Molecular structures of the inclusion complexes β-cyclodextrin–1,2-bis(4-aminophenyl)ethane and β-cyclodextrin–4,4′-diaminobiphenyl; packing of dimeric β-cyclodextrin inclusion complexes

2003 ◽  
Vol 59 (2) ◽  
pp. 287-299 ◽  
Author(s):  
Petros Giastas ◽  
Konstantina Yannakopoulou ◽  
Irene M. Mavridis
Keyword(s):  
Inclusion Complexes ◽  
Guest Molecule ◽  
Crystal Packing ◽  
Lateral Displacement ◽  
Molecular Structures ◽  
Guest Molecules ◽  
Space Group ◽  
Π Interactions ◽  
Dimeric Complexes ◽  
Spectroscopy Studies

The present investigation is part of an ongoing study on the influence of the long end-functonalized guest molecules DBA and BNZ in the crystal packing of β-cyclodextrin (βCD) dimeric complexes. The title compounds are 2:2 host:guest complexes showing limited host–guest hydrogen bonding at the primary faces of the βCD dimers. Within the βCD cavity the guests exhibit mutual π...π interactions and between βCD dimers perpendicular NH...π interactions. The DBA guest molecule exhibits one extended and two bent conformations in the complex. The BNZ guest molecule is not planar inside βCD, in contrast to the structure of BNZ itself, which indicates that the cavity isolates the molecules and forbids the π...π stacking of the aromatic rings. NMR spectroscopy studies show that in aqueous solution both DBA and BNZ form strong complexes that have 1:1 stoichiometry and structures similar to the solid state ones. The relative packing of the dimers is the same in both complexes. The axes of two adjacent dimers form an angle close to 20° and have a lateral displacement ≃2.45 Å, both of which characterize the screw-channel mode of packing. Although the βCD/BNZ complex indeed crystallizes in a space group characterizing the latter mode, the βCD/DBA complex crystallizes in a space group with novel dimensions not resembling any of the packing modes reported so far. The new lattice is attributed to the three conformations exhibited by the guest in the crystals. However, this lattice can be transformed into another, which is isostructural to that of the βCD/BNZ inclusion complex, if the conformation of the guest is not taken into account.

Inclusion compounds of plant growth regulators in cyclodextrins. V. 4-Chlorophenoxyacetic acid encapsulated in β-cyclodextrin and heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin

2005 ◽  
Vol 61 (2) ◽  
pp. 207-217 ◽  
Author(s):  
Frantzeska Tsorteki ◽  
Kostas Bethanis ◽  
Nikos Pinotsis ◽  
Petros Giastas ◽  
Dimitris Mentzafos
Keyword(s):  
Guest Molecule ◽  
Crystal Packing ◽  
Host Molecule ◽  
X Ray Diffraction ◽  
Guest Molecules ◽  
Space Group ◽  
X Ray ◽  
Dimeric Complexes ◽  
The Mean ◽  
Chlorophenoxyacetic Acid

The crystal structures of 4-chlorophenoxyacetic acid (4CPA) included in β-cyclodextrin (β-CD) and heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin (TMβCD) have been studied by X-ray diffraction. The 4CPA/β-CD complex crystallizes as a head-to-head dimer in the space group C2 in the Tetrad packing mode. The packing modes of some β-CD dimeric complexes, having unique stackings, are also discussed. The 4CPA/TMβCD inclusion complex crystallizes in the space group P21 and its asymmetric unit contains two crystallographically independent complexes, complex A and complex B, exhibiting different conformations. The host molecule of complex A is significantly distorted, as a glucosidic residue rotated about the O4′—C1 and C4—O4 bonds forms an aperture where the guest molecule is accommodated. The phenyl moiety of the guest molecule of complex B is nearly perpendicular to the mean plane of the O4n atoms. The conformations of the guest molecules of the two complexes are similar. The crystal packing consists of antiparallel columns as in the majority of the TMβCD complexes published so far.

Polysulfonylamine, CV. Die ersten N,N-disulfonylierten Sulfinsäureamide: Synthese und Kristallstrukturen von RS(O)-N(SO2Me)2 (R = Me, CCl3) / Polysulfonylamines, C V. The First N,N -Disulfonylated Sulfinic Amides: Synthesis and Crystal Stru ctures of RS(O)-N(SO2Me)2 (R = Me, CCl3)

1998 ◽  
Vol 53 (7) ◽  
pp. 734-741 ◽  
Author(s):  
Martina Näveke ◽  
Armand Blaschette ◽  
Peter G. Jones
Keyword(s):  
Crystal Packing ◽  
Molecular Structures ◽  
Monoclinic Space Group ◽  
The Novel ◽  
Double Chain ◽  
Space Group ◽  
Bond Angles ◽  
Oxygen Atoms

Abstract The novel sulfinamides RS(O) -N(SO2Me)2, where R = Me (1a) or CCl3 (1b), were obtained by treating the corresponding sulfinyl chlorides with Me3SiN(SO2Me)2 or AgN-(SO2Me)2, respectively. A presumedly ionic 1:1 adduct of 1b with 4-dimethylaminopyridine was isolated and analytically characterized. In the crystals of 1a (monoclinic, space group P21/c) and 1b (monoclinic, P21/c) , the molecules feature approximately planar NS3 moieties, unusually long S(O) -N bonds and, in the case of 1b, an extremely long S(O) -C bond [for la and 1b, in order: sum of bond angles at nitrogen 359.5 and 357.1°, S(O) -N 178.2(2) and 173.6(2) pm, S(O) -C 178.8(2) and 194.1(2) pm]. In both molecular structures, an attractive S(O) ··· O 1,4-interaction leads to a 7.3° discrepancy in the S(O) -N -SO2 angles. The crystal packing of 1a displays a tape (double-chain) motif generated by two prominent intermolecular C -H ··· O interactions involving one MeSO2 group and the sulfinyl oxygen atoms of two adjacent molecules, whereas in 1b the molecules are associated into parallel chains via a bonding Cl ⋯ O(sulfonyl) interaction.

Channel-Type Crystal Packing in the Very Rare Space Group P4212 with Z' = 3/4: Crystal Structure of the Complex γ-Cyclodextrin–Methanol–n-Hydrate

1998 ◽  
Vol 54 (4) ◽  
pp. 450-455 ◽  
Author(s):  
T. Steiner ◽  
W. Saenger
Keyword(s):  
Crystal Structure ◽  
Crystal Packing ◽  
Cell Content ◽  
Guest Molecules ◽  
Space Group ◽  
Cyclodextrin Inclusion Complexes ◽  
Packing Arrangement ◽  
Type Crystal ◽  
Channel Type

The crystal structure of the title compound is discussed with focus on its unusual crystal packing mode. The γ-cyclodextrin molecules stack in columns which have internal channels and additional large channels are formed between the columns. Both types of channels are so wide that more or less free diffusion of water and small guest molecules is possible, preventing characterization of the solvent and guest arrangements. Although the space group P4212 (no. 90) and the unit-cell content Z′ = 3\over 4 are extremely rare in general, this is the favorite crystal packing arrangement of γ-cyclodextrin inclusion complexes. This space group has not been observed as yet for other purely organic compounds.

scholarly journals Two polymorphs of 2-(prop-2-yn-1-yloxy)naphthalene-1,4-dione: solvent-dependent crystallization

2018 ◽  
Vol 74 (12) ◽  
pp. 1731-1734
Author(s):  
Flaviano Melo Ottoni ◽  
Raquel Geralda Isidório ◽  
Ricardo José Alves ◽  
Nivaldo Lúcio Speziali
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
Isopropyl Alcohol ◽  
Molecular Structures ◽  
Monoclinic Space Group ◽  
Monoclinic Crystal ◽  
Triclinic Space Group ◽  
Space Group ◽  
Π Interactions ◽  
Compound C

The title compound, C13H8O3, crystallizes in two polymorphs, namely the monoclinic (space groupP21/c) and triclinic (space groupPī) forms, obtained fromN,N-dimethylformamide and isopropyl alcohol solutions, respectively. The molecular structures and conformations in the two forms are essentially the same as each other. The naphthoquinone ring systems are essentially planar with r.m.s. deviations of 0.015 and 0.029 Å for the monoclinic and triclinic forms, respectively. TheO-propargyl groups are coplanar with the naphthoquinone units with r.m.s deviations ranging from 0.04 to 0.09 Å. In the monoclinic crystal, molecules are linkedviapairs of C—H...O hydrogen bonds, forming a tape structure running along [120]. The tapes are further linked by a C—H...π interaction into a layer parallel to theabplane. Adjacent layers are linked by another C—H...π interaction. In the triclinic crystal, molecules are linkedviaC—H...O and π–π interactions, forming a layer parallel to theabplane. Adjacent layers are linked by a C—H...π interaction.

scholarly journals Steric repulsion and supramolecular assemblies via a two-dimensional plate by C—H...O hydrogen bonds in two closely related 2-(benzofuran-2-yl)-2-oxoethyl benzoates

2017 ◽  
Vol 73 (8) ◽  
pp. 1227-1231
Author(s):  
Li Yee Then ◽  
C. S. Chidan Kumar ◽  
Huey Chong Kwong ◽  
Yip-Foo Win ◽  
Siau Hui Mah ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Packing ◽  
Molecular Structures ◽  
Steric Repulsion ◽  
Two Dimensional ◽  
Compound I ◽  
Intermolecular Hydrogen Bonds ◽  
Π Interactions ◽  
Phenyl Rings ◽  
Compound Ii

2-(Benzofuran-2-yl)-2-oxoethyl 2-chlorobenzoate, C17H11ClO4 (I), and 2-(benzofuran-2-yl)-2-oxoethyl 2-methoxybenzoate, C18H14O5 (II), were synthesized under mild conditions. Their chemical and molecular structures were analyzed by spectroscopic and single-crystal X-ray diffraction studies, respectively. These compounds possess different ortho-substituted functional groups on their phenyl rings, thus experiencing extra steric repulsion force within their molecules as the substituent changes from 2-chloro (I) to 2-methoxy (II). The crystal packing of compound (I) depends on weak intermolecular hydrogen bonds and π–π interactions. Molecules are related by inversion into centrosymmetric dimers via C—H...O hydrogen bonds, and further strengthened by π–π interactions between furan rings. Conversely, molecules in compound (II) are linked into alternating dimeric chains propagating along the [101] direction, which develop into a two-dimensional plate through extensive intermolecular hydrogen bonds. These plates are further stabilized by π–π and C—H...π interactions.

scholarly journals Construction of pillar[4]arene[1]quinone–1,10-dibromodecane pseudorotaxanes in solution and in the solid state

2020 ◽  
Vol 16 ◽  
pp. 2954-2959
Author(s):  
Xinru Sheng ◽  
Errui Li ◽  
Feihe Huang
Keyword(s):  
Solid State ◽  
Hydrogen Bonds ◽  
Single Crystal ◽  
Guest Molecule ◽  
X Ray Diffraction ◽  
Guest Molecules ◽  
X Ray ◽  
Π Interactions ◽  
Host Molecules ◽  
Complexation Stoichiometry

We report novel pseudorotaxanes based on the complexation between pillar[4]arene[1]quinone and 1,10-dibromodecane. The complexation is found to have a 1:1 host–guest complexation stoichiometry in chloroform but a 2:1 host–guest complexation stoichiometry in the solid state. From single crystal X-ray diffraction, the linear guest molecules thread into cyclic pillar[4]arene[1]quinone host molecules in the solid state, stabilized by CH∙∙∙π interactions and hydrogen bonds. The bromine atoms at the periphery of the guest molecule provide convenience for the further capping of the pseudorotaxanes to construct rotaxanes.

scholarly journals Crystal structures of two new six-coordinate iron(III) complexes with 1,2-bis(diphenylphosphane) ligands

2018 ◽  
Vol 74 (6) ◽  
pp. 803-807
Author(s):  
Derek L. McNeil ◽  
Daihlia J. Beckford ◽  
Jared L. Kneebone ◽  
Stephanie H. Carpenter ◽  
William W. Brennessel ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Structural Characterization ◽  
Molecular Structures ◽  
Mass Ratio ◽  
Triclinic Space Group ◽  
Space Group ◽  
Ionic Complexes ◽  
Π Interactions ◽  
Centrosymmetric Space Group

Structural characterization of the ionic complexes [FeCl2(C26H22P2)2][FeCl4]·0.59CH2Cl2 or [(dppen)2FeCl2][FeCl4]·0.59CH2Cl2 (dppen = cis-1,2-bis(diphenylphosphane)ethylene, P2C26H22) and [FeCl2(C30H24P2)2][FeCl4]·CH2Cl2 or [(dpbz)2FeCl2][FeCl4]·CH2Cl2 (dpbz = 1,2-bis(diphenylphosphane)benzene, P2C30H24) demonstrates trans coordination of two bidentate phosphane ligands (bisphosphanes) to a single iron(III) center, resulting in six-coordinate cationic complexes that are balanced in charge by tetrachloridoferrate(III) monoanions. The trans bisphosphane coordination is consistent will all previously reported molecular structures of six coordinate iron(III) complex cations with a (PP)2 X 2 (X = halido) donor set. The complex with dppen crystallizes in the centrosymmetric space group C2/c as a partial-occupancy [0.592 (4)] dichloromethane solvate, while the dpbz-ligated complex crystallizes in the triclinic space group P1 as a full dichloromethane monosolvate. Furthermore, the crystal studied of [(dpbz)2FeCl2][FeCl4]·CH2Cl2 was an inversion twin, whose component mass ratio refined to 0.76 (3):0.24 (3). Beyond a few very weak C—H...Cl and C—H...π interactions, there are no significant supramolecular features in either structure.

scholarly journals Insights into molecular recognition from the crystal structures of p-tert-butylcalix[6]arene complexed with different solvents

IUCrJ ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Maura Malinska
Keyword(s):  
Molecular Recognition ◽  
Ethyl Acetate ◽  
Inclusion Complexes ◽  
Methyl Acetate ◽  
Crystal Packing ◽  
X Ray Diffraction ◽  
Polar Solvents ◽  
Guest Molecules ◽  
X Ray ◽  
Fill Percentage

Calixarenes are host molecules that can form complexes with one or more guest molecules, and molecular recognition in calixarenes can be affected by many factors. With a view to establishing molecular recognition rules, the host p-tert-butylcalix[6]arene (TBC6) was crystallized with different guest molecules (cyclohexane, anisole, heptane, toluene, benzene, methyl acetate, ethyl acetate, dichloromethane, tetrahydrofuran and pyridine) and the obtained structures were characterized by X-ray diffraction. With most solvents, 1:1 and/or 1:3 host–guest complexes were formed, although other stoichiometries were also observed with small guest molecules, and crystallization from ethyl acetate produced the unsolvated form. The calculated fill percentage of the TBC6 cavity was ∼55% for apolar guests and significantly lower for polar solvents, indicating that polar molecules can bind to apolar cavities with significantly lower packing coefficients. The most stable crystals were formed by 1:1 host–guest inclusion complexes. The ratio between the apolar surface area and the volume was used to predict the formation of inclusion versus exclusion complexes, with inclusion complexes observed at ratios <40. These findings allow the binding of potential guest molecules to be predicted and a suitable crystal packing for the designed properties to be obtained.

Probing the shapes of chiral bis-(o-naphthalimidobenzoyl) systems using X-ray and circular dichroism methods

2009 ◽  
Vol 65 (1) ◽  
pp. 86-95 ◽  
Author(s):  
Urszula Rychlewska ◽  
Agnieszka Plutecka ◽  
Marcin Hoffmann ◽  
Paweł Skowronek ◽  
Krystyna Gawrońska ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Crystal Packing ◽  
Hirshfeld Surface ◽  
Molecular Structures ◽  
Supramolecular Organization ◽  
Small Contribution ◽  
X Ray ◽  
Π Interactions ◽  
Dipole Interactions ◽  
Circular Dichroïsm

CD (circular dichroism) and X-ray investigations have been carried out in order to identify the prevalent conformations and define the forces that determine the molecular and supramolecular organization of the alkyl-bridged bichromophoric [NAB, ortho-(1,8-naphthalimido)benzoyl] units, each consisting of the benzoyl substituted in the ortho position with the 1,8-naphthalimide group. The results reveal that NAB bichromophores incorporated into the same molecule exist in a variety of conformation/helicity combinations. The molecular structures are largely stabilized by local 1,3-CH/CO dipole–dipole interactions, while the crystal packing besides dispersive H...H interactions is mostly governed by multiple C—H...O(=C) and C—H...π interactions. The relatively small contribution of π...π interactions comes from a pairwise off-face stacking between naphthalimide rings or from pairwise carbonyl...π interactions. All these types of intermolecular interactions have been summarized quantitatively by means of a Hirshfeld surface analysis.

scholarly journals N-(2-Formylphenyl)-4-toluenesulfonamide: a second monoclinic polymorph

2012 ◽  
Vol 68 (4) ◽  
pp. o1009-o1010 ◽  
Author(s):  
S. Murugavel ◽  
N. Manikandan ◽  
D. Kannan ◽  
M. Bakthadoss
Keyword(s):  
Hydrogen Bonds ◽  
Dihedral Angle ◽  
Title Compound ◽  
Crystal Packing ◽  
Aromatic Rings ◽  
Acta Cryst ◽  
Space Group ◽  
Π Interactions ◽  
Compound C ◽  
Centroid Distance

The title compound, C14H13NO3S, (I), is a second monoclinic polymorph. The original polymorph, (II), was reported by Mahíaet al.[Acta Cryst.(1999), C55, 2158–2160]. Polymorph (II) crystalllized in the space groupP21/c(Z= 4), whereas the title polymorph (I) occurs in the space groupP21/n(Z= 4). The dihedral angle between the two aromatic rings is 75.9 (1)° in (I) compared to 81.9 (1)° for (II). In both polymorphs, twoS(6) rings are generated by intramolecular N—H...O and C—H...O hydrogen bonds, resulting in similar molecular geometries. However, the two polymorphs differ concerning their crystal packing. In (I), molecules are linked intoC(8) zigzag chains along thebaxis by C—H...O hydrogen bonds, whereas in (II) molecules are linked by C—H...O hydrogen bonds, formingC(7) chains along thebaxis. The title polymorph is further stabilized by intermolecular C—H...π and π–π interactions [centroid–centroid distance = 3.814 (1) Å]. These interactions are not evident in polymorph (II).

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