13 research outputs found
VIZSLA -- Versatile Ice Zigzag Sublimation Setup for Laboratory Astrochemistry
In this article a new, multi-functional, high-vacuum astrophysical ice setup,
VIZSLA (Versatile Ice Zigzag Sublimation Setup for Laboratory Astrochemistry),
is introduced. The instrument allows the investigation of astrophysical
processes both in a low-temperature para-H2 matrix and in astrophysical analog
ices. In para-H2 matrix the reaction of astrochemical molecules with H atoms
and H+ ions can be studied very effectively. For the investigation of
astrophysical analog ices the setup is equipped with different irradiation and
particle sources: an electron gun, for modeling cosmic rays; an H atom beam
source (HABS); a microwave H atom lamp, for generating H Lyman-alpha radiation,
and a tunable (213 nm to 2800 nm) laser source. For analysis, an FT-IR (and a
UV-Visible) spectrometer and a quadrupole mass analyzer are available. The
setup has two cryostats, offering novel features for analysis. Upon the
so-called temperature-programmed desorption (TPD) the molecules, desorbing from
the first cryostat, can be mixed with Ar and can be deposited onto the
substrate of the other cryostat. The well-resolved spectrum of the molecules
isolated in an Ar matrix serves a unique opportunity to identify the desorbing
products of a processed ice. Some examples are provided to show how the para-H2
matrix experiments and the TPD -- matrix-isolation recondensation experiments
can help to understand astrophysically important chemical processes at a low
temperature. It is also discussed, how these experiments can complement the
studies carried out by similar astrophysical ice setups.Comment: 37 pages, 14 figures, 1tabl
Why Density Functionals Should Not Be Judged Primarily by Atomization Energies
While most molecules and solids are spin-unpolarized, most chemically-active atoms are partly spin-polarized. As a result, the errors of the spin-dependence of a density functional are much more troublesome for atomization energies than they are for typical reaction or formation energies. This observation explains why the atomization energy errors of approximate functionals do not correlate with their other errors, and why the errors of atomization energies for a given functional can be radically reduced by fitting the energies of the atoms. We present an illustrative example from the recent nonempirical construction of the SCAN meta-generalized gradient approximation
Fém-ligandum kölcsönhatás vizsgálata gázfázisú molekulaspektroszkópiai módszerekkel = Investigation of transition metal complexes by gas phase molecular spectroscopic methods
- Új kvantumkémiai eljárást dolgoztunk ki az átmenetifém-származékok fotoelektron (pe) színképének értelmezéséhez. - UPS vizsgálatok alapján meghatároztuk a CS és CSe ligandumok CO-hoz viszonyított donor-akceptor sajátságát. - Előállítottuk a Co(CO)2(N | Novel quantumchemical method has been worked out for the interpretation of the photoelectron (pe) spectra of transition metal derivatives.-Donor-acceptor properties of CS and CSe related to CO have been determined on the basis of UPS investigations.-New compound of Co(CO)2(NO)(t-BuNC) has been prepared and investigated by HeI UPS and threshold PEPICO methods. From the PEPICO measurements energetic and thermochemical data were derived.-Trimethyl phosphane, -arsane, and –stibane derivatives of CpMnCO3 and CoCO3NO have been investigated by HeI and HeII UPS methods and conclusions were drawn concerning the ?-acceptor and ?-donor ability of the ligands.-A new series of isonitrile-substituted cobalt tricarbonyl nitrosyl (Co(CO)2(NO)CNR, R= Me, Et, nPr, iPr, nBu, nPe, CH2SiMe3) has been synthesized and studied by HeI UPS. The relative importance of electronic and steric effects of the isonitrile ligands, as a function of the size of group –R were determined. Metallocene ions (Cp2M+, M=Cr,Co,Ni) were studied by TPEPICO spectroscopy to investigate the mechanism, energetics and kinetics of the ionic dissociation processes.-Me3Si and Me3Ge radicals were generated by the gas phase thermolysis of (Me3Si/Ge)2Hg. The HeI pe spectra were recorded and assigned.-Electronic structure determination of precursors (diiodofuroxan and thiadiazoles) of some exotic molecules has been performed. Pyrolizer/ reactor directly attached to the pe spectrometer has been constructed
Prospects in computational molecular medicine: a millennial mega-project on peptide folding
During the second half of the 20th century, Molecular Computations have
reached to a level that can revolutionize chemistry. The next target
will be structural biology, which will be followed soon by Molecular
Medicine. The present paper outlines where we are at, in this field, at
the end of the 20th century, and in what direction the development may
take in the new millennium. In view of the gigantic nature of the
problem, it is suggested that a suitably designed cooperative
Millennial Mega-project might accelerate our schedule. (C) 2000
Elsevier Science B.V. All rights reserved
Pediatric Extra Renal Reno cellular Carcinoma with Xp11 Translocation Responding to Sunitinib, Everolimus and Metronomic Chemotherapy
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1,3-Bis(5′-methyl-4′-phenyl-2′-thiazolylimino)isoindoline
A new sterically hindered isoindoline-based 1,3-bis(5′-methyl-4′-phenyl-2′-thiazolylimino)isoindoline (1) was synthesized by fusion method with satisfyingly good yield. The structure of the newly synthesized compound was identified by FT-IR, UV-Vis, 1H-NMR, 13C-NMR and X-ray analysis