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1.
The synthesis and characterization of the unsymmetric hafnium dialkyl [1‐(η5‐9‐fluorenyl)‐2‐(η5‐1‐indenyl)ethane]HfCl2 ( 2 ) and corresponding dimethyl complex [1‐(η5‐9‐fluorenyl)‐2‐(η5‐1‐indenyl)ethane]Hf(CH3)2 ( 3 ) is described. The dialkyl hafnocene ( 3 ) crystallizes in monoclinic space group P21/c (No. 14) with a = 9.458(8), b = 8.541(8), c = 23.733(11) Å, β = 93.16(5) deg., V = 1914(3) Å3, Z = 4. Further on, complex 3 was activated with methylaluminiumoxane (MAO) and utilized as a catalyst in ethene polymerization.  相似文献   

2.
Synthesis and characterization of bis[2‐(arylimino)‐1,3‐thiazolidin‐4‐ones] are described. The one‐pot, pseudo‐five‐component reaction of an aliphatic diamine, isothiocyanatobenzene, and dialkyl but‐2‐ynedioate at room temperature in anhydrous CH2Cl2 gives the title compound in relatively high yield. Under the same conditions, aromatic 1,2‐diamines yield 2‐(arylimino)‐N‐(enaminoaryl)‐1,3‐thiazolidin‐4‐ones in a pseudo‐four‐component reaction. Their structures were corroborated spectroscopically (IR, 1H‐ and 13C‐NMR, and EI‐MS) and by elemental analyses. A plausible mechanism for this type of cyclization is proposed (Scheme 3).  相似文献   

3.
The reaction of dialkyl acetylenedicarboxylates 4 with 1‐aryl‐2‐[(3‐arylquinoxalin‐2(1H)‐ylidene)ethanones 3 in the presence of Ph3P leads to dialkyl (2Z)‐2‐[(E)‐1‐aryl‐2‐(3‐arylquinoxalin‐2‐yl)ethenyl]but‐2‐enedioates 1 in good yields.  相似文献   

4.
An efficient approach for the preparation of functionalized 2‐aryl‐2,5‐dihydro‐5‐oxo‐4‐[2‐(phenylmethylidene)hydrazino]‐1H‐pyrroles is described. The four‐component reaction between aldehydes, NH2NH2?H2O, dialkyl acetylenedicarboxylates, and 1‐aryl‐N,N′‐bis(arylmethylidene)methanediamines proceeds in EtOH under reflux in good‐to‐excellent yields (Scheme 1). The structures of 4 were corroborated spectroscopically (IR, 1H‐ and 13C‐NMR, and EI‐MS, and, in the case of 4f , by X‐ray crystallography). A plausible mechanism for this type of reaction is proposed (Scheme 2).  相似文献   

5.
A novel transformation involving phosphine? diazo ester zwitterions (generated from dialkyl azodicarboxylates with Ph3P) and α‐(alkoxycarbonyl)imidoyl chlorides (prepared from α‐addition of acyl chlorides to alkyl isocyanides) to afford dialkyl 2‐[3‐alkoxy‐1‐(alkylimino)‐1‐chloro‐3‐oxopropan‐2‐ylidene]hydrazine‐1,1‐dicarboxylates in moderate yields, is described.  相似文献   

6.
Crystals of poly[[aqua[μ3‐4‐carboxy‐1‐(4‐carboxylatobenzyl)‐2‐propyl‐1H‐imidazole‐5‐carboxylato‐κ5O1O1′:N3,O4:O5][μ4‐1‐(4‐carboxylatobenzyl)‐2‐propyl‐1H‐imidazole‐4‐carboxylato‐κ7N3,O4:O4,O4′:O1,O1′:O1]cadmium(II)] monohydrate], {[Cd2(C15H14N2O4)(C16H14N2O6)(H2O)]·H2O}n or {[Cd2(Hcpimda)(cpima)(H2O)]·H2O}n, (I), were obtained from 1‐(4‐carboxybenzyl)‐2‐propyl‐1H‐imidazole‐4,5‐dicarboxylic acid (H3cpimda) and cadmium(II) chloride under hydrothermal conditions. The structure indicates that in‐situ decarboxylation of H3cpimda occurred during the synthesis process. The asymmetric unit consists of two Cd2+ centres, one 4‐carboxy‐1‐(4‐carboxylatobenzyl)‐2‐propyl‐1H‐imidazole‐5‐carboxylate (Hcpimda2−) anion, one 1‐(4‐carboxylatobenzyl)‐2‐propyl‐1H‐imidazole‐4‐carboxylate (cpima2−) anion, one coordinated water molecule and one lattice water molecule. One Cd2+ centre, i.e. Cd1, is hexacoordinated and displays a slightly distorted octahedral CdN2O4 geometry. The other Cd centre, i.e. Cd2, is coordinated by seven O atoms originating from one Hcpimda2− ligand and three cpima2− ligands. This Cd2+ centre can be described as having a distorted capped octahedral coordination geometry. Two carboxylate groups of the benzoate moieties of two cpima2− ligands bridge between Cd2 centres to generate [Cd2O2] units, which are further linked by two cpima2− ligands to produce one‐dimensional (1D) infinite chains based around large 26‐membered rings. Meanwhile, adjacent Cd1 centres are linked by Hcpimda2− ligands to generate 1D zigzag chains. The two types of chains are linked through a μ2‐η2 bidentate bridging mode from an O atom of an imidazole carboxylate unit of cpima2− to give a two‐dimensional (2D) coordination polymer. The simplified 2D net structure can be described as a 3,6‐coordinated net which has a (43)2(46.66.83) topology. Furthermore, the FT–IR spectroscopic properties, photoluminescence properties, powder X‐ray diffraction (PXRD) pattern and thermogravimetric behaviour of the polymer have been investigated.  相似文献   

7.
The amino substituted bidentate chelating ligand 2‐amino‐5‐(2‐pyridyl)‐1,3,4‐thiadiazole (H2 L ) was used to prepare 3:1‐type coordination compounds of iron(II), cobalt(II) and nickel(II). In the iron(II) perchlorate complex [FeII(H2 L )3](ClO4)2·0.6MeOH·0.9H2O a 1:1 mixture of mer and fac isomers is present whereas [FeII(H2 L )3](BF4)2·MeOH·H2O, [CoII(H2 L )3](ClO4)2·2H2O and [NiII(H2 L )3](ClO4)2·MeOH·H2O feature merely mer derivatives. Moessbauer spectroscopy and variable temperature magnetic measurements revealed the [FeII(H2 L )3]2+ complex core to exist in the low‐spin state, whereas the [CoII(H2 L )3]2+ complex core resides in its high‐spin state, even at very low temperatures.  相似文献   

8.
A series of silver(I) supramolecular complexes, namely, {[Ag(L24)](NO3)}n ( 1 ), [Ag2(L24)(NO2)2]n ( 2 ), and {[Ag1.25(L24)(DMF)](PF6)1.25}n ( 3 ) were prepared by the reactions of 1‐(2‐pyridyl)‐2‐(4‐pyridyl)‐1,2,4‐triazole (L24) and silver(I) salts with different anions (AgNO3, AgNO2, AgPF6). Single‐crystal X‐ray diffraction indicates that 1 – 3 display diverse supramolecular networks. The structure of dinuclear complex 1 is composed of a six‐membered Ag2N4 ring with the Ag ··· Ag distance of 4.4137(3) Å. In complex 2 , the adjacent AgI centers are interlinked by L24 ligands into a 1D chain, the adjacent of which are further extended by the bridged nitrites to construct a 2D coordination architecture. Complex 3 shows a 3D (3,4)‐connected framework, which is generated by the linkage of L24 ligands. All complexes were characterized by IR spectra, elemental analysis, and powder X‐ray diffraction. Notably, a structural comparison of the complexes demonstrates that their structures are predominated by the nature of anions. Additionally, 1 and 2 show efficient dichromate (Cr2O72–) capture in water system, which can be ascribed to the anion‐exchange.  相似文献   

9.
薛思佳  卞王东  柴安  吁松瑞 《中国化学》2008,26(8):1501-1505
本文首次合成标题化合物N-(4-甲基苯甲酰氨基)-N’-[5-(2-三氟甲基苯基)-2-呋喃甲酰硫脲。化合物(C21H16F3N3O3S, Mr = 447.43)单晶经测定为单斜晶体,空间群为P -1。在晶体中,存在一些分子内和分子间的相互作用,分子间还有C—H···π 的相互作用,这可能导致晶体更稳定的原因。目标产物的结构经IR, H NMR和元素分析测定确证。初步生物活性测试表明,部分化合物对棉花枯萎病、黄瓜灰霉病、苹果轮纹病和棉花炭疽病有较好的选择性杀菌活性;部分目标化合物有较好的除草活性。  相似文献   

10.
In the title coordination polymer, [Zn2(C14H8N2O4)2(C12H10N2)]n, the asymmetric unit contains one ZnII cation, two halves of 2,2′‐(diazene‐1,2‐diyl)dibenzoate anions (denoted L2−) and half of a 1,2‐bis(pyridin‐4‐yl)ethene ligand (denoted bpe). The three ligands lie across crystallographic inversion centres. Each ZnII centre is four‐coordinated by three O atoms of bridging carboxylate groups from three L2− ligands and by one N atom from a bpe ligand, forming a tetrahedral coordination geometry. Two ZnII atoms are bridged by two carboxylate groups of L2− ligands, generating a [Zn2(CO2)2] ring. Each loop serves as a fourfold node, which links its four equivalent nodes via the sharing of four L2− ligands to form a two‐dimensional [Zn2L4]n net. These nets are separated by bpe ligands acting as spacers, producing a three‐dimensional framework with a 4664 topology. Powder X‐ray diffraction and solid‐state photoluminescence were also measured.  相似文献   

11.
The reactive 1 : 1 adducts in the reaction between Ph3P and dialkyl acetylenedicarboxylates have been trapped with ‘tosylmethyl isocyanide’ (TsMIC ; 1 ) to yield dialkyl 2‐[(4‐methylphenyl)sulfonyl]‐1H‐pyrrole‐3,4‐dicarboxylates 3 (Scheme 1). The structures of the highly functionalized compounds 3 were corroborated spectroscopically (IR, 1H‐ and 13C‐NMR, and EI‐MS) and by elemental analyses. A plausible mechanism for this type of cyclization is proposed (Scheme 2).  相似文献   

12.
Highly reactive 1 : 1 intermediates were produced in the reaction of Ph3P and dialkyl acetylenedicarboxylates (=dialkyl but‐2‐ynedioates). Protonation of these intermediates by alcohols (2,2,2‐trichloroethanol, propargyl alcohol (=prop‐2‐yn‐1‐ol), MeOH, benzyl alcohol, and allyl alcohol (=prop‐2‐en‐1‐ol) led to vinyltriphenylphosphonium salts 4 , which underwent a Michael addition reaction with the conjugate base to produce the corresponding stabilized phosphonium ylides 5 (Scheme). Wittig reaction of the stabilized phosphonium ylides with ninhydrin ( 6 ) led to the corresponding densely functionalized 2H‐indeno[2,1‐b]furans 10 in fairly good yields (Table 1). The structures of the final products were confirmed by IR, 1H‐ and 13C‐NMR spectroscopy, and mass spectrometry. The configuration of dimethyl 8,8a‐dihydro‐8‐oxo‐8a‐(2,2,2‐trichloroethoxy)‐2H‐indeno[2,1‐b]furan‐2,3‐dicarboxylate ( 10a ) was established by a single‐crystal X‐ray structure determination, establishing that the one‐pot multicomponent condensation reaction was completely diastereoselective.  相似文献   

13.
The zinc(II) pseudohalide complexes {[Zn(L334)(SCN)2(H2O)](H2O)2}n ( 1 ) and [Zn(L334)(dca)2]n ( 2 ) were synthesized and characterized using the ligand 3,4‐bis(3‐pyridyl)‐5‐(4‐pyridyl)‐1,2,4‐triazole (L334) and ZnCl2 in presence of thiocyanate (SCN) and dicynamide [dca, N(CN)2] respectively. Single‐crystal X‐ray structural analysis revealed that the central ZnII atoms in both complexes have similar octahedral arrangement. Compound 1 has a 2D sheet structure bridged by bidentate L334 and double μN,S‐thiocyanate anions, whereas complex 2 , incorporating with two monodentate dicynamide anions, displays a two‐dimensional coordination framework bridged by tetradentate L334 ligand. Structural analysis demonstrated that the influence of pseudohalide anions plays an important role in determining the resultant structure. Both complexes were characterized by IR spectroscopy, microanalysis, and powder X‐ray diffraction techniques. In addition, the solid fluorescence and thermal stability properties of both complexes were investigated.  相似文献   

14.
The title compound, C18H18N4OS2, was prepared by reaction of S,S‐diethyl 2‐thenoylimidodithiocarbonate with 5‐amino‐3‐(4‐methylphenyl)‐1H‐pyrazole using microwave irradiation under solvent‐free conditions. In the molecule, the thiophene unit is disordered over two sets of atomic sites, with occupancies of 0.814 (4) and 0.186 (4), and the bonded distances provide evidence for polarization in the acylthiourea fragment and for aromatic type delocalization in the pyrazole ring. An intramolecular N—H...O hydrogen bond is present, forming an S(6) motif, and molecules are linked by N—H...O and N—H...N hydrogen bonds to form a ribbon in which centrosymmetric R22(4) rings, built from N—H...O hydrogen bonds and flanked by inversion‐related pairs of S(6) rings, alternate with centrosymmetric R22(6) rings built from N—H...N hydrogen bonds.  相似文献   

15.
In the coordination polymer catena‐poly[[[diaqua[5‐carboxy‐2‐(pyridin‐3‐yl)‐1H‐imidazole‐4‐carboxylato‐κ2N3,O4]lead(II)]‐μ‐5‐carboxy‐2‐(pyridin‐3‐yl)‐1H‐imidazole‐4‐carboxylato‐κ3N3,O4:N2] dihydrate], {[Pb(C10H6N3O4)(H2O)2]·2H2O}n, the two 5‐carboxy‐2‐(pyridin‐3‐yl)‐1H‐imidazole‐4‐carboxylate ligands have different coordination modes, one being terminal and the other bridging. The bridging ligand links PbII cations into one‐dimensional coordination polymer chains. The structure is also stabilized by intra‐ and interchain π–π stacking interactions between the pyridine rings, resulting in the formation of a two‐dimensional network. Extensive hydrogen‐bonding interactions lead to the formation of a three‐dimensional supramolecular network.  相似文献   

16.
Through photocatalysed regiospecific and stereoselective additions of cycloamines to 5‐(R)‐(l)‐menthyloxy‐2 (5H)‐furanone (3), chiral 5‐(R)‐(l)‐menthyloxy‐4‐cycloaminobutyrolactones were synthesized. In the new asymmetric photoaddition of compound 3, the N‐methyl cyclic amines (4) gave novel chiral C? C photoadducts (5) in 24–50% isolated yields with d. e. ≥ 98%. However, the secondary cyclic amines (6) afforded optically active N? C photoadducts (7) in 34–58% isolated yields with d. e. ≥ 98% under the same condition. All the synthesized optically active compounds were identified on the basis of their analytical data and spectroscopic data, such as [α]58920, IR, 1H NMR, 13C NMR, MS and elementary analysis. The photosynthesis of chiral butyrolactones and its mechanism were discussed in detail.  相似文献   

17.
The crystal structures of 2‐hydroxy‐5‐[(E)‐(4‐nitrophenyl)diazenyl]benzoic acid, C13H9N3O5, (I), ammonium 2‐hydroxy‐5‐[(E)‐phenyldiazenyl]benzoate, NH4+·C13H9N2O3, (II), and sodium 2‐hydroxy‐5‐[(E)‐(4‐nitrophenyl)diazenyl]benzoate trihydrate, Na+·C13H8N3O5·3H2O, (III), have been determined using single‐crystal X‐ray diffraction. In (I) and (III), the phenyldiazenyl and carboxylic acid/carboxylate groups are in an anti orientation with respect to each other, which is in accord with the results of density functional theory (DFT) calculations, whereas in (II), the anion adopts a syn conformation. In (I), molecules form slanted stacks along the [100] direction. In (II), anions form bilayers parallel to (010), the inner part of the bilayers being formed by the benzene rings, with the –OH and –COO substituents on the bilayer surface. The NH4+ cations in (II) are located between the bilayers and are engaged in numerous N—H...O hydrogen bonds. In (III), anions form layers parallel to (001). Both Na+ cations have a distorted octahedral environment, with four octahedra edge‐shared by bridging water O atoms, forming [Na4(H2O)12]4+ units.  相似文献   

18.
The title CdII compound, {[Cd2(C13H7NO4)2(H2O)4]·5H2O}n, was synthesized by the hydrothermal reaction of Cd(NO3)2·4H2O and 5‐(pyridin‐4‐yl)isophthalic acid (H2L). The asymmetric unit contains two crystallographically independent CdII cations, two deprotonated L2− ligands, four coordinated water molecules and five isolated water molecules. One of the CdII cations adopts a six‐coordinate octahedral coordination geometry involving three O atoms from one bidentate chelating and one monodentate carboxylate group of two different L2− ligands, one N atom of another L2− ligand and two coordinated water molecules. The second CdII cation adopts a seven‐coordinate pentagonal–bipyramidal coordination geometry involving four O atoms from two bidentate chelating carboxylate groups of two different L2− ligands, one N atom of another L2− ligand and two coordinated water molecules. Each L2− ligand bridges three CdII cations and, likewise, each CdII cation connects to three L2− ligands, giving rise to a two‐dimensional graphite‐like 63 layer structure. These two‐dimensional layers are further linked by O—H...O hydrogen‐bonding interactions to form a three‐dimensional supramolecular architecture. The photoluminescence properties of the title compound were also investigated.  相似文献   

19.
Addition of various amines to the 3,3‐bis(trifluoromethyl)acrylamides 10a and 10b gave the tripeptides 11a – 11f , mostly as mixtures of epimers (Scheme 3). The crystalline tripeptide 11f 2 was found to be the N‐terminal (2‐hydroxyethoxy)‐substituted (R,S,S)‐ester HOCH2CH2O‐D ‐Val(F6)‐MeLeu‐Ala‐OtBu by X‐ray crystallography. The C‐terminal‐protected tripeptide 11f 2 was condensed with the N‐terminus octapeptide 2b to the depsipeptide 12a which was thermally rearranged to the undecapeptide 13a (Scheme 4). The condensation of the epimeric tripeptide 11f 1 with the octapeptide 2b gave the undecapeptide 13b directly. The undecapeptides 13a and 13b were fully deprotected and cyclized to the [5‐[4,4,4,4′,4′,4′‐hexafluoro‐N‐(2‐hydroxyethoxy)‐D ‐valine]]‐ and [5‐[4,4,4,4′,4′,4′‐hexafluoro‐N‐(2‐hydroxyethoxy)‐L ‐valine]]cyclosporins 14a and 14b , respectively (Scheme 5). Rate differences observed for the thermal rearrangements of 12a to 13a and of 12b to 13b are discussed.  相似文献   

20.
The NdIII coordination compounds [Nd(4‐pytza)3(H2O)2] · 2H2O ( 1 ) and [Nd(4‐pytza)2(H2O)4]Cl · 2H2O ( 2 ) [H4‐pytza = 5‐(4‐pyridyl)tetrazole‐2‐acetic acid] were synthesized by reactions of K4‐pytza and NdCl3 · 6H2O at different pH values. Single crystal X‐ray diffraction analysis reveals that 4‐pytza ligands in 1 in a μ1,3‐COO synsyn or μ1,1,3‐COO bridging mode coordinate to two central NdIII atoms to display a dinuclear unit, which is connected by one of these 4‐pytza ligands acting in end‐to‐end bridging mode to form a 1D ladder‐like chain. Different from 1 , each 4‐pytza in 2 with a μ1,3‐COO synanti bridging mode coordinates to two NdIII atoms to display a 1D zigzag chain. Furthermore, the luminescence properties of 1 and 2 were investigated at room temperature in the solid state.  相似文献   

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