C(NH2)3Cd(C2O4)Cl(H2O)<middle dot>H2O and BaCd(C2O4)1.5Cl(H2O)2: Two Oxalate Chlorides Obtained by Chemical Scissors Strategy Exhibiting Low-Dimensional Structural Networks and Balanced Overall Optical Properties

Low-dimensional crystalline materials have attracted much attention due to their special physical and chemical properties. Herein, two new oxalate chlorides, C(NH2)(3)Cd(C2O4)Cl(H2O)<middle dot>H2O and BaCd(C2O4)(1.5)Cl(H2O)(2), were synthesized. C(NH2)(3)Cd(C2O4)Cl(H2O)<middle dot>H2O presents the unique {[Cd(C2O4)Cl(H2O)](-)}(infinity)zigzag chain, while BaCd(C2O4)(1.5)Cl(H2O)(2) shows a novel {[Cd(C2O4)(1.5)Cl](2-)}(infinity) layer. They showed large measured band gaps, which were 3.76 and 4.53 eV, respectively, and the latter was the largest band gap in the A-M-C2O4-X (A = Monovalent cationic or alkaline earth metals, X = F, Cl, Br, I) family. They exhibit a large calculated birefringence of 0.075 and 0.096 at 1064 nm, respectively. This study promotes the exploration of synthesizing low-dimensional crystalline materials with balanced overall optical performances by a chemical scissors strategy.