman Bheki Xulu 《Transition Metal Chemistry》2016,41(6):629-635
In this research study, the formation and characterization of new ruthenium(II) and (III) complexes encompassing multidentate ligands derived from 6-acetyl-1,3,7-trimethyllumazine (almz) are reported. The 1:1 molar coordination reactions of trans-[RuCl2(PPh3)3] with N-1-[1,3,7-trimethyllumazine]benzohydride (bzlmz) and 6-(N-methyloxime)-1,3,7-trimethyllumazine (ohlmz) formed a diamagnetic ruthenium(II) complex, cis-[RuCl2(bzlmz)(PPh3)] (1), and paramagnetic complex, cis-[RuIIICl2(olmz)(PPh3)] (2) [Holmz = 6-(N-hydroxy-N′-methylamino)-1,3,7-trimethyllumazine], respectively. These ruthenium complexes were characterized via physico-chemical and spectroscopic methods. Structural elucidations of the metal complexes were confirmed using single crystal X-ray analysis. The redox properties of the metal complexes were investigated via cyclic voltammetry. Electron spin resonance spectroscopy confirmed the presence of a paramagnetic metal centre in 2. The radical scavenging activities of the metal complexes were explored towards the DPPH and NO radicals. Quantum calculations at the density functional theory level provided insight into the interpretation of the IR and UV–Vis experimental spectra of 1. 相似文献
6.
Interaction of the meso-substituted carbocyanine dye 3,3′-diethyl-9-chlorothiacarbocyanine (DCTC) perchlorate with DNA in phosphate buffer solutions (pH 7) was studied by spectral and kinetic methods. It was shown that the dye mainly exists in the cis-isomer form in water and aqueous-alcoholic solutions. The interaction with DNA leads to the formation of a trans-DCTC complex, which gradually (over a few tens of minutes) converts into the complex of the dye cis-isomer. It was revealed that the reactant concentration and ionic strength of solution have a considerable effect on the kinetic characteristics of trans-cis-reorganization of DCTC complexes, thus indicating a complex character of the process. 相似文献
7.
Hui Li Wei Yuan Luyi Zou Xingdong Wang Hongmei Zhan Yanxiang Cheng 《Transition Metal Chemistry》2018,43(3):231-241
Eight pairs of cis–trans isomeric homoleptic platinum(II) complexes based on N-alkyl- or aryl-substituted 2,2′-biimidazole ligands were synthesized, and their photophysical properties were investigated. The cis and trans isomers readily interconvert at slightly elevated temperature, implying that the activation barrier for this process is low. Single crystal X-ray diffraction analysis revealed that the complexes have an ideal square-planar geometry. Their UV–Vis spectra showed lower energy absorption bands in the range of 345–378 nm, which are assigned to the typical MLCT mixed with LC transitions. In frozen glass solution at 77 K and also in the powder state, these complexes exhibit green emission ranging from 440 to 540 nm with photoluminescence quantum yields of 3.3–24.4%. The emitting excited state is dominated by 3ππ* character with some contributions from 3MLCT according to the excitation spectra. 相似文献
8.
Horvth Gyrgyi Molnr Pter Farkas gnes Szab Lszl Gy. Turcsi Erika Deli Jzsef 《Chromatographia》2010,71(1):103-108
The current research project aimed at the carotenoid analysis of total extracts of the inflorescences of Canadian goldenrod (Solidago canadensis L.), and the flowers of greater celandine (Chelidonium majus L.). The plant extracts were separated and analyzed by column liquid chromatography (CLC) and LC. Carotenoids were identified on the basis of their UV–Vis spectroscopic properties in different solvents, chemical reactions [5,6-epoxide → 5,8-epoxide (furanoid oxide rearrangement), (E/Z)-isomerization] and by co-chromatography with authentic reference samples. The parallel use of CLC and LC allowed the identification of numerous minor carotenoids in all extracts and fractions. 相似文献
9.
T. N. Kropacheva A. S. Antonova V. I. Kornev 《Russian Journal of Inorganic Chemistry》2017,62(2):150-159
Effect of complexons of polyaminopolycarboxylic acid series (IDA, NTA, EDTA, and DTPA) and polyphosphonic acid series (HEDP, NTP, and EDTP) on Cu(II) cations sorption on goethite (α-FeOOH) from aqueous solutions has been studied. Obtained results have been considered in the context of complexation reactions in bulk solution and on sorbent surface. It has been found that all complexons (except for EDTA), depending on nature, produce on goethite surface (≡FeOH) triple complexes of type A (surface–metal–complexon) of composition ≡FeOCuLH i 1+i?n and ≡FeOCuL(OH) j 1?j?n or type B (surface–complexon–metal) of composition ≡FeLH i Cu3+i-n and ≡FeLCu(OH) j 3?j?n . pH-Ranges for complex existence and stability constants for the surface complexes have been determined. Factors affecting the character of complexon effect (immobilization/remobilization) on the sorbed metal have been analyzed. 相似文献
10.
S. M. Masoud T. R. Akmalov O. I. Artyushin C. Bruneau S. N. Osipov 《Russian Chemical Bulletin》2017,66(9):1601-1606
Novel ruthenium carbene complexes bearing unsymmetrical NHC-ligands based on N-alkyl-N´-arylimidazoline with hexafluoroisopropylmethoxy group in para-position of N-aryl moiety have been synthesized. Catalytic activity of complexes obtained was investigated on model reactions of intra- and intermolecular olefin metathesis. 相似文献
11.
L. A. Koroleva V. K. Matveev A. V. Koroleva Yu. A. Pentin 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2018,92(3):488-495
The UV absorption spectrum of methacryloyl fluoride molecule in the gas phase is obtained in the wavenumber range of 32300–35900 cm?1. The resolved vibrational structure of this spectrum consists of 153 absorption bands. The assignment of all bands has been made for the first time. Values ν00trans = 35670.0 сm?1 and ν00cis = 35371.1 cm?1 are determined. The fundamental frequencies for isomers in the S0 and S1 states are found. Several Deslandres Tables (DTs) are constructed for the torsional vibration of the s-trans- and s-cis-isomers of the investigated molecule using the NONIUS program. The origins in these DTs correspond to bands attributed to ν00, and to the fundamental frequencies of each isomer in states S0 and S1. These DTs are used to determine harmonic frequencies ωe, anharmonicity coefficients х11, and the frequencies of torsional vibration 0–v transitions up to high values of vibrational quantum number v for s-trans- and s-cis-isomers in both electronic states. The frequencies of torsional vibrations for the s-trans-isomer and the s-cis-isomer in the S0 state are ν″1 = 80.9 сm?1 and ν″1 = 59.8 сm?1, respectively. The frequencies for the s-trans- isomer and the s-cis-isomer in the S1 state are ν′1 = 134.1 сm?1 and ν′1 = 103.6 cm?1, respectively. 相似文献
12.
The thermal decomposition reactions of the complexescis/trans-[Cu(gly)2] ? H2O were studied by TG-DSC methods. The results showed that they have similar decomposition process, which occur in two steps. The first step is the loss of water and the second step is the decomposition of anhydrous complexes. But forcis-[Cu(gly)2]?H2O, the temperature of losing water is higher than that oftrans-isomer. Their reaction mechanisms of the two-step decomposition were also proposed. 相似文献
13.
A series of new arene ruthenium(II) complexes were prepared by reaction of ruthenium(II) precursors of the general formula [(η6-arene)Ru(μ-Cl)Cl]2 with N,N′-bidentate pyridyl-imine ligands to form complexes of the type [(η6-arene)RuCl(C5H4N-2-CH=N-R)]PF6, with arene = C6H6, R = iso-propyl (1a), tert-butyl (1b), cyclohexyl (1c), cyclopentyl (1d) and n-butyl (1e); arene = p-cymene, R = iso-propyl (2a), tert-butyl (2b). The complexes were fully characterized by 1H NMR and 13C NMR, UV–Vis and IR spectroscopies, elemental analyses, and the single-crystal X-ray structures of 2a and 2b have been determined. The single-crystal molecular structure revealed both compounds with a pseudo-octahedral geometry around the Ru(II) center, normally referred to as a piano stool conformation, with the pyridyl-imine as a bidentate N,N ligand. The activity of all complexes in the transfer hydrogenation of cyclohexanone in the presence of NaOH and iso-propanol is reported, the compounds showing turnover numbers of close to 1990 and high conversions. Complex 2b was also shown to be very effective for a range of aliphatic and cyclic ketones, giving conversions of up to 100 %. 相似文献
14.
Condensation of phthalimide and 4-tert-butylphthalimide with zinc(II) acetate gave 3-(3-oxo-2,3-dihydro-1H-isoindol-1-ylidenemethyl)-1H-isoindol-1-one and 5-tert-butyl-3-(5-tert-butyl-3-oxo-2,3-dihydro-1H-isoindol-1-ylidenemethyl)-1H-isoindol-1-one, respectively. Their reactions with 4-phenoxyphthalimide and quinoxaline-2,3-dicarboximide in the presence of Zn(OAc)2 led to the formation of zinc complexes of cis-4,4′-diphenoxytetrabenzoporphyrin and cis-di(4-tert-butylbenzo)diquinoxalinoporphyrin. The complexes were converted into the free bases by treatment with sulfuric acid. Spectral properties of the obtained porphyrin derivatives were studied. 相似文献
15.
Yanhong Liu Wei He Zehui Yang Yanwen Chen Xinwei Wang Ling Shi Dongcai Guo 《Research on Chemical Intermediates》2016,42(2):425-438
Amide-type podands derived from N,N′-(ethane-1,2-diyl)bis(2-hydroxybenzamide) and 2-chloro-N-phenylacetamide (substituted with methyl, methoxy, chlorine, nitrogen) were synthesized. Solid complexes of europium nitrate with podands were also synthesized and characterized by elemental analysis, ethylenediaminetetraacetic acid (EDTA) titrimetric analysis, thermal analysis, molar conductivity analysis, and infrared (IR) and ultraviolet–visible (UV–Vis) spectra analysis. The fluorescent properties of the europium(III) [Eu(III)] complexes in a solid state were also investigated. Under excitation of UV light, target Eu(III) complexes exhibited characteristic europium ion emissions. The influence of the substituent on the fluorescence intensity was discussed. Electrochemical properties were also investigated and discussed. 相似文献
16.
O. G. Khudina Ya. V. Burgart V. I. Saloutin 《Russian Journal of Organic Chemistry》2017,53(10):1556-1563
The alkylation of ambident anions of 2-(methylsulfanyl)-6-(polyfluoroalkyl)pyrimidin-4(3H)-ones with 4-bromobutyl acetate leads to concurrent formation of O- and N-(4-acetoxybutyl) derivatives. Polar aprotic solvents favor formation of the O-isomer, and weakly polar dioxane favors N-alkylation. The reaction of 2-(methylsulfanyl)-6-(trifluoromethyl)pyrimidin-4(3H)-one with an equimolar amount of 1,2-dibromoethane in polar acetonitrile gives a mixture of N,N-, O,O-, and N,O-bridged bis-pyrimidines, as well as N- and O-[2-(methylsulfanyl)ethyl] derivatives, whereas in the presence of 10 equiv of 1,2-dibromoethane the N,O-isomer is formed as the only product. The reaction in weakly polar tetrahydrofuran yields N,N- and N,O-bispyrimidines. 相似文献
17.
P. P. Mukovoz P. A. Slepukhin E. A. Danilova O. P. Aysuvakova A. P. Glinushkin 《Russian Journal of General Chemistry》2018,88(7):1363-1368
Bioactive derivatives of 1,4-benzoxazine have been prepared via reactions of 3,4-dioxohexane-1,6- dioic (ketipic) acid esters with 2-aminophenol. (2'Z)-2,2'-(2-Hydroxy-2H-1,4-benzoxazin-2-yl-3-ilidene)diacetic acid esters or (2Z)-[2-oxo-2H-1,4-benzoxazin-3(4H)-ylidene]acetic acid esters can be formed depending on the conditions. The structures of the products of dialkyl ketipate esters reactions with 2-aminophenol were determined by means of X-ray diffraction. It has been demonstrated that the prepared compounds exhibit antimycotic activity against test cultures of plant pathogenic fungi (Fusauium sp., Alternarium sp., and Bipolaris soraciniana). 相似文献
18.
Juan Du Zhie Zhou Xueqing Zhang Shuang Wu Jianhua Xiong Wenjun Wang Qiushui Luo 《Journal of Cluster Science》2017,28(6):3149-3158
Biosynthesis of gold nanoparticles (GNPs) by flavonoids from Lilium casa blanca has been developed. Several parameters such as pH, reaction temperature, reaction time and concentration of flavonoids were explored to control the formation of the GNPs. The synthesized GNPs were characterized by UV–Vis spectroscopy, transmission electron microscopy and X-ray diffraction. Stability and catalytic activity of the synthesized GNPs were also discussed. The results showed that the synthesized GNPs were in spherical, about 2.6 nm, with a face centered cubic structure. Synthesized GNPs showed good catalytic activity in the reduction of p-nitrophenol (p-NP) to p-aminphenol (p-AP). This method for synthesis of GNPs is simple, economic, nontoxic and efficient. 相似文献
19.
The present study reports the synthesis of silver nanoparticles (Ag NPs) from silver nitrate solution using leaf extracts of Commiphora caudata. The formation of Ag NPs in the colloidal solution is confirmed by UV–Vis spectroscopy analysis. The identification of biomolecules is analyzed through fourier transform infrared spectroscopy. X-ray diffraction pattern shows that an average particle size of the synthesized nanoparticles are in the range of 40–24 nm. Field emission scanning electron microscopy and transmission electron microscopy confirm the formation Ag NPs in spherical shape. The photoluminescence study of the synthesized Ag NPs interprets the influence of C caudata leaf concentrations on emission behavior. Zeta potential measurement is carried out to determine the stability of synthesized Ag NPs. GC–MS analysis revealed that the C. caudata contained 11 compounds, such as Stigmasterol (24.14 %), Hexacosanoic acid, methyl ester (15.13 %) and 2-bromophenyl morpholine-4-carboxylate (11.71 %). The antibacterial activity of Ag NPs shows that these bio capped Ag NPs have higher inhibitory action for Escherichia coli, Klebsiella pheumoniea, Micrococcus flavus, Pseudomonas aeruginosa, Bacillus subtilis, Bacillus pumilus, Staphylococcus aureus. 相似文献
20.
Lukáš Smolko Juraj Černák Juraj Kuchár Danica Sabolová Roman Boča 《Chemical Papers》2018,72(4):877-882
Interaction of two mononuclear tetracoordinate complexes [Co(dmphen)Br2] and [Co(dmphen)I2] (dmphen = 2,9-dimethyl-1,10-phenanthroline), which have been recently reported to behave as single-molecule magnets (SMMs) in an applied external field, with calf thymus (CT) DNA in solution was studied by spectral methods (UV–Vis, fluorescence, and circular dichroism). Results indicate that both complexes along with their chlorido analogue [Co(dmphen)Cl2] are able to bind with the CT DNA via intercalation, with the values of Stern–Volmer constants obtained from the linear quenching plot in range of 1.86 × 104–2.11 × 104 M?1. Furthermore, Topoisomerase I inhibition studies suggest that all three complexes exhibit inhibition activity at concentrations of 45 μM. 相似文献