scholarly journals Preferential N–H⋯:C hydrogen bonding involving ditopic NH-containing systems and N-heterocyclic carbenes

RSC Advances ◽  
2020 ◽  
Vol 10 (69) ◽  
pp. 42164-42171
Author(s):  
Zacharias J. Kinney ◽  
Arnold L. Rheingold ◽  
John D. Protasiewicz
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Heterocyclic Carbenes ◽  
Secondary Amines ◽  
Solution State

Non-traditional hydrogen bonds between a singlet carbene and a series of ditopic secondary amines is detailed. Both the solid- and solution-state metrics reveal the strength of these associations are dependent on the pKa of the NH-containing molecule.

Gold(I) Complexes of Open-chain and Cyclic Di-secondary Amines

1997 ◽  
Vol 52 (2) ◽  
pp. 209-213 ◽  
Author(s):  
José M. López-de-Luzuriaga ◽  
Marcus Söldner ◽  
Annette Schier ◽  
Hubert Schmidbaur
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Atom ◽  
Hydrogen Bonds ◽  
Chair Conformation ◽  
Secondary Amines ◽  
Binuclear Complexes ◽  
Open Chain ◽  
Piperazine Ring ◽  
Ethylene Bridge ◽  
Solvent Molecules

Abstract Treatment of N,N′-diisopropyl-ethylenediamine or 1,4-piperazine with two equivalents of [(Ph3P)Au]+ BF4- leads to binuclear complexes of the diamines: {[(Ph3P)Au]HN(iPro)NCH2-}22+ 2 BF4- (1) and {[(Ph3P)Au]HNCH2CH2}22+ 2 BF4- (2), respectively. In the products each quaternary ammonium center bears one gold ligand, one hydrogen atom and two alkyl substituents. The crystal structures of both compounds have been determined. Compound 1 contains discrete ion-triples. The ethylene bridge in the dications is in an unfolded conformation, with a crystallographic center of inversion, and allows for weak hydrogen bonding N-H--F [2.085 Å; N-H--F 169.2°] between the NH functions and the counterions. The existing distant contacts F--Au [3.599 Å] are probably less significant for the aggregation of the ion triples, but will contribute through Coulomb forces. Compound 2 crystallizes with two solvent molecules CH2CI2. The dication has a crystallographic center of inversion with the piperazine ring in a chair conformation and the gold atoms in equatorial positions. There are hydrogen bonds N-H--F [2.076 and 2.457 Å] between the dication and the anions which lead to the formation of ion-triples, with further contacts between the BF4- anions and the solvent molecules [C-H--F 2.340 and 2.446 Å].

Unveiling the peculiar hydrogen bonding behavior of solvated N-heterocyclic carbenes

2016 ◽  
Vol 18 (1) ◽  
pp. 126-140 ◽  
Author(s):  
Oldamur Hollóczki
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Force Field ◽  
Practical Importance ◽  
Md Simulations ◽  
Heterocyclic Carbenes ◽  
Mechanical Force

After fitting a molecular mechanical force field for imidazol-2-ylidenes, MD simulations revealed carbene–carbene and three-center hydrogen bonds of carbenes. The practical importance of these structures is also highlighted.

scholarly journals Hydrogen Bonds: Raman Spectroscopic Study

2021 ◽  
Vol 22 (10) ◽  
pp. 5380
Author(s):  
Boris A. Kolesov
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Spectroscopic Study ◽  
Raman Spectra ◽  
Temperature Region ◽  
Vibrational Frequency ◽  
Chemical Compounds ◽  
Raman Spectroscopic ◽  
Raman Spectroscopic Study ◽  
Proton Dynamics

The work outlines general ideas on how the frequency and the intensity of proton vibrations of X–H×××Y hydrogen bonding are formed as the bond evolves from weak to maximally strong bonding. For this purpose, the Raman spectra of different chemical compounds with moderate, strong, and extremely strong hydrogen bonds were obtained in the temperature region of 5 K–300 K. The dependence of the proton vibrational frequency is schematically presented as a function of the rigidity of O-H×××O bonding. The problems of proton dynamics on tautomeric O–H···O bonds are considered. A brief description of the N–H···O and C–H···Y hydrogen bonds is given.

N-Heterocyclic Carbenes and Parent Cations: Acidity, Nucleophilicity, Stability, and Hydrogen Bonding-Electrochemical Study and Ab Initio Calculations

2016 ◽  
Vol 3 (7) ◽  
pp. 1133-1141 ◽  
Author(s):  
Marta Feroci ◽  
Isabella Chiarotto ◽  
Francesca D'Anna ◽  
Fabrizio Gala ◽  
Renato Noto ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Heterocyclic Carbenes ◽  
Electrochemical Study

2-Hydroxy-3-methoxybenzaldehyde (pyridinium-4-ylcarbonyl)hydrazone chloride hemihydrate

2006 ◽  
Vol 62 (5) ◽  
pp. o2043-o2044 ◽  
Author(s):  
Shao-Wen Chen ◽  
Han-Dong Yin ◽  
Da-Qi Wang ◽  
Xia Kong ◽  
Xiao-Fang Chen
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Compound C

The crystal structure of the title compound, C14H14ClN3O3 +·Cl−·0.5H2O, exhibits O—H...O, C—H...O, C—H...Cl, N—H...Cl and O—H...Cl hydrogen bonds. The chloride anions participate in extensive hydrogen bonding with the aminium cations and link molecules through multiple N—H+...Cl− interactions.

Five pseudopolymorphs of 6-amino-2-thiouracil: absence of N—H...S hydrogen bonds

2012 ◽  
Vol 69 (1) ◽  
pp. 93-100 ◽  
Author(s):  
Wilhelm Maximilian Hützler ◽  
Michael Bolte
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Cambridge Structural Database ◽  
Hydrogen Bonding Pattern ◽  
Crystallization Experiments ◽  
Structural Database ◽  
Thiouracil Derivatives

In order to study the preferred hydrogen-bonding pattern of 6-amino-2-thiouracil, C4H5N3OS, (I), crystallization experiments yielded five different pseudopolymorphs of (I), namely the dimethylformamide disolvate, C4H5N3OS·2C3H7NO, (Ia), the dimethylacetamide monosolvate, C4H5N3OS·C4H9NO, (Ib), the dimethylacetamide sesquisolvate, C4H5N3OS·1.5C4H9NO, (Ic), and two different 1-methylpyrrolidin-2-one sesquisolvates, C4H5N3OS·1.5C5H9NO, (Id) and (Ie). All structures containR21(6) N—H...O hydrogen-bond motifs. In the latter four structures, additionalR22(8) N—H...O hydrogen-bond motifs are present stabilizing homodimers of (I). No type of hydrogen bond other than N—H...O is observed. According to a search of the Cambridge Structural Database, most 2-thiouracil derivatives form homodimers stabilized by anR22(8) hydrogen-bonding pattern, with (i) only N—H...O, (ii) only N—H...S or (iii) alternating pairs of N—H...O and N—H...S hydrogen bonds.

scholarly journals Two New Polyiodides in the 4,4´-Bipyridinium Diiodide/Iodine System

2012 ◽  
Vol 67 (1) ◽  
pp. 5-10
Author(s):  
Guido J. Reiss ◽  
Martin van Megen
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Complex I ◽  
The Other ◽  
Cyclic Dimer ◽  
Water Molecules ◽  
Spectroscopic Methods ◽  
Halogen Bonds ◽  
One Dimensional ◽  
Hydroiodic Acid

The reaction of bipyridine with hydroiodic acid in the presence of iodine gave two new polyiodide-containing salts best described as 4,4´-bipyridinium bis(triiodide), C10H10N2[I3]2, 1, and bis(4,4´-bipyridinium) diiodide bis(triiodide) tris(diiodine) solvate dihydrate, (C10H10N2)2I2[I3]2 · 3 I2 ·2H2O, 2. Both compounds have been structurally characterized by crystallographic and spectroscopic methods (Raman and IR). Compound 1 is composed of I3 − anions forming one-dimensional polymers connected by interionic halogen bonds. These chains run along [101] with one crystallographically independent triiodide anion aligned and the other triiodide anion perpendicular to the chain direction. There are no classical hydrogen bonds present in 1. The structure of 2 consists of a complex I144− anion, 4,4´-bipyridinium dications and hydrogen-bonded water molecules in the ratio of 1 : 2 : 2. The I144− polyiodide anion is best described as an adduct of two iodide and two triiodide anions and three diiodine molecules. Two 4,4´-bipyridinium cations and two water molecules form a cyclic dimer through N-H· · ·O hydrogen bonds. Only weak hydrogen bonding is found between these cyclic dimers and the polyiodide anions.

scholarly journals Bis(3-carbamoylpyridin-1-ium) phosphite monohydrate

2018 ◽  
Vol 74 (9) ◽  
pp. 1295-1298
Author(s):  
Jan Fábry
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Water Molecule ◽  
Secondary Amine ◽  
Symmetry Plane ◽  
Structural Features ◽  
Water Molecules ◽  
Amine Groups

Two of the constituent molecules in the title structure, 2C6H7N2O+·HPO3 2−·H2O, i.e. the phosphite anion and the water molecule, are situated on a symmetry plane. The molecules are held together by moderate N—H...O and O—H...N, and weak O—H...O and C—H...Ocarbonyl hydrogen bonds in which the amide and secondary amine groups, and the water molecules are involved. The structural features are usual, among them the H atom bonded to the P atom avoids hydrogen bonding.

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