A crystallographic AM1 and PM3 SCF-MO investigation of strong OH ⋯π-alkene and alkyne hydrogen bonding interactions

Rzepa, Henry; Smith, Mike; Webb, Michael L.

doi:10.1039/p29940000703

Cited by 49 publications

(22 citation statements)

References 22 publications

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“… Examples of bifurcated hydrogen bonds with a strong and a weak acceptor: a) with O and C≡C acceptors;8, 88a,88b b) with O and Ph acceptors;80, 88c c) with O and F−C acceptors 88d…”

Section: Geometrymentioning

confidence: 99%

The Hydrogen Bond in the Solid State

Steiner

2002

Angew. Chem. Int. Ed.

5,841

215

4,258

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The hydrogen bond is the most important of all directional intermolecular interactions. It is operative in determining molecular conformation, molecular aggregation, and the function of a vast number of chemical systems ranging from inorganic to biological. Research into hydrogen bonds experienced a stagnant period in the 1980s, but re‐opened around 1990, and has been in rapid development since then. In terms of modern concepts, the hydrogen bond is understood as a very broad phenomenon, and it is accepted that there are open borders to other effects. There are dozens of different types of X−H⋅⋅⋅A hydrogen bonds that occur commonly in the condensed phases, and in addition there are innumerable less common ones. Dissociation energies span more than two orders of magnitude (about 0.2–40 kcal mol−1). Within this range, the nature of the interaction is not constant, but its electrostatic, covalent, and dispersion contributions vary in their relative weights. The hydrogen bond has broad transition regions that merge continuously with the covalent bond, the van der Waals interaction, the ionic interaction, and also the cation–π interaction. All hydrogen bonds can be considered as incipient proton transfer reactions, and for strong hydrogen bonds, this reaction can be in a very advanced state. In this review, a coherent survey is given on all these matters.

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“… Examples of bifurcated hydrogen bonds with a strong and a weak acceptor: a) with O and C≡C acceptors;8, 88a,88b b) with O and Ph acceptors;80, 88c c) with O and F−C acceptors 88d…”

Section: Geometrymentioning

confidence: 99%

The Hydrogen Bond in the Solid State

Steiner

2002

Angew. Chem. Int. Ed.

5,841

215

4,258

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“…On the other hand, in contrast to its behavior in solution, diene diol 2a displays a positive CE in the solid state, suggesting significant chromophore chirality altering effects from ÀOHAEAEAEp-alkene hydrogen bonding in the crystalline state. 16 From the solution CD data, the cisoid diene moiety in 2 is predicted to have P chirality. This conclusion was confirmed by MM2 force-field energy minimization calculations and also by single-crystal X-ray crystallography (Fig.…”

Section: Resultsmentioning

confidence: 99%

Diene chirality and cotton effects of nonhomoannular cisoid conjugated dienes: Circular dichroism and crystal structure of a steroidal 19‐nor‐1(10),9(11)‐diene derived from westphalen's diol diacetate

Burgstahler¹,

Jahansouz²,

Véliz³

et al. 2002

Chirality

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Nonhomoannular cisoid conjugated dienes exhibit negative lowest energy pi-->pi* Cotton effects when they have P diene chirality and positive CEs when they have M diene chirality. We investigated this relationship further with a variety of such dienes by MM2 conformational energy-minimization calculations and by an X-ray crystal structure of a steroidal 19 nor 1(10),9(11) diene. CEs are stronger when each double bond of the diene is endocyclic in a different ring and weaker when only one of the double bonds is endocyclic or when neither double bond is endocyclic. They are also stronger when axial allylic and homoallylic substituents with CH/pi interactions are present that exert consignate chirality contributions.

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“…In most cases the quality of the results obtained approaches that of the ab initio calcula tions, being better that that provided by the MNDO method; this especially concerns the description of hydro gen bonds. 40 The final structure of the surfactant molecule with allowance for thermodynamic parameters was determined by the MD method, which has been successfully used in modeling of micellar systems and for the determination of geometric parameters and thermodynamic character istics. 41, 42 For convenience of calculations, processing of the results obtained, and reduction of the computing time, the effects of solvent on the polar and nonpolar fragments of the surfactant molecule were analyzed separately.…”

Section: Resultsmentioning

confidence: 99%

Geometric characteristics of micellar systems as precursors of lanthanide-containing lyotropic mesophases

et al. 2007

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The formation of three dimensional micellar structures was studied. The structures are precursors of lyotropic mesophases based on the nonionic surfactant, lanthanide nitrates, and water. The geometric parameters and configurations of the micellar structures were deter mined. Good agreement between experimental data and the results of quantum chemical calculations was obtained.Increased interest in nano organized materials and the development of basic and applied research in this field are due to the prospects for novel technological applica tions. A topical avenue of design of highly organized struc tures is to use self organization of nanoscale "building blocks" composed of colloidal particles. 1,2 In this con nection of particular interest are lyotropic liquid crys tals (LLC). Owing to unique properties and relative cheap ness of design the LLC have found application in various fields of modern science including molecular electron ics, 3,4 nanocatalysis, 5-7 pharmaceutics, 8 and serve models in studies of biological processes. 9Lyotropic mesophases can be functionalized in a pre set fashion via the synthesis of lyotropic metal containing mesogens in which the metal ion determines the neces sary (magnetic, electrical, polarization, and luminescent) properties of the nanomaterial. 10-14 At present, studies on the possibility of using such systems as matrices in the design of nano organized structures, e.g., nanowires and nanodots are in progress. 15-18 Application of LLC in vari ous devices requires the development of technologies that provide a particular molecular and spatial organization of these particles. In this connection a complex analysis of all stages of the evolution of a spontaneous molecular self organization, from micellization to aggregation into molecular blocks and further assembly into a liquid crys talline structure, is of paramount importance.Research on the supramolecular structure of lyotropic mesophases is based on studies of the structure, interac tions, and packing of particular fragments of the system in question. Using a specified structure element and the rules of filling the volume, it is possible to model the architec ture of the entire macrosystem. However, in the case of lyotropic systems containing the solvent as a consituent the single crystal X ray diffraction techniques are inap plicable and therefore corresponding information is scarce and of limited use. Here, a clear idea of the structure of the system under study, qualitative assessment of its ar chitecture, and prediction of the properties of lyotropic mesophases can be made using quantum chemical calcu lations of molecular characteristics and parameters of the entire system. 19 Earlier, 20 we reported the strategies of synthesis, the range of existence, and the liquid crystalline behavior of the first representatives of new lanthanide containing lyo tropic mesophases. Studies of the micellar behavior of such systems as precursors of liquid crystalline phases are of particular importance because the physicochemical charac...

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A crystallographic AM1 and PM3 SCF-MO investigation of strong OH ⋯π-alkene and alkyne hydrogen bonding interactions

Cited by 49 publications

References 22 publications

The Hydrogen Bond in the Solid State

The Hydrogen Bond in the Solid State

Diene chirality and cotton effects of nonhomoannular cisoid conjugated dienes: Circular dichroism and crystal structure of a steroidal 19‐nor‐1(10),9(11)‐diene derived from westphalen's diol diacetate

Geometric characteristics of micellar systems as precursors of lanthanide-containing lyotropic mesophases

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