Newrac-XP(O)(OC6H5)(NHC6H4-p-CH3) [X= N(CH3)(cyclo-C6H11) and NH(C3H5)] andrac-(C6H5CH2NH)P(O)(OC6H5)(NH-cyclo-C6H11) mixed-amide phosphinates

2013 ◽  
Vol 69 (10) ◽  
pp. 1181-1185 ◽  
Author(s):  
Mehrdad Pourayoubi ◽  
Fatemeh Karimi Ahmadabad ◽  
Hossein Eshtiagh-Hosseini ◽  
Monika Kučeráková ◽  
Václav Eigner ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Bond Lengths ◽  
Hydrogen Bonding Interactions ◽  
Chlorine Compound ◽  
First Time

The mixed-amide phosphinates,rac-phenyl (N-methylcyclohexylamido)(p-tolylamido)phosphinate, C20H27N2O2P, (I), andrac-phenyl (allylamido)(p-tolylamido)phosphinate, C16H19N2O2P, (II), were synthesized from the racemic phosphorus–chlorine compound (R,S)-(Cl)P(O)(OC6H5)(NHC6H4-p-CH3). Furthermore, the phosphorus–chlorine compound ClP(O)(OC6H5)(NH-cyclo-C6H11) was synthesized for the first time and used for the synthesis ofrac-phenyl (benzylamido)(cyclohexylamido)phosphinate, C19H25N2O2P, (III). The strategies for the synthesis of racemic mixed-amide phosphinates are discussed. The P atom in each compound is in a distorted tetrahedral (N1)P(=O)(O)(N2) environment. In (I) and (II), thep-tolylamido substituent makes a longer P—N bond than those involving theN-methylcyclohexylamido and allylamido substituents. In (III), the differences between the P—N bond lengths involving the cyclohexylamido and benzylamido substituents are not significant. In all three structures, the phosphoryl O atom takes part with the N—H unit in hydrogen-bonding interactions,viz.an N—H...O=P hydrogen bond for (I) and (N—H)(N—H)...O=P hydrogen bonds for (II) and (III), building linear arrangements along [001] for (I) and along [010] for (III), and a ladder arrangement along [100] for (II).

Correspondence: Hydrogen Bond to Gold? 1H NMR is Not a Proof of Hydrogen Bonds in Transition Metal Complexes

2018 ◽  
Author(s):  
Jan Vícha ◽  
Cina Foroutan-Nejad ◽  
Michal Straka
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Chemical Shifts ◽  
X Ray ◽  
Structure And Dynamics ◽  
Hydrogen Bonding Interactions ◽  
Overall Stability ◽  
Gold Compounds ◽  
C Nmr

Illusive Au<sup>I/III</sup>···H hydrogen bonds and their effect on structure and dynamics of molecules have been a matter of debate. While a number of X-ray studies reported gold compounds with short Au<sup>I/III</sup>···H contacts, a solid spectroscopic evidence for Au<sup>I/III</sup>···H bonding has been missing. Recently<a></a><a>, Bakar <i>et al.</i></a> (NATURE COMMUNICATIONS 8:576) reported compound with four short Au···H contacts (2.61­–2.66 Å; X-ray determined). Assuming the central cluster be [Au<sub>6</sub>]<sup>2+</sup>and observing the <sup>1</sup>H (<sup>13</sup>C) NMR resonances at relevant H(C) nuclei deshielded with respect to precursor compound, the authors concluded with reservations that <i>“the present Au···H–C interaction is a kind of “hydrogen bond”, where the [Au<sub>6</sub>]<sup>2+</sup>serves as an acceptor”</i>. Here, we show that the Au<sub>6</sub>cluster in their compound bears negative charge and the Au···H contacts lead to a weak (~1 kcal/mol) auride···hydrogen bonding interactions, though unimportant for the overall stability of<b></b>the molecule. Additionally, computational analysis of NMR chemical shifts reveals that the deshielding effects at respective hydrogen nuclei are not directly related to Au···H–C hydrogen bonding .

Study of Hydrogen Bonding in Carboxylic Acids by the MNDO/M Method

1994 ◽  
Vol 59 (6) ◽  
pp. 1251-1260 ◽  
Author(s):  
Michal Bureš ◽  
Jaroslav Bezus
Keyword(s):  
Experimental Data ◽  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Carboxylic Acids ◽  
Promising Method ◽  
Semiempirical Methods ◽  
Am1 Method ◽  
Bond Lengths ◽  
Pm3 Method

The semiempirical methods MNDO/M, AM1 and PM3 were applied to the study of hydrogen bonds in carboxylic acids. The calculated hydrogen bond lengths and enthalpies of dimerization were compared with experimental data. The AM1 method fails to properly describe systems with strong hydrogen bonds. The PM3 method predicts the hydrogen bond lengths correctly but underestimates systematically the enthalpies of dimerization. MNDO/M appears to be a promising method for the treatment of association of carboxylic acids.

Hydrogen bonding at C=Se acceptors in selenoureas, selenoamides and selones

2016 ◽  
Vol 72 (3) ◽  
pp. 317-325 ◽  
Author(s):  
Dikima Bibelayi ◽  
Albert S. Lundemba ◽  
Frank H. Allen ◽  
Peter T. A. Galek ◽  
Juliette Pradon ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Ab Initio ◽  
Crystal Engineering ◽  
Cambridge Structural Database ◽  
Bond Lengths ◽  
Partial Charges ◽  
Structural Database

In recent years there has been considerable interest in chalcogen and hydrogen bonding involving Se atoms, but a general understanding of their nature and behaviour has yet to emerge. In the present work, the hydrogen-bonding ability and nature of Se atoms in selenourea derivatives, selenoamides and selones has been explored using analysis of the Cambridge Structural Database andab initiocalculations. In the CSD there are 70 C=Se structures forming hydrogen bonds, all of them selenourea derivatives or selenoamides. Analysis of intramolecular geometries andab initiopartial charges show that this bonding stems from resonance-induced Cδ+=Seδ−dipoles, much like hydrogen bonding to C=S acceptors. C=Se acceptors are in many respects similar to C=S acceptors, with similar vdW-normalized hydrogen-bond lengths and calculated interaction strengths. The similarity between the C=S and C=Se acceptors for hydrogen bonding should inform and guide the use of C=Se in crystal engineering.

scholarly journals 2,2′-Bipyridin-1′-ium 1-oxide bromide monohydrate

2018 ◽  
Vol 74 (3) ◽  
pp. 341-344 ◽  
Author(s):  
Katharina Heintz ◽  
Helmar Görls ◽  
Wolfgang Imhof
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Water Molecule ◽  
Title Compound ◽  
Structural Disorder ◽  
Occupancy Rate ◽  
Hydrogen Bonding Interactions ◽  
Bromide Ions

The title compound 2,2′-bipyridin-1′-ium 1-oxide bromide crystallizes as a monohydrate, C10H9N2+·Br−·H2O. Structural disorder is observed due to the fact that protonation, as well as oxidation, of the N atoms of 2,2′-bipyridine occurs at either of the N atoms. The disorder extends to the remainder of the cation, with a refined occupancy rate of 0.717 (4) for the major moiety. An intramolecular N—H...O hydrogen bond forces the bipyridine unit into ans-cisconformation. Each pair of neighbouring 2,2′-bipyridin-1′-ium ions forms a dimeric aggregate by hydrogen bonds between their respective N—O and the N—H functions. These dimers and hydrogen-bonding interactions with bromide ions and the water molecule give rise to a complex supramolecular arrangement.

Correspondence: Hydrogen Bond to Gold? 1H NMR is Not a Proof of Hydrogen Bonds in Transition Metal Complexes

2018 ◽  
Author(s):  
Jan Vícha ◽  
Cina Foroutan-Nejad ◽  
Michal Straka
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Chemical Shifts ◽  
X Ray ◽  
Structure And Dynamics ◽  
Hydrogen Bonding Interactions ◽  
Overall Stability ◽  
Gold Compounds ◽  
C Nmr

Illusive Au<sup>I/III</sup>···H hydrogen bonds and their effect on structure and dynamics of molecules have been a matter of debate. While a number of X-ray studies reported gold compounds with short Au<sup>I/III</sup>···H contacts, a solid spectroscopic evidence for Au<sup>I/III</sup>···H bonding has been missing. Recently<a></a><a>, Bakar <i>et al.</i></a> (NATURE COMMUNICATIONS 8:576) reported compound with four short Au···H contacts (2.61­–2.66 Å; X-ray determined). Assuming the central cluster be [Au<sub>6</sub>]<sup>2+</sup>and observing the <sup>1</sup>H (<sup>13</sup>C) NMR resonances at relevant H(C) nuclei deshielded with respect to precursor compound, the authors concluded with reservations that <i>“the present Au···H–C interaction is a kind of “hydrogen bond”, where the [Au<sub>6</sub>]<sup>2+</sup>serves as an acceptor”</i>. Here, we show that the Au<sub>6</sub>cluster in their compound bears negative charge and the Au···H contacts lead to a weak (~1 kcal/mol) auride···hydrogen bonding interactions, though unimportant for the overall stability of<b></b>the molecule. Additionally, computational analysis of NMR chemical shifts reveals that the deshielding effects at respective hydrogen nuclei are not directly related to Au···H–C hydrogen bonding .

scholarly journals Zwitterionic 4-carboxy-2-(pyridinium-2-yl)-1H-imidazole-5-carboxylate

IUCrData ◽  
2016 ◽  
Vol 1 (10) ◽  
Author(s):  
Kanglong Zhang ◽  
Xiaojin Qi ◽  
Bingnian Yuan
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Pyridine Ring ◽  
Imidazole Ring ◽  
Chain Structure ◽  
Carboxyl Group ◽  
Pyridyl Group ◽  
Compound C ◽  
Hydrogen Bonding Interactions

The title compound, C10H7N3O4, is zwitterionic, with one carboxyl group deprotonated and the pyridyl group protonated. The pyridine ring is close to coplanar with the imidazole ring, making a dihedral angle of 2.79 (8)°, this conformation being maintained by the presence of an intramolecular O—H...O hydrogen bond. In the crystal, two sets of N—H...O hydrogen bonds link the molecules through three conjoined cyclic hydrogen-bonding interactions, with two R 1 2(7) and one R 2 2(10) motifs, forming centrosymmetric cyclic dimers. These are linked through C—H...O hydrogen bonds, giving a supramolecular chain structure extending along the b-axis direction.

Interaction of Gold Atom with Clusters of Water: Few Computational Mise-En-Scènes with Hydrogen Bonding Motif

2008 ◽  
Vol 73 (11) ◽  
pp. 1457-1474 ◽  
Author(s):  
Eugene S. Kryachko
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Computational Model ◽  
Photoelectron Spectroscopy ◽  
Water Clusters ◽  
Gold Atom ◽  
Proton Acceptor ◽  
Anion Photoelectron Spectroscopy ◽  
Relationship Of ◽  
First Time

The present work outlines the fair relationship of the computational model with the experiments on anion photoelectron spectroscopy for the gold-water complexes [Au(H2O)1≤n≤2]- that is established between the auride anion Au- and water monomer and dimer thanks to the nonconventional hydrogen bond where Au- casts as the nonconventional proton acceptor. This work also extends the computational model to the larger complexes [Au(H2O)3≤n≤5]- where gold considerably thwarts the shape of water clusters and even particularly breaks their conventional hydrogen bonding patterns. The fascinating phenomenon of the lavish proton acceptor character of Au- to form at least six hydrogen bonds with molecules of water is computationally unveiled in the present work for the first time.

scholarly journals Pentaaqua(1H-benzimidazole-5,6-dicarboxylato-κN3)cobalt(II) pentahydrate

2009 ◽  
Vol 65 (6) ◽  
pp. m702-m702 ◽  
Author(s):  
Wen-Dong Song ◽  
Hao Wang ◽  
Shi-Jie Li ◽  
Pei-Wen Qin ◽  
Shi-Wei Hu
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Organic Ligand ◽  
Octahedral Geometry ◽  
Mononuclear Complex ◽  
Distorted Octahedral Geometry ◽  
Water Molecules ◽  
Supramolecular Network ◽  
Hydrogen Bonding Interactions ◽  
Distorted Octahedral

In the title mononuclear complex, [Co(C9H4N2O4)(H2O)5]·5H2O, the CoIIatom exhibits a distorted octahedral geometry involving an N atom of a 1H-benzimidazole-5,6-dicarboxylate ligand and five water O atoms. A supramolecular network is generated through intermolecular O—H...O hydrogen-bonding interactions involving the coordinated and uncoordinated water molecules and the carboxyl O atoms of the organic ligand. An intermolecular N—H...O hydrogen bond is also observed.

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 1,4a,7-Trimethyl-7-vinyl-1,2,3,4,4a,4b,5,6,7,8,10,10a-dodecahydrophenanthrene-1-carboxylic acid

2009 ◽  
Vol 65 (6) ◽  
pp. o1429-o1429
Author(s):  
Zhen-Dong Zhao ◽  
Yu-Xiang Chen ◽  
Yu-Min Wang ◽  
Liang-Wu Bi
Keyword(s):  
Hydrogen Bonding ◽  
Carboxylic Acid ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Molecular Conformation ◽  
Slash Pine ◽  
Carboxyl Groups ◽  
Isopimaric Acid ◽  
Hydrogen Bonding Interactions ◽  
Cyclohexene Ring

The title compound, also known as isopimaric acid, C20H30O2, was isolated from slash pine rosin. There are two unique molecules in the unit cell. The two cyclohexane rings have classical chair conformations. The cyclohexene ring represents a semi-chair. The molecular conformation is stabilized by weak intramolecular C—H...O hydrogen-bonding interactions. The molecules are dimerized through their carboxyl groups by O—H...O hydrogen bonds, formingR22(8) rings.

Sign in / Sign up

Export Citation Format

Share Document