Related Experiment Video
Updated: Apr 12, 2026
06:15
Interactive Molecular Model Assembly with 3D Printing
Published on: August 13, 2020
11.2K
Electronic structure and conformational flexibility of D-cycloserine
Antonello Filippi1, Caterina Fraschetti, Felice Grandinetti
1Dipartimento di Chimica e Tecnologie del Farmaco, Universitá "Sapienza", P.le A. Moro 5, 00185, Roma, Italy. antonello.filippi@uniroma1.it.
Physical Chemistry Chemical Physics : PCCP
|May 14, 2015
Summary
This study reveals how D-cycloserine
Area of Science:
- Computational Chemistry
- Quantum Chemistry
- Spectroscopy
Background:
- Conformational flexibility significantly influences molecular properties.
- Understanding electronic structure is crucial for chemical and biological applications.
Purpose of the Study:
- Investigate the impact of D-cycloserine's conformational flexibility on its electronic structure.
- Assign experimental valence and core photoelectron spectra.
Main Methods:
- Ab initio calculations (MP2/6-311++G**, HF/6-311++G**).
- Outer Valence Green's Function (OVGF) for valence UPS simulation.
- ΔSCF approach for core XPS simulation.
- Natural Bond Orbital (NBO) analysis.
Main Results:
- Simulated UPS showed varying sensitivity to conformational flexibility.
- Detailed assignment of the outermost valence spectral region was achieved.
- Simulated XPS provided insight into core electronic structure and confirmed no mixing of atomic XPS components due to flexibility.
- Atomic XPS components are not mixed by conformational flexibility.
Conclusions:
- Conformational flexibility of D-cycloserine affects its electronic structure, particularly valence spectra.
- Theoretical simulations accurately reproduce experimental spectra, enabling detailed assignments.
- Vibronic structure is key to understanding spectral intensities and band shapes.
More Related Videos
Related Concept Videos
02:11Conformations of Cyclohexane
17.4K
Cyclohexane does not exist in a planar form due to the high angle and torsional strain it would experience in the planar structure. Instead, it adopts non-planar chair and boat conformations.
The chair form is the most stable and derives its name from its resemblance to the “easy chair.” In the chair conformation, two carbon atoms are arranged out-of-plane — one above and one below, minimizing the torsional strain. In the chair form, the bond angle is very close to the ideal...
The chair form is the most stable and derives its name from its resemblance to the “easy chair.” In the chair conformation, two carbon atoms are arranged out-of-plane — one above and one below, minimizing the torsional strain. In the chair form, the bond angle is very close to the ideal...
17.4K
02:02Chair Conformation of Cyclohexane
21.7K
The chair conformation is the most stable form of cyclohexane due to the absence of angle and torsional strain. The absence of angle strain is a result of cyclohexane’s bond angle being very close to the ideal tetrahedral bond angle of 109.5° in its chair conformer. Similarly, the torsional strain is also absent owing to the perfectly staggered arrangement of bonds.
The hydrogen atoms linked to carbons are arranged in two different axial and equatorial orientations to achieve this...
The hydrogen atoms linked to carbons are arranged in two different axial and equatorial orientations to achieve this...
21.7K
00:52¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
1.4K
At room temperature, the chair conformer of cyclohexane undergoes rapid ring flipping between two equivalent chair conformers at a rate of approximately 105 times per second. These two chair conformers are in equilibrium. The rapid ring flipping results in the interconversion of the axial proton to an equatorial proton and an equatorial to the axial proton. Such interconversions are too rapid and cannot be detected on the NMR timescale. Hence, the NMR spectrometer cannot distinguish between the...
1.4K
02:30Stability of Substituted Cyclohexanes
17.5K
This lesson discusses the stability of substituted cyclohexanes with a focus on energies of various conformers and the effect of 1,3-diaxial interactions.
The two chair conformations of cyclohexanes undergo rapid interconversion at room temperature. Both forms have identical energies and stabilities, each comprising equal amounts of the equilibrium mixture. Replacing a hydrogen atom with a functional group makes the two conformations energetically non-equivalent.
For example, in...
The two chair conformations of cyclohexanes undergo rapid interconversion at room temperature. Both forms have identical energies and stabilities, each comprising equal amounts of the equilibrium mixture. Replacing a hydrogen atom with a functional group makes the two conformations energetically non-equivalent.
For example, in...
17.5K
02:33Stereoisomerism of Cyclic Compounds
12.0K
In this lesson, we delve into the role of ring conformation and its stability, which determines the spatial arrangement and, consequently, the molecular symmetry and stereoisomerism of cyclic compounds. 1,2-Dimethylcyclohexane is used as a case study to evaluate the possible number of stereoisomers. Here, given the multiple (n = 2) chiral centers, there are 2n = 4 possible configurations that lack a plane of symmetry, as the ring skeleton exists in a non-planar chair conformation. In addition,...
12.0K
02:29Conformations of Cycloalkanes
16.8K
Adolf von Baeyer attempted to explain the instabilities of small and large cycloalkane rings using the concept of angle strain — the strain caused by the deviation of bond angles from the ideal 109.5° tetrahedral value for sp3 hybridized carbons. However, while cyclopropane and cyclobutane are strained, as expected from their highly compressed bond angles, cyclopentane is more strained than predicted, and cyclohexane is virtually strain-free. Hence, Baeyer’s theory that...
16.8K