Journal ArticleDOI
Coherent X‐Ray Scattering for the Hydrogen Atom in the Hydrogen Molecule
TLDR
In this paper, the x-ray form factors for a bonded hydrogen in the hydrogen molecule have been calculated for a spherical approximation to the bonded atom, and the corresponding complex scattering factors have also been calculated.Abstract:
The x‐ray form factors for a bonded hydrogen in the hydrogen molecule have been calculated for a spherical approximation to the bonded atom. These factors may be better suited for the least‐squares refinement of x‐ray diffraction data from organic molecular crystals than those for the isolated hydrogen atom. It has been shown that within the spherical approximation for the bonded hydrogens in H2, a least‐squares refinement of the atomic positions will result in a bond length (Re value) short of neutron diffraction or spectroscopic values. The spherical atoms are optimally positioned 0.07 A off each proton into the bond. A nonspherical density for the bonded hydrogen atom in the hydrogen molecule has also been defined and the corresponding complex scattering factors have been calculated. The electronic density for the hydrogen molecule in these calculations was based on a modified form of the Kolos—Roothaan wavefunction for H2. Scattering calculations were made tractable by expansion of a plane wave in spheroidal wavefunctions.read more
Citations
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Journal ArticleDOI
The crystal structures of four models for the binding to DNA of cisplatinum derivatives containing a bidentate tertiary diamine
John D. Orbell,Max R. Taylor,Sally L. Birch,Sharon E. Lawton,Louise M. Vilkins,Lisa J. Keefe +5 more
TL;DR: In this article, the properties of these compounds were compared with each other and with related compounds in terms of their base/base and base/coordination plane dihedral angles, and their different crystalline environments.
Journal ArticleDOI
Aminoacids in the synthesis of heterocyclic systems. The synthesis of methyl 2‐acetylamino‐3‐dimethylaminopropenoate and 2‐(N‐methyl‐N‐trifluoroacetyl)amino‐3‐dimethylaminopropenoate and their application in the synthesis of heterocyclic compounds
TL;DR: Methyl (Z)-2-acetylamino-3-dimethylaminopropenoate (3) was shown to be a versatile reagent in the synthesis of various heterocyclic systems as discussed by the authors.
Journal ArticleDOI
The molecular and crystal structure of bis(ethylene)(tricyclohexylphosphine)nickel
Carl Krüger,Yi‐Hung Tsay +1 more
TL;DR: The molecular and crystal structure of bis(π-ethylene)(tricyclohexylphosphine)nickel has been determined by direct methods and refined anisotropicically to a final R value of 6.48% as discussed by the authors.
Journal ArticleDOI
X-ray structural characterization of anhydrous metronidazole benzoate and metronidazole benzoate monohydrate
TL;DR: Thermomicroscopy, differential scanning calorimetry, and thermogravimetry were used for initial characterization of the title species and to investigate possible phase changes on heating, revealing that the metronidazole benzoate molecule adopts different conformations in the two crystal forms.
Journal ArticleDOI
Molecular structure and conformation of gaseous chloroacetyl chloride as determined by electron diffraction
TL;DR: In this paper, a gas-phase electron diffraction at nozzle-tip tempera- tures of 18, 110 and 215°C was performed on a mixture of anti and gauche confor- mers with the anti form the more stable.
References
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Journal ArticleDOI
The Physical Nature of the Chemical Bond
TL;DR: In this article, the quantum mechanical wave functions of molecules are discussed and an attempt is made to effect a simultaneous regional and physical partitioning of the molecular density, the molecular pair density, and the molecular energy, in such a way that meaningful concepts can be associated with the density and energy fragments thus formed.
Journal ArticleDOI
Accurate Electronic Wave Functions for the H 2 Molecule
W. Kolos,Clemens C. J. Roothaan +1 more
Journal ArticleDOI
The Problem of the Normal Hydrogen Molecule in the New Quantum Mechanics
TL;DR: The solution of Schroedinger's equation for the normal hydrogen molecule is approximated by the function $C[{e}^{\ensuremath{-}\frac{z({r}_{1}+{p}_{2})}{a}}+{e^{\ensem{-]-{m{e})+{m}−m{n}−n}]$ where m is the distance of one of the electrons to the two nuclei, and r is the distances of one electron to the other electron.
Journal ArticleDOI
The Normal State of the Hydrogen Molecule
TL;DR: In this paper, a simple wave function for the normal state of the hydrogen molecule, in which both the atomic and ionic configurations are taken into account, was set up and treated by a variational method.
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