“…In the case of methylenebis(phosphonate) MBP, [H 2 C(PO 3 H) 2 ] 2-, and its analogues etidronate, [(CH 3 )(HO)C(PO 3 H) 2 ] 2-, and alendronate, [(NH 3 CH 2 CH 2 CH 2 )(HO)C(PO 3 H) 2 ] 2-, some Zn and Cd complexes have already been reported. [14][15][16][17][18][19][20][21] Previously, we reported the structures of polymeric Ca and Ba complexes 22,23 and a monomeric Sr complex 24 of clodronate, [Cl 2 C(PO 3 H) 2 ] 2-, as well as alkaline earth metal complexes of P,P′-diethyl (dichloromethylene)bis(phosphonate), [Cl 2 C(PO 3 Et) 2 ] 2-, 25 and Mg and Ca complexes of P,P′-diisopropyl (dichloromethylene)bis(phosphonate), [Cl 2 C(PO 3 Pr i ) 2 ] 2-. 26 The results showed that clodronate and its ester derivatives produce both molecular and polymeric structures with metals, and moreover, the structures of the metal complexes indicate that the dimensionalities of the structures decrease with increasing size of the alkyl substituent.…”