Effect of Temperature on the Dynamics of Benzophenone Anion Solvation in Alcohol

Abstract

The solvation of the benzophenone anion in 1-propanol, 2-propanol, and 1-butanol has been measured over the temperature range -10 to -50°C. The initial spectra of the benzophenone anion were very similar in all three alcohols. The final spectrum of the benzophenone anion in 2-propanol is less blue-shifted (17 nm) than the spectrum of the anion in 1-propanol and 1-butanol. The activation energies for solvation are 22 kJ/mol for 1 propanol and 1-butanol and 16 kJ/mol for 2-propanol, which are similar to the energy for hydrogen bond breakage in the pure solvents. This suggests that the solvent H-bond

Picosecond Pulse Radiolysis Study of Dynamics of Solvation of Electron and Fluorenone Anion in Primary Alcohols

“…We have studied the dynamics of solvation of high energy (7 MeV) electrons injected directly into the solvent from an electron accelerator as well as several anionic species generated via direct capture of dry electron in linear alcohols having alkane chain lengths longer than five carbon atoms, i.e.1-pentanol and higher alcohols, using picosecond pulse radiolysis technique with about 15 ps time resolution. One of our motivation was focused on the solvation times of the fluorenone anion in the context of the earlier works of Jonah and co-workers, which report solvation times for electrons and benzophenone anion much faster than that for dipoles. ,− in the present work, we find that both electron and anion solvation processes are multiexponential in alcohols and the time scales are widely different.…”

“…450 nm. This kind of time evolution of the TA spectra has earlier been shown to be associated with the dipolar or anion solvation process, which is a consequence of lowering the free energy of the dipole or anion because of reorganization of the solvent molecules around it. ,− …”

“…Works of Marignier and Hickel , inspired Jonah and co-workers to further investigate solvation of benzophone anion in alcohols at room temperature using picosecond pulse radiolysis techniques. This led Jonah to publish an important series of papers from 1992 to 2003 mainly about benzophenone anion solvation and its comparison with that of electron as well as dipoles. ,,,,− For alcohols such as 1-propanol and 2-propanol, it was necessary to lower the temperature in the range 263–223 K to slow down the process, which was too rapid at room temperature to be measured . For larger alcohols, such as 1-butanol, 1-decanol, or 1-octanol, measurements could be achieved at room temperature. , Their works proposed that the spectral shift obey unambiguously to a continuous process and that the rotational motion of the C–OH bond influencing it.…”

Molecular Dynamics Simulation of Solvation Dynamics in Methanol−Water Mixtures

“…Further, we explore the effects of solute−solvent H-bonding on solvation dynamics by investigating the composition dependence of the solvation structure and by calculating the solute−solvent H-bond response functions in addition to S ( t ). It should be noted that several experimental studies of solvation dynamics in alcohols point to the contributions of solute−solvent H-bonding to this process. − For example, Jonah and co-workers 35 found that solvation dynamics of the benzophenone anion in various alcohols is considerably faster than predicted on the basis of nonspecific solvation models. ,, Evidence of specific solvation due to solute−solvent H-bond formation has been found by Berg and co-workers 36 for the absorption recovery of resorufin in ethanol and ethylene glycol and by Rullière and co-workers 35 for the fluorescence of the chromophore MPQB in 1-propanol. Maroncelli and co-workers 37 studied the solute dependence of solvation dynamics in 1-propanol and found that S ( t ) of some classes of chromophores differs considerably from what one would expect on the basis of nonspecific solvation models and that this difference can be correlated with the likely magnitude of the change in solute−solvent H-bond energies on electronic excitation.…”

Determination of Solubility and Thermodynamic Properties of Benzophenone in Different Pure Solvents

“…As an important organic intermediate, benzophenone (C 13 H 10 O, 182.2 g/mol, CAS: 119-61-9, Figure ) is widely used in the synthesis process of organic pigments, medicines, spices, and pesticides and is used as a photo initiator . Though the preparation of benzophenone has been well-known, the development of the crystalliztion to obtain highly stable and high purity products has still not been investigated well. , In order to get deeper insight into the crystallization process and the design of the crystallization strategy for benzophenone, it is important to establish the accurate equilibrium between the solid and liquid forms of benzophenone in different pure solvents. According to the survey of literatures, however, no reports related to the thermodynamics, especially to the solubility of benzophenone, have been published.…”