Polymorphism in an Ionic Pair 2-Aminopyridyl-CoIIComplex:  Role of N−H···Cl Hydrogen Bonds and π···π Interactions in Tuning the Columnar Packing

2006 ◽  
Vol 6 (1) ◽  
pp. 229-234 ◽  
Author(s):  
Guoqi Zhang ◽  
Guoqiang Yang ◽  
Nianzu Wu ◽  
Jin Shi Ma
Keyword(s):  
Hydrogen Bonds ◽  
Ionic Pair ◽  
Π Interactions

Structural insights into methyl- or methoxy-substituted 1-(α-aminobenzyl)-2-naphthol structures: the role of C—H...π interactions

2019 ◽  
Vol 75 (2) ◽  
pp. 189-195 ◽  
Author(s):  
Maria Annunziata M. Capozzi ◽  
Giancarlo Terraneo ◽  
Cosimo Cardellicchio
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Methoxy Group ◽  
Crystal Packing ◽  
Molecular Surface ◽  
Methyl Group ◽  
Π Interactions ◽  
Substituted 1 ◽  
Structural Insights

Aminobenzylnaphthols are a class of compounds containing a large aromatic molecular surface which makes them suitable candidates to study the role of C—H...π interactions. We have investigated the effect of methyl or methoxy substituents on the assembling of aromatic units by preparing and determining the crystal structures of (S,S)-1-{(4-methylphenyl)[(1-phenylethyl)amino]methyl}naphthalen-2-ol, C26H25NO, and (S,S)-1-{(4-methoxyphenyl)[(1-phenylethyl)amino]methyl}naphthalen-2-ol, C26H25NO2. The methyl group influenced the overall crystal packing even if the H atoms of the methyl group did not participate directly either in hydrogen bonding or C—H...π interactions. The introduction of the methoxy moiety caused the formation of new hydrogen bonds, in which the O atom of the methoxy group was directly involved. Moreover, the methoxy group promoted the formation of an interesting C—H...π interaction which altered the orientation of an aromatic unit.

Role of Anion–π Interactions in the Supramolecular Assembly of Salts Containing Asymmetrical Bis(pyridyl) Cations

2014 ◽  
Vol 67 (10) ◽  
pp. 1504
Author(s):  
Zhu-Yan Zhang ◽  
Zhao-Peng Deng ◽  
Li-Hua Huo ◽  
Shu-E Zhang ◽  
Hui Zhao ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Self Assembly ◽  
Supramolecular Assembly ◽  
Interpenetrating Networks ◽  
Π Interactions ◽  
Supramolecular Architectures ◽  
Left Handed ◽  
Inorganic Acids ◽  
Thermal Stability Of

Self-assembly of three flexible bis(pyridyl) molecules with different inorganic acids (HPF6, HClO4, and HNO3) leads to the formation of eight salts, which exhibit diverse architectures involving hydrogen bonding and anion–π interactions. The three types of inorganic anions in these salts formed anion–π interactions with HM+ and H2M2+ except for 2, in which the six F atoms were involved in hydrogen bonds. Anion–π interactions produced diverse motifs of one (anion)-to-one (cation) in 1, 3, 4, and 6, two (anion)-to-one (cation) in 5 and 7, and (4,4) layer in 8. Hydrogen bonds resulted in interesting supramolecular architectures, such as right- and left-handed helical chains in 3, 2-fold interpenetrating networks in 5, and 3-fold interpenetrating networks in 8. Structural analyses indicated that the conformations of the three flexible asymmetrical bis(pyridyl) molecules and the non-covalent bonding interactions, such as hydrogen bonds and anion···π interactions, play crucial roles in the final architectures of these salts. Thermogravimetric analyses indicated that the thermal stability of the eight salts decreased in the order of perchlorates, hexafluorophosphates, and nitrates. The emission intensity of the perchlorates is much stronger than that of the hexafluorophosphates, nitrates, and their corresponding organic molecules in the solid state at room temperature.

Design of Anion–π Interactions and Hydrogen Bonds to Recognition of the Chloride, Bromide and Nitrate Anions

2021 ◽  
Author(s):  
Renato Pereira Orenha ◽  
Vanessa Borges da Silva ◽  
Giovanni Finoto Caramori ◽  
Maurício Jeomar Piotrowski ◽  
Glaucio Régis Nagurniak ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Biochemical Processes ◽  
Π Interactions ◽  
Conjugated Compounds ◽  
Nitrate Anions

The role of anions in several biochemical processes gives rise to an enormous interest in the identification/exploration of compounds with potential ability to recognize anions. Here, the anthracene–squaramide conjugated compounds,...

scholarly journals Deciphering the Role of π-Interactions in Polyelectrolyte Complexes Using Rationally Designed Peptides

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2074
Author(s):  
Sara Tabandeh ◽  
Cristina Elisabeth Lemus ◽  
Lorraine Leon
Keyword(s):  
Hydrogen Bonding ◽  
Phase Separation ◽  
Liquid Phase ◽  
Charge Density ◽  
Secondary Structures ◽  
Liquid Phase Separation ◽  
Polyelectrolyte Complexes ◽  
Π Interactions ◽  
Liquid Liquid Phase Separation

Electrostatic interactions, and specifically π-interactions play a significant role in the liquid-liquid phase separation of proteins and formation of membraneless organelles/or biological condensates. Sequence patterning of peptides allows creating protein-like structures and controlling the chemistry and interactions of the mimetic molecules. A library of oppositely charged polypeptides was designed and synthesized to investigate the role of π-interactions on phase separation and secondary structures of polyelectrolyte complexes. Phenylalanine was chosen as the π-containing residue and was used together with lysine or glutamic acid in the design of positively or negatively charged sequences. The effect of charge density and also the substitution of fluorine on the phenylalanine ring, known to disrupt π-interactions, were investigated. Characterization analysis using MALDI-TOF mass spectroscopy, H NMR, and circular dichroism (CD) confirmed the molecular structure and chiral pattern of peptide sequences. Despite an alternating sequence of chirality previously shown to promote liquid-liquid phase separation, complexes appeared as solid precipitates, suggesting strong interactions between the sequence pairs. The secondary structures of sequence pairs showed the formation of hydrogen-bonded structures with a β-sheet signal in FTIR spectroscopy. The presence of fluorine decreased hydrogen bonding due to its inhibitory effect on π-interactions. π-interactions resulted in enhanced stability of complexes against salt, and higher critical salt concentrations for complexes with more π-containing amino acids. Furthermore, UV-vis spectroscopy showed that sequences containing π-interactions and increased charge density encapsulated a small charged molecule with π-bonds with high efficiency. These findings highlight the interplay between ionic, hydrophobic, hydrogen bonding, and π-interactions in polyelectrolyte complex formation and enhance our understanding of phase separation phenomena in protein-like structures.

scholarly journals N-(3-Chloro-4-ethoxy-1-methyl-1H-indazol-5-yl)-4-methoxybenzenesulfonamide

2014 ◽  
Vol 70 (6) ◽  
pp. o679-o679 ◽  
Author(s):  
Hakima Chicha ◽  
El Mostapha Rakib ◽  
Abdellah Hannioui ◽  
Mohamed Saadi ◽  
Lahcen El Ammari
Keyword(s):  
Hydrogen Bonds ◽  
Benzene Ring ◽  
Title Compound ◽  
Ring System ◽  
Dihedral Angles ◽  
Ethoxy Group ◽  
Π Interactions ◽  
Compound C ◽  
The Mean

The indazole ring system of the title compound, C17H18ClN3O4S, is almost planar (r.m.s. deviation = 0.0113 Å) and forms dihedral angles of 32.22 (8) and 57.5 (3)° with the benzene ring and the mean plane through the 4-ethoxy group, respectively. In the crystal, molecules are connected by pairs of N—H...O hydrogen bonds into inversion dimers, which are further linked by π–π interactions between the diazole rings [intercentroid distance = 3.4946 (11) Å], forming chains parallel to [101].

Role of non-covalent interactions in the supramolecular architectures of mercury(ii) diphenyldithiophosphates: An experimental and theoretical investigation

2021 ◽  
Vol 45 (4) ◽  
pp. 2249-2263
Author(s):  
Pretam Kumar ◽  
Snehasis Banerjee ◽  
Anu Radha ◽  
Tahira Firdoos ◽  
Subash Chandra Sahoo ◽  
...  
Keyword(s):  
Theoretical Investigation ◽  
Supramolecular Organization ◽  
Π Interactions ◽  
Supramolecular Architectures ◽  
Non Covalent Interactions ◽  
Covalent Interactions

The H-bond, spodium bond and CH⋯π interactions playing an important role in the supramolecular organization of two mercury(ii) diphenyldithiophosphate complexes have been discussed.

scholarly journals 3-(Adamantan-1-yl)-4-benzyl-1H-1,2,4-triazole-5(4H)-thione

2014 ◽  
Vol 70 (7) ◽  
pp. o766-o767 ◽  
Author(s):  
Fatmah A. M. Al-Omary ◽  
Hazem A. Ghabbour ◽  
Ali A. El-Emam ◽  
C. S. Chidan Kumar ◽  
Hoong-Kun Fun
Keyword(s):  
Hydrogen Bonds ◽  
Dihedral Angle ◽  
Title Compound ◽  
Crystal Packing ◽  
Triazole Ring ◽  
Axis Direction ◽  
Π Interactions ◽  
Compound C ◽  
Supramolecular Chains

The title compound, C19H23N3S, is a functionalized triazoline-3-thione derivative. The benzyl ring is almost normal to the planar 1,2,4-triazole ring (r.m.s. deviation = 0.007 Å) with a dihedral angle of 86.90 (7)°. In the crystal, molecules are linked by pairs of N—H...S hydrogen bonds, forming inversion dimers that encloseR22(8) loops. The crystal packing is further stabilized by weak C—H...π interactions that link adjacent dimeric units into supramolecular chains extending along thea-axis direction.

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