Review of non-crystalline and crystalline quaternary ammonium ions: Classification, structural and thermal insight into tetraalkylammonium ions

F.N. Jumaah, N.N. Mobarak, Nur Hasyareeda Hassan, Siti Aminah Mohd Noor, Sharifah Nurain Syed Nasir, Nor Azila Md Ludin, K.H. Badri, Azizan Ahmad, Elisabeth R. D. Ito, Masahiro Yoshizawa‐Fujita, Mohd Sukor Su’ait