화학공학소재연구정보센터
Journal of Physical Chemistry, Vol.98, No.17, 4677-4682, 1994
Raman-Spectra of the Unidimensional Aluminophosphate Molecular-Sieves ALPO(4)-11, ALPO(4)-5, ALPO(4)-8, and VPI-5
Laser Raman scattering spectra of the unidimensional molecular sieves AlPO4-11, AlPO4-5 (with and without Pr3N template), AlPO4-8, and VPI-5 are reported. The lattice deformation region, ca. 300-500 cm(-1), was observed to become increasingly complex as the contents of the Bravais cell increased and the factor group symmetry was reduced. Bands at ca. 400 and ca. 500 cm(-1), absent in the Raman spectrum of alpha-AlPO4 (berlinite), were attributed to the presence of four T-atom rings in the above molecular sieve structures. Bands at ca. 260-310 cm(-1) were ascribed to "pore-breathing" framework vibrational modes. The frequency (v) of these bands displayed a linear relationship of v(2) proportional to cos theta, where theta is dependent on the average Al-O-P angle around the unidimensional channel of each of these molecular sieve materials.