Structural transformations in crystals induced by radiation and pressure. Part 2. The path of a photochemical intramolecular reaction in crystals at different pressures

Konieczny, Krzysztof A.; Bąkowicz, Julia; Turowska‐Tyrk, Ilona

doi:10.1039/c5ce01238d

Cited by 15 publications

(12 citation statements)

References 57 publications

(63 reference statements)

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“…However, the crystallographic experiments on monitoring photochemical reactions and structural changes caused by them at high pressure are still rare. [1][2][3][4] Since pressure can influence the course of photochemical reactions and can change it in a different manner for different reactions, [1][2][3][4] further research is certainly required.…”

Section: Introductionmentioning

confidence: 99%

Structural transformations in crystals induced by radiation and pressure. Part 5. The influence of pressure on the course of the photochemical reaction in crystals of 2,6-difluorocinnamic acid

et al. 2016

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The [2 + 2] photodimerization of 2,6-difluorocinnamic acid was gradually induced in crystals by UV radiation at 0.5, 1.1 and 2.1 GPa. The crystal and molecular structures were determined before the photochemical reaction and for many of its steps. For the pure monomer structures, the following parameters were analyzed in order to gain knowledge of the influence of pressure on the reaction environment: (a) the volume of free space, (b) the geometry of close intermolecular interactions, including hydrogen bonds and (c) the geometry of intermolecular reactivity parameters. The following structural changes brought about by the [2 + 2] photodimerization at high pressure were monitored step-by-step: (a) the cell parameters and the cell volume, (b) the content of the monomer and the dimer, (c) the distance between the reactive carbon atoms in adjacent monomer molecules and (d) the geometry of mutual orientation of molecules in the crystals. The rate of the [2 + 2] photodimerization of 2,6-difluorocinnamic acid increased as follows: 0.1 MPa < 0.5 GPa < 1.1 GPa ≤ 2.1 GPa. This was rationalized by the decrease in the volume of free space columns protecting the intermolecular geometry suitable for the reaction and by the decrease of the distance between the reactive carbon atoms of adjacent monomer molecules.

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Section: Introductionmentioning

confidence: 99%

Structural transformations in crystals induced by radiation and pressure. Part 5. The influence of pressure on the course of the photochemical reaction in crystals of 2,6-difluorocinnamic acid

et al. 2016

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“…On the other hand, it should be taken into account that, in ambient conditions, the studied photochemical reaction proceeds with the increase of the unit cell volume (see Figure ) and that high pressure by counteracting this increase should decrease the reaction rate. The decrease of the rate of the Norrish-Yang reaction at high pressure was also observed in the case of another compound …”

Section: Resultsmentioning

confidence: 63%

The Reasons for Different Kinetics of the Norrish-Yang Reaction in Crystals. Structural and Spectroscopic Studies

Konieczny

Szczurek

Bąkowicz

et al. 2020

Crystal Growth & Design

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The kinetics of the photochemical Norrish-Yang reaction in single crystals was studied using the example of 1,3,5,7-tetraazatricyclo[3.3.1.13,7]decane 4-(2,4,6-triisopropylbenzoyl)benzoate by X-ray diffraction and Raman spectroscopy. The reaction in the studied compound proceeds in two stages described by the Johnson-Mehl-Avrami-Kolmogorov model. In the first stage the reaction progresses homogeneously at a constant rate, but for the second mode, which started at ca. 50% conversion, the reaction progresses with autoinhibition. The reasons for this autoinhibition are (i) the changes in the geometry of the reaction center during the second stage, which were not observed in the first stage, (ii) the C–H···π interactions, which become stronger along with the reaction progress, and (iii) the change in character of the carboxylate group toward the carboxylic-like group. The Norrish-Yang reaction also proceeds in crystals at 0.2 GPa, as stated on the grounds of the characteristic changes in the unit cell parameters along with UV irradiation.

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“…In the scientific literature there are known compounds that undergo the Norrish−Yang reaction for which D changes in one of the above manners. 11,15,28,29 The relationships described in the literature were interpreted as being a result of some stress of product molecules imposed on reactant molecules, which is stronger for a larger population of product molecules. 11,15,28,29 The same interpretation can be applied in the case of compound 1.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…Such an influence was evidenced quantitatively, for instance, in the case of benzylammonium, pyrrolidinium, and ammonium 4-(2,4,6-triisopropylbenzoyl)benzoate, 13 where the crystal lattice was changed by introducing different counterions and, in the case of benzylammonium 4-(2,4,6-triisopropylbenzoyl)benzoate, where the crystal lattice was modified by high pressure. 15 The role of the crystal lattice was also analyzed for 2,4,6-triisopropylbenzophenones with two molecules in the asymmetric unit. 10 The compound presented in this paper is the salt of 4-(2,4,6triisopropylbenzoyl)benzoic acid with methylamine, compound 1.…”

Section: ■ Introductionmentioning

confidence: 99%

Photoinduced Structural Changes as the Factor Influencing the Direction of the Photochemical Reaction in the Crystal

Konieczny

Bąkowicz

Siedlecka

et al. 2017

Crystal Growth & Design

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The path of the Norrish−Yang reaction of methylammonium 4-(2,4,6-triisopropylbenzoyl)benzoate was studied by means of X-ray structure analysis. The following parameters influenced by this photochemical reaction were monitored: (a) intramolecular distances and angles in the reaction center, (b) the size of the free space near the reactive atoms, (c) the mutual orientation of molecular fragments, (d) the cell parameters, and (e) the product content. Product molecules were created in two modes, namely, by the reaction of the 2-isopropyl or 6-isopropyl group, which has not been revealed previously for other 2,4,6triisopropylbenzophenones. The 2-isopropyl group took part in the photochemical reaction during the whole crystal transformation, whereas the reaction of the 6-isopropyl group started with a delay and ceased before the total crystal conversion. The reason for such behavior was explained by the analysis of changes in the free space near both o-isopropyl groups with the crystal phototransformation.

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Structural transformations in crystals induced by radiation and pressure. Part 2. The path of a photochemical intramolecular reaction in crystals at different pressures

Cited by 15 publications

References 57 publications

Structural transformations in crystals induced by radiation and pressure. Part 5. The influence of pressure on the course of the photochemical reaction in crystals of 2,6-difluorocinnamic acid

Structural transformations in crystals induced by radiation and pressure. Part 5. The influence of pressure on the course of the photochemical reaction in crystals of 2,6-difluorocinnamic acid

The Reasons for Different Kinetics of the Norrish-Yang Reaction in Crystals. Structural and Spectroscopic Studies

Photoinduced Structural Changes as the Factor Influencing the Direction of the Photochemical Reaction in the Crystal

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