The vibrational spectra of classically chaotic systems are usually very complicated and seemingly unassignable. In this paper, two methods for the analysis of spectra of highly vibrationally excited polyatomic molecules are described, and some results for the floppy molecules HCN and LiNC are presented. By application of these methods, relevant information on the underlying dynamics is obtained, thus establishing a bridge between the spectroscopy and the dynamics of these systems.
{"title":"Theoretical Methods for the Analysis of Spectra of Highly Vibrationally Excited Polyatomic Molecules","authors":"F. Borondo, J. Llorente, R. M. Benito","doi":"10.1155/LC.12.85","DOIUrl":"https://doi.org/10.1155/LC.12.85","url":null,"abstract":"The vibrational spectra of classically chaotic systems are usually very complicated and seemingly unassignable. In this paper, two methods for the analysis of spectra of highly vibrationally excited polyatomic molecules are described, and some results for the floppy molecules HCN and LiNC are presented. By application of these methods, relevant information on the underlying dynamics is obtained, thus establishing a bridge between the spectroscopy and the dynamics of these systems.","PeriodicalId":296295,"journal":{"name":"Laser Chemistry","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129718750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Molecular dynamics in organic solution is investigated by the transient grating method with a nanosecond pulsed laser and a fast detection system. First, the dynamics of methyl red (MR) is studied for the probe of the translational diffusion process of solution. The origin of the TG signal which represents the mass diffusion is attributed to the phase grating created by the different refractive indices of the cis and trans forms. The cis form of MR, which has a slightly smaller molecular volume than the trans form is found to diffuse more slowly in alcoholic and aldehyde solutions. The measured diffusion coefficients (D) are compared with theoretically calculated values. Second, the TG method is applied to elucidate the dynamics of transient radicals created by photochemical reactions. The determined D of the radicals are about 3∼4 times smaller than those of the parent non-radical molecules even though the molecular volumes are similar to each other. The advantages as well as the disadvantages of the TG method for elucidating the solvent dynamics are discussed.
{"title":"MOLECULAR DYNAMICS IN SOLUTION PROBED BY THE TRANSIENT GRATING METHOD WITH A NANOSECOND PULSED LASER","authors":"M. Terazima, K. Okamoto, N. Hirota","doi":"10.1155/1994/84218","DOIUrl":"https://doi.org/10.1155/1994/84218","url":null,"abstract":"Molecular dynamics in organic solution is investigated by the transient grating method with a nanosecond pulsed laser and a fast detection system. First, the dynamics of methyl red (MR) is studied for the probe of the translational diffusion process of solution. The origin of the TG signal which represents the mass diffusion is attributed to the phase grating created by the different refractive indices of the cis and trans forms. The cis form of MR, which has a slightly smaller molecular volume than the trans form is found to diffuse more slowly in alcoholic and aldehyde solutions. The measured diffusion coefficients (D) are compared with theoretically calculated values. Second, the TG method is applied to elucidate the dynamics of transient radicals created by photochemical reactions. The determined D of the radicals are about 3∼4 times smaller than those of the parent non-radical molecules even though the molecular volumes are similar to each other. The advantages as well as the disadvantages of the TG method for elucidating the solvent dynamics are discussed.","PeriodicalId":296295,"journal":{"name":"Laser Chemistry","volume":"02 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129724861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hole burning experiments with two CO2 lasers have been performed to obtain insight in the predissociation mechanism of SF6-dimers. For the well known double peak predissociation spectrum, always two correlated holes are observed. Strongly enhanced widths of the holes are found for dimers with higher internal energy.
{"title":"Hole Burning in the IR Predissociation Spectrum of SF6-dimers","authors":"B. Heijmen, C. Liedenbaum, S. Stolte, J. Reuss","doi":"10.1155/LC.8.275","DOIUrl":"https://doi.org/10.1155/LC.8.275","url":null,"abstract":"Hole burning experiments with two CO2 lasers have been performed to obtain insight in \u0000the predissociation mechanism of SF6-dimers. For the well known double peak predissociation \u0000spectrum, always two correlated holes are observed. Strongly enhanced widths of the holes are found for dimers with higher internal energy.","PeriodicalId":296295,"journal":{"name":"Laser Chemistry","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129875977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yousuke Inagaki, S. Shamsuddin, Y. Matsumi, M. Kawasaki
Doppler profiles of H and D atoms from the reaction S(1D) with HD and a 1:1 mixture of H2 and D2 have been measured by a laser-induced fluorescence technique with a vacuum ultraviolet laser. An isotopic channel branching ratio of φ (SD + H)/φ (SH + D) is measured to be 0.9 ± 0.1 in the reaction of S(1D) + HD at average collision energy Ecoll = 1.2 kcal/mol. In S(1D) + HD, D2, and H2, the translational energies released are almost the same, 4.6 ± 0.5 kcal/mol for H and D production channels. The measured branching ratio and translational energy release suggest that the reaction proceeds via a long-lived complex formed by insertion.
{"title":"DYNAMICS OF THE REACTION S(1D) + HD, H2, AND D2: ISOTOPIC BRANCHING RATIOS AND TRANSLATIONAL ENERGY RELEASE","authors":"Yousuke Inagaki, S. Shamsuddin, Y. Matsumi, M. Kawasaki","doi":"10.1155/1994/86820","DOIUrl":"https://doi.org/10.1155/1994/86820","url":null,"abstract":"Doppler profiles of H and D atoms from the reaction S(1D) with HD and a 1:1 mixture of H2 and D2 \u0000have been measured by a laser-induced fluorescence technique with a vacuum ultraviolet laser. An \u0000isotopic channel branching ratio of φ (SD + H)/φ (SH + D) is measured to be 0.9 ± 0.1 in the reaction \u0000of S(1D) + HD at average collision energy Ecoll = 1.2 kcal/mol. In S(1D) + HD, D2, and H2, the translational \u0000energies released are almost the same, 4.6 ± 0.5 kcal/mol for H and D production channels. The measured \u0000branching ratio and translational energy release suggest that the reaction proceeds via a long-lived complex \u0000formed by insertion.","PeriodicalId":296295,"journal":{"name":"Laser Chemistry","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128383313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. Martínez, F. Basterrechea, B. Cabañas, P. Puyuelo, M. R. López
The comment of Billy et al.1 on our paper about the dynamics of the B and A states of chlorine2 emphasizes mainly two points: a) our results about the radiative decay rate of the B state of Cl2 are incorrect, because our experimental system is unable to measure the true long lifetimes of this state; b) both A Π 3 ( 1 u ) and Π 1 ( 1 u ) states contribute to the Coriolis predissociation in the B state, in contradiction with our mechanism, which excludes the Π 1 ( 1 u ) state.
Billy等人对我们关于氯气B态和A态动力学的论文的评论主要强调两点:A)我们关于氯气B态的辐射衰减率的结果是不正确的，因为我们的实验系统无法测量出这种状态的真正长寿命;b) A Π 3 (1u)和Π 1 (1u)态都有助于b态的科里奥利预解，这与我们排除Π 1 (1u)态的机制相矛盾。
{"title":"Comment: Reply to Comment on “Dynamics of the B Π3(0u+) and a Π3(1u) States of Chlorine by Laser Induced Fluorescence”","authors":"E. Martínez, F. Basterrechea, B. Cabañas, P. Puyuelo, M. R. López","doi":"10.1155/1994/48678","DOIUrl":"https://doi.org/10.1155/1994/48678","url":null,"abstract":"The comment of Billy et al.1 on our paper about the dynamics of the B and A states of chlorine2 \u0000emphasizes mainly two points: a) our results about the radiative decay rate of the B state of Cl2 are \u0000incorrect, because our experimental system is unable to measure the true long lifetimes of this state; b) \u0000both A Π 3 ( 1 u ) and Π 1 ( 1 u ) states contribute to the Coriolis predissociation in the B state, in contradiction \u0000with our mechanism, which excludes the Π 1 ( 1 u ) state.","PeriodicalId":296295,"journal":{"name":"Laser Chemistry","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128748644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Cefalas, M. Dubinskii, E. Sarantopoulou, R. Abdulsabirov, S. Korableva, A. Naumov, V. Semashko, C. Nicolaides
Laser action in the VUV and UV region of the spectrum at 172 nm and at 260 nm had been obtained from LaF3:Nd3
得到了LaF3:Nd3在172 nm和260 nm的紫外区和紫外区的激光作用
{"title":"ON THE DEVELOPMENT OF NEW VUV AND UV SOLID STATE LASER SOURCES FOR PHOTOCHEMICAL APPLICATIONS","authors":"A. Cefalas, M. Dubinskii, E. Sarantopoulou, R. Abdulsabirov, S. Korableva, A. Naumov, V. Semashko, C. Nicolaides","doi":"10.1155/1993/75972","DOIUrl":"https://doi.org/10.1155/1993/75972","url":null,"abstract":"Laser action in the VUV and UV region of the spectrum at 172 nm and at 260 nm had been obtained from LaF3:Nd3","PeriodicalId":296295,"journal":{"name":"Laser Chemistry","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131044343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The applications of high resolution laser techniques to crossed-beam experiments which are examined in this paper concern: (a) the reactivity of atomic/molecular excited states and the influence of light polarization and (b) the measurement of absolute and differential cross sections by use of the laserinduced fluorescence technique performed in a coherent saturation regime.
{"title":"High Resolution Laser Techniques Applied to Reaction Dynamics","authors":"R. Vetter","doi":"10.1155/LC.11.177","DOIUrl":"https://doi.org/10.1155/LC.11.177","url":null,"abstract":"The applications of high resolution laser techniques to crossed-beam experiments which are examined in \u0000this paper concern: (a) the reactivity of atomic/molecular excited states and the influence of light \u0000polarization and (b) the measurement of absolute and differential cross sections by use of the laserinduced \u0000fluorescence technique performed in a coherent saturation regime.","PeriodicalId":296295,"journal":{"name":"Laser Chemistry","volume":"107 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131933065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
It is well known that in principle energy-resolved and time-resolved experiments provide complementary information. A few examples are reviewed where the time evolution of rapidly relaxing molecular systems is or could be better studied by energy-resolved experiments: (1) the evolution of a pair of resonances coupled with each other through a set of continua, (2) an irreversible relaxation of the intermediate state in the two-photon excitation of a polyatomic molecule, and (3) the derivation of a “dissociation time” from the angular distribution of fragments from photodissociation by linearly polarized light. In the first case it is shown how all parameters necessary for a time-dependent description may be obtained from the measurement, as functions of the excitation wavelength, of both the total absorption cross section across the resonances and the partial cross section for a single exit channel. In the last two cases the relevance of a description in terms of an “eigentime” of the molecule is demonstrated.
{"title":"On the Extraction of Time Information From Energy-Resolved Experiments","authors":"J. Durup","doi":"10.1155/LC.3.85","DOIUrl":"https://doi.org/10.1155/LC.3.85","url":null,"abstract":"It is well known that in principle energy-resolved and time-resolved experiments \u0000provide complementary information. A few examples are reviewed where the time \u0000evolution of rapidly relaxing molecular systems is or could be better studied by \u0000energy-resolved experiments: (1) the evolution of a pair of resonances coupled with \u0000each other through a set of continua, (2) an irreversible relaxation of the intermediate \u0000state in the two-photon excitation of a polyatomic molecule, and (3) the derivation of \u0000a “dissociation time” from the angular distribution of fragments from photodissociation \u0000by linearly polarized light. In the first case it is shown how all parameters necessary \u0000for a time-dependent description may be obtained from the measurement, as functions \u0000of the excitation wavelength, of both the total absorption cross section across the \u0000resonances and the partial cross section for a single exit channel. In the last two \u0000cases the relevance of a description in terms of an “eigentime” of the molecule is \u0000demonstrated.","PeriodicalId":296295,"journal":{"name":"Laser Chemistry","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130920263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
B. Bourguignon, J. Rostas, G. Taieb, Mohammed-Ali Gargoura, J. Mccombie
The internal state distribution of MgO(a3Π) formed from Mg(3P) + O2 and N2O reactions was determined from a reanalysis of the laser induced fluorescence spectra of the d3Δ - a3Π system previously published by Dagdigian. The MgO(a3Π) state formed in the reaction with O2 has a quasi-Boltzmann distribution. In the N2O reaction the rotational excitation is much greater and the vibrational population distribution is inverted with a maximum at v = 2 - 3. The a3Π rovibrational population distributions are compared with those of the X1∑+ ground state. The dynamics of these reactions are discussed on the basis of earlier ab-initio calculations and experimental data.
{"title":"Internal Energy Distribution in MgO(a3Π) Formed From Mg(3P)","authors":"B. Bourguignon, J. Rostas, G. Taieb, Mohammed-Ali Gargoura, J. Mccombie","doi":"10.1155/LC.6.15","DOIUrl":"https://doi.org/10.1155/LC.6.15","url":null,"abstract":"The internal state distribution of MgO(a3Π) formed from Mg(3P) + O2 and N2O reactions was determined from a reanalysis of the laser induced fluorescence spectra of the d3Δ - a3Π system previously published by Dagdigian. The MgO(a3Π) state formed in the reaction with O2 has a quasi-Boltzmann distribution. In the N2O reaction the rotational excitation is much greater and the vibrational population distribution is inverted with a maximum at v = 2 - 3. The a3Π rovibrational population distributions are compared with those of the X1∑+ ground state. The dynamics of these reactions are discussed on the basis of earlier ab-initio calculations and experimental data.","PeriodicalId":296295,"journal":{"name":"Laser Chemistry","volume":"146 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130936155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Colombo, M. George, John N Moore, D. Pattison, R. Perutz, I. G. Virrels, T. Ye
Microsecond and picosecond time-resolved infrared studies of Ru(PPh3)3(CO)(H)2 have demonstrated that reductive elimination of H2 is complete within 5 ps of UV photolysis.
{"title":"Ultrafast Photodissociation ofHydrogen From Ru(PPh3)3(CO)(H)2:A Time-Resolved Infrared Study","authors":"M. Colombo, M. George, John N Moore, D. Pattison, R. Perutz, I. G. Virrels, T. Ye","doi":"10.1155/1999/91069","DOIUrl":"https://doi.org/10.1155/1999/91069","url":null,"abstract":"Microsecond and picosecond time-resolved infrared studies of Ru(PPh3)3(CO)(H)2 have demonstrated that reductive elimination of H2 is complete within 5 ps of UV photolysis.","PeriodicalId":296295,"journal":{"name":"Laser Chemistry","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130233119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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