Three Polymorphic Forms of Ciprofloxacin Maleate: Formation Pathways, Crystal Structures, Calculations, and Thermodynamic Stability Aspects

2016 ◽  
Vol 16 (11) ◽  
pp. 6556-6567 ◽  
Author(s):  
Artem O. Surov ◽  
Andrei V. Churakov ◽  
German L. Perlovich
Keyword(s):  
Crystal Structures ◽  
Thermodynamic Stability ◽  
Polymorphic Forms

scholarly journals π-Stacking Stopper-Macrocycle Stabilized Dynamically Interlocked [2]Rotaxanes

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4704
Author(s):  
Sing-Ming Chan ◽  
Fung-Kit Tang ◽  
Ching-Yau Lam ◽  
Chak-Shing Kwan ◽  
Sam C. K. Hau ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Thermodynamic Stability ◽  
Combinatorial Library ◽  
Aromatic Rings ◽  
Interlocked Molecules ◽  
X Ray ◽  
Π Stacking ◽  
Dynamic Combinatorial Library

The synthesis of mechanically interlocked molecules is valuable due to their unique topologies. With π-stacking intercomponent interaction, e.g., phenanthroline and anthracene, novel [2]rotaxanes have been synthesized by dynamic imine clipping reaction. Their X-ray crystal structures indicate the π-stackings between the anthracene moiety (stopper) on the thread and the (hetero)aromatic rings at the macrocycle of the rotaxanes. Moreover, the length of glycol chains affects the extra π-stacking intercomponent interactions between the phenyl groups and the dimethoxy phenyl groups on the thread. Dynamic combinatorial library has shown at best 84% distribution of anthracene-threaded phenanthroline-based rotaxane, coinciding with the crystallography in that the additional π-stacking intercomponent interactions could increase the thermodynamic stability and selectivity of the rotaxanes.

Structural systematics of 4,4′-disubstituted benzenesulfonamidobenzenes. 1. Overview and dimer-based isostructures

2007 ◽  
Vol 63 (4) ◽  
pp. 621-632 ◽  
Author(s):  
Thomas Gelbrich ◽  
Michael B. Hursthouse ◽  
Terence L. Threlfall
Keyword(s):  
Hydrogen Bonding ◽  
Crystal Structures ◽  
Triple Bond ◽  
Common Type ◽  
Dimensional Structure ◽  
One Dimensional ◽  
Distinct Structure ◽  
Polymorphic Forms ◽  
A Chain

One hundred 4,4′-disubstituted benzenesulfonamidobenzenes, X–C6H5–SO2–NH–C6H5–Y, where X, Y = NO2, CN, CF3, I, Br, Cl, F, H, Me, OMe, have been synthesized and their crystal structures determined. The resulting set of 133 structures, which includes polymorphic forms, is used to make a comparative study of the molecular packing and the nature of the intermolecular interactions, including the formation of hydrogen-bonding motifs and the influence of the two substituents X and Y on these features. Nine distinct supramolecular connectivity motifs of hydrogen bonding are encountered. There are 74% of all the structures investigated which exhibit one of two motifs based on N—H...O=S interactions, a dimer or a chain. There are three other, infrequent motifs, also employing N—H...O=S links, which exhibit more complexity. Four different chain motifs result from either N—H...O=N, N—H...C[triple-bond]N or N—H...OMe interactions, arising from the presence of a nitro (position Y), nitrile (X or Y) or methoxy (Y) substituent. The program XPac [Gelbrich & Hursthouse (2005). CrystEngComm, 7, 324–336] was used to systematically analyse the packing relationships between crystal structures. Similar discrete (zero-dimensional) and extended (one-dimensional and two-dimensional) structure components, as well as cases of isostructurality were identified. A hierarchy for the classification of the 56 distinct structure types of this set is presented. The most common type, a series of 22 isostructures containing the simple centrosymmetric N—H...O=S-bonded dimer, is discussed in detail.

The Flavonoids of Combretum quadrangulare: Crystal structures of the Polymorphic Forms of 5-Hydroxy-2-(4'-hydroxy-3',5'-dimethoxyphenyl)-3,7-dimethoxy-4H-1-benzopyran-4-one

1985 ◽  
Vol 38 (8) ◽  
pp. 1177 ◽  
Author(s):  
IR Castleden ◽  
SR Hall ◽  
S Nimgirawath ◽  
S Thadaniti ◽  
AH White
Keyword(s):  
Least Squares ◽  
Crystal Structures ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
X Ray ◽  
Β Phase ◽  
Α Phase ◽  
Polymorphic Forms

The following substituted 2-phenyl-4H-1-benzopyran-4-ones have been isolated from the dried flowers of Combretum quadrangulare Kurz ( Combretaceae ): 5-hydroxy-3,3′,4′,5′,7-pentamethoxy ( combretol ) (1), 3′,5-dihydroxy-3,4′,7-trimethoxy ( ayanin ) (2) and 4′,5-dihydroxy- 3,3′,5′,7-tetramethoxy (3). The last substance (3) was obtained as a mixture of two polymorphic forms (α and β) each of which was characterized by X-ray diffraction. Diffractometer data at 295 K were refined by full matrix least squares to residuals of 0.043 (1181 'observed' reflections) for the α-phase and 0.044 (1421) for the β phase of (3). Crystals of the α-phase of (3) are triclinic, Pī, a 12.663(6), b 9.592(4), c 7.444(4) Ǻ, α 102.48(3), β 101.39(4), γ 91.72(4)°,Z 2. Crystals of the β-phase of (3) are monoclinic P21/n, a 17.139(8), b 12.728(6), c 7.845(7) Ǻ, β 95.07(6)°, Z 4. An unambiguous synthesis of (3) was also achieved.

New Solid Forms of the Antiviral Drug Arbidol: Crystal Structures, Thermodynamic Stability, and Solubility

2015 ◽  
Vol 12 (11) ◽  
pp. 4154-4165 ◽  
Author(s):  
Artem O. Surov ◽  
Alex N. Manin ◽  
Andrei V. Churakov ◽  
German L. Perlovich
Keyword(s):  
Crystal Structures ◽  
Thermodynamic Stability ◽  
Antiviral Drug

Crystal structures of three polymorphic forms of 4-hydroxy-3-methoxy-4′-nitro-trans-stilbene

1998 ◽  
Vol 213 (7-8) ◽  
Author(s):  
A. Gleixner ◽  
J. Hiller ◽  
T. Debaerdemaeker ◽  
A. Lentz ◽  
L. Walz
Keyword(s):  
Crystal Structures ◽  
Trans Stilbene ◽  
Polymorphic Forms

AbstractThe structures of three polymorphic forms of 4-hydroxy-3-methoxy-4′-nitro-trans-stilbene (HMONS; C

Insights into the new 3d–5f heterometallic quaternary fluorides: Synthesis, crystal structures, spectroscopic properties, and thermodynamic stability

2019 ◽  
Vol 487 ◽  
pp. 362-368 ◽  
Author(s):  
Qi Liu ◽  
Huiqin Yin ◽  
Hongliang Bao ◽  
Zenghui Yue ◽  
Kariem Diefenbach ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Thermodynamic Stability ◽  
Spectroscopic Properties

Crystal structures of two polymorphic forms of bis-(zinc-dibutyldithiopercarbamate)

1995 ◽  
Vol 210 (10) ◽  
Author(s):  
G. Reck ◽  
R. Becker ◽  
G. Walther
Keyword(s):  
Crystal Structures ◽  
Polymorphic Forms

AbstractBis(zinc-dibutyldithiopercarbamate)/I crystallizes in two polymorphic forms herein named as I

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