Convenient solvatochromic probes for the determination of solvent properties: β-carotene and 2-chloro-7-nitro-9H-fluorene

Journal of the Brazilian Chemical Society

Omar A. El Seoud¹  Paulo A. R. Pires¹  Carina Loffredo¹  Muhammad Imran¹  Paolo D. Pulcini¹  Michelle F. Corrêa¹  Rizwana Mustafa¹ 

[1] ,University of São Paulo Institute of Chemistry São Paulo SP ,Brazil

关键词: solvatochromism;    solvent dipolarity;    solvent dipolarity;    solvent polarizability;    β-carotene;   

DOI  :  10.5935/0103-5053.20130142

来源: SciELO

【 摘 要 】

Solvent dipolarity/polarizability (SDP) has been previously calculated from the UV-Vis spectra of 2-(N,N-dimethylamino)-7-nitro-9H-fluorene and 2-fluoro-7-nitro-9H- fluorene. Based on theoretical calculations (23 solvents) and experimental data (56 solvents), it is shown that 2-chloro-7-nitro-9H-fluorene (commercially available) can be conveniently employed for the calculation of this property, instead of its 2-fluoro-7-nitro counterpart. The splitting of SDP into its components (solvent dipolarity (SD) and polarizability (SP)) requires the use of a synthetic polyene compound whose synthesis is laborious, involving 15 steps. Our research group has recently shown that the natural dye β-carotene can be conveniently employed for the determination of SP, allowing the calculation of SD. Using these solvatochromic probes, SDP, SP and SD for a series of 1-bromoalkanes were calculated. For several homologous series, the dependence of solvent SDP (SD and SP for one series) on the number of carbon atoms in the 1-alkyl- or acyl-group was calculated and discussed.

【 授权许可】

CC BY   
 All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License