Molecular reorientational motion in liquid deuterated dimethyl-sulfoxide (DMSO-d6) from Raman line widths

Bratu, Ioan; Iliescu, T.; Milea, I.

doi:10.1016/0167-7322(85)80017-9

Cited by 8 publications

(5 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the study of the molecular relaxation processes [15], one of the well-known procedures of obtaining the relaxation times and the activation energy was developed by Rakov [16].…”

Section: Resultsmentioning

confidence: 99%

Molecular dynamics in calf‐thymus DNA, at neutral and low pH, in the presence of Na⁺, Ca²⁺ and Mg²⁺ ions: A Raman microspectroscopic study

Muntean

Bratu

2007

Journal of Spectroscopy

View full text Add to dashboard Cite

In this paper the Raman total half bandwidths of calf-thymus DNA vibrations have been measured as a function of pH, monovalent and divalent cations' type and concentration. The dependence of different band parameters on DNA molecular subgroup structure, on pH and on Na+, Ca2+and Mg2+ions concentrations, respectively, are reported. It is shown that changes in (sub)picosecond dynamics of molecular subgroups in calf-thymus DNA can be monitored with confocal Raman microspectroscopy.The half bandwidths and the global relaxation times for the vibrations at 728 cm−1(dA), 785 cm−1(dC), 1094 cm−1(PO2−), 1377 cm−1(dA, dG, dT, dC), 1488 cm−1(dG, dA) and 1580 cm−1(dG, dA) of calf-thymus DNA are presented. The full-widths at half-height (FWHH) of the bands in calf-thymus DNA are typically in the wavenumber range from 7.4 to 31 cm−1. The bandwidths in the Raman spectra are sensitive to a dynamics active on a time scale from 0.34 to 1.44 ps.Low pH-induced melting of double helical structure in calf-thymus DNA results for some bands in shorter global relaxation times, as a consequence of the increased interaction of the base moieties with the solvent molecules.The molecular dynamics characterizing the 785, 1094, 1377 and 1580 cm−1vibrations, is faster in the case of high divalent cations DNA sample (pH 7), as compared to the respective low divalent cations DNA sample (pH 7), for both Ca2+and Mg2+ions. The vibrational energy transfer process of the guanine band at 1488 cm−1is slower for the high salt DNA sample, pH 7 as compared to the corresponding low salt DNA sample, pH 7, for both Ca2+and Mg2+. Molecular dynamics characterizing the vibration at 1488 cm−1is faster for DNA sample at high Na+ions (pH 7), as compared to the DNA sample at low Na+ions (pH 7).As far as the CaDNA and MgDNA complexes are concerned (pH 7), the global relaxation times of some base vibrations decrease for the case of magnesium ions, as compared to the case of the same concentration of calcium ions. The different ionic radius of the two types of metal cations (0.72 Å for Mg and 0.99 Å for Ca) were considered in explaining these results.Molecular relaxation processes of DNA subgroups, upon lowering the pH, in the presence of Na+, Ca2+and Mg2+ions are presented. Particularly, at low Ca2+concentration, upon lowering the pH, the molecular dynamics of DNA subgroups corresponding to vibrations at 728, 1376, 1488 and 1580 cm−1is much faster, probably due to the denaturation process of the double helical DNA.

show abstract

“…In the study of the molecular relaxation processes [15], one of the well-known procedures of obtaining the relaxation times and the activation energy was developed by Rakov [16].…”

Section: Resultsmentioning

confidence: 99%

Molecular dynamics in calf‐thymus DNA, at neutral and low pH, in the presence of Na⁺, Ca²⁺ and Mg²⁺ ions: A Raman microspectroscopic study

Muntean

Bratu

2007

Journal of Spectroscopy

View full text Add to dashboard Cite

show abstract

“…The Raman bandwidth of a molecule is influenced by both vibrational and rotational broadenings, whose contributions to the bandwidth can be separated by polarized Raman spectroscopy. In the framework of the polarizability approximation, the isotropic ( I iso ) and anisotropic components ( I aniso ) of the Raman band of a molecule are given by eqs and , respectively − where I VV or I VH is the Raman scattering intensity of the band peak at a wavenumber ν̃ 0 polarized to the vertical (V) or horizontal direction (H), respectively, upon Raman excitation along a vertical polarization direction (V). ν̃ is a given wavenumber of a Raman band, while Δν̃ vib and Δν̃ rot represent the full-widths at the half maxima of the Raman bands responsible for the vibrational and rotational components, respectively.…”

Section: Methodsmentioning

confidence: 99%

“…Since the τ rot value of a DMSO ([KI] = 0.1 M) solution has not been hitherto determined experimentally, the present data cannot be compared directly with the literature values. As important information, the T -dependence of the τ rot value of DMSO or deuterated DMSO (DMSO- d 6 ) has been studied by molecular dynamic simulations and Raman spectroscopy, ,, and the data are summarized in the Supporting Information, Figure S1. As seen in Figure S1, the present τ rot data determined for bulk DMSO liquid by polarized Raman spectroscopy in +17.4 < T < +79.8 °C are comparable with those reported for DMSO and DMSO- d 6 (without KI).…”

Section: Methodsmentioning

confidence: 99%

Optical Trapping–Microspectroscopy of Single Aerosol Microdroplets in Air: Supercooling of Dimethylsulfoxide Microdroplets

et al. 2020

View full text Add to dashboard Cite

We report temperature (T = +22.5 ∼ −57.0 °C)-controlled optical trapping of single dimethylsulfoxide (DMSO) droplets with the diameter (d) of 7−15 μm in air. Optically levitated DMSO microdroplets containing 0.1 mol/dm 3 (=M) potassium iodide (KI) as an additive for reducing the vapor pressure of DMSO in air have been suggested to take supercooled liquid states even below the freezing temperature (f p ) of the bulk DMSO liquid (f p = +18.4 °C in the presence of 0.1 M KI) as seen in bright-field microscopic observations of the droplet. Clear evidence for supercooling of an aerosol DMSO microdroplet below f p has been obtained by in situ optical trapping−polarized Raman microspectroscopy of the droplet down to −14.9 °C. Analysis of the polarized Raman spectral data of an aerosol DMSO droplet (d = ∼10 μm) has demonstrated that the droplet at +22.5, +0.2, or −14.9 °C is characterized by the rotational relaxation time (τ rot ) of a DMSO molecule in the droplet being 1.95, 2.58, or 3.90 ps, respectively. On the basis of the τ rot values and the Stokes−Einstein equation (τ rot = 8πa 3 η/k B T where a, η, k B are the radius (1.883 Å) of a DMSO molecule, the viscosity in DMSO, and the Boltzmann constant, respectively), the η values in the DMSO microdroplet in air at +22.5, +0.2, or −14.9 °C have been estimated to be 2.39, 2.94, or 4.20 cP, respectively, while that of bulk DMSO liquid at +20.5 °C is 1.98 cP. We also report the T-dependence (+22.5 > T > −14.9 °C) of the viscosity in a single aerosol DMSO microdroplet (d = ∼10 μm) and the effects of aerosolization in air on the viscosity in DMSO.

show abstract

“…It has been reported that the isotropic ( I iso ) and anisotropic components ( I aniso ) of a polarized Raman spectrum are given by eqs and , − respectively where ν 0 and ν are the peak wavenumber of a Raman band and a given wavenumber, respectively. Δν vib and Δν rot represent the fwhm values of the bands responsible for the vibrational and rotational components of the band, respectively.…”

Section: Results and Discussionmentioning

confidence: 99%

“…In order to check the validity of the τ vib and τ rot values in Table , furthermore, we also evaluated these parameters based on the Δν vib and Δν rot values of I iso and I aniso through the relations − where c is the velocity of light. The τ vib ν and τ rot ν values calculated by eqs and , respectively, are included in Table , while other parameters (Δν iso , Δν aniso , ν iso , and ν aniso ) are reported in the Supporting Information, Table S1.…”

Section: Results and Discussionmentioning

confidence: 99%

Optical Trapping–Polarized Raman Microspectroscopy of Single Ethanol Aerosol Microdroplets: Droplet Size Effects on Rotational Relaxation Time and Viscosity

et al. 2021

View full text Add to dashboard Cite

Optical trapping–polarized Raman microspectroscopy of single ethanol (EtOH) microdroplets with a diameter (d) of 6.1–16.5 μm levitated in an EtOH vapor-saturated air/N2 gas atmosphere has been explored to elucidate the vibrational and rotational motions of EtOH in the droplets at 22.0 °C. The Raman spectral bandwidth of the C–C stretching vibrational mode observed for an aerosol EtOH microdroplet was narrower than that of bulk EtOH, suggesting that the vibrational/rotational motions of EtOH in the aerosol system were restricted compared to those in the bulk system. In practice, polarized Raman microspectroscopy demonstrated that the rotational relaxation time (τrot) of EtOH in an aerosol microdroplet with d = 16. 5 μm was slower (2.33 ps) than that in a bulk EtOH (1.65 ps), while the vibrational relaxation times (τvib) in the aerosol and bulk EtOH systems were almost comparable with one another: 0.86–0.98 ps. Furthermore, although the τvib value of an aerosol EtOH microdroplet was almost unchanged irrespective of d as described above, the τrot value increased from 2.33 to 3.57 ps with a decrease in d from 16.5 to 6.1 μm, which corresponded to the increase in EtOH viscosity (η) from 1.33 to 2.04 cP with the decrease in d. The droplet size dependences of τrot and η in an aerosol EtOH microdroplet were discussed in terms of the gas/droplet interfacial molecular arrangements of EtOH and Laplace pressure experienced by a spherical EtOH microdroplet in the gas phase.

show abstract

Molecular reorientational motion in liquid deuterated dimethyl-sulfoxide (DMSO-d6) from Raman line widths

Cited by 8 publications

References 4 publications

Molecular dynamics in calf‐thymus DNA, at neutral and low pH, in the presence of Na⁺, Ca²⁺ and Mg²⁺ ions: A Raman microspectroscopic study

Molecular dynamics in calf‐thymus DNA, at neutral and low pH, in the presence of Na⁺, Ca²⁺ and Mg²⁺ ions: A Raman microspectroscopic study

Optical Trapping–Microspectroscopy of Single Aerosol Microdroplets in Air: Supercooling of Dimethylsulfoxide Microdroplets

Optical Trapping–Polarized Raman Microspectroscopy of Single Ethanol Aerosol Microdroplets: Droplet Size Effects on Rotational Relaxation Time and Viscosity

Contact Info

Product

Resources

About

Molecular reorientational motion in liquid deuterated dimethyl-sulfoxide (DMSO-d6) from Raman line widths

Cited by 8 publications

References 4 publications

Molecular dynamics in calf‐thymus DNA, at neutral and low pH, in the presence of Na+, Ca2+ and Mg2+ ions: A Raman microspectroscopic study

Molecular dynamics in calf‐thymus DNA, at neutral and low pH, in the presence of Na+, Ca2+ and Mg2+ ions: A Raman microspectroscopic study

Optical Trapping–Microspectroscopy of Single Aerosol Microdroplets in Air: Supercooling of Dimethylsulfoxide Microdroplets

Optical Trapping–Polarized Raman Microspectroscopy of Single Ethanol Aerosol Microdroplets: Droplet Size Effects on Rotational Relaxation Time and Viscosity

Contact Info

Product

Resources

About

Molecular dynamics in calf‐thymus DNA, at neutral and low pH, in the presence of Na⁺, Ca²⁺ and Mg²⁺ ions: A Raman microspectroscopic study

Molecular dynamics in calf‐thymus DNA, at neutral and low pH, in the presence of Na⁺, Ca²⁺ and Mg²⁺ ions: A Raman microspectroscopic study