The Crystal Structure of a New Borogermanosilicate

The structure of Nd₃BGe_1.08Si_0.92O₁₀ has been determined by a single crystal investigation. The orthorhombic cell parameters are a = 9.845(1) Å, b = 7.146(1) Å, and c = 23.382(2) Å. The space group is Pbca (Z = 8). Out of 10,833 measured reflections, 3,099 independent reflections (I > 3σ(I)) have been used in the refinement of the structure. The R factor value is 0.026 (wR = 0.023). The neodymium ions occupy three different sites with eight or nine oxygen bonds in the lattice. The germanium and silicon ions are located in a distorted tetrahedral environment. The boron atom coordination is triangular with a shorter B-O distance of 1.384 Å.     

Crystal Structure of a New Cembranolide Diterpene

ＩｎｔｒｏｄｕｃｔｉｏｎＳｏｍｅｃｅｍｂｒａｎｏｌｉｄｅｄｉｔｅｒｐｅｎｅｓｗｅｒｅｉｓｏｌａｔｅｄｆｒｏｍＳｉｎｕｌａｒｉａｇｅｎｕｓｅｓ[1— 5] .ＴｈｅａｕｔｈｏｒｓｈａｖｅｉｓｏｌａｔｅｄａｎｅｗｃｅｍｂｒａｎｏｌｉｄｅｄｉｔｅｒｐｅｎｅｆｒｏｍｔｈｅｓｏｆｔｃｏｒａｌＳｉｎｕ ｌａｒｉａｃａｐｉｌｌｏｓａＴｉｘ . Ｄｕｘ .[4 ] .Ａｌｍｏｓｔａｔｔｈｅｓａｍｅｔｉｍｅ ,ｗｅｏｂｔａｉｎｅｄｔｈｉｓｃｏｍｐｏｕｎｄｆｒｏｍａｎｏｔｈｅｒｓｐｅｃｉｅｓｏｆｓｏｆｔｃｏｒａｌ,Ｓｉｎｕｌａｒｉａｔｅ…     

Crystal Structure and Conformation of a 10-Thiabilirubin

Summary.  A crystal structure determination of a bilirubin analog with a sulfur instead of a C(10)–CH₂ linking the two dipyrrinones is reported. Conformation-determining torsion angles and key hydrogen bond distances and angles are compared to those obtained from molecular dynamics calculations as well as to the corresponding data from X-ray determinations and molecular dynamics calculations of bilirubin. Like other bilirubins, the component dipyrrinones of the analog are present in the bis-lactam form with (Z)-configurated double bonds at C(4) and C(15). Despite the large differences in bond lengths and angles at –S–vs.–CH₂–, the crystal structure shows considerable similarity to bilirubin: both pigments adopt a folded, intramolecularly hydrogen-bonded ridge-tile conformation stabilized by six hydrogen bonds – although the interplanar angle of the ridge-tile conformation of the title compound is smaller (∼ 86°) than that of bilirubin (∼ 98°). The collective data indicate that even with long C–S bond lengths and a smaller C–S–C bond angle at the pivot point on the ridge-tile seam, intramolecular hydrogen bonding persists. Received August 16, 2001. Accepted September 12, 2001     

Synthesis and Crystal Structure of a Genistein-derived Compound

A genistein derivative, 5-hydroxy-3-（4-hydroxyphenyl）-7-（2-（piperidin- 1-yl）ethoxy）- 4H-chromen-4-one 3, was designed, prepared and structurally characterized by single-crystal X-ray diffraction. X-ray structure analysis reveals that 3 crystallizes in the orthorhombic system, space group Pbca, with a = 16.238（3）, b = 10.308（2）, c = 22.987（5）A, V = 3847.6（13）A3, Z = 8,μ= 0.093 mm^-1, Dc = 1.317 g/cm^3, F（000） = 1616, R = 0.0789 and wR = 0.1554 for 1463 observed reflections with I 〉 2σ（I）.     

Synthesis and Crystal Structure of a New Binaphthylamide

Novel binaphthylamide has been synthesized and characterized by IR and ¹H NMR spectra. The crystal structure of the compound was determined by X-ray diffraction (MoK radiation, 8629 reflections,R_F = 0.0436, R_W= 0.0856). Monoclinic crystals with unit cell parameters a=10.796(3), b=11.441(3), and c=34.565(9) , Z=4. The results reveal that the title compound forms a supramolecular structure.     

Crystal Structure and Conformation of a 10-Thiabilirubin

 A crystal structure determination of a bilirubin analog with a sulfur instead of a C(10)–CH₂ linking the two dipyrrinones is reported. Conformation-determining torsion angles and key hydrogen bond distances and angles are compared to those obtained from molecular dynamics calculations as well as to the corresponding data from X-ray determinations and molecular dynamics calculations of bilirubin. Like other bilirubins, the component dipyrrinones of the analog are present in the bis-lactam form with (Z)-configurated double bonds at C(4) and C(15). Despite the large differences in bond lengths and angles at –S–vs.–CH₂–, the crystal structure shows considerable similarity to bilirubin: both pigments adopt a folded, intramolecularly hydrogen-bonded ridge-tile conformation stabilized by six hydrogen bonds – although the interplanar angle of the ridge-tile conformation of the title compound is smaller (∼ 86°) than that of bilirubin (∼ 98°). The collective data indicate that even with long C–S bond lengths and a smaller C–S–C bond angle at the pivot point on the ridge-tile seam, intramolecular hydrogen bonding persists.     

D,L-1,2,2-三甲基环戊烷-1,3-二胺硝酸镍配合物的合成、结构及其和手性D-(+)-1,2,2-三甲基环戊烷-1,3-二胺氯化镍配合物的对比分析(英)

A nickel(Ⅱ) complex [Ni(La)₂](NO₃)₂ (1) with bidentate racemic 1,2,2-trimethylcyclopentane-1,3-diamine ligand has been synthesized and characterized by IR, EA, ES-MS, and its X-ray diffraction study reveals that the nickel(Ⅱ) center is tetra-coordinated by one D- and one L- diamine ligands, and a three-dimensional hydrogen-bond-sustained network is formed in the solid state by means of the eight-membered N-H…O hydrogen bond cycle. This compound also supplies a good comparison to the chiral complex [Ni(L_b)₂]Cl₂·2H₂O (2) (L_b=D-(+)-1,2,2-trimethylcyclopentane-1,3-diamine). CCDC: 218122.     

抗高血压新药DDPH的晶体结构

1－（2，6-二甲基苯氧基）－2－（3，4二甲氧苯乙胺基）丙烷盐酸盐（简称DDPH）是一种降血压新药。用X射线衍射法测定了两个晶体结构，（±）DDPH和（＋）DDPH单晶的空间群分别为P21/a和P212121。（±）DDPH分子呈弓形，整体近似一个平面结构；（＋）DDPH的2个苯环夹角较大，整个分子比较伸展。     

Crystal Structure and Conformation of a Bilirubin Ester

Summary. Crystal structures determined for three bilirubin analogs with gem-dimethyl groups at C(10) are reported, including the first X-ray structure of a bilirubin dimethyl ester. Conformation-determining torsion angles and key hydrogen bond distances and angles were compared to those from molecular dynamics calculations. Like other rubins, the component dipyrrinones of the three compounds were found to adopt the syn conformation, with Z-configuration double bonds at C(4) and C(15) and bis-lactam tautomeric structures of the end rings. No large differences in bond lengths and bond angles at C(10) were found, and the crystal structures of the two 10,10-dimethyl rubin acids showed considerable similarity to that of bilirubin: both pigments adopt a folded, intramolecularly hydrogen bonded ridge-tile conformation stabilized by six hydrogen bonds, with an interplanar angle in ridge-tile of 98° and 86°. In contrast, the dimethyl ester is intermolecularly hydrogen bonded in the crystal. Each molecule of the ester has its two syn-Z-dipyrrinones rotated into a conformation syn to the gem-dimethyl group, whereas in the acids they are anti.     

Crystal Structure of N-Phenylisothiocyanatido-Phosphonamidothioate

1INTRODUCTIONLawess0n,Sreagent(LR),2,4-Bis(4-meth0xyphenyl)-1,3,2'4-dithiadiphosphetane-2,4-disulfide,notonlyisaselectivereagentf0rthi0natingcar-bonylcompounds,buta1soreactswithcertainsubstratestogivephosph0rushetero-cyclecompoundswhichcontainthe(4-methoxyphenyl)phosphinothi0ylidene"4-CH,OC,H'P(S)"m0iety.Theseheterocycliccompoundshavesomepotentialbiologi-calactivitiesasherbicides,fungicides,andinsecticides[l'2J.Wehavestudiedthecy-clizationofthebifunctionalsubstrateswithLRtogive5-and6…     

冬凌草甲素的晶体结构

冬凌草甲素,C_(20)H_(28)O_6,Mr=364.44,是一种从中药中提取的抗癌药,它的晶体结构分析表明晶体属正交晶系的空间群P2_12_12_1,晶胞参数为α=13.316(9),b=21.302(2),c=13.015(1),V=3697(9)~3。Z=8,D_c=1.31g/cm~3,D_o=1.30g/cm~3,F(000)=1568。该分子是四环二萜类化合物,A环和C环是椅型结构,B环是船型结构;D环是部分共轭五员环,为半椅型结构,环上相邻的两个双重键侧基组成一个六原子的共轭平面。     

Crystal Structure of Li-Analcime

Li-analcime Li_1.69Na_0.14[Al_1.83Si_4.17O₁₂] · 2.05H₂O has been prepared and studied by single-crystal X-ray structural analysis: a = 13.510(2), b = 13.520(1), c = 13.503(2) , V = 2466.4(9) ³, Z = 8, space group Pbca. The structure is compared with that of the starting Na-analcime. Lithium atoms lie near Na sites with a distorted octahedral coordination O₄(H₂O)₂. Due to the smaller size of Li atoms, their real environment is differentiated into 3+3 or 4+2. The off-network cations and the H₂O molecules are shifted from the sites which they normally occupy in analcime in a cooperative manner. The changes in the unit cell dimensions and symmetry are explained from crystal-chemical viewpoint.     

螺[1—溴—4—l—孟氧其—5—氧杂—6—氧代双环[3.1.0]已烷2,3‘—（4’—甲氧 …

本文报道了利用新手性还源合成的标题化合物Ｃ２９Ｈ４５ＢｒＯ７（Ｍｒ＝５８５．５６）的晶体结构,该晶体属正交晶系,空间群为Ｐ２１２１２１,晶胞参数α＝９．７４８（４）,ｂ＝１２．５３７（５）,ｃ＝２５．８５１（９）Ａ,Ｖ＝３１５９（２）Ａ＾３,Ｚ＝４,Ｄｘ＝１．２３１ｇ／ｃｍ＾２,μ１．３４１ｍｍ＾－１,Ｆ（０００）＝１２４０,偏离因子Ｒ＝０．０４７５,ＲＷ＝０．０６０９,分子中共有５个环,１２个手     

Crystal Structure of L-Quebrachitol

L-Quebrachitol (1) isolated from the root of Elaeagnus formosana Nakai (Elaeagnaceae) has not been reported before for any species of the genus of Elaeasnus. Its structure was established from spectral data and was completely characterized by single-crystal X-ray analysis. L-Quebrachitol crystallizes in the monoclinic system, space group P2₁, with cell parameters are a = 6.702(4), b = 7.207(4), c = 8.758(5) Å, β = 90.24(5)° and Z = 2.