Four isostructural metal organic frameworks (MOFs), namely [Co6(HipO)6]·6H2O (), [Mn6(HipO)6]·6H2O (), [Cd6(HipO)6]·6H2O () and [Zn6(HipO)6]·7H2O () (H3ipO = 2-hydroxyisophthalic acid), were synthesized and structurally characterized. They have a 3D (4,6)-connected framework based on [24-MC-6] metallacrown clusters ([24-MC-6]-based MOFs). The arrangements of the 24-MC-6 metallacrown SBUs show a regular change indicated by the orientation of their symmetry axes, resulting in a special dense packing mode different from other [24-MC-6]-based MOFs. The analysis of SQUID measurements reveal that compound displays the dominant antiferromagnetic exchanges in 300-10 K between the adjacent Co(ii) ions and a ferromagnetic-like behavior at lower temperatures, whereas compound shows an antiferromagnetic interaction between the adjacent Mn(ii) ions. Compound exhibits a magnetocaloric effect (MCE) with the resulting entropy change (-ΔSm) of 15.20 J kg(-1) K(-1) for ΔH = 50 kG at 6 K, which is the highest value among the cobalt-based MOFs with MCE reported so far. The luminescence properties of compounds and were studied, both of them exhibit photoluminescence in the solid state at room temperature which can be ascribed to intraligand π→π* transitions.