Millimeter-Wave Spectroscopy of Sulfur Dichloride
Bizzocchi1, Cludi, Degli Esposti C
1Dipartimento di Chimica "G. Ciamician,", Università di Bologna, Via F. Selmi 2, Bologna, 40126, Italy
Journal of Molecular Spectroscopy
|January 10, 2001
Summary
This study precisely measured the rotational spectra of sulfur dichloride isotopomers. These measurements yielded accurate structural parameters and refined the molecule
Area of Science:
- Molecular Spectroscopy
- Quantum Chemistry
- Chemical Physics
Background:
- Sulfur dichloride (SCl2) is a key molecule in atmospheric and industrial chemistry.
- Accurate structural and dynamic parameters are essential for understanding its chemical behavior.
Purpose of the Study:
- To precisely determine the rotational and centrifugal distortion constants for various sulfur dichloride isotopomers.
- To calculate the complete r(s) structure of sulfur dichloride.
- To refine the quadratic force field of sulfur dichloride.
Main Methods:
- High-resolution rotational spectroscopy in the 100-370 GHz frequency range.
- Analysis of transitions involving a wide range of quantum numbers.
- Application of single- and double-isotopic substitution methods for structural determination.
Main Results:
- Precise rotational and quartic centrifugal distortion constants were determined for (32)S(35)Cl(2), (32)S(35)Cl(37)Cl, (32)S(37)Cl(2), and (34)S(35)Cl(2) in their ground and excited vibrational states.
- The complete set of sextic distortion constants was obtained for the most abundant isotopomer.
- The complete r(s) structure of sulfur dichloride was calculated.
- The quadratic force field was refined using extensive distortion constants and inertial defects.
Conclusions:
- The study provides highly accurate molecular parameters for sulfur dichloride isotopomers.
- The refined structural and force field data enhance our understanding of SCl2's molecular properties and reactivity.
- This work establishes a benchmark for future spectroscopic and theoretical studies of sulfur-containing compounds.
Related Concept Videos
02:26Preparation and Reactions of Sulfides
Sulfides are the sulfur analog of ethers, just as thiols are the sulfur analog of alcohol. Like ethers, sulfides also consist of two hydrocarbon groups bonded to the central sulfur atom. Depending upon the type of groups present, sulfides can be symmetrical or asymmetrical. Symmetrical sulfides can be prepared via an SN2 reaction between 2 equivalents of an alkyl halide and one equivalent of sodium sulfide.
01:192D NMR: Heteronuclear Single-Quantum Correlation Spectroscopy (HSQC)
Heteronuclear single-quantum correlation spectroscopy (HSQC) is a 2D NMR technique that reveals one-bond correlations between hydrogen and a heteronucleus. The HSQC experiment is similar to the heteronuclear correlation experiment (HETCOR) but is more sensitive. In the HSQC spectrum, the proton chemical shift is plotted on the horizontal F2 axis, while the 13C chemical shift is plotted on the vertical F1 axis. The corresponding proton and 13C spectra are also shown. The HSQC contour plot does...
01:21Chemical Ionization (CI) Mass Spectrometry
The molecular ion peak of a molecule in the mass spectrum provides vital information for molecular identification. However, conventional electron impact ionization can lead to the rapid dissociation of some molecular ions before they reach the detector. A milder ionization method is required to increase the lifetime of such ionized analyte molecules. Chemical ionization (CI) is a gas-phase protonation reaction useful for mass-analyzing analyte molecules that are easily protonated to yield the...
01:15NMR Spectroscopy: Chemical Shift Overview
The position of the absorption signal of a sample is reported relative to the position of the signal of tetramethylsilane (TMS), which is added as an internal reference while recording spectra. The difference between the absorption frequencies of the sample and TMS (in Hz) is divided by the spectrometer operating frequency (in MHz) to obtain a dimensionless quantity called the chemical shift. It is reported on the δ (delta) scale and expressed in parts per million.
For instance, the proton...
For instance, the proton...
01:22Mass Spectrometry: Alkyl Halide Fragmentation
Chlorine isotopes exist as 35Cl and 37Cl in a 3:1 ratio, while bromine isotopes exist as 79Br and 81Br in a 1:1 ratio. The mass spectrum of alkyl halides typically produces two distinct molecular ion peaks, the molecular ion peak, [M], and the molecular ion plus two, [M + 2] peak. The relative heights of these two peaks are proportional to the isotopic abundance ratios of the halide. For example, 2‐chloropropane and 1‐bromopropane display two peaks with relative peak heights in a 3:1 and 1:1...
01:20Raman Spectroscopy: Overview
The underlying principle of Raman spectroscopy is based on the interaction between light and matter, specifically molecules' inelastic scattering of photons. When a monochromatic beam of light, typically from a laser source, interacts with a sample, most scattered light has the same frequency as the incident light. This is known as Rayleigh scattering.
However, a small fraction of the scattered light exhibits a frequency shift due to the exchange of energy between the incident photons and the...
However, a small fraction of the scattered light exhibits a frequency shift due to the exchange of energy between the incident photons and the...