scholarly journals Synthesis, Physicochemical Properties, and Hydrogen Bonding of 4(5)-Substituted 1-H-Imidazole-2-carboxamide, a Potential Universal Reader for DNA Sequencing by Recognition Tunneling

2012 ◽  
Vol 18 (19) ◽  
pp. 5998-6007 ◽  
Author(s):  
Feng Liang ◽  
Shengqing Li ◽  
Stuart Lindsay ◽  
Peiming Zhang
Keyword(s):  
Hydrogen Bonding ◽  
Physicochemical Properties ◽  
Dna Sequencing ◽  
Recognition Tunneling ◽  
Substituted 1

scholarly journals Non-covalent interactions of Acipimox in Multi-component Crystals

2014 ◽  
Vol 70 (a1) ◽  
pp. C1014-C1014
Author(s):  
Vaughan Maurel ◽  
Nicola Dare ◽  
Susan Bourne ◽  
Mino Caira
Keyword(s):  
Hydrogen Bonding ◽  
Physicochemical Properties ◽  
Carboxyl Group ◽  
Pyridyl Nitrogen ◽  
Urea Molecule ◽  
Space Group ◽  
Donor And Acceptor ◽  
Non Covalent Interactions ◽  
Solvent Molecules ◽  
Bonding Systems

The hypolipidemic agent acipimox has various potential hydrogen bonding donor and acceptor sites. A series of multi-component crystals can be formed owing to these moieties. Acipimox forms such structures with benzamide, isonicotinamide and urea. Each of these systems has a unique hydrogen bonding arrangement leading to changes in the physicochemical properties of acipimox. X-ray analysis of a hydrated co-crystal, acipimox·benzamide·0.5H2O (space group C2/c) revealed layers of dimeric acipimox-benzamide units, the layers being linked by hydrogen bonding from a bridging water molecule. A salt with formula (acipimox)- (isonicotinamide)+ (space group P2(1)/c) results from proton transfer from the carboxyl group of acipimox to the pyridyl nitrogen of isonicotinamide. The carboxyl group engages in an electrostatic interaction with the protonated pyridyl nitrogen. In addition, a hydrogen bond is formed between the donor amide and the acceptor carboxyl group of a second acipimox anion. These form a macrocyclic structure composed of two pairs of acipimox-isonicotinamide counterions in a R44(22) H-bonded motif, giving rise to interlaced layers. Acipimox and urea form two distinct systems, both crystallising in the space group P(-1). The kinetic crystallisation product is a co-crystal with 1:1 acipimox:urea stoichiometry (R22(8) motif), a second distinct urea molecule self-assembles forming infinite chains within channels formed by the packing arrangement. The thermodynamic form is an acetonitrile solvate in which the solvent molecules are included in isolated sites. The different H-bonding systems in each of these multi-component crystals give rise to differing physicochemical properties. For example the melting and degradation temperatures for each of these systems is distinct: that of the acipimox·benzamide co-crystal is lower than that of acipimox while the crystals containing isonicotinamide and urea have higher melting and degradation temperatures.

scholarly journals Hydrogen Bonding of Pyrrole, Indole and Carbazole with Substituted 1-Phenyl-2-pyrrolidinones.

1979 ◽  
Vol 33a ◽  
pp. 76-78 ◽  
Author(s):  
J. Karjalainen ◽  
P. O. I. Virtanen ◽  
Ragnhild Seip ◽  
Knut A. Strand ◽  
Eberhard Hoyer ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Substituted 1

Vibrational spectra, hydrogen bonding interactions and chemical reactivity analysis of nicotinamide–citric acid cocrystals by an experimental and theoretical approach

2019 ◽  
Vol 43 (40) ◽  
pp. 15956-15967 ◽  
Author(s):  
Priya Verma ◽  
Anubha Srivastava ◽  
Anuradha Shukla ◽  
Poonam Tandon ◽  
Manishkumar R. Shimpi
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Citric Acid ◽  
Physicochemical Properties ◽  
Vibrational Spectra ◽  
Theoretical Approach ◽  
Chemical Reactivity ◽  
Hydrogen Bond Interactions ◽  
Hydrogen Bonding Interactions

The hydrogen bond interactions in the cocrystal lead to spatial arrangements enhancing the physicochemical properties.

The formation and physicochemical properties of PEGylated deep eutectic solvents

2019 ◽  
Vol 43 (22) ◽  
pp. 8804-8810 ◽  
Author(s):  
Wenjun Chen ◽  
Xiyue Bai ◽  
Zhimin Xue ◽  
Hongyu Mou ◽  
Jiangang Chen ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Physicochemical Properties ◽  
Deep Eutectic Solvents ◽  
Molecular Liquids

Polymer PEG was used to form eutectic molecular liquids with hydrogen bonding acceptors.

scholarly journals Symmetrical and unsymmetrical α,ω-nucleobase amide-conjugated systems

2010 ◽  
Vol 6 ◽  
Author(s):  
Sławomir Boncel ◽  
Maciej Mączka ◽  
Krzysztof K K Koziol ◽  
Radosław Motyka ◽  
Krzysztof Z Walczak
Keyword(s):  
Physicochemical Properties ◽  
Carboxylic Group ◽  
Aromatic Diamines ◽  
Conjugated Systems ◽  
Michael Adducts ◽  
Carboxylic Groups ◽  
A Subunit ◽  
Target Molecules ◽  
Hydrolysis Of ◽  
Substituted 1

We present the synthesis and selected physicochemical properties of several novel symmetrical and unsymmetrical α,ω-nucleobase mono- and bis-amide conjugated systems containing aliphatic, aromatic or saccharidic linkages. The final stage of the synthesis involves condensation of a subunit bearing carboxylic group with an amine subunit. 4-(4,6-Dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMT-MM) was found to be a particularly effective condensing agent. The subunits containing carboxylic groups were obtained by acidic hydrolysis of N-1 Michael adducts of uracils or N-9 Michael adducts of 6-chloropurine with methyl acrylate. The amines used were aliphatic/aromatic diamines, adenine, 5-substituted 1-(ω-aminoalkyl)uracils and 5′-amino-2′,5′-dideoxythymidine. The title compounds may find application as antiprotozoal agents. Moreover, preliminary microscopy TEM studies of supramolecular behaviour showed that target molecules with bolaamphiphilic structures were capable of forming highly ordered assemblies, mainly nanofibres.

scholarly journals Caffeine Adsorption by Fique Bagasse Biochar Produced at Various Pyrolysis Temperatures

2019 ◽  
Vol 35 (2) ◽  
pp. 538-546 ◽  
Author(s):  
Yaned Milena Correa-Navarro ◽  
Juan Carlos Moreno-Piraján ◽  
Liliana Giraldo ◽  
Paola Rodríguez-Estupiñan
Keyword(s):  
Experimental Data ◽  
Hydrogen Bonding ◽  
Physicochemical Properties ◽  
Agricultural Residues ◽  
Layer Adsorption ◽  
Different Temperatures ◽  
Π Stacking Interaction ◽  
Ph Dependent ◽  
Bagasse Biochar ◽  
Adsorption Capability

Biochar obtained from agricultural residues is ever more recognized as a multifunctional porous solid for multiples applications. In this study, fique bagasse biochars were produced at different temperatures and their corresponding deashing. These materials were investigated about physicochemical properties and adsorption capability of caffeine. The pH solution was an influential parameter, and it was determined that a pH =2.0 for washed biochar and pH= 6.0 for not washed biochar were the best conditions for adsorption. Langmuir, Freundlich and Redlich-Peterson isotherms models provided a good fit for the experimental data, indicating a surface and multi-layer adsorption. From the adsorption capacity at equilibrium of fique bagasse biochars it was concluded that pH-dependent interactions, hydrogen bonding and π- π stacking interaction were found to be responsible for caffeine adsorption. The results allow to visualize the biochar obtained from fique bagasse as a sustainable alternative for the waste derived from the production of the cabuya.

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