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1.
Contributions to the Chemistry of Phosphorus. 243 On the Oxocyclotetraphosphanes (PBut)4O1–4 Under suitable conditions, the reaction of tetra‐tert‐butylcyclotetraphosphane, (PBut)4, with dry atmospheric oxygen gives rise to the corresponding monoxide (PBut)4O ( 1 ) which has been isolated by column chromatography. The reaction with hydrogen peroxide furnishes a mixture of oxocyclotetraphosphanes (PBut)4O1–4 consisting of two constitutionally isomeric dioxides (PBut)4O2 ( 2 a , 2 b ), the trioxide (PBut)4O3 ( 3 ), and the tetraoxide (PBut)4O4 ( 4 ), in addition to 1 . According to the 31P NMR parameters the oxygen atoms are exclusively exocyclically bonded to the phosphorus four‐membered ring. Which of the P atoms are present as λ5‐phosphorus follows from the different low‐field shifts of the individual P nuclei compared with the starting compound. Accordingly, 1 is 1,2,3,4‐Tetra‐tert‐butyl‐1‐oxocyclotetraphosphane, 2 a and 2 b are 1,2,3,4‐Tetra‐tert‐butyl‐1,2‐dioxo‐ and ‐1,3‐dioxocyclotetraphosphane, respectively, 3 is 1,2,3,4‐Tetra‐tert‐butyl‐1,2,3‐trioxocyclotetraphosphane, and 4 is 1,2,3,4‐Tetra‐tert‐butyl‐1,2,3,4‐tetraoxocyclotetraphosphane. When the oxidation reaction proceeds a fission of the P4 ring takes place.  相似文献   

2.
The title enanti­omorphic compounds, C16H23NO4S, have been obtained in an enanti­omerically pure form by crystallization from a diastereomeric mixture either of (2S,4S)‐ and (2R,4S)‐ or of (2R,4R)‐ and (2S,4R)‐2‐tert‐butyl‐4‐methyl‐3‐(4‐tolyl­sulfon­yl)‐1,3‐oxazolidine‐4‐carbaldehyde. These mixtures were prepared by an aziridination rearrangement process starting with (S)‐ or (R)‐2‐tert‐butyl‐5‐methyl‐4H‐1,3‐dioxine. The crystal structures indicate an envelope conformation of the oxazolidine moiety for both compounds.  相似文献   

3.
In the title compounds, 4‐aminopyridinium 4‐aminobenzoate dihydrate, C7H6NO2·C5H7N2+·2H2O, (I), and 4‐aminopyridinium nicotinate, C5H7N2+·C6H4NO2, (II), the aromatic N atoms of the 4‐aminopyridinium cations are protonated. In (I), the asymmetric unit is composed of two 4‐aminopyridinium cations, two 4‐aminobenzoate anions and four water molecules, and the compound crystallizes in a noncentrosymmetric space group. The two sets of independent molecules of (I) are related by a centre of symmetry which is not part of the space group. In (I), the protonated pyridinium ring H atoms are involved in bifurcated hydrogen bonding with carboxylate O atoms to form an R12(4) ring motif. The water molecules link the ions to form a two‐dimensional network along the (10) plane. In (II), an intramolecular bifurcated hydrogen bond generates an R12(4) ring motif and inter‐ion hydrogen bonding generates an R42(16) ring motif. The packing of adduct (II) is consolidated via N—H...O and N—H...N hydrogen bonds to form a two‐dimensional network along the (10) plane.  相似文献   

4.
The crystal structure of the ζ2‐phase Al3Cu4‐δ was determined by means of X‐ray powder diffraction: a = 409.72(1) pm, b = 703.13(2) pm, c = 997.93(3) pm, space group Imm2, Pearson symbol oI24‐3.5, RI = 0.0696. ζ2‐Al3Cu4‐δ forms a distinctive a × √3a × 2c superstructure of a metal deficient Ni2In‐type‐related structure. The phase is meta‐stable at ambient temperature. Between 400 °C and 450 °C it decomposes into ζ1‐Al3Cu4 and η2‐AlCu. Entropic contributions to the stability of ζ2‐Al3Cu4‐δ are reflected in three statistically or partially occupied sites.  相似文献   

5.
The title compounds, C8H10O2, (I), and C12H14O2, (II), occurred as by‐products in the controlled synthesis of a series of bis­(gem‐alkynols), prepared as part of an extensive study of synthon formation in simple gem‐alkynol derivatives. The two 4‐(gem‐alkynol)‐1‐ones crystallize in space group P21/c, (I) with Z′ = 1 and (II) with Z′ = 2. Both structures are dominated by O—H?O=C hydrogen bonds, which form simple chains in the cyclo­hexane derivative, (I), and centrosymmetric dimers, of both symmetry‐independent mol­ecules, in the cyclo­hexa‐2,5‐diene, (II). These strong synthons are further stabilized by C[triple‐bond]C—H?O=C, Cmethylene—H?O(H) and Cmethyl—H?O(H) interactions. The direct intermolecular interactions between donors and acceptors in the gem‐alkynol group, which characterize the bis­(gem‐alkynol) analogues of (I) and (II), are not present in the ketone derivatives studied here.  相似文献   

6.
The structures of three compounds with potential anti­malarial activity are reported. In N,N‐diethyl‐N′‐(7‐iodo­quinolin‐4‐yl)ethane‐1,2‐diamine, C15H20IN3, (I), the mol­ecules are linked into ribbons by N—H⋯N and C—H⋯N hydrogen bonds. In N‐(7‐bromo­quinolin‐4‐yl)‐N′,N′‐diethyl­ethane‐1,2‐diamine dihydrate, C15H20BrN3·2H2O, (II), two amino­quino­line mol­ecules and four water mol­ecules form an R54(13) hydrogen‐bonded ring which links to its neighbours to form a T5(2) one‐dimensional infinite tape with pendant hydrogen bonds to the amino­quinolines. The phosphate salt 7‐chloro‐4‐[2‐(diethyl­ammonio)ethyl­amino]quinolinium bis­(dihydrogen­phosphate) phospho­ric acid, C15H22ClN32+·2H2PO4·H3PO4, (III), was prepared in order to establish the protonation sites of these compounds. The phosphate ions form a two‐dimensional hydrogen‐bonded sheet, while the amino­quino­line cations are linked to the phosphates by N—H⋯O hydrogen bonds from each of their three N atoms. While the conformation of the quinoline region hardly varies between (I), (II) and (III), the amino side chain is much more flexible and adopts a significantly different conformation in each case. Aromatic π–π stacking inter­actions are the only supramolecular inter­actions seen in all three structures.  相似文献   

7.
The title compound, C21H28O4, has a 4‐acetoxy substituent positioned on the steroid α face. The six‐membered ring A assumes a conformation intermediate between 1α,2β‐half chair and 1α‐sofa. A long Csp3—Csp3 bond is observed in ring B and reproduced in quantum‐mechanical ab initio calculations of the isolated molecule using a molecular‐orbital Hartree–Fock method. Cohesion of the crystal can be attributed to van der Waals interactions and weak C—H...O hydrogen bonds.  相似文献   

8.
The molecule of 3,5‐bis{4‐[(benzimidazol‐1‐yl)methyl]phenyl}‐4H‐1,2,4‐triazol‐4‐amine (L), C30H24N8, has an antiperiplanar conformation of the two terminal benzimidazole groups and forms two‐dimensional networks along the crystallographic b axis via two types of intermolecular hydrogen bonds. However, in catena‐poly[[[dichloridomercury(II)]‐μ‐3,5‐bis{4‐[(benzimidazol‐1‐yl)methyl]phenyl}‐4H‐1,2,4‐triazol‐4‐amine] dichloromethane hemisolvate], {[HgCl2(C30H24N8)]·0.5CH2Cl2}n, synthesized by the combination of L with HgCl2, the L ligand adopts a synperiplanar conformation. The HgII cation lies in a distorted tetrahedral environment, which is defined by two N atoms and two Cl atoms to form a one‐dimensional zigzag chain. These zigzag chains stack via hydrogen bonds which expand the dimensionality of the structure from one to two.  相似文献   

9.
Cs2[MnSnTe4]: Uncommon Synthesis of a Quaternary Phase Based on One‐dimensional, Ternary Anionic Chains Reaction of a methanol solvate of yet not reported ortho‐tellurostannate(IV) salt Cs4[SnTe4] ( 1 ) with MnCl2·4H2O in aqueous solution led to the formation of the novel compound Cs2[MnSnTe4] ( 2 ), the crystal structures of which was determined by means of single crystal X‐ray diffraction. 2 crystallizes in the space group Fddd. Lattice dimensions at 203 K: a = 681.9(1), b = 1506.3(3), c = 2596.7(5) pm, V = 2667.2(9)·106pm3; R1 = 0.0655. By synthesis of 2 , transfer of complete ortho‐tellurostannate anions into the coordination sphere of a 3d‐transition metal atom succeeded for the first time. The structure of 2 is based on a ternary anionic substructure formed by one‐dimensional, parallel 1{[MnSnTe4]2—} strands. In spite of the preparation in solution, 2 does not provide any solvent molecules in the crystal lattice.  相似文献   

10.
The structure of lophine peroxide was confirmed to be 2,4,5‐tri­phenyl‐4H‐imidazol‐4‐yl hydro­peroxide and not the 2,5‐endoperoxide. The asymmetric unit is composed of an O—H?N hydrogen‐bonded dimer of lophine peroxide with an R/R or S/S configuration and a CH2Cl2 solvent mol­ecule, i.e. 2C21H16N2O2·CH2Cl2.  相似文献   

11.
The design and synthesis of metal–organic frameworks (MOFs) have attracted much interest due to the intriguing diversity of their architectures and topologies. However, building MOFs with different topological structures from the same ligand is still a challenge. Using 3‐nitro‐4‐(pyridin‐4‐yl)benzoic acid (HL) as a new ligand, three novel MOFs, namely poly[[(N,N‐dimethylformamide‐κO)bis[μ2‐3‐nitro‐4‐(pyridin‐4‐yl)benzoato‐κ3O,O′:N]cadmium(II)] N,N‐dimethylformamide monosolvate methanol monosolvate], {[Cd(C12H7N2O4)2(C3H7NO)]·C3H7NO·CH3OH}n, ( 1 ), poly[[(μ2‐acetato‐κ2O:O′)[μ3‐3‐nitro‐4‐(pyridin‐4‐yl)benzoato‐κ3O:O′:N]bis[μ3‐3‐nitro‐4‐(pyridin‐4‐yl)benzoato‐κ4O,O′:O′:N]dicadmium(II)] N,N‐dimethylacetamide disolvate monohydrate], {[Cd2(C12H7N2O4)3(CH3CO2)]·2C4H9NO·H2O}n, ( 2 ), and catena‐poly[[[diaquanickel(II)]‐bis[μ2‐3‐nitro‐4‐(pyridin‐4‐yl)benzoato‐κ2O:N]] N,N‐dimethylacetamide disolvate], {[Ni(C12H7N2O4)2(H2O)2]·2C4H9NO}n, ( 3 ), have been prepared. Single‐crystal structure analysis shows that the CdII atom in MOF ( 1 ) has a distorted pentagonal bipyramidal [CdN2O5] coordination geometry. The [CdN2O5] units as 4‐connected nodes are interconnected by L? ligands to form a fourfold interpenetrating three‐dimensional (3D) framework with a dia topology. In MOF ( 2 ), there are two crystallographically different CdII ions showing a distorted pentagonal bipyramidal [CdNO6] and a distorted octahedral [CdN2O4] coordination geometry, respectively. Two CdII ions are connected by three carboxylate groups to form a binuclear [Cd2(COO)3] cluster. Each binuclear cluster as a 6‐connected node is further linked by acetate groups and L? ligands to produce a non‐interpenetrating 3D framework with a pcu topology. MOF ( 3 ) contains two crystallographically distinct NiII ions on special positions. Each NiII ion adopts an elongated octahedral [NiN2O4] geometry. Each NiII ion as a 4‐connected node is linked by L? ligands to generate a two‐dimensional network with an sql topology, which is further stabilized by two types of intermolecular OW—HW…O hydrogen bonds to form a 3D supramolecular framework. MOFs ( 1 )–( 3 ) were also characterized by powder X‐ray diffraction, IR spectroscopy and thermogravimetic analysis. Furthermore, the solid‐state photoluminescence of HL and MOFs ( 1 ) and ( 2 ) have been investigated. The photoluminescence of MOFs ( 1 ) and ( 2 ) are enhanced and red‐shifted with respect to free HL. The gas adsorption investigation of MOF ( 2 ) indicates a good separation selectivity (71) of CO2/N2 at 273 K (i.e. the amount of CO2 adsorption is 71 times higher than N2 at the same pressure).  相似文献   

12.
傅铭堃  吴宪  宁君  李建中 《中国化学》2005,23(7):901-904
To implement the solid phase synthesis of 4““-epi-methylamino-4““-deoxyavermecfin B1 benzoate, tert-butyldimethylsilylchloride was chosen for the first solution synthesis. Then a novel silyl chloride resin 1, achieved from hydroxymethyl polystyrene resin and dimethyldichlorosilane, was used successfully for the attachment of avermectin B1 2. Through oxidation, amination formation, cleavage, and benzoate formation, resin bounded avermectin B1 9 gave 4““-epi-methylamino-4““-deoxyavermectin B1 benzoate 3.  相似文献   

13.
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   

14.
The derivatives of pyrimidin‐4‐one can adopt either a 1H‐ or a 3H‐tautomeric form, which affects the hydrogen‐bonding interactions in cocrystals with compounds containing complementary functional groups. In order to study their tautomeric preferences, we crystallized 2,6‐diaminopyrimidin‐4‐one and 2‐amino‐6‐methylpyrimidin‐4‐one. During various crystallization attempts, four structures of 2,6‐diaminopyrimidin‐4‐one were obtained, namely solvent‐free 2,6‐diaminopyrimidin‐4‐one, C4H6N4O, (I), 2,6‐diaminopyrimidin‐4‐one–dimethylformamide–water (3/4/1), C4H6N4O·1.33C3H7NO·0.33H2O, (Ia), 2,6‐diaminopyrimidin‐4‐one dimethylacetamide monosolvate, C4H6N4O·C4H9NO, (Ib), and 2,6‐diaminopyrimidin‐4‐one–N‐methylpyrrolidin‐2‐one (3/2), C4H6N4O·1.5C5H9NO, (Ic). The 2,6‐diaminopyrimidin‐4‐one molecules exist only as 3H‐tautomers. They form ribbons characterized by R22(8) hydrogen‐bonding interactions, which are further connected to form three‐dimensional networks. An intermolecular N—H...N interaction between amine groups is observed only in (I). This might be the reason for the pyramidalization of the amine group. Crystallization experiments on 2‐amino‐6‐methylpyrimidin‐4‐one yielded two isostructural pseudopolymorphs, namely 2‐amino‐6‐methylpyrimidin‐4(3H)‐one–2‐amino‐6‐methylpyrimidin‐4(1H)‐one–dimethylacetamide (1/1/1), C5H7N3O·C5H7N3O·C4H9NO, (IIa), and 2‐amino‐6‐methylpyrimidin‐4(3H)‐one–2‐amino‐6‐methylpyrimidin‐4(1H)‐one–N‐methylpyrrolidin‐2‐one (1/1/1), C5H7N3O·C5H7N3O·C5H9NO, (IIb). In both structures, a 1:1 mixture of 1H‐ and 3H‐tautomers is present, which are linked by three hydrogen bonds similar to a Watson–Crick C–G base pair.  相似文献   

15.
In 4‐fluoroisoquinoline‐5‐sulfonyl chloride, C9H5ClFNO2S, (I), one of the two sulfonyl O atoms lies approximately on the isoquinoline plane as a result of minimizing the steric repulsion between the chlorosulfonyl group and the neighbouring F atom. In (S)‐(−)‐4‐fluoro‐N‐(1‐hydroxypropan‐2‐yl)isoquinoline‐5‐sulfonamide, C12H13FN2O3S, (II), there are two crystallographically independent molecules (Z′ = 2). The molecular conformations of these two molecules differ in that the amine group of one forms an intramolecular bifurcated hydrogen bond with the F and OH groups, whilst the other forms only a single intramolecular N—H...F hydrogen bond. The N—H...F hydrogen bonds correspond to weak coupling between the N(H) and 19F nuclei, observed in the 1H NMR solution‐state spectra. In (S)‐(−)‐4‐[(4‐fluoroisoquinolin‐5‐yl)sulfonyl]‐3‐methyl‐1,4‐diazepan‐1‐ium chloride, C15H19FN3O2S+·Cl, (III), the isoquinoline plane is slightly deformed, suggestive of a steric effect induced by the bulky substituent on the sulfonyl group.  相似文献   

16.
In the title compound, 4‐(4H‐1,2,4‐triazol‐4‐yl­imino­methyl)­phenol hemi­hydrate, C9H8N4O·0.5H2O or (I)·0.5H2O, mol­ecules of (I) are arranged as layers running along the b axis through intermolecular O—H?N and C—H?O hydrogen bonds. These layers are stabilized by hydrogen‐bonded water mol­ecules to form three‐dimensional networks.  相似文献   

17.
The compounds [(η6p‐cymene)RuCl2(4‐nitroaniline)] and [(η6p‐cymene)RuCl2(2‐halogen‐4‐nitroaniline)] were synthesized and characterized by various means. The [(η6p‐cymene)RuCl2(4‐nitroaniline)] and [(η6p‐cymene)RuCl2(2‐fluoro‐4‐nitroaniline)] compounds were determined by X‐ray diffraction, appearing in a distorted piano‐stool type of arrangement with similar bond lengths and angles around the ruthenium. The compounds exhibited moderate to strong in vitro cytotoxicity against A549 and MCF‐7 human cancer cells. Substitution of heavy halogen atom on the ortho position of para‐nitroaniline weakened the cytotoxicity against both of MCF‐7 and A549, except the cases of fluorine substitution for hydrogen atom regarding A549 and bromine substitution for chlorine atom regarding MCF‐7, which showed minor deviation.  相似文献   

18.
Two chemical isomers of 3‐nitro­benzotrifluoride, namely 1‐(4‐chloro­phenyl­sulfanyl)‐2‐nitro‐4‐(tri­fluoro­methyl)­benzene, C13H7ClF3NO2S, (I), and 1‐(4‐chloro­phenyl­sulfanyl)‐4‐nitro‐2‐(tri­fluoro­methyl)­benzene, C13H7ClF3NO2S, (II), have been prepared and their crystal structures determined with the specific purpose of forming a cocrystal of the two. The two compounds display a similar conformation, with dihedral angles between the benzene rings of 83.1 (1) and 76.2 (1)°, respectively, but (I) packs in P while (II) packs in P21/c, with C—H⋯O interactions. No cocrystal could be formed, and it is suggested that the C—H⋯O associations in (II) prevent intermolecular mixing and promote phase separation.  相似文献   

19.
This study presents the coordination modes and crystal organization of a calcium–potassium coordination polymer, poly[hexaaquabis(μ4‐4‐carboxybenzenesulfonato‐κ4O1:O1′:O1′′:O4)bis(μ3‐4‐carboxybenzenesulfonato‐κ2O1:O1′)calcium(II)dipotassium(I)], [CaK2(C7H5O5S)4(H2O)6]n, displaying a novel two‐dimensional framework. The potassium ion is seven‐coordinated by four sulfonate and one carboxyl O atom located on five different acid ligands, two of which are unique, and by two symmetry‐independent water O atoms. A pair of close potassium ions share two inversion‐related sulfonate O‐atom sites to form a dimeric K2O12 unit, which is extended into a one‐dimensional array along the a‐axis direction. The six‐coordinate Ca2+ ion occupies a special position () at (0, , ) and is surrounded by four sulfonate O atoms from two inversion‐related pairs of unique acid monoanions and by two O atoms from aqua ligands. The compound displays a layered structure, with K2O12 and CaO6 polyhedra in the layers and aromatic linkers between the layers. The three‐dimensional scaffold is open, with nano‐sized channels along the c axis.  相似文献   

20.
The structures of five metal complexes containing the 4‐oxo‐4H‐pyran‐2,6‐dicarboxylate dianion illustrate the remarkable coordinating versatility of this ligand and the great structural diversity of its complexes. In tetraaquaberyllium 4‐oxo‐4H‐pyran‐2,6‐dicarboxylate, [Be(H2O)4](C7H2O6), (I), the ions are linked by eight independent O—H...O hydrogen bonds to form a three‐dimensional hydrogen‐bonded framework structure. Each of the ions in hydrazinium(2+) diaqua(4‐oxo‐4H‐pyran‐2,6‐dicarboxylato)calcate, (N2H6)[Ca(C7H2O6)2(H2O)2], (II), lies on a twofold rotation axis in the space group P2/c; the anions form hydrogen‐bonded sheets which are linked into a three‐dimensional framework by the cations. In bis(μ‐4‐oxo‐4H‐pyran‐2,6‐dicarboxylato)bis[tetraaquamanganese(II)] tetrahydrate, [Mn2(C7H2O6)2(H2O)8]·4H2O, (III), the metal ions and the organic ligands form a cyclic centrosymmetric Mn2(C7H2O6)2 unit, and these units are linked into a complex three‐dimensional framework structure containing 12 independent O—H...O hydrogen bonds. There are two independent CuII ions in tetraaqua(4‐oxo‐4H‐pyran‐2,6‐dicarboxylato)copper(II), [Cu(C7H2O6)(H2O)4], (IV), and both lie on centres of inversion in the space group P; the metal ions and the organic ligands form a one‐dimensional coordination polymer, and the polymer chains are linked into a three‐dimensional framework containing eight independent O—H...O hydrogen bonds. Diaqua(4‐oxo‐4H‐pyran‐2,6‐dicarboxylato)cadmium monohydrate, [Cd(C7H2O6)(H2O)2]·H2O, (V), forms a three‐dimensional coordination polymer in which the organic ligand is coordinated to four different Cd sites, and this polymer is interwoven with a complex three‐dimensional framework built from O—H...O hydrogen bonds.  相似文献   

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