Incorporation and electron transfer of anthracene in pores of ZSM-5 zeolites. Effect of Brønsted acid site density.

The sorption course of anthracene (ACENE-3) into Brønsted-acidic medium pore MFI zeolites was monitored by in situ EPR and diffuse reflectance UV-visible absorption over one year. Weighed amounts of solid ACENE-3 were merely exposed to H(n)ZSM-5 (H(n)(AlO(2))(n)(SiO(2))(96-n)), with the following Brønsted acid site (BAS) densities, n = 0.0, 0.

Photochemistry of a chiral salen aluminum complex in nonconventional solvents: use of imidazolium ionic liquids and chiral alcohols.

The photochemistry of a chiral (salen)aluminum(III) chloride complex has been studied in nonconventional solvents, namely, two imidazolium ionic liquids differing on the hydrophobicity (hydrophilic BF(4)(-) or hydrophobic PF(6)(-) counter anions) and in chiral 2-butanols (R and S). Upon 355 nm laser excitation, the same transient absorption spectrum (with some solvatochromic shift in lambda(max)) was recorded in all cases and assigned to the (salen)Al(II) complex with radicaloid character at the metal atom. This intermediate arises from the photoinduced homolytic cleavage of the apical Al-Cl bond.

Photoinduced electron transfer in ionic liquids: use of 2,4,6-triphenylthiapyrylium as a photosensitizer probe.

The photochemistry of 2,4,6-triphenylthiapyrylium, TPTP+, in an ionic liquid, bmim-PF6, and in zeolite Y has been investigated and compared. Fluorescence spectroscopy was used to characterize the singlet excited state and to demonstrate singlet quenching by dicyclopentadiene, DCP, as an electron donor. Time-resolved laser spectroscopy documents generation of the triplet excited state, 3TPTP+, and reduction by DCP, generating the corresponding radical, TPTP*, and radical ion, DCP+*.

Long-lived radical cation-electron pairs generated by anthracene sorption in non Brønsted acidic zeolites.

The sorption of anthracene (ANT) in non Brønsted acidic ZSM-5 zeolite through the mere exposure at room temperature of solid ANT and dehydrated zeolite crystals with Li(3.4)(AlO2)n(SiO2)(96-n) chemical formulas per unit cell generates spontaneous ionization of ANT (IP 7.44 eV in the gas phase).

Incorporation of anthracene into zeolites: confinement effect on the recombination rate of photoinduced radical cation-electron pair.

FT-Raman spectrometry in combination with diffuse reflectance UV/Vis absorption (DRUVv) and fluorescence emission indicate that complete anthracene (ANT) sorption as intact molecules takes place over 6 months in the medium pores of non-Brønsted acidic M(n)ZSM-5 zeolites (n=0.0, 3.4, 6.

Long-lived spin-correlated pairs generated by photolysis of naphthalene occluded in non-Brønsted acidic ZSM-5 zeolites.

Long-lived spin-correlated pairs were generated by laser irradiation of naphthalene (NAP) occluded as intact molecule within non-Brønsted acidic MnZSM-5 zeolites with MnSiO(2))(96-n)(AlO(2)n formula per unit cell. The laser UV photoionization generates primary NAP.+-electron pair as a fast phenomenon.