Carbonate and phosphite encaged in frameworks constructed from square lanthanum aminopolycarboxylates and sodium chlorideElectronic supplementary information (ESI) available. CCDC 1884396-1884398. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c8dt04940h

Novel additives of lanthanum aminopolycarboxylates with inorganic anions, Na 12 n [La(edta)L] 4 n ·8 n NaCl·4 n H 2 O ( 1 : L = HPO 3 2− ; 2 : L = CO 3 2− ) and K 12 n [La(cdta)(CO 3 )] 4 n ·35 n H 2 O ( 3 ) (H 4 edta = ethylenediaminetetraacetic acid; H 4 cdta = cyclohexanediaminetetraacetic acid), were obtained in alkaline solution. Structural analyses reveal that 1 and 2 are isomorphous and contain interesting square structures. HPO 3 2− (CO 3 2− ) was encaged in the constructed tetranuclear frameworks. Tetranuclear lanthanum ethylenediaminetetraacetate was further encaged in superstructures of sodium chloride. 3 has a similar square structure, in which edta is replaced by cdta. All complexes are fully characterized via elemental, FT-IR, NMR, thermogravimetric and structural analyses. Solution 13 C NMR spectra show that 1 and 2 dissociate into mononuclear units in water. Interestingly, 2 possesses 3.7 Å diameter holes inside its crystals, which can adsorb a small amount of O 2 or CO 2 selectively. The amounts of O 2 and CO 2 adsorbed increase gradually from 0.32 and 0.38 mg g −1 at 0.4 bar to 15.90 and 10.54 mg g −1 at 29.9 bar, respectively. Lanthanum aminopolycarboxylates, Na 12 n [La(edta)L] 4 n ·8 n NaCl·4 n H 2 O ( 1 : L = HPO 3 2− ; 2 : L = CO 3 2− ) and K 12 n [La(cdta)(CO 3 )] 4 n ·35 n H 2 O ( 3 ), with square structures were obtained. Carbonate 2 possesses 3.7 Å diameter holes that can adsorb a small amount of O 2 or CO 2 selectively.