Structural Study of Hydrogen-Bond Driven Cocrystallization of Pyridyl-Bithiophene Based Compounds

2021 ◽  
Author(s):  
Nandini Sarkar ◽  
Sean Parkin ◽  
Aron J. Huckaba
Keyword(s):  
Hydrogen Bond ◽  
Structural Study

A structural study of (1RS,2SR,3RS,4SR,5RS)-2,4-dibenzoyl-1,3,5-triphenylcyclohexan-1-ol chloroform hemisolvate and (1RS,2SR,3RS,4SR,5RS)-2,4-dibenzoyl-1-phenyl-3,5-bis(2-methoxyphenyl)cyclohexan-1-ol

2015 ◽  
Vol 71 (6) ◽  
pp. 491-498 ◽  
Author(s):  
Mikhail E. Minyaev ◽  
Dmitrii M. Roitershtein ◽  
Ilya E. Nifant'ev ◽  
Ivan V. Ananyev ◽  
Tatyana V. Minyaeva ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Single Crystals ◽  
Structural Study ◽  
Chair Conformation ◽  
Cyclohexane Ring ◽  
Nmr Studies ◽  
Acta Cryst

(1RS,2SR,3RS,4SR,5RS)-2,4-Dibenzoyl-1,3,5-triphenylcyclohexan-1-ol or (4-hydroxy-2,4,6-triphenylcyclohexane-1,3-diyl)bis(phenylmethanone), C38H32O3, (1), is formed as a by-product in the NaOH-catalyzed synthesis of 1,3,5-triphenylpentane-1,5-dione from acetophenone and benzaldehyde. Single crystals of the chloroform hemisolvate, C38H32O3·0.5CHCl3, were grown from chloroform. The structure has triclinic (P-1) symmetry. One diastereomer [as a pair of (1RS,2SR,3RS,4SR,5RS)-enantiomers] of (1) has been found in the crystal structure and confirmed by NMR studies. The dichoromethane hemisolvate has been reported previously [Zhanget al.(2007).Acta Cryst.E63, o4652]. (1RS,2SR,3RS,4SR,5RS)-2,4-Dibenzoyl-3,5-bis(2-methoxyphenyl)-1-phenylcyclohexan-1-ol or [4-hydroxy-2,6-bis(2-methoxyphenyl)-4-phenylcyclohexane-1,3-diyl]bis(phenylmethanone), C40H36O5, (2), is also formed as a by-product, under the same conditions, from acetophenone and 2-methoxybenzaldehyde. Crystals of (2) have been grown from chloroform. The structure has orthorhombic (Pca21) symmetry. A diastereomer of (2) possesses the same configuration as (1). In both structures, the cyclohexane ring adopts a chair conformation with all bulky groups (benzoyl, phenyl and 2-methoxyphenyl) in equatorial positions. The molecules of (1) and (2) both display one intramolecular O—H...O hydrogen bond.

A structural study of 4-aminoantipyrine and six of its Schiff base derivatives

2015 ◽  
Vol 71 (2) ◽  
pp. 103-109 ◽  
Author(s):  
Malitsatsi J. Mnguni ◽  
Andreas Lemmerer
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Schiff Base ◽  
Hydrogen Bonds ◽  
Structural Study ◽  
General Position ◽  
Screw Axis ◽  
Π Interactions ◽  
Schiff Base Derivatives ◽  
Derivatives Of

Six derivatives of 4-amino-1,5-dimethyl-2-phenyl-2,3-dihydro-1H-pyrazol-3-one (4-aminoantipyrine), C11H13N3O, (I), have been synthesized and structurally characterized to investigate the changes in the observed hydrogen-bonding motifs compared to the original 4-aminoantipyrine. The derivatives were synthesized from the reactions of 4-aminoantipyrine with various aldehyde-, ketone- and ester-containing molecules, producing (Z)-methyl 3-[(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)amino]but-2-enoate, C16H19N3O3, (II), (Z)-ethyl 3-[(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)amino]but-2-enoate, C17H21N3O3, (III), ethyl 2-[(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)amino]cyclohex-1-enecarboxylate, C20H25N3O3, (IV), (Z)-ethyl 3-[(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)amino]-3-phenylacrylate, C22H23N3O3, (V), 2-cyano-N-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)acetamide, C14H14N4O2, (VI), and (E)-methyl 4-{[(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)amino]methyl}benzoate, C20H19N3O3, (VII). The asymmetric units of all these compounds have one molecule on a general position. The hydrogen bonding in (I) forms chains of moleculesviaintermolecular N—H...O hydrogen bonds around a crystallographic sixfold screw axis. In contrast, the formation of enamines for all derived compounds except (VII) favours the formation of a six-membered intramolecular N—H...O hydrogen-bonded ring in (II)–(V) and an intermolecular N—H...O hydrogen bond in (VI), whereas there is an intramolecular C—H...O hydrogen bond in the structure of imine (VII). All the reported compounds, except for (II), feature π–π interactions, while C—H...π interactions are observed in (II), C—H...O interactions are observed in (I), (III), (V) and (VI), and a C—O...π interaction is observed in (II).

Competition between hydrogen bonds and halogen bonds: a structural study

2018 ◽  
Vol 42 (13) ◽  
pp. 10539-10547 ◽  
Author(s):  
Janaka C. Gamekkanda ◽  
Abhijeet S. Sinha ◽  
John Desper ◽  
Marijana Đaković ◽  
Christer B. Aakeröy
Keyword(s):  
Hydrogen Bond ◽  
Solid State ◽  
Hydrogen Bonds ◽  
Structural Study ◽  
Halogen Bond ◽  
Halogen Bonds ◽  
Hydrogen Bond Donors

O–H hydrogen-bond donors and R–CC–I halogen-bond donors are close competitors for suitable acceptor sites in solid-state assembly.

Electronic and Molecular Structures of Heteroradialenes: A Combined Synthetic, Computational, Spectroscopic, and Structural Study Identifying IR Spectroscopy as a Simple but Powerful Experimental Probe

2013 ◽  
Vol 68 (1) ◽  
pp. 64-86 ◽  
Author(s):  
Carl-Georg Freiherr von Richthofen ◽  
Bastian Feldscher ◽  
Kai-Alexander Lippert ◽  
Anja Stammler ◽  
Hartmut Bögge ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Schiff Bases ◽  
Structural Study ◽  
Electronic Structures ◽  
Molecular Structures ◽  
Resonance Structure ◽  
Hydrogen Bond Donor ◽  
Donor Acceptor ◽  
Intramolecular Hydrogen

The vicinity of a hydrogen bond donor (O-H) and a hydrogen bond acceptor (C=O or C=N- R) in salicylaldehydes and ortho-Schiff bases results in significant structural variations compared to the monosubstituted derivatives that are reflected in the electronic structure and thus in the spectroscopic properties. This interplay between intramolecular hydrogen bonding and multicenter p- electron delocalization is the origin of the concept of resonance-assisted hydrogen bonding (RAHB). Herein, the complexity is extended from one hydrogen bond donor-acceptor pair in salicylaldehyde and ortho-Schiff bases to three hydrogen bond donor-acceptor pairs in 2,4,6-tricarbonyl- and 2,4,6- triimine-substituted phloroglucinols (1,3,5-trihydroxybenzene), respectively. To evaluate the changes in the molecular and electronic structures, we have performed a comprehensive computational, spectroscopic, and structural study starting from monosubstituted benzene derivatives as references over ortho-disubstituted derivates to the sixfold-substituted derivatives. Whereas in salicylaldehydes, ortho- Schiff bases, and 2,4,6-tricarbonyl-phloroglucinols the phenolic O-protonated tautomers represent the energy minima, the N-protonated tautomers represent the energy minima in 2,4,6-triiminephloroglucinols. The analysis provides a keto-enamine resonance structure with six exocyclic double bonds to be dominant for these species reminiscent of [6]radialenes, which were termed heteroradialenes. These heteroradialenes are non-aromatic alicycles. However, the predominance of this resonance structure does not represent a sudden change going from the 2,4,6-tricarbonyl- to the 2,4,6-triimine-phloroglucinols, but a gradual increase of analogous resonance structure contributions is observed even in salicylaldehyde and ortho-Schiff bases demonstrating some hetero-orthoquinodimethane character. These changes are, besides in the molecular structures, well reflected in the IR spectra, which can therefore be used as a simple tool to probe the electronic structures in these systems. Interruption of the delocalized p system supporting the intramolecular hydrogen bond, i. e. going from 2,4,6-triimine- to 2,4,6-triamine-substituted phloroglucinols, reestablishes an O-protonated aromatic phloroglucinol system.

Site-directed mutagenesis in hemoglobin: Functional and structural study of the intersubunit hydrogen bond of threonine-38(C3).alpha. at the .alpha.1-.beta.2 interface in human hemoglobin

Biochemistry ◽  
1993 ◽  
Vol 32 (49) ◽  
pp. 13688-13695 ◽  
Author(s):  
Masakazu Hashimoto ◽  
Koichiro Ishimori ◽  
Kiyohiro Imai ◽  
Gentaro Miyazaki ◽  
Hideki Morimoto ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Structural Study ◽  
Site Directed Mutagenesis ◽  
Directed Mutagenesis ◽  
Human Hemoglobin ◽  
Beta 2

Hydrogen-bond mediation of supramolecular aggregation in neutral bis-(C6F5)Pt complexes with aromatic H-bond donating ligands. A synthetic and structural study

2004 ◽  
pp. 2733-2740 ◽  
Author(s):  
José M. Casas ◽  
Beatriz E. Diosdado ◽  
Larry R. Falvello ◽  
Juan Forniés ◽  
Antonio Martín ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Structural Study ◽  
Supramolecular Aggregation

An Ultra-Structural Study of Human Melanoma in Vivo and Vitro

1976 ◽  
Vol 34 ◽  
pp. 258-259
Author(s):  
James R. Gaylor ◽  
Fredda Schafer ◽  
Robert E. Nordquist
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Protein Aggregation ◽  
Structural Study ◽  
Human Melanoma ◽  
Protein Matrix ◽  
Early Form ◽  
Endoplasmic Reticulum Protein ◽  
Mitochondrial Origin

Several theories on the origin of the melanosome exist. These include the Golgi origin theory, in which a tyrosinase-rich protein is "packaged" by the Golgi apparatus, thus forming the early form of the melanosome. A second theory postulates a mitochondrial origin of melanosomes. Its author contends that the melanosome is a modified mitochondria which acquires melanin during its development. A third theory states that a pre-melanosome is formed in the smooth or rough endoplasmic reticulum. Protein aggregation is suggested by one author as a possible source of the melanosome. This fourth theory postulates that the melanosome originates when the protein products of several genetic loci aggregate in the cytoplasm of the melanocyte. It is this protein matrix on which the melanin is deposited. It was with these theories in mind that this project was undertaken.

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