Polymer complexes: XLXII-interplay of coordination π–π stacking and hydrogen bonding in supramolecular assembly of [sulpha drug derivatives-N,S:N,O] complexes

2010 ◽  
Vol 77 (4) ◽  
pp. 755-766 ◽  
Author(s):  
A.Z. El-Sonbati ◽  
M.A. Diab ◽  
M.M. El-Halawany ◽  
N.E. Salam
Keyword(s):  
Hydrogen Bonding ◽  
Supramolecular Assembly ◽  
Polymer Complexes ◽  
Π Stacking ◽  
Sulpha Drug

Hierarchy of π-Stacking Determines the Conformational Preference of Bis-Squaraines

2020 ◽  
Author(s):  
Abhishek Singh ◽  
Reman K. Singh ◽  
G Naresh Patwari
Keyword(s):  
Hydrogen Bonding ◽  
Rational Design ◽  
Biological Molecules ◽  
Conformational Space ◽  
X Ray Crystallography ◽  
Simple Strategy ◽  
Induced Folding ◽  
Π Stacking ◽  
Varying Length ◽  
Dynamics Simulations

The rational design of conformationally controlled foldable modules can lead to a deeper insight into the conformational space of complex biological molecules where non-covalent interactions such as hydrogen bonding and π-stacking are known to play a pivotal role. Squaramides are known to have excellent hydrogen bonding capabilities and hence, are ideal molecules for designing foldable modules that can mimic the secondary structures of bio-molecules. The π-stacking induced folding of bis-squaraines tethered using aliphatic primary and secondary-diamine linkers of varying length is explored with a simple strategy of invoking small perturbations involving the length linkers and degree of substitution. Solution phase NMR investigations in combination with molecular dynamics simulations suggest that bis-squaraines predominantly exist as extended conformations. Structures elucidated by X-ray crystallography confirmed a variety of folded and extended secondary conformations including hairpin turns and 𝛽-sheets which are determined by the hierarchy of π-stacking relative to N–H···O hydrogen bonds.

Hierarchy of π-Stacking Determines the Conformational Preference of Bis-Squaraines

2020 ◽  
Author(s):  
Abhishek Singh ◽  
Reman K. Singh ◽  
G Naresh Patwari
Keyword(s):  
Hydrogen Bonding ◽  
Rational Design ◽  
Biological Molecules ◽  
Conformational Space ◽  
X Ray Crystallography ◽  
Simple Strategy ◽  
Induced Folding ◽  
Π Stacking ◽  
Varying Length ◽  
Dynamics Simulations

The rational design of conformationally controlled foldable modules can lead to a deeper insight into the conformational space of complex biological molecules where non-covalent interactions such as hydrogen bonding and π-stacking are known to play a pivotal role. Squaramides are known to have excellent hydrogen bonding capabilities and hence, are ideal molecules for designing foldable modules that can mimic the secondary structures of bio-molecules. The π-stacking induced folding of bis-squaraines tethered using aliphatic primary and secondary-diamine linkers of varying length is explored with a simple strategy of invoking small perturbations involving the length linkers and degree of substitution. Solution phase NMR investigations in combination with molecular dynamics simulations suggest that bis-squaraines predominantly exist as extended conformations. Structures elucidated by X-ray crystallography confirmed a variety of folded and extended secondary conformations including hairpin turns and 𝛽-sheets which are determined by the hierarchy of π-stacking relative to N–H···O hydrogen bonds.

The 1-Naphthol Dimer and Its Surprising Preference for π–π Stacking over Hydrogen Bonding

2019 ◽  
Vol 10 (11) ◽  
pp. 2836-2841 ◽  
Author(s):  
Nathan A. Seifert ◽  
Arsh S. Hazrah ◽  
Wolfgang Jäger
Keyword(s):  
Hydrogen Bonding ◽  
Π Stacking

Rietveld refinement of the cocrystal 2,4-dihydroxybenzoic acid–N′-(propan-2-ylidene)nicotinohydrazide (1/1)

2012 ◽  
Vol 68 (9) ◽  
pp. o335-o337 ◽  
Author(s):  
Saul H. Lapidus ◽  
Andreas Lemmerer ◽  
Joel Bernstein ◽  
Peter W. Stephens
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Powder Diffraction ◽  
Supramolecular Assembly ◽  
Covalent Bond ◽  
Analytical Tool ◽  
Powder Diffraction Data ◽  
Dihydroxybenzoic Acid ◽  
Bond Forming ◽  
Hydrogen Bond Interactions

A further example of using a covalent-bond-forming reaction to alter supramolecular assembly by modification of hydrogen-bonding possibilities is presented. This concept was introduced by Lemmerer, Bernstein & Kahlenberg [CrystEngComm(2011),13, 55–59]. The title structure, C9H11N3O·C7H6O4, which consists of a reacted niazid molecule,viz.N′-(propan-2-ylidene)nicotinohydrazide, and 2,4-dihydroxybenzoic acid, was solved from powder diffraction data using simulated annealing. The results further demonstrate the relevance and utility of powder diffraction as an analytical tool in the study of cocrystals and their hydrogen-bond interactions.

3-n-Butyl-2-methoxy-1-benzothieno[3,2-d]pyrimidin-4(3H)-one

2006 ◽  
Vol 62 (4) ◽  
pp. o1319-o1320 ◽  
Author(s):  
Min-Hui Cao ◽  
Sheng-Zhen Xu ◽  
Yang-Gen Hu
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Benzene Ring ◽  
Title Compound ◽  
Thiophene Ring ◽  
Stacking Interactions ◽  
Asymmetric Unit ◽  
Compound C ◽  
Π Stacking ◽  
Independent Molecules

The title compound, C15H16N2O2S, contains a five-membered thiophene ring fused to a benzene ring and a substituted pyrimidinone ring. All three rings in each of the independent molecules of the asymmetric unit lie in approximately the same plane. The crystal structure is stabilized by intermolecular C—H...O hydrogen bonding and π–π stacking interactions.

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