MOLECULAR STRUCTURES AND CRYSTAL PACKINGS OF STYRYLDIAZINES

Journal of Structural Chemistry - Crystal structures of three isomeric styryldiazine derivatives (E)-2-(3,4-dimetoxystryl)pyrazine, (E)-2-(3,4-dimetoxystryl)pyrimidine, and...     

1,2-二甲基-3-吲哚甲叉(异丙叉)丁二酸酐(1)和1,2-二甲基-3-吲哚乙叉(异丙叉)丁二酸酐(2)的晶体结构

1.2-二甲基-3-吲哚甲叉(异丙叉)丁二酸酐(1)(C_(18)H_(17)NO_3)与1.2-二甲基-3-吲哚乙叉(异丙叉)丁二酸酐(2)(C_(19)H_(19)NO_3)同属于吲哚俘精酸类化合物,它们的分子结构非常类似,只是(1)中为吲哚甲叉,(2)中为吲哚乙叉.但它们的光色性却差别很大.化合物(1)无光致变色性,化合物(2)则表现为良好的光致变色性.其原因在于结构的不同。     

MOLECULAR AMD CRYSTAL STRUCTURES OF LIPIDS AND RELATED COMPOUNDS

Molecular-level structures of lipids and related organic long-chain compounds were investigated by means of vibrational spectroscopic and X-ray diffraction methods. Various spectroscopic techniques applicable to structural studies of lipid systems were developed. Various types of solid-state phase transformations were found in even- and odd-numbered saturated fatty acids and their molecular mechanisms were considered. Crystal structures of some modifications of a series of cis-mono-unsaturated fatty acids were determined by the three-dimensional X-ray analysis and new types of molecular conformation as well as of subcell arrangement of the cis-mono-unsaturated acyl chains were found. An order-disorder type phase transformation accompanied with a partial melting at the interface of the molecular layers was found in some modifications of cis-mono-unsaturated fatty acids. Molecular conformations and crystal structures of the polymorphs of methyl oleate and triglycerides containing an oleoyl chain at the 2-position were investigated on the basis of the spectroscopic data.     

SYNTHESIS OF THE 8-PHOSPHABICYCLO[3.2.1]OCTA-2,6-DIENE RING SYSTEM

Abstract

The 8-phosphabicyclo[3.2.1]octa-2,6-diene ring system is conveniently synthesized by the addition of chloro(diisopropylamino)phosphenium ion ((Cl)(i-Pr₂N)P⁺,1) to cycloheptatriene. Hydrolysis of the primary adduct yields the corresponding phosphinamide (3). The NMR of 3 is discussed in terms of its structure, and the orientation at P is assigned by a combination of 2-D NMR techniques. The structure of 3 is also probed by model calculations at the MNDO level.     

CRYSTAL AND MOLECULAR STRUCTURES OF 2-ACETYLDIFER-ROCENYLMETHANE AND 3'''' - ACETYLDIFERROCENYLMETHANE

<正> 2 - acetyldiferrocenylmethane, C5H5FeC5H4CH2C5H3 (COCH3) FeC5H5 ( I ),Mr=426. 1,violet-red prism-like crystal,m. p. 163. 7~166. 3℃,obtained from benzene-ligroin solution (benzene : ligroin=1 : 3). A crystal of approximate dimensions 0. 20×0. 40×0. 45 mm was selected for data collection from a CAD4 diffractometer with graphite monochromated MoKa radiation (λ=0. 71069A). Compound Ⅰ crystallized in the triclinic space group P1 with unit cell dimensions;a = 9. 597(2),b=9. 768 (2),c=11.540(1) A ,α= 111-93(1),β=111. 42(1),γ= 92. 46(2)°,V = 913. 9 A3, Z= 2, and Dc= 1. 548 g/cm3. 3' - Acetyldiferrocenylmethane, C5H5FeC5H4CH2C5H4FeC5 H4-COCH3(Ⅱ) ,is an isomer of compound Ⅰ ,yellow needle-like crystal,m. p. 110. 5~ 111. 0℃ ,obtained by the same method. A crystal of approximate dimensions 0. 025×0. 01×0. 45 mm was selected for data collection. Compound Ⅱ crystallized in monoclinic space group P21/c with a = 10. 930 (2), b= 5. 907(6) ,c= 27. 729(5) A ,β= 92. 64 (1)°,V=1788. 4A3,Z=4,Dc=1. 583 g/cm3.     

CRYSTAL AND MOLECULAR STRUCTURE OF 1，2，3—TRIBENZOYLINDOLIZINE

<正> Crystal and molecujar structure of the title compound, C29H19NO3, was determined by single crystal X-ray diffraction analysis. .Mt=429. 48, monoclin-ic, space group P21/n, a = 10. 365 (3), b= 14. 614(4), c= 14. 857 (4) A ,β= 103.55(2)°,V=2186. 1(10) A3, Z=4, Dc= 1. 30g/cm3,μ(MoKa) = 0. 81cm-1, F (000) = 919. 87. Final residual R value was 0. 0704 and Rw = 0. 0704. The indo-hzine ring is conjugated only with the 1-benzonyl group.     

CRYSTAL STRUCTURE OF p—PROPIONYLCALIX [4]ARENE

<正> The title compound was synthesized by Friedel-Crafts reaction of tetrahydroxycalix [4] arene and propionyl choride, and its crystal structure was determined by X-ray diffraction technique. C10O8H40,Mr = 648. 75, triclinic, space group P1 with cell parameters, a = 9. 930(5), b = 11. 838(3), c=14. 522(7) A,α= 94. 92(3),β=102. 96(4),γ= 98. 32(3)°, V = 1635A3, Z = 2, Dc = 1. 399g/ cm3, μ(CuKa) = 3. 27cm-1, F (000) = 344. The final R = 0. 075, Rw = 0.092 for 5716 independent reflections with I>3σ(I). The crystal structure analysis shows that the molecule exists in fine cone conformation.     

PHASE STRUCTURES AND TRANSITION BEHAVIORS OF A TRIPHENYLENE DISCOTIC LIQUID CRYSTAL

The phase behaviors and structures of a triphenylene-derived discotic liquid crystal (LC) hexa-n-octoxyl-triphenylene (C8HET) were studied using the combined techniques of differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD), selected area electron diffraction (SAED) and polarized light microscopy (PLM). Onedimensional (1D) powder WAXD results at different temperatures coupled with DSC and PLM observations revealed that the C8HET compound possessed an LC phase and three different crystalline (K3, K2 and K1) phases below the isotropic (Ⅰ)melt. The I (←→) LC phase transition was thermodynamically reversible and independent of the heating and cooling rates. The development and experimental observation of the three crystalline phases relied on different thermal histories. Among the three crystalline phases in C8HET, the K3 phase is the most stable phase, while the K2 and K1 phases are metastable. Note that the K1 phase only formed via a quenching process. On the basis of structure sensitive diffraction experiments such as 2D WAXD of oriented samples and SAED of single crystals, detailed structures and molecular packings of these four ordered phases were identified. The LC phase exhibited a hexagonal columnar phase with 2D lattice dimensions of a = b = 2.38 nm and γ= 120°. All the three crystalline phases possess monoclinic unit cells, yet the γ angle is not 90° in the cases of the K2 and the K3 phases, while in the case of the K1 phase the α angle is not 90°.     

THE CRYSTAL STRUCTURES OF d-PINITOL AND l-QUEBRACHITOL BY LOW-TEMPERATURE X-RAY DIFFRACTION

The crystal and molecular structures of d-pinitol and l-quebrachitol were determined from low temperature x-ray diffraction data. Pinitol crystallizes in an orthorhombic system, P2₁2₁2₁ (Z=4), with unit cell dimensions of a=6.8345(8) Å, b=9.3233(10) Å, and c=12.8911(14) Å. Quebrachitol crystallizes in a monoclinic system, P2₁ (Z=2), with unit cell dimensions of a=6.6289(4) Å, b=7.1895(4) Å, c=8.6843(5) Å, and β=90.5690(10)°. No unusual bond lengths or valence angles are present within either structure. Both rings are in chair conformations, with the majority of the pendent groups in equatorial orientations. As found for many compounds with multiple hydroxyl groups, the structures have extensive networks of hydrogen bonds. Both structures have infinite chain sequences of hydrogen bonds incorporating the O-1 and O-4 hydroxyl groups and finite chain sequences incorporating the other hydroxyl groups.     

Vapor deposition polymerization of heteroatom-bridged [2.2]paracyclophanes: 1,9-dithia[2.2]paracyclophane and 1,9-dithia[2.2]paracyclophane-1,1,9,9-tetroxide

1,9-Dithia[2.2]paracyclophane-1,1,9,9-tetroxide ( 3 ) was synthesized as white needles in a high yield from 1,9-dithia[2.2]paracyclophane ( 2 ) by oxidation with m-chloroperbenzoic acid, and its molecular structure was determined with single-crystal X-ray diffraction analysis. Vapor deposition polymerizations of 2 and 3 gave amorphous and brittle polymer films along with considerable amounts of nonpolymeric byproducts. A polymer film from 2 was a copolymer of p-(phenylene-methylenesulfide) with p-(phenylene-methylene) units, and a polymer film from 3 was a homopolymer of p-(phenylene-methylene) units with head-to-tail, head-to-head, and tail-to-tail placements. The elimination of sulfur atoms in 2 and sulfone units in 3 took place during their pyrolysis reactions. Plausible mechanisms for vapor deposition polymerizations of both cyclophanes are proposed. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1892–1900, 2001     

SYNTHESES AND CRYSTAL STRUCTURES, REACTION OF α -THIOPI-COLIN-o-TOLUIDIDE AND ITS ORGANOTIN COMPLEX

<正> α-thiopicolin-o-toluidide and its organotin complex have been synthesized, and both crystal structures have been determined by X-ray analysis. The ligand:C13 H12N2S,Mr = 228. 3,monoclinic,P21/n,a=16. 387(1),b = 7. 752(2),c=18. 334(1) A ,β=95. 52(1),V = 2324. 8A3,Z = 8,DC=1. 305g·cm-3,F(000) = 960e. The final R= 0. 053 for 3291 observed unique reflections. There are two molecules in the asymmetric unit,which are confirmed to exist as the keto,cis-N configuration in the solid state. The complex:C17H21N2SClSn,Mr = 439. 6,orthorhombic,P212121,a = 8. 801(3),b = 9. 188 (2),c=24. 087(6) A,V=1947. 9A3,Z = 4,DC=1. 499g·cm-3,F(000) = 880e. The final R = 0. 041 for 1694 observed unique reflections. The tin atom is surrounded by an irregular (5 + 1) coordination geometry with five normal bonds and one weak bond [Sn....C1]. The molecules join each other through the weak bonds to form infinite polymeric chains parallel to the a axis. In addition, the possible reaction mechanism in coordination is discussed.     

THE CRYSTAL STRUCTURES OF AMMONIUM AND SODIUM 2-AMINO-3,5-DICHLOROBENZOATES

Abstract

The crystal structures of ammonium and sodium 2-amino-3,5-dichlorobenzoates were determined by the X-ray diffraction method. The ammonium salt crystallizes in the monoclinic system (space group P2₁/c) with a = 13.941(3), b = 9.128(3), c = 7.349(2) Å, β = 90.80(3)° and Z = 4. The structure consists of an ammonium cation hydrogen bonded to a carboxylate oxygen of the 2-amino-3,5-dichlorobenzoate anion. The sodium salt of 2-amino-3,5-dichlorobenzoic acid crystallizes in the triclinic system (space group P 1) with a = 8.033(2), 6 = 8.944(2), c = 17.350(3) Å, α = 76.72(3)°, β = 79.69(3)°, γ = 72.54(3)° and Z = 4. The compound is a polymer in which the sodium ions are coordinated by carboxylate oxygen atoms of the organic ligand and water molecules in an octahedral arrangement. IR spectra of the salts are discussed.