scholarly journals Three differently coloured polymorphs of 3,6-bis(4-chlorophenyl)-2,5-dipropyl-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione

2019 ◽  
Vol 75 (3) ◽  
pp. 414-422
Author(s):  
Hee-Soo So ◽  
Shinya Matsumoto
Keyword(s):  
Crystal Structure ◽  
Crystal Structure Analysis ◽  
The Other ◽  
Stable Form ◽  
Bonding System ◽  
Hydrogen Bonding System ◽  
Crystallization Conditions ◽  
Polymorphic Forms ◽  
The Difference ◽  
Packing Effect

In this paper, the conformational polymorphism of a chlorinated diketopyrrolopyrrole (DPP) dye having flexible substituents in a non-hydrogen-bonding system is reported. The propyl-substituted DPP derivative (PR3C) has three polymorphic forms, each showing a different colour (red, orange and yellow). All polymorphs could be obtained concomitantly under various crystallization conditions. The results of the crystal structure analysis indicate that PR3C adopts different conformations in each polymorph. The packing effect caused by the difference in the arrangement of neighbouring molecules was found to play an important role in the occurrence of the observed polymorphism. The thermodynamic stability relationship between the three polymorphs was identified by thermal analysis and indicates that the yellow polymorph is the thermally stable form. The results indicate that the yellow form and orange form are enantiotropically related, and the other polymorph is monotropically related to the others.

Strukturen zweier Salze des Bis(thioharnstoff)gold(I)-Kations

2018 ◽  
Vol 73 (5) ◽  
pp. 349-354
Author(s):  
Mark Strey ◽  
Peter G. Jones
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Three Dimensional ◽  
Crystal Structure Analysis ◽  
Double Layers ◽  
Mirror Plane ◽  
Bonding System ◽  
Hydrogen Bonding System ◽  
Ionic Nature ◽  
Graph Set

AbstractAttempts to isolate the compound (tu2Au)SCN 1 (tu=thiourea), first reported in 1949, at first led to [(tu)2Au]2SO4·CH3OH 2 after crystallization from methanol-petroleum ether. Crystallization from isopropanol led to the required compound 1. The crystal structure analysis of 1 confirmed its ionic nature, (tu2Au)+ SCN−. The tu ligands are mutually trans (torsion angle C–S···S–C 175.4(2)°), and the entire cation is approximately planar (r.m.s. deviation 0.08 Å). Eight classical hydrogen bonds connect the residues to form layers parallel to the bc plane at x≈⅛, ⅜, ⅝ and ⅞; the layers are connected by aurophilic contacts, which link the cations to form chains parallel to the a axis. In the structure of compound 2 the S=C groups are synclinal to each other; two NH2 groups are connected via a bifurcated hydrogen bonding system to a sulfate oxygen, forming a ring of graph set ${\rm{R}}_2^1(10).$ In a complex three-dimensional packing, the cations are connected by various interactions to form layers parallel to the ac plane at y≈½, whereas the sulfates are the centres of hydrogen-bonded double layers on both sides of the mirror plane at y≈¾. The structure contains a convincing example of a hydrogen bond to a gold centre.

Ethylenediammonium thiophene-2,5-dicarboxylate dihydrate, an acid–base complex with a three-dimensional hydrogen-bonding system

2006 ◽  
Vol 62 (7) ◽  
pp. o2951-o2952 ◽  
Author(s):  
Si-Min Wu ◽  
Ming Li ◽  
Jiang-Feng Xiang ◽  
Liang-Jie Yuan ◽  
Ju-Tang Sun
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Three Dimensional ◽  
Water Molecules ◽  
Inversion Center ◽  
Acid Base ◽  
Special Position ◽  
Compound C ◽  
Bonding System ◽  
Hydrogen Bonding System

The crystal structure of the title compound, C2H10N2 2+·C6H2O4S2−·2H2O, is built of ethylenediammonium dications, occupying a special position on an inversion center, thiophene-2,5-dicarboxylate dianions, in a special position on the twofold axis, and water molecules in general positions. All residues are involved in an extensive hydrogen-bonding system, which links them into a three-dimensional supramolecular arrangement.

(3-Acetylpyridine-κN)chlorobis(triphenylphosphine-κP)copper(I): a suitable candidate for absolute asymmetric synthesis?

2006 ◽  
Vol 62 (7) ◽  
pp. m1569-m1571
Author(s):  
Anders Lennartson ◽  
Kent Salo ◽  
Mikael Håkansson
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Title Compound ◽  
The Other ◽  
Nucleophilic Attack ◽  
Suitable Candidate ◽  
Π Interactions ◽  
Crystallization Conditions ◽  
Chiral Crystals ◽  
Triphenylphosphine Ligand

It was found that 3-acetylpyridine is capable of displacing triphenylphosphine from [CuCl(PPh3)3], forming the title compound, [CuCl(C7H7NO)(C18H15P)2]. The two triphenylphosphine ligands possess the same sense of chirality, and the molecules are therefore conformationally chiral. The compound was found to crystallize as a racemate (centrosymmetric space group) under the crystallization conditions employed. The molecular structure shows that the carbonyl C atom is blocked at one side by a triphenylphosphine ligand, while the other face is open for nucleophilic attack. Obtaining chiral crystals of the title compound is thus a future objective. In the crystal structure, C—H...O(=C)-bonded dimers are formed, which are further stabilized by π–π interactions. The dimers form infinite chains through weak C—H...π interactions.

Structures and photochemistry of 1,5-disubstituted dibenzobarrelenes

1996 ◽  
Vol 52 (1) ◽  
pp. 151-158
Author(s):  
R. Jones ◽  
S. J. Rettig ◽  
J. R. Scheffer ◽  
J. Trotter ◽  
J. Yang
Keyword(s):  
Crystal Structure ◽  
Double Bond ◽  
Crystal Structures ◽  
Structure Analysis ◽  
Crystal Structure Analysis ◽  
The Other ◽  
Steric Effects ◽  
Molecular And Crystal Structures ◽  
Electronic And Steric Effects

The effect of 1,5-disubstitution on the photochemistry of 9,10-ethenoanthracene-11,12-diesters has been studied and correlated with the crystal structures determined for several derivatives; photoproduct structures have been established from a crystal structure analysis of one of the products and from NMR correlations. The crystals studied are: (1)-Cl, dimethyl 1,5-dichloro-9,10-dihydro-9,10-ethenoanthracene-11,12-dicarboxylate, C20H14Cl2O4, P21/n; (1)-CN, 1,5-dicyano derivative, C22H14N2O4, P21/n; (1)-CN.0.5p-xylene, C22H14N2O4.0.5C8H10, P21/c; (1)-CN.xxylene, C22H14N2O4.xC8H10, P21/n; (1)-OMe, 1,5-dimethoxy derivative, C22H20O6, P{\bar 1}; (2b)-Cl, C20H14C12O4, dimethyl 1,5-dichloro-4b,8b,8c,8d-tetrahydrodibenzo[a, f]cyclopropa[c,d]pentalene-8c,8d-dicarboxylate, Pna21. The dibenzobarrelene molecules all have geometries and dimensions similar to those of related materials. In particular, the orientations of the two ester groups in each molecule differ, one being in general almost fully conjugated with the C(11)=C(12) double bond and the other almost non-conjugated. Relationships are sought between the ratios of the two regioisomeric photoproducts and molecular and crystal structures; both electronic and steric effects are considered, but no one effect seems to dominate.

scholarly journals Role of halogen substituents in a series of polymorphic 2,5-diamino-3,6-dicyanopyrazine derivatives with highly flexible groups

2017 ◽  
Vol 232 (5) ◽  
pp. 395-405 ◽  
Author(s):  
Yoko Akune ◽  
Risa Hirosawa ◽  
Atsushi Koseki ◽  
Shinya Matsumoto
Keyword(s):  
Crystal Structure ◽  
Crystal Structures ◽  
Electrostatic Interactions ◽  
Crystal Structure Analysis ◽  
Stable Form ◽  
Thermally Stable ◽  
Close Packed Structure ◽  
Packed Structure ◽  
Stable Forms ◽  
Metastable Forms

AbstractThe crystal structures of the ortho-X-benzyl derivatives, where X=F, Cl, Br, I, and Me, of 2,5-bis(N,N-dibenzylamino)-3,6-dicyanopyrazine dyes (C34H24N6X4) were analysed to evaluate the effect of a systematic series of structures on the occurrence of polymorphism. Detailed crystal structure analysis indicated that the thermally stable forms of the polymorphic derivatives (Cl and Br derivatives) were close-packed, whereas those of the non-polymorphic derivatives (F and I derivatives) were stabilised by an intermolecular interaction involving the ortho-substituents. In the thermally metastable forms of the polymorphic derivative, halogen-halogen and halogen-nitrogen interactions contributed to the stabilisation of these crystals in the same way as the thermally stable form of the non-polymorphic derivatives. This indicated that the ease of polymorph occurrence would require an appropriate balance between the crystal energy of the close-packed structure and that of the crystal structure generated mainly by the electrostatic interactions involving the halogens in these halogenated pyrazine derivatives. In addition, the similar tendency of the occurrence of polymorphs in these halogenated pyrazine derivatives was found in 19 sets of halogenated compounds having known crystal structures of F, Cl, Br and I derivatives including at least one polymorphic derivative in the crystal structure database.

scholarly journals The effect of hydrogen bonding on the conformations of 2-(1H-indol-3-yl)-2-oxoacetamide and 2-(1H-indol-3-yl)-N,N-dimethyl-2-oxoacetamide

2012 ◽  
Vol 68 (10) ◽  
pp. o405-o407 ◽  
Author(s):  
Vijayakumar N. Sonar ◽  
Sean Parkin ◽  
Peter A. Crooks
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Three Dimensional ◽  
Carbonyl Groups ◽  
Single Bond ◽  
Torsion Angles ◽  
Bonding System ◽  
Dimensional Network ◽  
Hydrogen Bonding System

In the title compounds, C10H8N2O2, (I), and C12H12N2O2, (II), the two carbonyl groups are oriented with torsion angles of −149.3 (3) and −88.55 (15)°, respectively. The single-bond distances linking the two carbonyl groups are 1.528 (4) and 1.5298 (17) Å, respectively. In (I), the molecules are linked by an elaborate system of N—H...O hydrogen bonds, which form adjacentR22(8) andR42(8) ring motifs to generate a ladder-like construct. Adjacent ladders are further linked by N—H...O hydrogen bonds to build a three-dimensional network. The hydrogen bonding in (II) is far simpler, consisting of helical chains of N—H...O-linked molecules that follow the 21screw of thebaxis. It is the presence of an elaborate hydrogen-bonding system in the crystal structure of (I) that leads to the different torsion angle for the orientation of the two adjacent carbonyl groups from that in (II).

The halotrichite group: the crystal structure of apjohnite

1976 ◽  
Vol 40 (314) ◽  
pp. 599-608 ◽  
Author(s):  
S. Menchetti ◽  
C. Sabelli
Keyword(s):  
Crystal Structure ◽  
Least Squares Method ◽  
Direct Methods ◽  
Water Molecules ◽  
Monoclinic Space Group ◽  
Direct Connection ◽  
Asymmetric Unit ◽  
X Ray ◽  
Bonding System ◽  
Hydrogen Bonding System

SummaryApjohnite, MnAl2(SO4)4·22H2O, is monoclinic, space group P21/c, a 6·198 (2), b 24·347 (4), c 21·266 (4) Å, β 100·28 (3)° and Z = 4. The crystal structure was determined by means of direct methods applied to X-ray data collected with a single-crystal diffractometer. At the end of the refinement, performed with least-squares method, the R index was 0·039.The SO4 tetrahedra, Al(H2O)5 octahedra, and MnO(H2O)5 octahedra are connected by a hydrogen bonding system; the only direct connection between polyhedra is by sharing of an oxygen between S(4) and Mn. In the asymmetric unit there are twenty-two water molecules, five of which lie in channels of the structure and are not linked to the cations but only to ligand water oxygens by means of hydrogen bonds.Powder data indicate a close structural relationship between apjohnite, halotrichite, and pickeringite.

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