[CN3H6](2)[Zn(CO3)(2)], the first organically templated open-framework carbonate

[CN3H6](2)[Zn(CO3)(2)], the first organically templated open-framework carb onate has been synthesized hydrothermally and its single crystal structure and some properties have been determined. This phase is built up from a thr ee-dimensional framework of vertex-linked ZnO4 and CO3 building units encap sulating the extra-framework guanidinium cations. Template-to-framework hyd rogen bonding appears to play an important role in stabilizing the structur e. The zincocarbonate framework shows a surprising similarity to those of k nown zinc phosphates and phosphites.