Thermodynamic properties of microporous crystals of Na2[ZnB3P2O11(OH)]·0.67H2O

► Microporous material of Na2[ZnB3P2O11(OH)]·0.67H2O has been synthesized and characterized. ► The enthalpies of solution of title compound and NaH2PO4·2H2O (s) were measured. ► ΔfHm∘ of -(5200.3 ± 2.5) kJ · mol−1 for title compound was obtained by a thermochemical cycle.