Photoexcitation dynamics of p-nitroaniline and N,N-dimethyl-p-nitroaniline in 1-alkyl-3-methylimidazolium-cation based ionic liquids with different alkyl-chain lengths was written by Kimura, Y.;Ibaraki, S.;Hirano, R.;Sugita, Y.;Yasaka, Y.;Ueno, M.. And the article was included in Physical Chemistry Chemical Physics in 2017.Formula: C18H31F6N3O4S2 This article mentions the following:
Photoexcitation dynamics of p-nitroaniline (pNA) and N,N-dimethyl-p-nitroaniline (DMpNA) in 1-alkyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([Cnmim][NTf2]) with different alkyl chain lengths (from C2 to C12) was investigated using transient absorption spectroscopy. The internal conversion rate from the excited state to the ground state was estimated from bleach recovery around the ground state absorption center, and the successive vibrational cooling rate in the ground state was estimated from the decay of the hot band observed at the red-edge of ground state absorption. The internal conversion rate slightly decreased with an increase in the alkyl-chain length of the cation, while the dependence of DMpNA was more significant than that of pNA. The extent of change was correlated with the change of the reaction free energy and solvent reorganization energy estimated from the absorption spectrum assuming that the internal conversion process is modeled by a back-electron-transfer process. The vibrational cooling rate estimated from the decay of hot-band absorption slightly decreased with an increase in the alkyl-chain length of the cation for both solutes. The hot-band decay of pNA was about 1.5-times faster than that of DMpNA, irresp. of the alkyl-chain length. In the experiment, the researchers used many compounds, for example, 3-Dodecyl-1-methyl-1H-imidazol-3-ium bis((trifluoromethyl)sulfonyl)amide (cas: 404001-48-5Formula: C18H31F6N3O4S2).
3-Dodecyl-1-methyl-1H-imidazol-3-ium bis((trifluoromethyl)sulfonyl)amide (cas: 404001-48-5) belongs to imidazole derivatives. Imidazole is the basic core of some natural products such as histidine, purine, histamine and DNA based structures, etc. Among the different heterocyclic compounds, imidazole is better known due to its broad range of chemical and biological properties. This ring system is present in important biological building blocks, such as histidine and the related hormone histamine.Formula: C18H31F6N3O4S2
Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem