Empirical treatment of solvent-solute interactions: medium effects on the electronic absorption spectrum of ?-carotene

Abstract

Solvent effects on the wavenumber of the maximum of the longest wavelength electronic absorption band of all-trans-b-carotene were determined in 34 solvents. Together with results from previous studies, a data set for 51 solvents, mostly non-hydrogen bond donors, was constructed. This information was analyzed in terms of reaction field models and also showed its value for correlation purposes when used either alone or in combination with standard empirical solvent polarity-polarizability scales.

On the use of β‐carotene as a probe for solvent polarizability

“…Also, in 1998, Abe et al . found that the function f ( n ) = ( n 2 − 1)/( n 2 + 1) can be related to the absorption maxima of β‐carotene in nonpolar solvents by Eqn , from which they estimated the absorption maximum in the gas phase to be 0 = 24 678 cm −1 : with n = 17, r = 0.996, and sd = 31 cm −1 .…”

“…in reference), and we used the 0–0 component of its first absorption band to develop an empirical solvent polarizability scale called SP scale. Before employing ttbP9, our group had examined many other polyenes (including β‐carotene) but concluded that, as shown by the available evidence – and discussed below –, they failed to meet the requirements. Thus, Andersson et al .…”

“…found that the peak maxima of their target absorption bands undergo a red shift with increasing polarizability of the medium, and that the position of the maxima also depends additionally on solvent polarity. Abe et al . found that not only β‐carotene behaves differently in polar and nonpolar solvents, but also that its UV/Vis spectrum is dependent on the acidity of the medium.…”

Critical compilation of scales of solvent parameters. Part I. Pure, non-hydrogen bond donor solvents

“…It is also much more sensitive to medium effects than the long wavelength absorption band of these compounds. This has prompted Abe and colleagues [66] to extend the study of the long wavelength absorption band of ␤-carotene to a wider set of solvents at 25.0 ЊC and 0.1 MPa. Their results are also presented in the compilation.…”

Investigation of structural effects on the anticonvulsant activity of 3,5-disubstituted-5-phenylhydantoins by the linear solvation relationship method

“…Репрезентативан пример за полиенске π-системе је β-каротен. Његова π→ π* апсорпција на око λmax = 454 nm помери се за само Δν = 239 cm -1 (Δλmax = 5 nm) при промени растварача од циклохексана до метанола [85]. Пример за полиметински π-систем је хептаметинијумска цијанинска боја (слика 1.13), чија се π→ π* апсорпциона трака батохромно помери за Δν = 304 cm -1 (Δλmax = 17 nm) при промени растварача од метанола до хлороформа [86].…”