A series of aryl-substituted β-diketonate adducts with 5,5′-di(heptadecyl)-2,2′-bipyridine has been synthesised. All the compounds exhibit a mesomorphic (smectic) behaviour. It has been shown that the metal ion does not drastically influence the mesophase type and the transition temperatures. A thin film of Eu(III) complex shows more effective luminescence in the aligned state.

The spin-coating technique was used to produce composite films consisting of PMMA polymer doped with anisometric complexes of Eu(III) and Tb(III). It was found that an increase in the content of Tb³⁺ complexes intensifies emission of both ions due to the intermolecular energy transfer from the Tb(III) complex to the Eu(III) complex, which results in the increase in the relative luminescence quantum yield of Eu(III) ion by 36%. The temperature sensitivity of the film luminescence intensity and lifetime in the range of 296–363 K was investigated. The maximum relative sensitivity of the films reaches 5.44% × K⁻¹ and exceeds that of all known lanthanide-containing thermal sensors designed for measuring physiological temperatures. In combination with changing luminescence color, such a sensitivity makes these films promising colorimetric thermal sensors for in situ temperature measurements.