{"@context":"http://iiif.io/api/presentation/2/context.json","@id":"https://repo.library.stonybrook.edu/cantaloupe/iiif/2/manifest.json","@type":"sc:Manifest","label":"Analysis of the vibrational structure in the electronic \nspectra of molecules: Phenylacetylene as a prototype \nmolecule","metadata":[{"label":"dc.description.sponsorship","value":"This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree."},{"label":"dc.format","value":"Monograph"},{"label":"dc.format.medium","value":"Electronic Resource"},{"label":"dc.identifier.uri","value":"http://hdl.handle.net/1951/59769"},{"label":"dc.language.iso","value":"en_US"},{"label":"dc.publisher","value":"The Graduate School, Stony Brook University: Stony Brook, NY."},{"label":"dcterms.abstract","value":"Experimental studies of \nphenylacetylene (PA) in the gas phase previously revealed an unusual new \nset of photophysical properties following the S1←S0 \nexcitation. The decay of the initially excited level showed the expected \nshort (75ns) lifetime component assigned to the S1 state and a second \nvery long lifetime (>100 microsec) component that were both created \nduring the excitation laser pulse [Hofstein J., Xu H., Sears T. J., \nJohnson P. M., J. Phys. Chem. A 112 (2008)].  To investigate the \nidentity and formation mechanism of the long-lived species, a good \nunderstanding of the vibrational structure in the S1←S0 \nspectrum of PA is required. The interaction of the vibrational and \nelectronic (vibronic) motions was calculated in order to predict the \nS1 and \u2190S0 electronic spectrum of PA using a combination of \ntime-dependent density functional theory (TD-DFT) electronic structure \ncodes, Franck-Condon integral calculations, and a second order vibronic \nmodel developed previously [Johnson P. M., Xu H. F., Sears T. J., J. \nChem. Phys. 125 (2006)]. The sensitivity of the calculations to \ndifferent DFT functionals (B3LYP, LC-BLYP and CAM-B3LYP) and basis sets \n(aug-cc-pVDZ and aug-cc-pVTZ) was explored and compared to accurate \nexperimental relative intensities of the vibrational bands up to \nenergies of 2000 cm-1 above the band origin obtained by recording the \nS1(A 1B2) and #61663; S0(X 1A1) electronic transition using \nresonance-enhanced multiphoton ionization spectroscopy (1+1 REMPI) in a \nmolecular beam and cavity-ringdown (CRD) absorption spectroscopy in a \nslit jet-cooled sample. The long-range corrected functional CAM-B3LYP \nresulted in a 5 times bigger equilibrium transition moment than B3LYP, a \nresult more closely matching the observations. The LC-BLYP result is yet \n36% higher than CAM-B3LYP.  It was observed that CAM-B3LYP produced a \ngood match to most of the experimental spectrum. However, a superior \nmatch was observed when the CAM-B3LYP equilibrium transition moment and \nthe moment derivatives from the B3LYP calculation were combined in the \nsimulation. Results from the CRD experiment showed errors in relative \nintensities derived from the REMPI spectra, showing that REMPI \nspectroscopy is a less than accurate technique in this regard.  Further \npump-probe photoionization experiments not only confirmed Hofstein et \nal.'s observations but showed that some of strong assigned \nvibrational modes (\u039d\u0392cc and \u039d15) enhanced the formation of \nthe long-lived species compared to others. The motion of the atoms in \n\u039d\u0392cc and \u039d15, along with the computational analysis of the \nenergies of electronic states of different PA isomers with respect to \nthe S1 state of PA., suggest isomer formation as a possible explanation \nfor the observed long-lived species.  The triplet ground state of \nCycloocta-1,3,5-trien-7-yne (COTY), for example, appears to be a good \ncandidate However, the evidence is still far from conclusive and \nadditional experimental work is required to investigate the intriguing \ncomplexity in the photophysics of PA."},{"label":"dcterms.available","value":"2013-05-22T17:35:08Z"},{"label":"dcterms.contributor","value":"Sears, Trevor J"},{"label":"dcterms.creator","value":"Lopez, Gary Vladimir"},{"label":"dcterms.dateAccepted","value":"2015-04-24T14:47:03Z"},{"label":"dcterms.dateSubmitted","value":"2013-05-22T17:35:08Z"},{"label":"dcterms.description","value":"Department of Chemistry"},{"label":"dcterms.extent","value":"204 pg."},{"label":"dcterms.format","value":"Monograph"},{"label":"dcterms.identifier","value":"http://hdl.handle.net/1951/59769"},{"label":"dcterms.issued","value":"2012-08-01"},{"label":"dcterms.language","value":"en_US"},{"label":"dcterms.provenance","value":"Made available in DSpace on 2015-04-24T14:47:03Z (GMT). No. of bitstreams: 3\nLopez_grad.sunysb_0771E_11007.pdf.jpg: 1894 bytes, checksum: a6009c46e6ec8251b348085684cba80d (MD5)\nLopez_grad.sunysb_0771E_11007.pdf.txt: 265181 bytes, checksum: 501df2b2f38ea0e1c3345af1a5ed9491 (MD5)\nLopez_grad.sunysb_0771E_11007.pdf: 4458822 bytes, checksum: 862482515965f0868262e5d0887291bb (MD5)\n  Previous issue date:    1"},{"label":"dcterms.publisher","value":"The Graduate School, Stony Brook University: Stony Brook, NY."},{"label":"dcterms.subject","value":"Chemistry--Physical \nchemistry"},{"label":"dcterms.title","value":"Analysis of the vibrational structure in the electronic \nspectra of molecules: Phenylacetylene as a prototype \nmolecule"},{"label":"dcterms.type","value":"Dissertation"},{"label":"dc.type","value":"Dissertation"}],"description":"This manifest was generated dynamically","viewingDirection":"left-to-right","sequences":[{"@type":"sc:Sequence","canvases":[{"@id":"https://repo.library.stonybrook.edu/cantaloupe/iiif/2/canvas/page-1.json","@type":"sc:Canvas","label":"Page 1","height":1650,"width":1275,"images":[{"@type":"oa:Annotation","motivation":"sc:painting","resource":{"@id":"https://repo.library.stonybrook.edu/cantaloupe/iiif/2/11%2F86%2F20%2F118620742644810254770321501198895123263/full/full/0/default.jpg","@type":"dctypes:Image","format":"image/jpeg","height":1650,"width":1275,"service":{"@context":"http://iiif.io/api/image/2/context.json","@id":"https://repo.library.stonybrook.edu/cantaloupe/iiif/2/11%2F86%2F20%2F118620742644810254770321501198895123263","profile":"http://iiif.io/api/image/2/level2.json"}},"on":"https://repo.library.stonybrook.edu/cantaloupe/iiif/2/canvas/page-1.json"}]}]}]}