Table 2 Characteristic Raman bands and their corresponding assignments

Framework Si–O and Al–O vibration in the zeolite³⁹

Stretching vibration of C–Br bond in 3-bromopropylamine⁴⁰

N–CH₃ stretching and ring bending (in-plane)⁴¹

CH₃ bending and ring bending (in-plane)^41,42

Ring stretching and CH₃ bending^41,42

CH₃ symmetrical bending^41,42

CH₂ deformation in the side chain⁴³

CH₂ stretching in the side chain⁴³

CH₃ symmetrical stretching in the side chain⁴³