Sodium-centered dodecanuclear Co(II) and Ni(II) complexes with 2-(phosphonomethylamino)succinic acid: studies of spectroscopic, structural, and magnetic properties.

Two new isostructural cobalt(II) and nickel(II) polynuclear complexes with 2-(phosphonomethyl)aminosuccinic acid, H4PMAS, namely, Na[Co12(PMAS)6(H2O)17(OH)]·x2H2O, 1·x2H2O, and Na[Ni12(PMAS)6(H2O)17(OH)]·xH2O, 2·xH2O, have been synthesized for the first time from aqueous solutions and studied by single crystal X-ray diffraction, infrared, and UV-visible diffuse reflectance spectroscopy; TG/DTA analysis; and magnetochemistry. Both 1 and 2 crystallize in the rhombohedral crystal system with the R3[overline] space group with 1/6 of the Co12(PMAS)6 or Ni12(PMAS)6 moieties in the asymmetric unit. The X-ray refinements reveal the presence of 18 water sites, but unit cell charge balance requires that one water molecule must be an OH(-) anion, an anion which is disordered over the 18 sites.

Poly[[diaqua[μ(5)-(R,S)-2-({2-[(1,2-di-carboxyl-atoeth-yl)amino]-eth-yl}amino)-butane-dioato]cobaltate(III)sodium] di-hydrate].

In the asymmetric unit of the title coordination polymer, {[CoNa(C(10)H(12)N(2)O(8))(H(2)O)(2)]·2H(2)O}(n), the Co(II) ion is coord-inated in a distorted octa-hedral environment, defined by two N atoms and four carboxyl-ate O atoms. Two Co(II) ions and two 2-({2-[(1,2-dicarboxyl-atoeth-yl)amino]-eth-yl}amino)-butane-dio-ate (EDDS) ligands form a dimeric complex dianion [Co(2)(EDDS)(2)]. These dimeric units are connected via Na(+) ions, forming a three-dimensional polymeric structure.