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1.
Iodophthalocyaninato(2–)thallium(III) – Synthesis and Crystal Structure Oxidation of dithalliumphthalocyaninate(2–) with excess iodine yields crystalline, blue-green iodophthalocyaninato(2–)thallium(III). It crystallizes in the orthorhombic space group Pnma (no. 62) with lattice parameters: a = 13.778(3) Å, b = 14.649(2) Å, c = 14.907(1) Å, Z = 4. The Tl atom coordinates four Niso atoms (isoindole N atoms) and one I atom in a tetragonal pyramidal arrangement. The Tl atom is located out of the centre of the (Niso)4 plane towards the iodine atom by 0.959(3) Å. The Tl–I distance is 2.674(1) Å, the Tl–Niso distances range from 2.20(1) to 2.23(1) Å (average 2.22(1) Å). The phthalocyaninate(2–) is severely distorted from planarity (concave distortion). 相似文献
2.
Jan Janczak Ryszard Kubiak 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(1):55-57
The title antimony(III) complex, [Sb(C32H16N8)]Cl or [SbPc]Cl (where Pc = C32H16N82−), has been obtained from the reaction of pure powdered antimony with 1,2-dicyanobenzene under a stream of ICl vapour. The asymmetric unit of this complex consists of an [SbPc]+ cation and a Cl− anion. The phthalocyaninate residue [SbPc]+ is not planar. The Sb atom lies 1.057 (3) Å from the plane defined by the four isoindole N atoms. A combination of ionic and donor–acceptor interactions links the [SbPc]Cl molecules to form centrosymmetric [(SbPc)Cl]2 pseudo-dimers in the crystal. The Sb—Cl distances in the pseudo-dimer are not equivalent [3.043 (2) and 3.201 (2) Å]. The pseudo-dimers are weakly linked through Cl⃛H—Cbenzo interactions to form a three-dimensional network. As a result of these interactions, the four Sn—Nisoindole bond lengths in the [SbPc]+ residue are not equivalent and the symmetry of the Sb—N core is only close to Cs. 相似文献
3.
Su-Fan Wang Ji-Kang Feng Chia-Chung Sun Peng Liu Zhen Gao Fan-Ao Kong 《Theoretical chemistry accounts》2001,106(3):163-170
The possible geometrical structures and relative stability of (SiS2)
n
(n=1–6) silicon–sulfur clusters are explored by means of density functional theory quantum chemical calculations. The effects
of polarization functions and electron correlation are included in these calculations. The electronic structures and vibrational
spectra of the most stable geometrical structures of (SiS2)
n
are analyzed by the same method. As a result, the regularity of the (SiS2)
n
cluster growth is obtained, and the calculation may used for predicting the formation mechanism of the (SiS2)
n
cluster.
Received: 17 November 1999 / Accepted: 3 November 2000 / Published online: 3 May 2001 相似文献
4.
Photoredox-catalyzed radical reactions have attracted intense interest from synthetic chemists over the past several years. The photoredox-catalyzed C(sp2)–N coupling reactions, including Ullmann type C–N coupling (C–X/N–H type coupling), redox neutral C–N coupling (C–H/N–X type coupling) and oxidative C–N coupling (C–H/N–H type coupling), have been summarized in this digest. 相似文献
5.
Tsukasa Tawatari Ritsuki Kato Riku Kudo Prof. Dr. Kiyosei Takasu Prof. Dr. Hiroshi Takikawa 《Angewandte Chemie (International ed. in English)》2023,62(19):e202300907
We report herein intramolecular (3+2) cycloaddition reactions between ynamides as three-atom components and benzyne. In these intramolecular reactions, the two-bond formation is realized by exploiting benzyne precursors that contain a chlorosilyl group as a linking functionality. This method thus highlights the ambivalent character of the intermediate indolium ylide, which exhibits both nucleophilic and electrophilic properties at its C2 atom. 相似文献
6.
An enantiospecific route to the synthesis of tetrahydroquinoline alkaloids (–)-cuspareine and (–)-galipinine is reported. Coupling of an iodide derivative of D-serine with aromatic dithianes and Pd-catalyzed intramolecular C–N coupling are the key steps in the synthesis. 相似文献
7.
Guseva A. F. Pestereva N. N. Otcheskikh D. D. Vostrotina E. L. 《Russian Journal of Electrochemistry》2019,55(6):544-551
Russian Journal of Electrochemistry - Composites of (1 – x)Al2(WO4)3–xWO3 and (1 – x)Al2(WO4)3–xAl2O3 are synthesized and their conductivity is studied as dependent on the... 相似文献
8.
Dhanpat Rai Mikazu Yui H. Todd Schaef Akira Kitamura 《Journal of solution chemistry》2011,40(7):1155-1172
The solubility of SnO2(cassiterite) was studied at 23±2?°C as a function of time (7 to 49 days) and pH (0 to 14.5). Steady state concentrations were reached in <7 days. The data were interpreted using the SIT model. The data show that SnO2(cassiterite) is the stable phase at pH values of ~11.7. These extensive data provided a log?10 K 0 value of ?64.39±0.30 for the reaction (SnO2(cassiterite) +2H2O?Sn4++4OH?) and values of 1.86±0.30, ≤?0.62, ?9.20±0.34, and ?20.28±0.34 for the reaction ( $\mathrm{Sn}^{4+} + n\mathrm{H}_{2}\mathrm{O} \rightleftarrows \mathrm{Sn}(\mathrm{OH})_{n}^{4 - n} + n\mathrm{H}^{+}$ ) with values of “n” equal to 1, 4, 5, and 6 respectively. These thermodynamic hydrolysis constants were used to reinterpret the extensive literature data for SnO2(am) solubility, which provided a log?10 K 0 value of ?61.80±0.29 for the reaction (SnO2(am)+2H2O?Sn4++4OH?). SnO2(cassiterite) is unstable under highly alkaline conditions (NaOH concentrations >0.003 mol?dm?3) and transforms to a double salt of SnO2 and NaOH. Although additional well-focused studies will be required for confirmation, the experimental data in the highly alkaline region (0.003 to 3.5 mol?dm?3 NaOH) can be well described with log?10 K 0 of ?5.29±0.35 for the reaction Na2Sn(OH)6(s)?Na2Sn(OH)6(aq). 相似文献
9.
Using ESR and IR spectroscopy, the structures of >Si(O–C·=O)(CH2–CH3) (1) and >Si(CH2–CH·–CH3)(CH2–CH3) (2) radicals were deciphered. The directions and kinetic parameters of reactions of intramolecular rearrangements in these radicals were determined. The reactions of hydrogen atom abstraction in radical (1) from the CH2 and CH3 groups were studied. It was found that the endothermic reaction of hydrogen atom abstraction from the methyl group occurs at a higher rate than the exothermic reaction with the methylene group. The differences are determined by changes in the size of a cyclic transition state. Based on the experimental data, the strengths of separate C–H bonds in surface fragments are compared. The rearrangement >Si(CH2–CH·–CH3)(CH2–CH3) >Si(C·(CH3)2)(CH2–CH3) was discovered and its mechanism was determined. One of its steps is the skeletal isomerization Si-
(2)-
.
(1)Si-
(1)-
.
(2). Experimental data are analyzed using the results of quantum-chemical calculations of model systems. 相似文献
10.
It has been shown that the presence of small amounts of di-(2-ethylhexyl)phosphoric acid (below 6 mol % in the mixture of surfactants) in a sodium di-(2-ethylhexyl)phosphate–di-(2-ethylhexyl)phosphoric acid–decane–water system widens the region of microemulsion existence with respect water and decreases the slope of the dependence of hydrodynamic droplet diameter of on water-to-sodium di-(2-ethylhexyl) phosphate molar ratio. At di-(2-ethylhexyl)phosphoric acid concentrations in its mixture with sodium di-(2-ethylhexyl)phosphate higher than 6 mol %, the fraction of water bound with ions in microemulsion droplets decreases, the region of microemulsion existence narrows, specific conductance decreases, and the slope of the dependence of the hydrodynamic droplet diameter of on the water-to-sodium di-(2-ethylhexyl) phosphate molar ration increases. 相似文献
11.
《Analytical letters》2012,45(6):1165-1173
Abstract The polarographic behavior of the complex of iron–4– (2–pyridylazo) resorcin(PAR) was studied. In HAc– NaAc– EDTA buffer solution, the complex can be adsorped on a hanging mercury drop electrode giving a sensitive adsorptive complex reduction peak with a peak potential at -0.36V(vs. SCE). Optimum experimental conditions were found by the use of 0.08mol/L HAc, 0.06mol/L NaAc, 5.0 × 10?3mol/L EDTA and 1.0 × 10?5mol/L PAR. With preconcentration for 60s, the derivative peak height of the complex compound is linearly proportional to the concentration for Fe in the range from 1.0 × 10?9mol/L to 1.0 × 10?7mol/L. For a 2–min pre–concentration time, the detection limit found was 2.0 × 10?10mol/L. This method has high sensitivity and selectivity. It has been applied to the determination of trace iron in food and water samples without any pre–separation step. 相似文献
12.
13.
M. Selvi S. Devaraju M. R. Vengatesan M. Alagar 《Journal of Sol-Gel Science and Technology》2014,72(3):518-526
In the present work, silica and titania reinforced polybenzoxazine (PBZ–SiO2–TiO2) hybrid nanomaterial possessing high surface free energy have been developed using dimethylol-functional benzoxazine monomer (4HBA-BZ), tetraethoxysilane (TEOS), 3-(isocyanatopropyl)triethoxysilane (ICPTS), titaniumisopropoxide (TIPO) through an in situ sol–gel process. Data obtained from the contact angle measurement indicate that the hybrid materials are hydrophilic in nature and possess a high surface free energy. For example, hybrid PBZ obtained from 1:1:0.6:0.4 (m:m:w:w) ratio of 4HBA-BZ:ICPTS:TEOS:TIPO (PBST4) exhibit a high surface free energy of 38.2 mJm?2 which is higher than that of neat polybenzoxazine (29.5 mJm?2). Further data resulted from thermal studies indicate that the hybrid PBZ possess higher values of Tg, thermal stability and char yield than those of neat PBZ. 相似文献
14.
《Journal of Coordination Chemistry》2012,65(20):3544-3560
In this work, complexation between lead ion and the ligands 3-[N,N-bis(2-hydroxyethyl)amino]-2-hydroxypropanesulfonic acid (DIPSO) and N-(1,1-dimethyl-2-hydroxyethyl)-3-amino-2-hydroxypropanesulfonic acid (AMPSO), which are commercial pH buffers, is presented. Both ligands form complexes with lead in their pH buffer range (between pH 6.5 and 8.5 for DIPSO and between pH 8.0 and 9.0 for AMPSO). The final models and the overall stability constants, which are reported here, were determined by direct current polarography and glass electrode potentiometry [only for the Pb–(DIPSO)x–(OH)y system] at 25.0 °C and 0.1 M KNO3 ionic strength. For the Pb–(DIPSO)x–(OH)y system, the proposed final model contains PbL, PbL2, PbL2(OH), and PbL2(OH)2 with stability constants, as log β, of 3.4 ± 0.1, 6.35 ± 0.15, 12.8 ± 0.2, and 18.0 ± 0.3, respectively. For the Pb–(AMPSO)x–(OH)y system, the species observed are PbL, PbL(OH), and PbL(OH)2 with stability constants, as log β, of 2.9 ± 0.5, 9.4 ± 0.1, and 14.5 ± 0.2, respectively. For AMPSO, the possible adsorption of the ligand at the mercury electrode surface was evaluated by alternating current polarography through calculation of the capacitance of the double layer. 相似文献
15.
Mikhailov Oleg V. Tatarintseva Tatyana B. Sopin Vladimir F. 《Transition Metal Chemistry》2000,25(1):32-36
The complex formation that occurs in gelatin-immobilized copper(II)hexacyanoferrate(II) matrices upon contact with aqueous alkaline (pH 12.0) solutions of 1,2-bis(thiocarbamoyl)hydrazine, H2NC(S)NHNHC(S)NH2 and 1-carbamoyl-2-(thiocarbamoyl)hydrazine, H2NC(O)NHNHC(S)NH2 has been studied. The reaction of each of these ligands with copper(II) is preceded by the destruction of copper(II)hexacyanoferrate(II) in an alkaline medium to form a polymeric copper(II) hydroxide, which is involved in the subsequent copper(II)–ligand complex formation. In both CuII–N ligand systems, two complex compounds are formed; the water-insoluble Cu2B2(H2O)2 dimer and a water-soluble product of tentative composition [CuB(HB)]– (H2B=ligand). 相似文献
16.
Suresh Babu Meruva Raghavendra Rao K. Aaseef Mohammed Vilas H. Dahanukar U. K. Syam Kumar P. K. Dubey 《合成通讯》2016,46(2):187-196
A concise and enantioselective syntheses of antileukemic natural products such as (–)-(S)-goniothalamin and (–)-leiocarpin A has been accomplished in excellent yields. By employing reported conditions on suitable substrates via Julia–Kocienski olefination, intramolecular lactonization, and subsequently dehydroxylative olefination, (–)-(S)-goniothalamin was synthesized. Then Sharpless asymmetric dihydroxylation–intramolecular Michael addition on (–)-(S)-goniothalamin provided (–)-leiocarpin A. 相似文献
17.
采用离子色谱法测定土壤浸提液中的Cl–和SO42–。选择2.0 mmol/L Na2CO3–1.3 mmol/L NaHCO3混合液为淋洗液,流速为2 mL/min,在此条件下,Cl–保留时间为1.96 min,SO42–保留时间约为12.26 min,Cl–,SO42–的质量浓度分别在2~8,10~30 mg/L范围内与色谱参数线性相关,相关系数分别为0.999 4和0.999 7,Cl–,SO42–的平均加标回收率分别为93.8%,105.4%,测量结果的相对标准偏差均小于1%(n=6)。该法适用于土壤中Cl–和SO42–的测定。 相似文献
18.
Kai Wu Dr. Liang-Liang Wu Dr. Cong-Ying Zhou Prof. Dr. Chi-Ming Che 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(37):16336-16342
A transition-metal-free C(sp2)−C(sp2) bond formation reaction by the cross-coupling of diazo quinones with catechol boronic esters was developed. With this protocol, a variety of biaryls and alkenyl phenols were obtained in good to high yields under mild conditions. The reaction tolerates various functionalities and is applicable to the derivatization of pharmaceuticals and natural products. The synthetic utility of the method was demonstrated by the short synthesis of multi-substituted triphenylenes and three bioactive natural products, honokiol, moracin M, and stemofuran A. Mechanistic studies and density functional theory (DFT) calculations revealed that the reaction involves attack of the boronic ester by a singlet quinone carbene followed by a 1,2-rearrangement through a stepwise mechanism. 相似文献
19.
《Journal of Coordination Chemistry》2012,65(17):2954-2966
A 2-D coordination polymer, [Cu(1,2-en)2(μ3-I)2Cu2(μ2-I)2]n (1), was formed at room temperature by in situ insertion of [Cu(1,2-en)2]2+ guests into 1-D chains of a [Cu2I4]2? host [1,2-en?=?1,2-diaminoethane]. The structure of the complex was confirmed by single-crystal X-ray diffraction study. The shortest copper(I)–copper(I) distance within the complex is 2.89?Å. 相似文献
20.
P. Melnikov H. W. L. dos Santos R. V. Gonçalves 《Journal of Thermal Analysis and Calorimetry》2010,101(3):907-911
The study of the system xSb2O3–(1 ? x)Bi2O3–6(NH4)2HPO4 has been carried out to identify the phases and simulate the mechanisms of their formation, using the technique of thermal analysis in association with X-ray diffractometry. The main stages observed during thermal treatment of the samples include: (1) elimination of water and ammonia leading to the formation of (NH4)5P3O10; (2) reaction of the latter with M 2 III O3 and the formation of acidic polyphosphates M 2 III H2P3O10; (3) their dehydration with the formation of the polyphosphates MIII(PO3)3. Then Sb(PO3)3 decomposes giving SbPO4 and P2O5. In the presence of excessive P2O5, two moles of Bi(PO3)3 condensate into oxophosphates Bi2P4O13 and BiP5O14. The data of thermal analysis match with the composition of intermediate and final products. The hygroscopicity of the samples diminishes with growing bismuth content. 相似文献