biostudies-literatureClark TENCRR NIH HHSNIGMS NIH HHS3211-3217https://www.ebi.ac.uk/biostudies/studies/S-EPMC2906806biostudies-literatureUnknown10(7)Hexamethoxy-calix[6]arene has been fully functionalized with p-phosphonic acid groups on the upper rim in 57% yield over three steps, and has been authenticated in the solid state by X-ray diffraction as either a nitrate salt or one of two calcium complexes. The latter differ by the ratio of calcium ions per calixarene, either 3:1 or 4:1. In both structures the coordination sphere of the calcium ions is made up of oxygen atoms from the phosphonic acid groups and from water of crystallization, as part of extended polymeric layers in the extended 3D packing. Hirshfeld surface analysis shows extensive O...H and O...Ca interactions for the phosphonic acid moieties in both calcium structures. MALDI-TOF MS of the hexaphosphonic acid shows nano-arrays consisting of up to a maximum of 28 calixarenCrystal growth & designLayered Calcium Structures of p-Phosphonic Acid O-Methyl-Calix[6]arene.PMC2906806P41 RR000954-317546P41 GM103422P41 RR000954Su DRaston CLRohrs HWGross MLMakha MSobolev ANClark TEMartin AfalseLayered Calcium Structures of p-Phosphonic Acid O-Methyl-Calix[6]arene.Hexamethoxy-calix[6]arene has been fully functionalized with p-phosphonic acid groups on the upper rim in 57% yield over three steps, and has been authenticated in the solid state by X-ray diffraction as either a nitrate salt or one of two calcium complexes. The latter differ by the ratio of calcium ions per calixarene, either 3:1 or 4:1. In both structures the coordination sphere of the calcium ions is made up of oxygen atoms from the phosphonic acid groups and from water of crystallization, as part of extended polymeric layers in the extended 3D packing. Hirshfeld surface analysis shows extensive O...H and O...Ca interactions for the phosphonic acid moieties in both calcium structures. MALDI-TOF MS of the hexaphosphonic acid shows nano-arrays consisting of up to a maximum of 28 calixaren2010-01-01T00:00:00Z2010 Jul2025-06-01T01:15:07.277Z2025-06-01T01:15:07.277ZS-EPMC29068062065779310.1021/cg1003484