Heat of reaction and reaction volume for the formation of ethers from diazo compounds in methanol

Yamaguchi, Shinji; Hirota, Noboru; Terazima, Masahide

doi:10.1016/s0009-2614(98)00101-8

Cited by 16 publications

(14 citation statements)

References 25 publications

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“…The method has been applied to study the photodissociation of diphenylcyclopropenone 90,91 and diazo compounds. 92 Finally, it has been suggested that fast structural changes may generate a grating signal with a rate constant different from the rate at which the density grating of thermal origin is formed. 95 However, unequivocal experimental confirmation of this is still missing.…”

Section: Separation Of Various Contributions To the Refractive Index ...mentioning

confidence: 99%

Time-resolved photothermal methods: accessing time-resolved thermodynamics of photoinduced processes in chemistry and biology

Gensch

Viappiani

2003

Photochem Photobiol Sci

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Photothermal methods are currently being employed in a variety of research areas, ranging from materials science to environmental monitoring. Despite the common term which they are collected under, the implementations of these techniques are as diverse as the fields of application. In this review, we concentrate on the recent applications of time-resolved methods in photochemistry and photobiology.

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Section: Separation Of Various Contributions To the Refractive Index ...mentioning

confidence: 99%

Time-resolved photothermal methods: accessing time-resolved thermodynamics of photoinduced processes in chemistry and biology

Gensch

Viappiani

2003

Photochem Photobiol Sci

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“…[3][4][5][6][7] On the other hand, the positive ␦n s 0 means that this chemical species is created by the reaction ͑product͒. [3][4][5][6][7] On the other hand, the positive ␦n s 0 means that this chemical species is created by the reaction ͑product͒.…”

Section: Resultsmentioning

confidence: 99%

“…Our group so far has applied these techniques to reveal the dynamics of photoexcited states, 1-3 photodissociation reaction of diphenylcyclopropenone, 4 isomerization reaction of azobenzene and p-coumaric acid, 5,6 protein dynamics after photoexcitation, and so on. This property makes the photothermal technique very powerful to study chemical reactions, because the energetics and the volume changes associated with the reactions are essential properties to understand the reaction.…”

Section: Introductionmentioning

confidence: 99%

Energy and volume changes induced by photoinitiated proton releasing reaction with apomyoglobin

Choi

Terazima

2003

Review of Scientific Instruments

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“…Then it is considered that the generated globule molecule as a product species and the coil molecule as a reactant species counter-propagate due to diffusion, which would be the origin of the HD-TG response. It is known that the refractive index is sensitive to the molecular volume changes due to changes in polarizability, 36,37 this effect has been utilized for detection of protein folding and unfolding processes, etc. 38,39 So far, it has been believed that the turbidity relaxation corresponded due to the process of the globule-to-coil transition, 15 but we consider that it corresponds to the process from aggregates to globule molecules.…”

Section: Microscopic Observationmentioning

confidence: 99%

Conformational relaxation dynamics of a poly(N-isopropylacrylamide) aqueous solution measured using the laser temperature jump transient grating method

Inoue

Katayama

Iwai

et al. 2012

Phys. Chem. Chem. Phys.

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We observed phase transition and phase relaxation processes of a poly(N-isopropylacrylamide) (PNIPAM) aqueous solution using the heterodyne transient grating (HD-TG) method combined with the laser temperature jump technique. The sample temperature was instantaneously raised by about 1.0 K after irradiation of a pump pulse to crystal violet (CV) molecules for heating, and the phase transition was induced for the sample with an initial temperature just below the lower critical solution temperature (LCST); the following phase relaxation dynamics was observed. Turbidity relaxation was observed in both the turbidity and HD-TG responses, while another relaxation process was observed only in the HD-TG response, namely via the refractive index change. It is suggested that this response is due to formation of globule molecules or their assemblies since they would have nothing to do with turbidity change but would affect the refractive index, which is dependent on the molar volume of a chemical species. Furthermore, the grating spacing dependence of the HD-TG responses suggests that the response was caused by the counter propagating diffusion of the coil molecules as a reactant species and the globule molecules as a product species and the lifetime of the globule molecules ranged from 1.5 to 5 seconds. Thus, we conclude that the turbidity reflects the dynamics of aggregate conditions, not molecular conditions. The coil and globule sizes were estimated from the obtained diffusion coefficient. The sizes of the coil molecules did not change at the initial temperatures below the LCST but increased sharply as it approaches LCST. We propose that the coil-state molecules associate due to hydrophobic interaction when the initial temperature was higher than LCST minus 0.5 K and that the globule-state molecules generated from the coil-state molecules showed a similar trend in temperature. The phase transition was also induced by heating under a microscope, and the relaxation process was followed using the fluorescence peak shift of a fluorescent molecule-labeled PNIPAM. The result also supports the existence of a globule molecule or its assembly remains for several seconds in the phase relaxation.

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Heat of reaction and reaction volume for the formation of ethers from diazo compounds in methanol

Cited by 16 publications

References 25 publications

Time-resolved photothermal methods: accessing time-resolved thermodynamics of photoinduced processes in chemistry and biology

Time-resolved photothermal methods: accessing time-resolved thermodynamics of photoinduced processes in chemistry and biology

Energy and volume changes induced by photoinitiated proton releasing reaction with apomyoglobin

Conformational relaxation dynamics of a poly(N-isopropylacrylamide) aqueous solution measured using the laser temperature jump transient grating method

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