It is a well established fact that several molecular liquids experiences a series of thermal anomalies as measured by microscopic and macroscopic techniques. A remarkable case is quinoline, since it shows these anomalies, whereas in the closely related chemical analog isoquinoline, these anomalies are absent, and therefore suggesting a microscopic origin of the observed behaviour and constitutes a benchmark case to study the origin of intriguing properties in liquids. The purpose of this experiment is to measure the evolution of the quasielastic line with temperature, and thus the rotational diffusion constants, as the short and long range interactions changes from that of pure quinoline to pure isoquinoline.