New heteroscorpionate ligands with hydrogen bond donor and acceptor groups: synthesis, characterization and reactivity with divalent Co, Zn and Ni ions

Polyhedron ◽  
2004 ◽  
Vol 23 (2-3) ◽  
pp. 239-244 ◽  
Author(s):  
Zahida Shirin ◽  
Carl J. Carrano
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bond Donor ◽  
Donor And Acceptor

scholarly journals Machine learning models for hydrogen bond donor and acceptor strengths using large and diverse training data generated by first-principles interaction free energies

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Christoph A. Bauer ◽  
Gisbert Schneider ◽  
Andreas H. Göller
Keyword(s):  
Machine Learning ◽  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Training Data ◽  
Free Energies ◽  
Hydrogen Bond Donor ◽  
Chemical Application ◽  
Hydrogen Bond Acceptor ◽  
Donor And Acceptor ◽  
Target Values

Abstract We present machine learning (ML) models for hydrogen bond acceptor (HBA) and hydrogen bond donor (HBD) strengths. Quantum chemical (QC) free energies in solution for 1:1 hydrogen-bonded complex formation to the reference molecules 4-fluorophenol and acetone serve as our target values. Our acceptor and donor databases are the largest on record with 4426 and 1036 data points, respectively. After scanning over radial atomic descriptors and ML methods, our final trained HBA and HBD ML models achieve RMSEs of 3.8 kJ mol−1 (acceptors), and 2.3 kJ mol−1 (donors) on experimental test sets, respectively. This performance is comparable with previous models that are trained on experimental hydrogen bonding free energies, indicating that molecular QC data can serve as substitute for experiment. The potential ramifications thereof could lead to a full replacement of wetlab chemistry for HBA/HBD strength determination by QC. As a possible chemical application of our ML models, we highlight our predicted HBA and HBD strengths as possible descriptors in two case studies on trends in intramolecular hydrogen bonding.

The hydrogen bond donor and acceptor ability of thioformic acid

2011 ◽  
Vol 22 (5) ◽  
pp. 1015-1030 ◽  
Author(s):  
Damanjit Kaur ◽  
Ritika Sharma ◽  
Darpandeep Aulakh
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bond Donor ◽  
Donor And Acceptor

Synthesis and preliminary bioactivity evaluation of new pregnane brassinosteroid-like compounds

2005 ◽  
Vol 83 (8) ◽  
pp. 1084-1092 ◽  
Author(s):  
Daniel G Rivera ◽  
Francisco Coll
Keyword(s):  
Hydrogen Bond ◽  
Plant Growth ◽  
Hypocotyl Elongation ◽  
Hydrogen Bond Donor ◽  
Donor And Acceptor ◽  
Plant Growth Promoting ◽  
Plant Growth Promoting Activity ◽  
Growth Promoting ◽  
Cotyledon Expansion

Seven new pregnane compounds bearing some representative A- and B-ring brassinosteroid functions, as well as hydrogen bond donor and acceptor ones on the D ring, were efficiently synthesized. The obtained compounds did not show remarkable plant growth-promoting activity in the radish hypocotyl elongation and cotyledon expansion bioassays, however, introducing oxygen and amino functions on the D ring led to an enhancement of the bioactivity. The 16β-functionalized pregnane brassinosteroid-like compounds were slightly more active than the 16α-functionalized ones.Key words: steroids, brassinosteroids, pregnane analogues.

C–H⋯S interaction exhibits all the characteristics of conventional hydrogen bonds

2020 ◽  
Vol 22 (31) ◽  
pp. 17482-17493 ◽  
Author(s):  
Sanat Ghosh ◽  
Pragya Chopra ◽  
Sanjay Wategaonkar
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Hydrogen Bond Donor ◽  
Donor And Acceptor

This is a tale of a pair of a hydrogen bond donor and acceptor, namely the CH donor and sulphur acceptor, neither of which is a conventional hydrogen bond participant.

New polymorphs of an old drug: conformational and synthon polymorphism of 5-nitrofurazone

2016 ◽  
Vol 72 (2) ◽  
pp. 263-273 ◽  
Author(s):  
Dorota Pogoda ◽  
Jan Janczak ◽  
Veneta Videnova-Adrabinska
Keyword(s):  
Hydrogen Bond ◽  
Molecular Conformation ◽  
Crystal Packing ◽  
Molecular Organization ◽  
Hydrogen Bond Donor ◽  
Scanning Calorimetry ◽  
Geometrical Isomers ◽  
Crystal Forms ◽  
Donor And Acceptor ◽  
Polymorphic Forms

Two new polymorphic forms of 5-nitrofurazone (5-nitro-2-furaldehyde semicarbazone) have been synthesized and structurally characterized by single-crystal and powder X-ray diffraction methods, vibrational spectroscopy (FT–IR and temperature Raman), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and Hirshfeld surface analysis. The compound crystallizes in three different polymorphic formsP21/a(polymorph α),P21(polymorph β) andP21/c(polymorph γ), the crystal structures of two of which (polymorphs β and γ) represent new structure determinations. The solid-state molecular organization in the three crystal forms is analyzed and discussed in terms of molecular conformation, crystal packing and hydrogen-bonded networks. All three crystals are formed fromtransgeometrical isomers, but the molecular conformation of the α-polymorph issyn–anti–anti–anti, while that of β- and γ-polymorphs issyn–anti–syn–syn. As a consequence of this the hydrogen-bond donor and acceptor sites of the molecules are oriented differently, which in turn results in different hydrogen-bond connectivity and packing patterns.

Hydrogen-bonded liquid crystals. Novel mesogens incorporating nonmesogenic bipyridyl compounds through complexation between hydrogen-bond donor and acceptor moieties

1993 ◽  
Vol 5 (8) ◽  
pp. 1094-1100 ◽  
Author(s):  
Takashi Kato ◽  
Jean M. J. Frechet ◽  
Paul G. Wilson ◽  
Takeshi Saito ◽  
Toshiyuki Uryu ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Liquid Crystals ◽  
Hydrogen Bond Donor ◽  
Donor And Acceptor ◽  
Hydrogen Bonded

ChemInform Abstract: New Hydrogen Bond Donor and Acceptor Groups in Organometallic Solids

ChemInform ◽  
2000 ◽  
Vol 31 (39) ◽  
pp. no-no
Author(s):  
Dario Braga ◽  
Fabrizia Grepioni ◽  
Emilio Tedesco
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bond Donor ◽  
Donor And Acceptor
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