Diffuse reflectance UV-visible in combination with FT-Raman spectroscopies demonstrate the total incorporation without any solvent of p-terphenyl (p-TP) as an intact molecule in the medium size channel of non-acidic M(n)ZSM-5 (M = Li(+), Na(+), K(+), Rb(+), Cs(+) and n = 0, 3.4, 6.6) zeolites. The combined effects of confinement and electrostatic field induced by alkaline ions in the M(n)ZSM-5 zeolites lead only to weak conformational changes in the occluded p-TP after very long organization periods. The interaction between the counterbalancing cation and p-TP occurs through one phenyl group facially coordinated to the cation near the O atoms binding Al atoms. The laser UV photolysis of p-terphenyl occluded as intact molecules in non-acidic M(n)ZSM-5 zeolites generates long-lived charge separated states. The photoionization induces a p-TP*(+)-electron pair as a primary phenomenon. The recombination of the p-TP*(+)@M(n)ZSM-5*(-) radical cation moiety occurs mainly through unusual electron abstraction from the zeolite framework and p-TP@M(n)ZSM-5*(-)*(+) electron-hole pair formation which exceeds several days at room temperature in Li(6.6)ZSM-5. The very long-lived radical pairs are characterized by conventional DRUVv, FT-Raman and CW-EPR spectroscopy. Two-dimensional hyperfine sublevel correlation (2D-HYSCORE) experiments reveal the structural surroundings of the unpaired electrons through the proper assignment of unpaired electron couplings. The subsequent hole transfer from the radical cation of the channels as well as the final electron-hole pair recombination appear to be largely controlled by the aluminium content, the size of the extra framework cation and the associated local electrostatic field. The effects of the counterbalancing cations have been investigated and because the zeolite electron affinity increases on going from Li(+) to Cs(+), the electron transfer rates increase according to the following order Li(+) < Na(+) < K(+) < Rb(+) < Cs(+).

The locations of Brønsted acid sites (BAS) in the channels of medium-pore zeolites have a significant effect on the spontaneous ionization of para-terphenyl (PP(3)) insofar as spatial constraints determine the stability of transition states and charge-transfer complexes relevant to charge separation. The ionization rates and ionization yield values demonstrate that a strong synergy exists between the H(+) polarization energy and spatial constraints imposed by the channel topology. Spectroscopic and modeling results show that PP(3) incorporation, charge separation, charge transfer and charge recombination differ dramatically among zeolites with respect to channel structure (H-FER, H-MFI, H-MOR) and BAS density in the channel. Compartmentalization of ejected electrons away from the initial site of ionization decreases dramatically the propensity for charge recombination. The main mode of PP(3)(.+) decay is hole transfer to form AlO(4)H(.+) ⋅⋅⋅PP(3) charge-transfer complexes characterized by intense absorption in the visible range. According to the nonadiabatic electron-transfer theory, the small reorganization energy in constrained channels explains the slow hole-transfer rate.

Zinc oxide nanoparticles (ZnO NPs) are prepared by sol-gel process, using both polyethylene glycol (PEG-400) as surfactant and propyltrimethoxysilane (PTMS) as capping agent. Surface modification is performed in situ procedure. The physical parameters such as strain and stress values are calculated via the Williamson-Hall plot (W&H) assuming a uniform deformation model (UDM) and uniform stress deformation model, and by the size and strain plot method (SSP). The results show that the crystallite size estimated from Scherrer's formula, (W&H), (UDM), (SSP) and the particle size estimated from DSL are inter-correlated, which confirm the small size and the isotropic nature of our ZnO NPs. The FTIR spectroscopy illustrates that PEG-400 and PTMS could be adsorbed at the ZnO NPs surface. The distinct emission peak in the blue band is located at 490 nm and E 2 (high) mode is situated at 436 cm -1 . Both results confirm the oxygen deficiency in the ZnO NPs.