Low Temperature Crystal Structure of 5-Hydroxy-1,7-Bis-(4-Hydroxy-3-Methoxy-Phenyl)-Hepta-1,6-Dien-3-one

Abstract  

The title compound 5-Hydroxy-1,7-bis-(4-hydroxy-3-methoxy-phenyl)-hepta-1,6-dien-3-one crystallizes in orthorhombic space group Pca2₁ with two molecules in the asymmetric unit. The unit cell parameters are: a = 35.5368(8), b = 7.7799(2), c = 12.6796(3) ?, D _calc = 1.396 Mgm⁻³, V = 3505.6(2) ?³ and Z = 8. The two aromatic rings in both the molecules are found almost coplanar, their dihedral angles are 18.8° and 13.8°, respectively. The molecular packing is stabilized by strong O–H···O and C–H···O types of hydrogen bonding interactions. The keto and enol groups form an strong O–H···O intra-molecular interaction in both molecules of asymmetric unit. The molecular alignment in the crystal forming a staircase type of stacking through cross link intermolecular interactions.     

Crystal Structure of a Metallohybrid Acid of 1,3,5-Benzenetricarboxylic Acid of Copper(II)

Abstract The crystal structure of a metallohybrid carboxylic acid obtained from the reaction of 1,3,5-benzenetricarboxylic acid (TCAH3) with copper(II)acetate monohydrate in the presence of pyridine (py) having composition Cu(py)₂(TCAH2)₂(H₂O)₂ [1] is reported. It crystallizes in triclinic space group P-1 and with a = 7.0110(3)?, b = 8.9523(5)?, c = 11.5370(5) ?, α = 79.776(3) °, β = 82.881(3)°, γ = 83.628(3)°, and V = 704.18(6)?³. The hydrogen bond in 1 is compared with the hydrogen bond pattern in the structure of 1,3-dicarbomethoxy 4,6-benzenedicarboxylic acid, which crystallizes in mononclinic space group P21/c and has unit cell parameters of a = 6.9549(16)?, b = 8.7676(15)?, c = 20.111(4)?; β = 92.585(17) ° and V = 1225.1(4) ?³. Index Abstract Crystal structure of a metallohybrid carboxylic acid obtained from the reaction of 1,3,5-benzenetricarboxylic acid with copper(II)acetate monohydrate in the presence of pyridine is determined and compared with hydrogen bond pattern present in the structure of 1,3-dicarbomethoxy 4,6-benzenedicarboxylic acid. Crystal structure of a metallohybrid acid of 1,3,5-benzenetricarboxylic acid of copper(II). Kusum Bania, Nilotpal Barooah, Rupam Sarma, Jubaraj B. Baruah     

The Synthesis and Crystal Structure of 5-Methyl-1-(1-naphthyl)-1,2,3-triazol-4-carboxyl Acid

Abstract  5-Methyl-1-(1-naphthyl)-1,2,3-triazol-4-carboxyl acid 3 was synthesized from 1-aminonaphthalene. The yielded product 3 was investigated with X-ray crystallographic, NMR, MS and IR techniques. Compound 3, C₁₄H₁₁N₃O₂, Mr = 253.26, crystallizes in the orthorhombic space group Pbca with unit cell parameters a = 10.068(2), b = 12.353(2), c = 20.102(4) ?, V = 2500.1(8) ?³, Z = 8, Dx = 1.346 Mgm^-3. The final R was 0.0474. The molecular packing is stabilized by intermolecular O–H···N interactions. Index Abstract  5-Methyl-1-(1-naphthyl)-1,2,3-triazol-4-carboxyl acid 3 was synthesized from 1-aminonaphthalene. The yielded product 3 was investigated with X-ray crystallographic, NMR, MS and IR techniques. Compound 3, C₁₄H₁₁N₃O₂, Mr = 253.26, crystallizes in the orthorhombic space group Pbca with unit cell parameters a = 10.068(2), b = 12.353(2), c = 20.102(4) ?, α = β = γ = 90.00o. V = 2,500.1(8) ?³, Z = 8, Dx = 1.346 Mgm⁻³. The final R was 0.0474. The molecular packing is stabilized by intermolecular O–H···N interactions.      

Structure of 2-[(Phenyl)-(3,5-Dimethyl-Pyrazol-1-yl)-Methyl]-Malonic Acid Diethyl Ester

Abstract  

The titled new functionalized ligand of type 2-[(phenyl)-(3,5-dimethyl-pyrazol-1-yl)-methyl]-malonic acid diethyl ester (4) is prepared in good yield through condensation of 3,5-dimethyl-pyrazole, with 2-arylidene-malonic acid diethyl esters 3. The structure of 4 was determined by spectral (IR, ¹H and ¹³C NMR), elemental analyses and X-ray diffraction data. The title compound (4) crystallizes in the monoclinic space group P2₁/a, with a = 7.9253 (2), b = 17.1299 (5), c = 13.4522 (4) ?, β = 90.220 (2)°, V = 1,826.25 (9) ?³, Z = 4 and with R _int = 0.021. The molecular conformation shows two possible pockets ready to coordinate two metal atoms. The crystal structure of (4) is stabilized by inter-molecular C–H⋯O and C–H⋯N hydrogen bonding.     

4-(2,5-二甲基-3,4-二乙酰基)-1-吡咯基苯甲酸的合成及其晶体结构

在强酸性介质中,3,4-二乙酰基-2,5-己二酮与对氨基苯甲酸作用,满意地得到了4-(2,5-二甲基-3,4-二乙酰基)-1-吡咯基苯甲酸,用IR、1H NMR、高分辩质谱等对其进行了表征,用X射线衍射测定了晶体结构.该晶体属三斜晶系,P1空间群,a＝0.80950(10)nm,b＝0.81910(10)nm,c＝1.1900(2)nm,α＝101.600(10)°,β＝98.820(10)°,γ＝104.960(10)°,Z＝2,Dc＝1.364×103kg/m3.拟合了苯环平面和吡咯环平面的平面方程,并求出两平面之间的二面角为68.11°.     

A Sm(III) Coordination Polymer Containing 2,5-Furandicarboxylic Acid: Crystal Structure and Recognition of Oxalate in Water

Crystallography Reports - The {[Sm2(FDC)2](FDC) · 10H2O}n complex, where H2FDC is a 2,5-furandicarboxylic acid, has been prepared by hydrothermal reaction and structurally characterized by...     

The OD Structure of Dinitrosylcobalt Chloride, [Co(NO)2Cl]2

The OD groupoid family of the structure of dinitrosylcobalt chloride, [Co(NO)₂Cl]₂, is characterized by the symbol: The OD groupoid family of the structure is deduced from the observed arrangement of points in reciprocal space, the symmetry of the intensity distribution and the systematic absences. The structure is built of OD layers of one kind. The determination of the structure of the ordered orthorhombic form (MDO₂) has been determined from Weissenberg data obtained by JAGNER and VANNERBERG refined with OD full-matrix least-squares methods, based on a total of 150 reflections and anisotropic temperature coefficients. An R value of 0.13 has been obtained. The assumption of JAGNER that the structure is composed of dimers has been found to be justified.     

Crystal and Molecular Structure of the 1:2 Salt Formed Between 1,2-(4-Pyridyl)Ethane and 2-(4-Hydroxyphenylazo)Benzoic Acid

Abstract  Proton transfer occurred during co-crystallization of 1,2-(4-pyridyl)ethane with 2-(4-hydroxyphenylazo)benzoic acid to yield a salt comprising a 1:2 ratio of 1,2-bis(4-pyridinium)ethane dications and 2-(4-hydroxyphenylazo)benzoate anions. Centrosymmetrically related anions associate by charge-assisted O–H···O hydrogen bonds to form 24-membered {···OC₃N₂C₄OH}₂ synthons. These are connected into a supramolecular polymer via charge-assisted N–H···O hydrogen bonds involving the 1,2-bis(4-pyridinium)ethane dications. The compound crystallizes in the triclinic space group P−1 with a = 8.517(4) ?, b = 9.110(5) ?, c = 10.477(5) ?, α = 96.850(13)°, β = 94.446(12)°, γ = 104.946(10)° and Z = 1 {two anions and a dication}. Index Abstract  Supramolecular chains mediated by charge-assisted O–H···O and N–H···O hydrogen bonding are found in the salt containing a 1:2 ratio of 1,2-bis(4-pyridinium)ethane dications and 2-(4-hydroxyphenylazo)benzoate anions.      

Synthesis,Crystal Structure and Hydrogen-Bonding Patterns in (RS)-1-Carbamoyl Pyrrolidine-2-Carboxylic Acid

Abstract  

The title compound, N-carbamoyl-dl-proline, C₆H₁₀N₂O₃, crystallizes in the triclinic P-1 space group with unit cell parameters a = 7.610 (4) Å, b = 9.259 (5) Å, c = 11.749 (7) Å, α = 110.294 (11)°, β = 101.304 (13)°, γ = 91.391 (16)°, with two crystallographically independent molecules in the asymmetric unit. The ureido and carboxyl groups are equatorial and axial to the pyrrolidine rings, respectively. The pyrrolidine rings adopt envelope and twisted conformations in the residue A and B, respectively. The molecules are joined by N–H···O and O–H···O hydrogen bonds into cyclic structures with graph set R ₂²(8), forming infinite chains parallel to the cb plane with graph set C ₂²(14), that are further connected via N–H···O hydrogen bonds into a three-dimensional network.     

锆钛酸钡陶瓷的超低温烧结及其介电特性

利用钛酸四丁酯、硝酸锆、氢氧化钡为原料在室温下,直接合成了颗粒尺寸均匀,组分连续可调的高性能锆钛酸钡纳米粉体.在此基础上,通过添加不同比例的Bi2O3和Li2CO3为助烧剂,实现了900℃下的陶瓷的超低温烧结.确立了烧结时间与陶瓷微观结构之间的相关性.研究表明,助烧剂的加入,可以使介电峰强烈地向低温方向移动,室温介电常数可大于5000以上.某些情况下使介电峰分裂,由单一峰变为明显的双峰,这样使得介电常数的温度稳定性得到提高.     

Structure of 1-tris(trimethylsilyl)silyl-3,4,5,6-tetrakis(trimethylsilyl)cyclohex-1-ene

C₂₇H₆₈Si₈,1, monoclinic, P2₁/n;a=9.849(1)Å,b=22.599(3)Å,c=18.596(3)Å, =94.78(1)Å;Z=4,D _c=0.99 g cm^–3,R=035,R _w=0.044, GOF=1.73. Compound1 is obtained in one step by the reductive silylation of PhSiCl₃ in the presence of a large excess of Li metal and Me₃SiCl. The structure of1 has been studied by X-ray crystallography and solution phase NMR techniques.     

Pyridine-2,6-Dicarboxylic Acid (Dipic): Crystal Structure from Co-Crystal to a Mixed Ligand Nickel(II) Complex

Abstract  

Pyridine-2,6-dicarboxylic acid (dipic) was used for the synthesis of a co-crystal with 1,10-phenanthroline-5,6-dione (phen-dione) and a nickel(II) complex. The co-crystal dipic·phen-dione·4H₂O (1) has been synthesized and studied by X-ray crystallography. The structure is stabilized with hydrogen bonds between dipic, H₂O and phen-dione. It is surprising that there is no direct hydrogen bonding between phen-dione and dipic and yet the molecules co-crystallize in aqueous solution. A new complex of nickel(II), [Ni(phen)(dipic)(H₂O)]·4H₂O (2), (where phen = 1,10-phenanthroline) has been synthesized and characterized by elemental and thermogravimetric analyses, FT-IR, UV–Vis and ¹H-NMR spectroscopy. The structure of (2) has been studied by X-ray crystallography. The coordination around Ni(II) is a distorted octahedron. The crystal packing shows that the dimensionality of (2) is enlarged to 3D, through hydrogen bonds and π–π interactions. Cyclic voltammetry of (2) shows that the Ni(II/I) couple is irreversible.     

Crystal Structure of [4-(Methylsulfanyl)Phenyl]Acetic Acid

Abstract  

The title compound, C₉H₁₀O₂S, (I), crystallizes in the triclinic space group, P − 1, with unit cell parameters a = 6.2249(3), b = 7.3733(5), c = 19.5708(12), Å, α = 86.746(5)°, β = 88.682(5)°, γ = 86.988(5)°, Z = 4. The molecule consists of a methyl sulfanyl group bonded to benzyl acetic acid at the 4 position crystallizing with two molecules in the asymmetric unit. The carboxylic acid group from the acetic acid moiety in these two molecules forms a classic O–H···O hydrogen bonded dimer with O···O distances of 2.673(2) and 2.646(2) Å, in a R₂² (8) graph-set motif which link the molecules into pairs around inversion centers in the unit cell. The dihedral angles between the mean planes of the R₂² (8) graph-set motif with the mean planes of the two nearby benzyl groups within the same dimer in the unit cell are 64.1(6)° and 71.3(4)°, respectively. Within the same dimer the dihedral angle between the two benzyl groups is 45.2(1)°. The structure is supported by a weak intermolecular C–H···Cg π-ring interaction and gives support to molecular packing stability in the unit cell. Comparison to a MOPAC AM1 computational calculation provides support to these observations.     

Spectroscopic Studies and Structure of 4-(3-Benzoylthioureido)benzoic Acid

Abstract  

4-(3-Benzoylthioureido)benzoic acid has been synthesized from the reaction of 4-aminobenzoic acid with benzoyl isothiocyanate. The title compound has been characterized by elemental analysis, MS, FT-IR, ¹H-NMR, ¹³C-NMR and UV–Visible techniques. The structure of the compound has also been examined crystallographically. The title compound crystallizes in the triclinic space group P-1 with a = 3.969(1), b = 13.039(1), c = 13.504(1) ?, α = 96.50(1)°, β = 92.25(1)°, γ = 94.94(1), V = 691.0(1) ?³ and D _x  = 1.444 g cm⁻³, respectively. The crystal structure has been solved by direct methods and refined by full-matrix least squares and found R ₁ = 0.031 and wR ₂ = 0.081 for 2909 observed reflections [I > 2σ(I)].     

p型掺杂晶体硅的低温液相(001)外延生长研究

为寻求以低成本制备n型太阳电池的pn结,进行了Al-17.6wt;Si合金熔体中(001)n型单晶硅衬底上液相外延生长p型掺杂硅实验.所用方法为垂直浸渍法,实验了过冷恒温生长与回熔处理后连续冷却生长两种模式,过程中体系以流动高纯氩保护.对所得外延生长晶体结构、形貌及所得pn结开路电压进行了分析和测定.结果显示,合金熔体中硅晶体(001)液相外延生长能够实现,但一般呈离散分布的金字塔型岛状生长;只有衬底回熔处理后原位连续降温生长模式可获得连续外延薄膜,之后在其上出现岛状生长,呈现Stranski-Krastanov生长模式.所得连续外延薄膜形成的pn结开路电压比恒温生长所得的提升约100 mV;连续外延薄膜形成后期出现的岛状生长使开路电压明显下降;生长速度提高会使连续降温外延生长pn结开路电压略有降低.     

Molecular Structure and Dynamics in Organic Solids: High Resolution Low Temperature 13 C NMR Studies

The development of cross polarization-magic angle spinning (CPMAS) has resulted in the achievement of near-liquid resolution in solid state ¹³ C NMR spectra. Therefore, the structure and dynamics of organic solids can now be studied on a carbon-by-carbon basis. Low temperature CPMAS capability permits the investigation of molecular dynamics in solids, and in particular in a temperature range heretofore inaccessible to high resolution NMR (15-200 K). We have developed and used low temperature CPMAS to study solid state effects on chemical exchange processes in organic and organometallic compounds and in carbonium ions. We have also developed a technique for measuring carbon-carbon bond lengths in amorphous solids using NMR. The geometry of cis-and trans-polyacetylene has been determined using this method.     

Catalyzed Nucleation of Poly (Vinyl Chloride)

Microscopically visible crystallization in a typical non-crystallizing organic polymer - poly(vinyl chloride) (PVC) is achieved by dissoloving it in an appropriate solvent (cyclohexanone) and inducing the nucleation by introducing various insolube crystallization cores - microcrystals of noble metals (Au, Pd, Pt, Rh, Ir, Ru, Os). It is established that the higher the melting temperature of the metal the higher its activity as a crystallization core in the heterogeneous nucleation of PVC. The reverse process-oriented crystallization of a foreign substance - NaCl crystals on PVC films is also demonstrated. This result gives an indication of precrystalline structures in seemingly amorphous PVC films.