Theoretical investigation of intermolecular hydrogen bond induces fluorescence quenching phenomenon for Coumarin-1

2020 ◽  
Vol 221 ◽  
pp. 117110 ◽  
Author(s):  
You Li ◽  
Chaofan Sun ◽  
Jianhui Han ◽  
Qiao Zhou ◽  
Bifa Cao ◽  
...  
2021 ◽  
Author(s):  
Shu bin Li ◽  
Xiao Wang ◽  
Jiang Zhu ◽  
Zhenyu Wang ◽  
Lu Wang

In this work, using carboxyl-modified Fe3O4 nanoparticles as a photothermal agent, combining the chemical amide bond and intermolecular hydrogen bond crosslinking force, a photothermal hydrogel with enhanced mechanical properties was...


1985 ◽  
Vol 63 (11) ◽  
pp. 2915-2921 ◽  
Author(s):  
Ian M. Piper ◽  
David B. MacLean ◽  
Romolo Faggiani ◽  
Colin J. L. Lock ◽  
Walter A. Szarek

The products of a Pictet–Spengler condensation of tryptamine and of histamine with 2,5-anhydro-D-mannose have been studied by X-ray crystallography to establish their absolute configuration. 1(S)-(α-D-Arabinofuranosyl)-1,2,3,4-tetrahydro-β-carboline (1), C16H20N20O4, is monoclinic, P21 (No. 4), with cell dimensions a = 13.091(4), b = 5.365(1), c = 11.323(3) Å, β = 115.78(2)°, and Z = 2. 4-(α-D-Arabinofuranosyl)imidazo[4,5-c]-4,5,6,7-tetrahydropyridine (3), C11H17N3O4, is orthorhombic, P212121 (No. 19), with cell dimensions a = 8.118(2), b = 13.715(4), c = 10.963(3) Å, and Z = 4. The structures were determined by direct methods and refined to R1 = 0.0514, R2 = 0.0642 for 3210 reflections in the case of 1, and to R1 = 0.0312, R2 = 0.0335 for 1569 reflections in the case of 3. Bond lengths and angles within both molecules are normal and agree well with those observed in related structures. In 3 the base and sugar adopt a syn arrangement, which is maintained by an internal hydrogen bond between O(2′) and N(3). The sugar adopts a normal 2T3 twist conformation. The sugar has the opposite anti arrangement in the β-carboline 1 and the conformation of the sugar is unusual; it is close to an envelope conformation with O(4′) being the atom out of the plane. This conformation is caused by a strong intermolecular hydrogen bond from O(5′) in a symmetry-related molecule to O(4′). Both compounds are held together in the crystal by extensive hydrogen-bonding networks. The conformations of the compounds in solution have been investigated by 1H nmr spectroscopy, and the results obtained were compared with those obtained by X-ray crystallography for 1 and 3.


2021 ◽  
Author(s):  
Huamei Chen ◽  
Guangyuan Feng ◽  
Qiu Liang ◽  
Enbing Zhang ◽  
Yongtao Shen ◽  
...  

Herein, we illustrate how the cooperation of intermolecular hydrogen bonds and conformation flexibility leads to the formation of diverse complex covalent nanostructures on the surface, while the relative abundance of...


2017 ◽  
Vol 46 (15) ◽  
pp. 4960-4967 ◽  
Author(s):  
Ferdinand Groenewald ◽  
Helgard G. Raubenheimer ◽  
Jan Dillen ◽  
Catharine Esterhuysen

MP2/aug-cc-pVTZ-pp calculations show that the Au(i) atom of dimethylaurate behaves as a hydrogen-bond acceptor to a range of hydrogen-bond donors.


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