How Strong is Hydrogen Bonding to Amide Nitrogen?

ChemPhysChem ◽  
2020 ◽  
Vol 21 (7) ◽  
pp. 651-658
Author(s):  
Vladimir Y. Mikshiev ◽  
Alexander F. Pozharskii ◽  
Alexander Filarowski ◽  
Alexander S. Novikov ◽  
Alexander S. Antonov ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Amide Nitrogen

scholarly journals Crystal structure ofcatena-poly[bis(tetraethylammonium) [tetraaquatris(μ-dicyanamido-κ2N1:N5)bis(dicyanamido-κN1)dicobaltate(II)] dicyanamide]

2016 ◽  
Vol 72 (11) ◽  
pp. 1603-1606
Author(s):  
Chen Liu ◽  
Annaliese E. Thuijs ◽  
Khalil A. Abboud
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Coordination Polymer ◽  
Title Compound ◽  
Three Dimensional ◽  
Framework Structure ◽  
Amide Nitrogen ◽  
Covalently Linked

The structure of the title compound, [N(C2H5)4]2[Co2(C2N3)5(H2O)4](C2N3), is a new example of a metal–dicyanamide coordination polymer which exhibits a unique three-dimensional framework of covalently linked CoIIchains. All bridging dicyanamide ligands in the title structure are in theμ1,5-bridging mode. The anionic CoII-dicyanamide network is templated by tetraethylammonium cations residing in a series of channels extending along thebaxis where additional non-coordinating dicyanamidate anions are also located. The framework structure is further stabilized by O—H...N hydrogen bonding between aqua ligands and dicyanamido ligands or the dicyanamide anion. In addition, C—H...N interactions are present between the tetraethylammonium cations and dicyanamide amide nitrogen atoms.

The Distal Effect of N-Electron-withdrawing Groups on the Stability of Peptide Carbon Radicals

2011 ◽  
Vol 64 (4) ◽  
pp. 403 ◽  
Author(s):  
Junming Ho ◽  
Michelle L. Coote ◽  
Christopher J. Easton
Keyword(s):  
Hydrogen Bonding ◽  
Ab Initio ◽  
Radical Formation ◽  
Ab Initio Methods ◽  
Amide Nitrogen ◽  
Amide Carbonyl ◽  
Carbon Radicals ◽  
The Stability ◽  
High Level ◽  
Calculated Activation

The effect of electron-withdrawing substituents, hydrogen bonding and protonation at amide nitrogen on the stability of radicals formed by loss of either a distal C–H adjacent to the amide carbonyl or one proximal to the amide nitrogen for a series of acetamides and diketopiperazines has been studied via high-level ab initio methods. These studies show that the effect is to destabilize the radicals formed by abstraction of the proximal hydrogens, typically by 10–20 kJ mol–1, and stabilize the distal radicals typically by 5–10 kJ mol–1, but only if the distal radicals are polarized by another dative substituent. The different radical stabilities are not directly mirrored in calculated activation energies or experimental rates of radical formation in bromination reactions, because there is significant charge development in these reaction transition states.

Hydrogen bonding in liquid methanol at ambient conditions and at high pressure

2000 ◽  
Vol 98 (3) ◽  
pp. 125-134 ◽  
Author(s):  
T. Weitkamp, J. Neuefeind, H. E. Fisch
Keyword(s):  
High Pressure ◽  
Hydrogen Bonding ◽  
Ambient Conditions

Fluorescence and pi-hydrogen bonding in naphthols

1968 ◽  
Vol 65 ◽  
pp. 1587-1589 ◽  
Author(s):  
Bithika Ghosh ◽  
Sadhan Basu
Keyword(s):  
Hydrogen Bonding

Theoretical study of intramolecular hydrogen bonding and molecular geometry of 2-trifluoromethylphenol

10.1002/jcc.2 ◽  
1996 ◽  
Vol 17 (16) ◽  
pp. 1804-1819 ◽  
Author(s):  
Attila Kov�cs ◽  
Istv�n Kolossv�ry ◽  
G�bor I. Csonka ◽  
Istv�n Hargittai
Keyword(s):  
Hydrogen Bonding ◽  
Theoretical Study ◽  
Molecular Geometry ◽  
Intramolecular Hydrogen Bonding ◽  
Intramolecular Hydrogen

PEMANFAATAN GLISERIN DARI RESIDU GLISERIN SEBAGAI PLASTICIZER UNTUK PEMBUATAN BIOPLASTIK DENGAN BAHAN BAKU PATI BONGGOL PISANG KEPOK

2017 ◽  
Vol 5 (4) ◽  
pp. 26-32 ◽  
Author(s):  
Azaria Robiana ◽  
M. Yashin Nahar ◽  
Hamidah Harahap
Keyword(s):  
Tensile Strength ◽  
Hydrogen Bonding ◽  
Fatty Acid ◽  
Maximum Yield ◽  
Sem Analysis ◽  
Water Molecules ◽  
Banana Weevil ◽  
Gelatinization Temperature ◽  
Recharge Area ◽  
Maximum Quantity

Glycerin residue is waste oleochemical industry that still contain glycerin. To produce quality and maximum quantity of glycerin, then research the effect of pH acidification using phosphoric acid. Glycerin analysis includes the analysis of pH, Fatty Acid and Ester (FAE), and analysis of the levels of glycerin. The maximum yield obtained at pH acidification 2 is grading 91,60% glycerin and Fatty Acid and Ester (FAE) 3,63 meq/100 g. Glycerin obtained is used as a plasticizer in the manufacture of bioplastics. Manufacture of bioplastics using the method of pouring a solution with varying concentrations of starch banana weevil (5% w/v and 7% w/v), variations of the addition of glycerin (1 ml, 3 ml, 5 ml and 7 ml), and a variety of gelatinization temperature (60°C, 70°C, and 80°C). Analysis of bioplastics include FTIR testing, tensile strength that is supported by SEM analysis. The results obtained in the analysis of FTIR does not form a new cluster on bioplastics starch banana weevil, but only a shift in the recharge area only, it is due to the addition of O-H groups originating from water molecules that enter the polysaccharide through a mechanism gelatinitation that generates interaction hydrogen bonding strengthened. The maximum tensile strength of bioplastics produced at a concentration of starch 7% w/v, 1 ml glycerine and gelatinization temperature of 80°C is 3,430 MPa. While the tensile strength bioplastic decreased with increasing glycerin which can be shown from the results of SEM where there is a crack, indentations and lumps of starch insoluble.

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