SYNTHESIS AND SPECTROSCOPIC CHARACTERIZATION OF ZINC TETRA(3,4-PYRIDINE)PORPHYRAZINE ENTRAPPED WITHIN THE SUPERCAGES OF Y-ZEOLITE

In this work, the generation of Y-zeolite-entrapped zinc tetra(3,4-pyr idine)porphyrazine (ZnPz-Z) at several loading levels is reported. The ZnPz-Z samples were obtained using the template synthesis method invo lving condensation of 3,4-dicyanopyridine (DCP) around Zn2+ cations wh ich had been ion-exchanged into the Y-zeolite supercages (Zn2+-Z). The integrity of the sample was documented by diffuse reflectance (DR), e mission (Em) and resonance Raman (RR) spectroscopic data. The Raman sp ectrum for the ground state ZnPz-Z intrazeolitic complex, with the las er excitation at lambda(ex) = 568.2 nm. closely matched that obtained for the free ZnPz porphyrazine, with some bands exhibiting slight freq uency shifts of 1-5 cm(-1). The DR spectrum of ZnPz-Z exhibited maxima at lambda(max) = 414 and 682 nm. and the emission spectrum of ZnPz-Z revealed fluorescence at lambda(em) = 705 nm, with lambda(ex) = 350.9, 406.7. or 647.1 nm. This emission was 22 nm red shifted with respect to that recorded for the free ZnPz complex in pyridine solution and 24 nm red shifted relative to that acquired fur the ZnPz complex adsorbe d on the outer surface of the zeolite. Pill these spectroscopic data s uggest that the: ZnPz molecules within the zeolite supercages were onl y slightly distorted. The ZnPz-Z samples contain a small amount of lum inescent (lambda(em) = 500 nm) impurities assigned to products of 3,4- dicyanopyridine noncyclic condensation.