3.3.1. [Fe(HL)(H2O)2(NO3)]NO3 (**1**)

In this study, 0.404 g (1.00 mmol) of Fe(NO3)3.9H2O was added to a 30 mL methanol solution of H2L (0.180 g, 1.00 mmol). Then, at room temperature, the reaction mixture was stirred for 30 min, in open air. The resultant reddish brown solution was filtered and the filtrate was kept in air. Single crystals of **1** were isolated after 3 days, washed twice with cold CHCl3, and dried in open air.

Yield 66%. Anal. Calcd. for C7H11FeN6O10: C, 21.28; H, 2.81; N, 21.27. Found: C, 21.20; H, 2.72; N, 21.18. IR (KBr pellet, cm<sup>−</sup>1): 3136 ν(NH), 1383 ν(NO3)-, 1678 <sup>ν</sup>(C=O), 1646 <sup>ν</sup>(C=O), 1032 ν(N–N). ESI-MS (+): *m*/*z* 333 [M-(NO3)]+ (100%).

### 3.3.2. [Fe(HL)Cl2] (**2**) and [Fe(HL)Cl(μ-OMe)]2 (**3**)

Both **2** and **3** were synthesized according to the literature [45]. [Fe(HL)Cl2](**2**)

Yield 70%. Anal. Calcd. for C7H7Cl2FeN4O2: C, 27.48; H, 2.31; N, 18.31. Found: C, 27.42; H, 2.28; N, 18.25. IR (KBr pellet, cm<sup>−</sup>1): 3134 ν(NH), 1702 <sup>ν</sup>(C=O), 1668 <sup>ν</sup>(C=O), 1037 ν(N–N). ESI-MS (+): *m*/*z* 306 [M+H]<sup>+</sup> (100%).
