H-2 NMR powder patterns of [N(CH3)(4)][Cd-3(CN)(7)].nG type benzene (n = 1.5, G = C6D6), toluene (n = 1, G = C6D5CD3 and C6D5CH3), and ethylbenzene (n = 1, G = C6D5CD2CD3, C6D6CH2CH3, and C6H5CD2CH3) clathrates have been measured between 128 and 468 K and analyzed in order to obtain information about motional behavior of the guest molecules before and during their thermal decomposition. (1) Benzene clathrate: below ca. 300 K the benzene molecule undergoes an ordinary in-plane rotational motion. Above 300 K, a sign of an out-of-plane motion like a precessional motion, which comes from the benzene escaping from the clathrate host owing to its thermal decomposition, was observed. (2) Toluene clathrate: below ca. 320 K the main motion is a 180 degrees flip motion of the aromatic ring and its activation energy is estimated to be 33(1) kJ/mol. Above 320 K, in its thermal decomposition process, an in-plane two-site reorientational motion of the whole toluene molecule takes place. (3) Ethylbenzene clathrate: below ca. 350 K the main motion is a 180 degrees flip motion of the aromatic ring whose activation energy is estimated to be 36(4) kJ/mol, and the ethyl group is undergoing a fast two-site reorientational motion within a restricted space even at 133 K. In a higher temperature region, the reorientational motion of the ethyl group changes to a rotational motion. Detailed motional models for each case have been constructed with several simple motions based on their molecular and crystal structures.