Turning ON/OFF the fluorescence of the ESIPT state by changing the hydrogen bond distance and orientation in quinoline–pyrazole derivatives

2021 ◽  
pp. 132146
Author(s):  
Hui Li ◽  
Hongyan Mu ◽  
Chao Xin ◽  
Jixing Cai ◽  
Boshi Yuan ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Bond Distance ◽  
Pyrazole Derivatives ◽  
Hydrogen Bond Distance

Manganese-Hydrogen Bond Distance in HMn(CO)5

1966 ◽  
Vol 88 (1) ◽  
pp. 184-185 ◽  
Author(s):  
Thomas C. Farrar ◽  
W. Ryan ◽  
Alan Davison ◽  
J. W. Faller
Keyword(s):  
Hydrogen Bond ◽  
Bond Distance ◽  
Hydrogen Bond Distance

Competition of hydrogen-bond acceptors for the strong carboxyl donor

2001 ◽  
Vol 57 (1) ◽  
pp. 103-106 ◽  
Author(s):  
Thomas Steiner
Keyword(s):  
Hydrogen Bond ◽  
Bond Distance ◽  
Database Study ◽  
Relative Success ◽  
Hydrogen Bond Distance

A database study on the competition of hydrogen-bond acceptors for the strong carboxyl donor in crystals is reported. The relative success in attracting this donor is determined for 34 types of acceptor (O, N, S, halogen and π acceptors), and a correlation between the success in competition and the average hydrogen-bond distance is established.

Tin‐Hydrogen Bond Distance

1956 ◽  
Vol 25 (4) ◽  
pp. 784-784 ◽  
Author(s):  
George R. Wilkinson ◽  
M. Kent Wilson
Keyword(s):  
Hydrogen Bond ◽  
Bond Distance ◽  
Hydrogen Bond Distance

Infrared studies of water in crystalline hydrates: K2HgCl4.H2O

1977 ◽  
Vol 55 (10) ◽  
pp. 1736-1744 ◽  
Author(s):  
Michael Falk ◽  
Osvald Knop
Keyword(s):  
Hydrogen Bond ◽  
Neutron Diffraction ◽  
Bond Distance ◽  
Single Type ◽  
Water Molecules ◽  
Dynamic Coupling ◽  
X Ray ◽  
Hydrogen Bond Distance ◽  
Infrared Studies ◽  
Crystalline Hydrates

Infrared spectra of polycrystalline K2HgCl4.H2O at different degrees of deuteration were recorded, in the 4000–250 cm−1 region, at temperatures between liquid-nitrogen and 130 °C. The spectra confirm the existence of a single type of water molecule, engaged in two equivalent hydrogen bonds. The value of 2548 cm−1 for the isolated O—D stretching frequency leads to an estimate of 3.25(3) Å for the O … Cl hydrogen-bond distance, in excellent agreement with the results of X-ray and neutron diffraction. Dynamic coupling is appreciable for stretch, bend, and librational fundamentals but is weaker than in CuCl2.2H2O or K2CuCl4.2H2O, in which the water molecules in the crystal are more tightly bonded.A number of corrected values are reported of isolated O—D stretching frequencies in hydrates studied previously.

Supramolecular structure of 1H-pyrazoles in the solid state: a crystallographic and ab initio study

2000 ◽  
Vol 56 (6) ◽  
pp. 1018-1028 ◽  
Author(s):  
Concepción Foces-Foces ◽  
Ibon Alkorta ◽  
José Elguero
Keyword(s):  
Hydrogen Bond ◽  
Solid State ◽  
Secondary Structure ◽  
Ab Initio ◽  
Relative Stability ◽  
Quaternary Structure ◽  
Quantitative Model ◽  
Pyrazole Derivatives ◽  
Donor Group ◽  
Ab Initio Study

The secondary structure of 1H-unsubstituted pyrazole derivatives bearing only one hydrogen donor group and one or more acceptor groups has been analyzed in terms of some descriptors representing the substituents at C3 and C5. The substituent at C4 appears to affect mainly the tertiary or quaternary structure of these compounds. The proposed semi-quantitative model, which explains most hydrogen-bonded motifs as a combination of the effects of substituents at C3 and C5, has also been examined as a function of the steric and polarizability effects of these substituents represented by molar refractivity. The model also applies to other five-membered rings (1,2,4-triazoles, 1,2,4-diazaphospholes and 1,2,4-diazaarsoles). Furthermore, ab initio calculations at RHF/6-31G* have been performed to discover the relative stability of three of the four hydrogen-bond patterns displayed by several symmetrical pyrazoles (dimers, trimers, tetramers). The fourth motif, catemers, has only been discussed geometrically.

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