Synthesis and structural characterization of new lanthanide coordination polymers with nitrilotriacetic acid

Reported herein are the hydrothermal synthesis and crystal structures of four lanthanide coordination polymers with nitrilotriacetic acid (H(3)NTA) [Ln(NTA)(H2O)](n) (Ln = La, 1; Pr, 2; Nd, 3; Eu, 4). Despite similar syntheses, compounds I to 4 show transformation in coordination mode of NTA and coordination number of Ln(3+) duo to lanthanide contraction. The Ln(III) ions in 1 and 2 are nine-coordinated and connected through octadentate bridging ligands (NTA) to form a three-dimensional network. The Ln(III) ions in 3 and 4 are eight-coordinated and bridged by heptadentate bridging ligands (NTA) to form an extended two-dimensional layer structure, which further construct a three-dimensional supramolecular structure via coordination bond and three-centered hydrogen bonding between adjacent layers. (C) 2004 Elsevier B.V. All rights reserved.