2.3.1. [Zn(**L**)(1,4-NDC)·H2O]n, **1**

Zn(OAc)2·2H2O (0.022 g, 0.10 mmol), **L** (0.041 g, 0.10 mmol) and 1,4-H2NDC (0.022 g, 0.10 mmol) in 8 mL H2O and 2 mL methanol were sealed in a 23 mL Teflon-lined flask inside a stainless steel autoclave, which was heated at 120 ◦C for 2 days, and then the reaction system was cooled down at a rate of 2 ◦C per hour until the room temperature was reached. Colorless crystals were obtained, which were purified with methanol. Yield: 0.041 g (58%), using Zn(II) as the limited reagent. Anal. calcd. for C36H26N4O8Zn (MW = 707.98): C, 61.07; N, 7.91; H, 3.70%. Found: C, 61.22; N, 8.07; H, 4.01%. FT-IR (cm<sup>−</sup>1): 3237(m, N-H), 3168(m, N-H), 3070(w), 1686(s), 1596(s), 1512(s), 1490(s), 1429(m), 1332(m), 1236(m), 1210(m), 1170(s).
