Two azo substituted achiral bent-core mesogens have been synthesized. Optical polarizingmicroscopy and synchrotron X-ray scattering studies of both compounds reveal the existence of thethermotropic uniaxial and biaxial nematic and three smectic phases at different temperatures in these singlecomponent small molecule systems. The transition from the uniaxial to biaxial nematic phase is confirmedto be second order. The transitions from the biaxial nematic to the underlying smectic phase and betweenthe smectic phases have barely discernible heat capacity signatures and thus are also second order.