X-ray, miscibility and calorimetric studies of four homologous 2-(trans-4-n-alkylcyclohexyl)-propan-1,3-diols are reported. The specific intermolecular interactions lead to novel variants of smectic structures of types A and B, designated with A+and B+. They are explained by a bi-molecular layer with intercalated alkyl chains. The hydrogen bonded molecular arrangement causes a well defined layer periodicity even in the A+phases. Both phases A+and B+do not show a complete miscibility with conventional liquid crystals.