The host-guest complex of 𝐶-methyl resorcin[4]arene with coumarin and thiocoumarin has been characterized by single crystal X-ray diffraction technique. Structural analysis shows that the host forms an infinitie nanotubular array in which the guest coumarin shows a `head to tail’ arrangement of dimers held together by $\pi\ldots \pi$ interaction in the host framework. Similar structural motif is observed when thiocoumarin used as a guest.

Scheelite type solid electrolytes, Li_0.5Ce$_{0.5−x}$Ln$_x$MoO₄ ($x = 0$ and 0.25, Ln = Pr, Sm) have been synthesized using a solid state method. Their structure and ionic conductivity (𝜎) were obtained by single crystal X-ray diffraction and ac-impedance spectroscopy, respectively. X-ray diffraction studies reveal a space group of $I4_1/a$ for Li_0.5Ce$_{0.5−x}$Ln$_x$MoO₄ ($x = 0$ and 0.25, Ln = Pr, Sm) scheelite compounds. The unsubstituted Li_0.5Ce_0.5MoO₄ showed lithium ion conductivity $\sim 10^{−5}-10^{−3} \Omega^{−1}$cm^-1 in the temperature range of 300-700°C ($\sigma = 2.5 \times 10^{−3} \Omega^{−1}$cm^-1 at 700°C). The substituted compounds show lower conductivity compared to the unsubstituted compound, with the magnitude of ionic conductivity being two (in the high temperature regime) to one order (in the low temperature regime) lower than the unsubstituted compound. Since these scheelite type structures show significant conductivity, the series of compounds could serve in high temperature lithium battery operations.