Hydrated Rare Earth Structural Networks containing the Phenylene‐1, 2‐dioxydiacetate (PDDA) Ligand

Reaction of LnCl 3 with Na 2 (PDDA) (PDDA = phenylene‐1, 2‐dioxydiacetate) in a 1 to 2 mol ratio in aqueous solution yielded [Ln 2 (PDDA) 3 (H 2 O) 6 ] · 2H 2 O, structurally characterized for Ln = Ce ( 1 ), Sm ( 2 ) (redetermination), Tb ( 3 ) and Y ( 4 ) in a monoclinic C 2/ c array, a second related structural form [orthorhombic, Pbcn ] being obtained for Tb ( 5 ), Ho ( 6 ) and Er ( 7 ). The ‘domains of existence' of these two previously described forms are now extended to Ce–Dy, Y, and Eu–Er, respectively. Reaction under the same conditions for the heavier Yb 3+ ion yielded [Yb 2 (PDDA) 3 (H 2 O) 6 ] (∞|∞) · 4H 2 O ( 8 ), orthorhombic, Pbca . In the case of Ln = La the bimetallic species [NaLa(PDDA) 2 (H 2 O) 2 ] (∞|∞) · 4H 2 O ( 9 ) was obtained, while reaction of LnCl 3 with Na 2 (PDDA) in a 1 to 3 mol ratio led to the isolation of the isotypic (monoclinic, P 2 1 / c ) [NaLn(PDDA) 2 (H 2 O) 2 ] (∞|∞) · 4H 2 O) for Ln = Ce ( 10 ) and Sm ( 12 ). With the smaller Ln = Yb, the more definitively bimetallic [NaYb(PDDA) 2 (H 2 O) 2 ] (∞|∞) · 3H 2 O ( 13 ) (triclinic, P $\bar{1}$ )) was obtained, the trihydrate solvation ascribed differing from that recorded (dihydrate) in a cosynchronous report.