Standard molar enthalpies of formation for a series of microporous crystals of Na2[MIIB3P2O11(OH)]·0.67H2O (MII = Mg, Mn, Fe, Co, Ni, Cu, Zn)

► Na2[CoB3P2O11(OH)]·0.67H2O has been synthesized and characterized. ► Three kinds of molar enthalpies of solution were measured, respectively. ► ΔfHmo for Na2[CoB3P2O11(OH)]·0.67H2O was obtained by a thermochemical cycle. ► ΔfHmo of a series of Na2[MIIB3P2O11(OH)]·0.67H2O have been estimated.