Two structures of the Ni(SCN)2(4-EtPy)4 Werner clathrate (4-EtPy=4-ethylpyridine) and one structure of Ni(SCN)2(4-AcPy)4 clathrate (4-AcPy=4-acetylpyridine) withp-dichlorobenzene (PDCB) as a guest molecule have been elucidated. The host molecules have the usual octahedral ldquopropellerrdquo conformations and form channel-type cavities. Effective librational frequencies of the PDCB molecule in these clathrates, and in 14 other Werner clathrates, have been determined from the temperature dependence of the35Cl nuclear quadrupole resonance (NQR) frequencies.