Ultraviolet spectroscopy

A new series of octahedral cobalt(II) complexes are formed when CoX2(X = Cl, Br, I, SCN) reacts with Hg(SCN)2 in the presence of Lewis bases. These complexes of stoichiometry CoHg(SCN)4•2L (L = THF, dioxane, pyridine, aniline) are pink to violet solids which slowly decompose to the blue crystalline solid, CoHg(SCN)4, the stable magnetic susceptibility standard. On further reaction of CoHg(SCN)4•2THF with mono-, bi-, and polydentate ligands in dry ethanol, complexes of the following types are obtained: CoHg(SCN)4•2L (L = PΦ3), CoHg(SCN)4•2LL (LL = trien), CoHg(SCN)4•3LL (LL = en, bipy), and CoHg(SCN)4•4LL (LL = phen). The stoichiometry of these were determined by elemental analysis. Possible structures of these are discussed with the help of mid and far infrared, visible, and ultraviolet spectroscopy, magnetic susceptibility, and X-ray powder diffraction. Some new i.r. bands like Co—P, Co—N, and Hg—S are assigned in the low region.

Download Full-text

Ultraviolet spectroscopy of pressurized and supercritical carbon dioxide

Communications Chemistry ◽

10.1038/s42004-021-00516-z ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Timothy W. Marin ◽

Ireneusz Janik

Keyword(s):

Carbon Dioxide ◽

Potential Energy Surfaces ◽

Vacuum Ultraviolet ◽

Electronic Absorption Spectra ◽

Industrial Applications ◽

Ultraviolet Spectroscopy ◽

Collisional Broadening ◽

Thermodynamic Critical Point ◽

State Potential ◽

Energy Surfaces

AbstractCarbon dioxide (CO2) is prevalent in planetary atmospheres and sees use in a variety of industrial applications. Despite its ubiquitous nature, its photochemistry remains poorly understood. In this work we explore the density dependence of pressurized and supercritical CO2 electronic absorption spectra by vacuum ultraviolet spectroscopy over the wavelength range 1455-2000 Å. We show that the lowest absorption band transition energy is unaffected by a density increase up to and beyond the thermodynamic critical point (137 bar, 308 K). However, the diffuse vibrational structure inherent to the spectrum gradually decreases in magnitude. This effect cannot be explained solely by collisional broadening and/or dimerization. We suggest that at high densities close proximity of neighboring CO2 molecules with a variety of orientations perturbs the multiple monomer electronic state potential energy surfaces, facilitating coupling between binding and dissociative states. We estimate a critical radius of ~4.1 Å necessary to cause such perturbations.

Download Full-text

Structures of Pyridine–Water Clusters Studied with Infrared–Vacuum Ultraviolet Spectroscopy

The Journal of Physical Chemistry A ◽

10.1021/acs.jpca.1c05782 ◽

2021 ◽

Vol 125 (34) ◽

pp. 7489-7501

Author(s):

Jun-Ying Feng ◽

Yuan-Pern Lee ◽

Henryk A. Witek ◽

Po-Jen Hsu ◽

Jer-Lai Kuo ◽

...

Keyword(s):

Vacuum Ultraviolet ◽

Water Clusters ◽

Ultraviolet Spectroscopy ◽

Vacuum Ultraviolet Spectroscopy

Download Full-text

Far-ultraviolet spectroscopy of solid and liquid states: characteristics, instrumentation, and applications

The Analyst ◽

10.1039/c6an00522e ◽

2016 ◽

Vol 141 (13) ◽

pp. 3962-3981 ◽

Cited By ~ 20

Author(s):

Yukihiro Ozaki ◽

Ichiro Tanabe

Keyword(s):

Electronic Structures ◽

Basic Science ◽

Ultraviolet Spectroscopy ◽

Far Ultraviolet ◽

Liquid States ◽

Almost All ◽

Solid And Liquid States

Far-ultraviolet spectroscopy (≥200 nm) can greatly contribute to the basic science of electronic structures for almost all materials and their applications.

Download Full-text