scholarly journals The Molecular Conformations and Intermolecular Correlations in Positional Isomers 1- and 2- Propanols in Liquid State Through Neutron Diffraction

10.5772/37488 ◽  
2012 ◽  
Author(s):  
R.N. Joarder
Keyword(s):  
Neutron Diffraction ◽  
Liquid State ◽  
Positional Isomers ◽  
Molecular Conformations

Synthesis and crystallographic, spectroscopic and computational characterization of 3,3′,4,4′-substituted biphenyls: effects of OR substituents on the intra-ring torsion angle

2020 ◽  
Vol 76 (3) ◽  
pp. 366-377
Author(s):  
Nahir Vadra ◽  
Sebastian A. Suarez ◽  
Leonardo D. Slep ◽  
Veronica E. Manzano ◽  
Emilia B. Halac ◽  
...  
Keyword(s):  
Quantum Mechanics ◽  
Torsion Angle ◽  
Liquid State ◽  
Molecular Conformation ◽  
X Ray Diffraction ◽  
Aromatic Rings ◽  
Molecular Conformations ◽  
X Ray ◽  
Selection Of

Presented here are the synthesis, characterization and study (using single crystal X-ray diffraction, Raman scattering, quantum mechanics calculations) of the structures of a series of biphenyls substituted in positions 3, 3′, 4 and 4′ with a variety of R (R = methyl, acetyl, hexyl) groups connected to the biphenyl core through oxygen atoms. The molecular conformation, particularly the torsion angle between aromatic rings has been extensively studied both in the solid as well as in the liquid state. The results show that the compounds appearing as rigorously planar in the solid present instead a twisted conformation in the melt. The solid versus melt issue strongly suggests that the reasons for planarity are to be found in the packing restraints. A `rule of thumb' is suggested for the design of biphenyls with different molecular conformations, based on the selection of the OR substituent.

scholarly journals Neutron Diffraction Study of Krypton in the Liquid State

1961 ◽  
Vol 121 (3) ◽  
pp. 649-653 ◽  
Author(s):  
Glen T. Clayton ◽  
LeRoy Heaton
Keyword(s):  
Neutron Diffraction ◽  
Diffraction Study ◽  
Liquid State ◽  
Neutron Diffraction Study

Polymorphs of the antiviral drug ganciclovir

2017 ◽  
Vol 73 (12) ◽  
pp. 1116-1120 ◽  
Author(s):  
Roxana L. Roque-Flores ◽  
Ilia A. Guzei ◽  
Jivaldo do Rosario Matos ◽  
Lian Yu
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Liquid State ◽  
Crystalline State ◽  
Antiviral Drug ◽  
Molecular Conformations ◽  
X Ray ◽  
Metastable Form ◽  
Cytomegalovirus Infections ◽  
Single Conformer

Ganciclovir (GCV; systematic name: 2-amino-9-{[(1,3-dihydroxypropan-2-yl)oxy]methyl}-6,9-dihydro-1H-purin-6-one), C9H13N5O4, an antiviral drug for treating cytomegalovirus infections, has two known polymorphs (Forms I and II), but only the structure of the metastable Form II has been reported [Kawamura & Hirayama (2009). X-ray Struct. Anal. Online, 25, 51–52]. We describe a successful preparation of GCV Form I and its crystal structure. GCV is an achiral molecule in the sense that its individual conformers, which are generally chiral objects, undergo fast interconversion in the liquid state and cannot be isolated. In the crystalline state, GCV exists as two inversion-related conformers in Form I and as a single chiral conformer in Form II. This situation is similar to that observed for glycine, also an achiral molecule, whose α-polymorph contains two inversion-related conformers, while the γ-polymorph contains a single conformer that is chiral. The hydrogen bonds are exclusively intermolecular in Form I, but both inter- and intramolecular in Form II, which accounts for the different molecular conformations in the two polymorphs.

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