New deep cavitand with imidazoquinoxaline flaps: formation of static helical alkane inclusion complexes by enhanced CH/π interactions

2009 ◽  
pp. 4971 ◽  
Author(s):  
Heung-Jin Choi ◽  
Quoc-Thiet Nguyen ◽  
Yeon Sil Park ◽  
Cheol-Ho Choi ◽  
Kyungsoo Paek ◽  
...  
Keyword(s):  
Inclusion Complexes ◽  
Π Interactions

Structures and C–H⋯π interactions in DMF inclusion complexes of homoazacalix[4]arenes

2005 ◽  
Vol 46 (39) ◽  
pp. 6687-6690 ◽  
Author(s):  
Hiroyuki Takemura ◽  
Tetsuo Iwanaga ◽  
Teruo Shinmyozu
Keyword(s):  
Inclusion Complexes ◽  
Π Interactions

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.

scholarly journals Inclusion complexes of Cethyl-2-methylresorcinarene and pyridine N-oxides: breaking the C–I⋯−O–N+ halogen bond by host–guest complexation

CrystEngComm ◽  
2016 ◽  
Vol 18 (5) ◽  
pp. 793-799 ◽  
Author(s):  
Rakesh Puttreddy ◽  
Ngong Kodiah Beyeh ◽  
Kari Rissanen
Keyword(s):  
Inclusion Complexes ◽  
Halogen Bond ◽  
Halogen Bonding ◽  
Π Interactions ◽  
Guest Chemistry

Cethyl-2-Methylresorcinarene and aromatic N-oxides manifest host–guest chemistry by C–H⋯π interactions and halogen bonding; the C–I⋯−O–N+ halogen bond with 2-iodopyridine N-oxide is broken by the in-cavity C–I⋯π interactions.

Studies on the Preparation, Characterization and Solubility of -Cyclodextrin-Roxythromycin Inclusion Complexes

2009 ◽  
Vol 2 (2) ◽  
pp. 523-530
Author(s):  
D. Nagasamy Venkatesh ◽  
S. Karthick ◽  
M. Umesh ◽  
G. Vivek ◽  
R.M. Valliappan ◽  
...  
Keyword(s):  
Dissolution Rate ◽  
Inclusion Complexes ◽  
Phase Solubility ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ir Studies ◽  
Poorly Soluble ◽  
Poorly Soluble Drug

Roxythromycin/ β-cyclodextrin (Roxy/ β-CD) dispersions were prepared with a view to study the influence of β-CD on the solubility and dissolution rate of this poorly soluble drug. Phase-solubility profile indicated that the solubility of roxythromycin was significantly increased in the presence of β-cyclodextrin and was classified as AL-type, indicating the 1:1 stoichiometric inclusion complexes. Physical characterization of the prepared systems was carried out by differential scanning calorimetry (DSC), X-ray diffraction studies (XRD) and IR studies. Solid state characterization of the drug β-CD binary system using XRD, FTIR and DSC revealed distinct loss of drug crystallinity in the formulation, ostensibly accounting for enhancement of dissolution rate.

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