12979

1087 دكتري

دكتري

شيمي فيزيك

اصفهان: دانشگاه صنعتي اصفهان، دانشكده شيمي

۱۳۹۶

بيست، [۱۴۷]ص.: مصور، جدول، نمودار

حسين فرخ پور

محمود تبريزچي، كيامرث اسكندري

بيژن نجفي، حسن حدادزاده، رضا اميديان

1396/08/15

كتابنامه

شيمي

شيمي

ID1087 دكتري

Study of Ionization and Excitation of Helium Nanoclusters and Doped SF6 in the Gas Phase Maryam Dehdashti Jahromi m dehdashti@ch iut ac ir madehdashti@gmail com 2017 Department of Chemistry Isfahan University of Technology Isfahan 84156 83111 Iran supervisor Dr H Farrokhpour h farrokh@cc iut ac ir farrokhphossein@gmail com AbstractIn this thesis the helium He nanoclusters in the size range of 2 to 100 He atoms were considered The structures belong to di erent symmetry point groups Besides the SF6 molecule was selectedand put inside the He nanoclusters including 20 40 and 60 He atoms The structures were optimizedemploying DFT methods The He2 to He29 nanoclusters were used to study the absorption spectraat the CIS 6 311 G 2d p level of theory The photoelectron spectra of He structures in the sizerange of 2 to 100 He atoms were calculated using SAC CI 6 31 G 3df level of theory The spectro scopic properties of SF6 in the He nanoclusters including the photoelctron spectrum the absorptionspectrum and IR and Raman spectra of doped SF6 and the e ect of the size on these spectroscopicproperties were studied The absorption spectra and the photoelectron spectra were plotted Thephotoelectron spectra were compared to each other and compared to experimental spectrum and theionization bands were assigned using NBO methods For the rst time in this thesis the intermolec ular interaction e ect and the deformation e ect on the spectroscopic properties were separatedlystudied It was found that the shape of the absorption spectra were generally independant of thecluster size The excitation energies of He20 and He29 were compared with the experimental spec tra It was deduced that the rst ionization energies were independant of the size in the range ofn 50 and the variation of the calculated rst ionization energies versus the size were tted into anextended Morse potential equation The e ect of intermolecular interaction on the photoelctron andabsorption spectra of SF6 reduced by the increase of the size so that the spectra in the bigger clustersof He resemble to the related spectra of free SF6 It was found that the intermolecular interactione ect on the absorption spectrum of SF6 was more than that on its photoelectron spectrum By theincrease of the size the intermolecular interaction e ect decreases Keywords Helium nanocluster photoelectron spectrum absorption spectrum SF6 molecule SAC CI calculation TD DFT Introduction During the past decade helium nano clusters and nano scale droplets have been used as a uniquecryogenic matrix for spectroscopy of dopants immersed in the He droplets interior or located on thesurface of a droplet 13 He nano structures can be formed when the attraction energies among thehelium atoms are comparable with their kinetic energies The sizes of the helium nano structuresmay vary in the range of several to many thousands of atoms and in the latter case they shouldbe called helium nano droplets Helium nano droplets are transparent for visible and UV light and

حسين فرخ پور

محمود تبريزچي، كيامرث اسكندري

بيژن نجفي، حسن حدادزاده، رضا اميديان