共查询到20条相似文献,搜索用时 15 毫秒
1.
A method is described for determination of fenbufen that is based on the chemiluminescence (CL) reaction of the ${\text{Ru}}\left( {{\text{phen}}} \right)_3^{2 + } $ –cerium(IV)–fenbufen system. An enhanced CL reaction was developed, and optimum conditions for CL were investigated. The CL was linearly dependent on fenbufen concentration in the range 4.0?×?10?8–9.0?×?10?6 mol L?1. The detection limit was 2.0?×?10?8 mol L?1. The relative standard deviation (RSD) was 2.8% for eleven measurements of 6.0?×?10?7 mol L?1 fenbufen standard solution. The new method enables simple, sensitive, and rapid determination of fenbufen and has been used for determination of fenbufen in pharmaceutical preparations in capsule, spiked serum and urine samples. 相似文献
2.
Hossein Azizi-Toupkanloo Sayyed Faramarz Tayyari Paul Nancarrow 《Journal of the Iranian Chemical Society》2017,14(6):1281-1300
This work is aimed at providing physical insights about the interactions of cations, anion, and ion pairs of four imidazolium-based ionic liquids of \(\left[ {{\text{C}}_{\text{n}} {\text{mim}}} \right]\left[ {{\text{NTF}}_{2} } \right]\) with varying alkyl chain lengths (n = 2, 4, 6, and 8) using both DFT calculations and vibrational spectroscopic measurements (IR absorption and Raman scattering) in the mid- and far regions. The calculated Mulliken charge distributions of \(\left[ {{\text{C}}_{\text{n}} {\text{mim}}} \right]\left[ {{\text{NTF}}_{2} } \right]\) ion pairs indicate that hydrogen-bonding interactions between oxygen and nitrogen atoms (more negative charge) on \(\left[ {{\text{NTF}}_{2} } \right]^{ - }\) anion and the hydrogen atoms (more positive charge) on the imidazolium ring play a dominating role in the formation of ion pair. Thirteen stable conformers of \(\left[ {{\text{C}}_{2} {\text{mim}}} \right]\left[ {{\text{NTF}}_{2} } \right]\) were optimized. According to our results, the strongest and weakest hydrogen bonds were existing in \(\left[ {{\text{C}}_{2} {\text{mim}}} \right]\left[ {{\text{NTF}}_{2} } \right]\) and \(\left[ {{\text{C}}_{8} {\text{mim}}} \right]\left[ {{\text{NTF}}_{2} } \right]\), respectively. A redshift of 290, 262, 258, and 257 cm?1 has been observed for cations involving \(\left[ {{\text{C}}_{2} {\text{mim}}} \right]^{ + }\), \(\left[ {{\text{C}}_{4} {\text{mim}}} \right]^{ + }\),\(\left[ {{\text{C}}_{6} {\text{mim}}} \right]^{ + }\), and stretching vibrations of \({\text{C}}12{-}{\text{H}}3\), respectively. By increasing the chain length, the strength of hydrogen bonds decreases as a result of \({\text{C}}12{-}{\text{H}}3\) bond elongation and less changes are observed in stretching vibrations of \({\text{C}}12{-}{\text{H}}3\) compared to the free cations. To the best of our knowledge, this research is the first work which reports the far-IR of \(\left[ {{\text{C}}_{4} {\text{mim}}} \right]\left[ {{\text{NTF}}_{2} } \right]\), \(\left[ {{\text{C}}_{6} {\text{mim}}} \right]\left[ {{\text{NTF}}_{2} } \right]\), and \(\left[ {{\text{C}}_{8} {\text{mim}}} \right]\left[ {{\text{NTF}}_{2} } \right]\) and the mid-IR of \(\left[ {{\text{C}}_{8} {\text{mim}}} \right]\left[ {{\text{NTF}}_{2} } \right]\). 相似文献
3.
Hussain Shafqat Jamal Muhammad Maatki Chemseddine Ghachem Kaouther Kolsi Lioua 《Journal of Thermal Analysis and Calorimetry》2021,144(6):2219-2233
Journal of Thermal Analysis and Calorimetry - This study deals with mixed convection of $$ {\text{Al}}_{2} {\text{O}}_{3} $$ –Cu–water hybrid nanofluid in a wavy channel having a... 相似文献
4.
R. F. Klevtsova L. A. Glinskaya T. G. Leonova S. V. Larionov 《Journal of Structural Chemistry》2002,43(1):125-132
The mixed-ligand complexes Zn(2,
-Bipy)(i-PrOCS2)2 (I) and Zn(2,
-Bipy)(i-BuOCS2)2 (II) were synthesized. Their structures were solved using the X-ray diffraction data (CAD-4 diffractometer, MoK
radiation, 1873 and 1948 F
hkl
, R = 0.0357 and 0.0338). The crystals are triclinic with unit cell dimensions a = 10.002(2), b = 11.080(2), c = 11.756(2) , = 78.46(3), = 75.49(3), = 63.50(3)°, V = 1122.9(4) 3, Z = 2, space group
(for complex I) and a = 8.760(2), b = 12.520(3), c = 13.252(3) , = 63.93(3), = 71.10(3), = 88.01(3)°, V = 1225.2(5) 3, Z = 2, space group
(for II). The structures are based on discrete monomeric molecules. The polyhedra of Zn atoms are tetragonal pyramids (ZnN2S3, c.n. 4+1, both bidentate and monodentate
ligands coordinated to the Zn atom). The packing of molecules and the character of their interaction in the structures are considered. 相似文献
5.
Russian Journal of Coordination Chemistry - A quantum chemical study of fluorinated europium alcoholate $${\text{Eu}}_{{\text{2}}}^{{{\text{II}}}}$$... 相似文献
6.
Arielle Milliet Eric Lecarpentier Henri-Edouard Audier 《Journal of mass spectrometry : JMS》1994,29(2):90-95
The β-distonic ion $ ^ \cdot {\rm CH}_2 {\rm CH}_2 \mathop {\rm O}\limits^ + {\rm HCH}_2 {\rm CH}_2 {\rm CH}_3 $ has been shown previously to be an intermediate in the fragmentation of ionized ethyl propyl ether. The reactions of this ion (generated by fragmentation in the ion source of alkyl propyl ethers of glycol) were studied in this work. Labelling showed that this ion undergoes competing hydrogen transfers leading to a series of isomeric distonic ions. Each of them was submitted to an isotope effect. 相似文献
7.
Dhanpat Rai Mikazu Yui H. Todd Schaef Akira Kitamura 《Journal of solution chemistry》2010,39(7):999-1019
Prior to this study no data for the solubility product of BiPO4(cr) or the complexation constants of Bi with phosphate were available. The solubility of BiPO4(cr) was studied at 23±2?°C from both the over- and under-saturation directions as functions of a wide range in time (6–309 days), pH values (0–15), and phosphate concentrations (reaching as high as 1.0 mol?kg?1). HCl or NaOH were used to obtain a range in pH values. Steady state concentrations and equilibrium were reached in <6 days. The data were interpreted using the SIT model. These extensive data provided a solubility product value for BiPO4(cr) and an upper limit value for the formation of BiPO4(aq). Because the aqueous system in this study involved relatively high concentrations of chloride, reliable values for the complexation constants of Bi with chloride were required to accurately interpret the solubility data. Therefore as a part of this investigation, existing Bi–Cl data were critically reviewed and used to obtain values of equilibrium constants for various Bi–Cl complexes at zero ionic strength along with the values for various SIT ion interaction parameters. Predictions based on these thermodynamic quantities agreed closely with our experimental data, the chloride concentrations of which ranged as high as 0.7 mol?kg?1. The study showed that BiPO4(cr) is stable at pH values <9.0. At pH values >9.0, Bi(OH)3(am) is the solubility controlling phase. Reliable values for the Bi(OH)3(am) solubility reactions involving Bi(OH)3(aq) and $\mathrm{Bi}(\mathrm{OH})_{4}^{-}$ and the formation constants of these aqueous species are also reported. 相似文献
8.
Journal of Structural Chemistry - Reduction of 4,4′-bis-(phenyl azo)-diphenyl thiodiimide S(=N–C6H4–N=N–C6H5)2 (1) in tetrahydrofuran (ТHF) with potassium-intercalated... 相似文献
9.
Rumyantsev R. V. Fukin G. K. Baranov E. V. Cherkasov A. V. Kozlova E. A. 《Russian Journal of Coordination Chemistry》2021,47(4):235-243
Russian Journal of Coordination Chemistry - The electron density distributions obtained by the quantum-chemical (density functional theory) calculations and molecular invariom model in the trimeric... 相似文献
10.
Xiao-Ling Zhao Hong-Qi Zhang Bin Zhao Hong-Fei Guo Ji-Lin Cao 《Journal of solution chemistry》2018,47(9):1419-1437
The solubilities in the quaternary system K+, \( {\text{NH}}{_4^{+}} \)//Cl?, \( {\text{SO}}{_4^{2-}} \)–H2O and its two ternary subsystems NH4Cl–KCl–H2O, (NH4)2SO4–K2SO4–H2O at 80.0 °C were measured using the isothermal dissolution equilibrium method under atmospheric pressure, and the corresponding phase diagrams were plotted. In the phase diagram of the NH4Cl–KCl–H2O system, there are three crystalline zones, which correspond to (K1?m,(NH4)m)Cl, ((NH4)n,K1?n)Cl and the co-existence zone of (K1?m,(NH4)m)Cl and ((NH4)n,K1?n)Cl, respectively. In the phase diagram of the (NH4)2SO4–K2SO4–H2O system, there is only one crystalline zone for (K1?t,(NH4)t)2SO4. In the phase diagram of the K+, \( {\text{NH}}{_4^{+}} \)//Cl?, \( {\text{SO}}{_4^{2-}} \)–H2O system, there are three crystal zones, which correspond to (K1?t,(NH4)t)2SO4, (K1?m,(NH4)m)Cl and ((NH4)n,K1?n)Cl, respectively. According to the analysis and the calculations for the phase diagrams of the K+, \( {\text{NH}}{_4^{+}} \)//Cl?, \( {\text{SO}}{_4^{2 -}} \)–H2O system at 80.0 °C and 50.0 °C, this paper proposes a technological process. In the process, the (K1?t,(NH4)t)2SO4 can be prepared at 80.0 °C and the ((NH4)n,K1?n)Cl can crystallize out at 50.0 °C. The mass fraction of K2SO4 in product L1 (K1?t,(NH4)t)2SO4 (t?=?0.1465) is 88.48%. The composition of solid solutions in the K+, \( {\text{NH}}{_4^{+}} \)//Cl?, \( {\text{SO}}{_4^{2 -}} \)–H2O system was experimentally determined and then theoretical calculations about the process can be carried out. 相似文献
11.
《化学研究》2016,(4)
通过水热合成的方法,以1,4-环己烷二羧酸、2,4-二氨基-6-甲基三嗪和CdCl_2·2.5H_2O为原料合成了一种单核的化合物{Cd(dmt)_2(Hchdc)_2(H_2O)_2}_n(dmt=2,4-diamino-6-methyl-triazine,H2chdc=1,4-cyclohexanedicarboxylic acid),并进行了IR和X射线单晶衍射(常温)的分析.结果表明,该化合物属于P2/c空间群,单斜晶系,晶胞参数:a=1.330 26(11)nm,b=0.541 47(4)nm,c=2.415 54(16)nm,β=115.751(3)°,V=1.567 1(2)nm~3,Z=2,Dc=1.570g/cm~3,F(000)=764,R1=0.035 2,wR2=0.092 7.该化合物中,中心金属离子Cd(II)与氧相连形成六配位构型,并通过4种不同的氢键作用最终形成了三维的堆积结构. 相似文献
12.
我们合成了化合物{Mo[S_2CN(C_2H_5)_2]_4}~ {MoCl_6}~-,确定了其所属晶系、空间群及晶胞参数,并确定了重原子与其它全部非氢原子坐标等. 相似文献
13.
WEN Yi-Hang ZHANG Jian QIN Ye-Yan LI Zhao-Ji KANG Yao CHEN Yu-Biao CHENG Jian-Kai YAO Yuan-Gen② 《结构化学》2004,(9)
1 INTRODUCTION The increasing interest in inorganic-organic hybrid framework assemblies has resulted in a great number of research efforts focused on the develop- ment of new functional materials possessing various potential applications on catalysis, electrical conduc- tivity and magnetism[1~4]. In recent years, the inter- action of H2pdc with several metal ions has been extensively studied[5, 6] due to its unique ability to form stable chelates in diverse coordination modes such as bid… 相似文献
14.
The structure and the stability of pentazolide compounds $\hbox{A}_{\it n}(\hbox{N}_5)_{\rm 6-{\it n}}^{\it q}$ (A = B, Al, Si, P, and S; n= 1–3; q = +1, 0, ?1, ?2, and ?3), as high energy-density materials (HEDMs), have been investigated at the B3LYP/6-311+G* level of theory. The natural bond orbital analysis shows that the charge transfer plays an important role when the $\hbox{A}_{\it n}(\hbox{N}_5)_{\rm 6-{\it n}}^{\it q}$ species are decomposed to $\hbox{A}_{\it n}(\hbox{N}_5)_{\rm 5-{\it n}}\hbox{N}_3^{\it q}$ and N2. The more negative charges are transferred from the N2 molecule after breaking the N5 ring, the more stable the systems are with respect to the decomposition. Moreover, the conclusion can be drawn that ${\hbox{Al}(\hbox{N}_5)_5^{2-}}$ and ${\hbox{Al}_2(\hbox{N}_5)_4^{2-}}$ are predicted to be suitable as potential HEDMs. 相似文献
15.
HUANG Xi-He XIANG Sheng-Chang FU Rui-Biao SHENG Tian-Lu ZHANG Jian-Jun LI Ya-Min WANG Long-Sheng WU Xin-Tao ② 《结构化学》2006,(7)
1 INTRODUCTION Polyoxomolybdates have been of great interest due to their unique structural varieties, associated multitude of properties and applications as catalysis, medicine and material[1, 2]. One of the most impor- tant aspects is the synthesis and investigation of the materials on polyoxomolybdates containing organo- metallic groups[3~5]. Such materials can provide molecular models for heterogeneous catalysis and display cooperative effects or bifunctional catalytic activity[6]. O… 相似文献
16.
V. V. Sharutin O. K. Sharutina V. S. Senchurin P. V. Andreev 《Russian Journal of Inorganic Chemistry》2018,63(9):1178-1185
Complexes \(\rm[{Ph_{3}PR]_2^+[RuCl_6]^{2-}}\), where R = C2H5 (I), CH=CHCH3 (II), CH2CH=CHCH3 (III), and CH2OCH3 (IV), have been prepared by the reaction between ruthenium(III) chloride hydrate and triphenylorganylphosphonium chlorides in dimethylsulfoxide in the presence of hydrochloric acid. A hydrochloric acid solution of ruthenium(III) chloride hydrate when mixed with an aqueous solution of 2-butylene-1,4- bis(triphenylphosphonium dichloride) followed by recrystallization from dimethylsulfoxide results in complex \(\rm[{Ph_{3}PCH_2CH=CHCH_2{PPh_3}]_2^{2+}[Ru_2Cl_{10}O]^{4-}}\)· 4H2O (V). According to X-ray diffraction data, phosphorus atoms in mono- and binuclear cations have slightly distorted tetrahedral coordination (CPC 105.54(13)°?113.00(8)°, P?C 1.758(9)?1.839(7) Å). In slightly distorted octahedral anions [RuCl6]2? of complexes I–IV, the Ru?Cl bond lengths vary in the range 2.3222(6)?2.340(2) Å; the cis-ClRuCl and trans-ClRuCl angles are 89.133(18)°–90.867(18)° and 179.53(13)°–180°, respectively. In the binuclear [(RuCl5)2O]4? anion of complex V, RuCl5 fragments are bonded by a bridging oxygen atom. The Ru–Cl bond lengths fall in the range 2.3375(8)?2.3957(8) Å; the Ru–O bond length is 1.7832(2) Å. The cis-ClRuCl, trans-ClRuCl, cis-ORuCl, and trans-ORuCl angles are 86.67(3)°?91.28(3)°, 174.60(3)°?174.83(3)°, 91.49(2)°?93.65(2)°, and 178.39(2)°, respectively. In crystals I–V, interionic hydrogen bonds Cl···Hcation (2.63?2.95 Å), Cl··· \({\rm{H}_{{H_2}O}}\) (2.35?2.79 Å), and Hcation···\({\rm{O}_{{H_2}O}}\) (1.72?1.93 Å) (for V) are found. 相似文献
17.
Francesco Crea Alessandro De Robertis Concetta De Stefano Silvio Sammartano 《Journal of solution chemistry》2007,36(4):479-496
The formation constants of dioxouranium(VI)—1,2,3,4,5,6-benzenehexacarboxy- late [mellitate(6?)] complexes were determined in NaCl aqueous solutions at 0.1 ≤ I ≤ 1.0 mol·L?1 and t = 25 °C by ISE-[H+] glass-electrode potentiometry. The speciation model obtained at each ionic strength includes the following species: ML4?, MLH3?, MLH2 2 ?, MLH3 ?, M2L2?, MLOH5? and ML(OH)2 6? (M = UO2 2 + and L6? = mellitate). The ionic strength dependence of the protonation constants of mellitate and of the metal-ligand complexes was investigated using the SIT (Specific Ion Interaction Theory) approach. Formation constants at infinite dilution are [for the generic equilibrium $p{\rm UO}_{\rm 2}^{{\rm 2 + }} + q({\rm L}^{{\rm 6} - }) + r{\rm H}^{\rm + }\rightleftharpoons({\rm UO}_{\rm 2}^{{\rm 2 +}})_p({\rm L})_q {\rm H}_r^{(2p - 6q + r)};\,\beta _{pqr}$ ]: log10 β 110 = 10.155, log10 β 111 = 16.084, log10 β 112 = 20.749, log10 β 113 = 24.038, log10 β 210 = 17.936, log10 β 11?1 = 2.327 and log10 β 11?2 = ?6.804. Simple linear relationships between the formation constants and the stoichiometric coefficients of reactants are reported. The sequestering capacity of mellitate towards UO2 2+ was quantified using a sigmoid Boltzman-type equation. 相似文献
18.
成分为MoFeS_(10)Cl_4N_4C_(34)H_(54)的单晶样品,用SYNTEX-R3型四圆衍射仪以θ/2θ扫描方式收集3499个独立的X射线衍射强度数据进行结构分析。晶体属空间群C_s~4—C_c,晶胞参数a=17.900(5),b=18.466(7),c=15.483(4),β=92.78(2)°,Z=4,经PL,K,B及吸收因子的校正得绝对强度,由Patterson函数先导出Mo参数,随后用Fourier法有层次地导出S,Fe,Cl,N,C等非氢原子的坐标参数,另由直接法亦导出大部分非氢原子的位置,所得结果是平行的。用块矩阵最小二乘法对坐标及各向同性与各向异性的热参数进行多轮的修正,最后加入全部氢原子,同时进行氢原子各向同性热参数的修正,得一致性因子R=0.054,结构分析证实:晶体中存在有三类物种,四个二乙胺基硫代甲酸根与Mo(Ⅴ)组成了{Mo[S_2CN(C_2H_5)_2]_4}~(=1)络离子,它与负络离子{FeCl_4}~(-1)交替排列构成了沿c轴方向伸展的空腔,而电中性的苄基二硫化物,则充填其间组成了结构新颖的三元体系包合物。 相似文献
19.
《结构化学》1991,(1)
<正> {[Eu(OOCCH2NHCOCH2NH3)2(H2O)2]·(ClO4)3·2H2O}2,Mr = 1572,P21/n,a=12. 014(4),b=8. 910(5),c=22. 749(5)A ,β=91. 73(3)°,V = 2034 A3,Z=2,Dx=2. 15g·cm-3,λ(MoKa) = 0. 71073A,R=0. 060 for 3107 unique observed reflections (I≥3σ(I)). The complex cation is of one-dimensional chain structure in which the basic unit is a dinuclear complex and the gly-gly ligands are coordinated to metal atoms in two kinds of forms. The overall structure of the dinuclear unit is dioxo and dicarboxyl-bridged. 相似文献
20.
1 INTRODUCTION Though the investigation on chemistry of tran- sition metal-peroxy complexes has been extensively carried out, up to now, only four structures of purely inorganic dimeric peroxovanadates have been deter- mined by single-crystal X-ray meth… 相似文献