Participation of S and Se in hydrogen and chalcogen bonds

CrystEngComm ◽  
2021 ◽  
Vol 23 (39) ◽  
pp. 6821-6837
Author(s):  
Steve Scheiner
Keyword(s):  
Electron Acceptor ◽  
Noncovalent Interactions ◽  
Proton Donor ◽  
Chalcogen Bond ◽  
Donor And Acceptor

The heavier chalcogen atoms S, Se, and Te can each participate in a range of different noncovalent interactions. They can serve as both proton donor and acceptor in H-bonds. Each atom can also act as electron acceptor in a chalcogen bond.

Theoretical study on the torsional potential of alkyl, donor, and acceptor substituted bithiophene: the hidden role of noncovalent interaction and backbone conjugation

2015 ◽  
Vol 17 (6) ◽  
pp. 4127-4136 ◽  
Author(s):  
Tzu-Jen Lin ◽  
Shiang-Tai Lin
Keyword(s):  
Theoretical Study ◽  
Noncovalent Interactions ◽  
Noncovalent Interaction ◽  
Steric Repulsion ◽  
Torsional Potential ◽  
Donor And Acceptor

The torsional potential of substituted bithiophene is influenced not only by steric repulsion, but also by backbone conjugation and noncovalent interactions.

'Breaking' and formation of hydrogen bonds by proton donor anesthetics

1977 ◽  
Vol 55 (18) ◽  
pp. 3211-3217 ◽  
Author(s):  
Rachel Massuda ◽  
C. Sandorfy
Keyword(s):  
Hydrogen Atom ◽  
Hydrogen Bonds ◽  
Electron Acceptor ◽  
Proton Donor ◽  
Point Of View ◽  
Mobile Hydrogen ◽  
Competitive Mechanism ◽  
Text Types ◽  
Anesthetic Potency ◽  
Mobile Hydrogen Atom

It has been shown previously that halofluorocarbons having anesthetic potency hinder the formation of hydrogen bonds (HB) of the [Formula: see text] types and it has been suggested that this is linked to a competitive mechanism involving another type of association. Since some of the most potent and widely used fluorocarbon anesthetics contain a mobile hydrogen atom the question arises if in such molecules the competitive mechanism involves the formation of HB's with the anesthetic as the proton donor instead of, or in addition to, association due to the electron acceptor properties of the higher halogens as seems to be the case for those fluorocarbon anesthetics which contain no hydrogen. Chloroform, halothane, methoxyflurane, enflurane, and 4,5-dichloro-2,2-difluoro-l,3-dioxolane have been studied from this point of view with the result that both mechanisms appear to operate.

Electrical properties of crystal compounds of graphite - III. The role of electron donors

1960 ◽  
Vol 258 (1294) ◽  
pp. 339-349 ◽  
Keyword(s):  
Alkali Metal ◽  
Thermoelectric Power ◽  
Electron Donor ◽  
Electron Acceptor ◽  
Electrical Resistance ◽  
Pyrolytic Graphite ◽  
Electron Donors ◽  
Aluminium Chloride ◽  
Metal Atoms ◽  
Donor And Acceptor

Crystal compounds between potassium and well-oriented pyrolytic graphite have been prepared with a range of compositions up to saturation. Measurements have been made of changes of electrical resistance and of thermoelectric power as a function of composition in both a - and c -axis directions. Anisotropy of electrical resistance becomes smaller, and of thermoelectric power sinks to practically zero, on compound formation. Compounds between graphite and rubidium or caesium have been studied more briefly under conditions approximating to saturation. In the direction of the a -axis, the large decreases of electrical resistance observed can be interpreted on the basis that the alkali metal atoms inject electrons into the upper π -band of graphite. This is confirmed by the observed changes of thermoelectric power. Changes resemble but do not completely mirror those observed with electron acceptor compounds; the fractional transfer of electrons appears to be less complete with the electron donors. In the direction of the c -axis, intercalation of the electron donor alkali metal atoms leads to a much more striking decrease of electrical resistance than is observed with various electron acceptor groups. To supplement results previously published, brief studies are reported on crystal compounds between graphite and aluminium chloride, and graphite and iodine monochloride. Possible band models for graphite compounds with both electron donor and acceptor atoms are discussed in the light of the experimental findings.

Catalytic Activation of a Carbon–Chloride Bond by Dicationic Tellurium-Based Chalcogen Bond Donors

Synthesis ◽  
2021 ◽  
Author(s):  
Stefan M. Huber ◽  
Tim Steinke ◽  
Patrick Wonner ◽  
Elric Engelage
Keyword(s):  
Noncovalent Interactions ◽  
Halogen Bonding ◽  
Side Reaction ◽  
Catalyst Stability ◽  
Strong Activity ◽  
Chalcogen Bond ◽  
Catalytic Activation ◽  
Minor Activity

AbstractNoncovalent interactions such as halogen bonding (XB) and chalcogen bonding (ChB) have gained increased interest over the last decade. Whereas XB-based organocatalysis has been studied in some detail by now, intermolecular ChB catalysis only emerged quite recently. Herein, bidentate cationic tellurium-based chalcogen bond donors are employed in the catalytic chloride abstraction of 1-chloroisochroman. While selenium-based ChB catalysts showed only minor activity in this given benchmark reaction, tellurium-based variants exhibited strong activity, with rate accelerations of up to 40 relative to non-chalogenated reference compounds. In general, the activity of the catalysts improved with weaker coordinating counterions, but tetrafluoroborate took part in a fluoride transfer side reaction. Catalyst stability was confirmed via a fluoro-tagged variant.

scholarly journals Comparison of Energy and Growth Yields forDesulfitobacterium dehalogenans during Utilization of Chlorophenol and Various Traditional Electron Acceptors

1998 ◽  
Vol 64 (1) ◽  
pp. 352-355 ◽  
Author(s):  
M. Mackiewicz ◽  
J. Wiegel
Keyword(s):  
Electron Donor ◽  
Electron Acceptor ◽  
Reductive Dechlorination ◽  
Dry Weight ◽  
Electron Acceptors ◽  
Growth Yields ◽  
Donor And Acceptor ◽  
Electron Donor And Acceptor

ABSTRACT Desulfitobacterium dehalogenans grew with formate as the electron donor and 3-chloro-4-hydroxyphenylacetate (3-Cl-4-OHPA) as the electron acceptor, yielding Y X/formate,Y X/2e− , andY X/ATP ranging from 3.2 to 11.3 g of biomass (dry weight)/mol, thus indicating that energy was conserved through reductive dechlorination. Pyruvate was utilized as the electron donor and acceptor, yielding stoichiometric amounts of acetate and lactate, respectively, and a Y X/reduced acceptor of 13.0 g of biomass (dry weight)/mol. The supplementation of pyruvate-containing medium with additional electron acceptors, such as 3-Cl-4-OHPA, nitrate, fumarate, or sulfite, caused pyruvate to be replaced as the electron acceptor and nearly doubled theY X/ATP (Y X/acetate formed). A comparison of the yields for 3-Cl-4-OHPA with those for other traditional electron acceptors indicates that the dehalogenation reaction led to the formation of similar amounts of energy equivalents. The various electron acceptors were used concomitantly with 3-Cl-4-OHPA in nonacclimated cultures, but the utilization rates and amounts utilized differed.

scholarly journals Rotational Spectroscopy Meets Quantum Chemistry for Analyzing Substituent Effects on Non-Covalent Interactions: The Case of the Trifluoroacetophenone-Water Complex

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 4899
Author(s):  
Juncheng Lei ◽  
Silvia Alessandrini ◽  
Junhua Chen ◽  
Yang Zheng ◽  
Lorenzo Spada ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Substituent Effects ◽  
Equilibrium Structure ◽  
Proton Donor ◽  
Rotational Spectroscopy ◽  
Donor And Acceptor ◽  
Analogous Complex ◽  
Non Covalent Interactions ◽  
Covalent Interactions

The most stable isomer of the 1:1 complex formed by 2,2,2-trifluoroacetophenone and water has been characterized by combining rotational spectroscopy in supersonic expansion and state-of-the-art quantum-chemical computations. In the observed isomer, water plays the double role of proton donor and acceptor, thus forming a seven-membered ring with 2,2,2-trifluoroacetophenone. Accurate intermolecular parameters featuring one classical O-H···O hydrogen bond and one weak C-H···O hydrogen bond have been determined by means of a semi-experimental approach for equilibrium structure. Furthermore, insights on the nature of the established non-covalent interactions have been unveiled by means of different bond analyses. The comparison with the analogous complex formed by acetophenone with water points out the remarkable role played by fluorine atoms in tuning non-covalent interactions.

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