*3.1. Structure Analysis*

Uniform single crystals of **1** and **2** were harvested under hydrothermal conditions (Figure 1). Single-crystal X-ray diffraction (SCXRD) analysis revealed that **1** crystallizes in a monoclinic crystal system *P*21*/n*. The asymmetrical unit of **1** is composed of fully deprotonating dtp2−, one Cu(II) ion, and a guest molecule of H2O (Figure 2a). The Cu(II) ion is five-coordinated by nitrogen atoms from pyridine rings and two oxygen atoms from the carboxylic group of neighboring dtp2<sup>−</sup>, forming a distorted tetragonal-pyramidal coordination sphere with the Cu(II)−N and Cu(II)−O bond length in the scale of 1.9463(14)–2.0452(15) Å and 1.9399(12)–2.0950(13) Å, respectively. The coordination properties enable the asymmetry unit of **1** to behave as a four-connective node to link the neighboring units, further forming a "wave-shaped" 2D layer (Figure 2b). The void between the neighboring layers is dotted by the guest water molecules. The two hydrogen atoms of H2O form a double H-bond (O−H···O) interaction with the carboxylic groups of neighboring layers with the D-A length of 2.757(2) and 2.880(2) Å [28]. Besides this, π-π stacking interactions with a center–center distance of 3.71 and 4.25 Å [29] are also found between the pyridines of dtp2<sup>−</sup> from the neighboring layers (Figure 3). Those intermolecular forces direct the 3D packing of the "wave-shaped" layers in the crystal *b* direction (Figure 2c).

**Figure 1.** The obtained single crystal photos for **1** (**a**) and **2** (**b**).

**Figure 2.** Asymmetric unit of **1** (**a**); the 2D "wave-shaped" layer structure as well as the linking mode of the nodes in **1** (**b**) and the 3D stacking mode of the layers in **1** (**c**) (some H atoms are omitted for clarity).

**Figure 3.** H-bond and π-π stacking as the interlayer force in **1**.

SCXRD analysis revealed that **2** crystallizes in monoclinic crystal system *P* − 1. The asymmetry unit of **2** is composed of partially deprotonating Hdtp−, one Cu(II) ion, and half of bdc2<sup>−</sup> (Figure 4a). The Cu(II) ion is five-coordinated by nitrogen atoms from pyridine rings and two oxygen atoms from carboxylic group of bdc− and neighboring Hdtp−, forming a distorted tetragonal-pyramidal coordination sphere with Cu(II)-N and Cu(II)-O bond lengths in the scale of 1.9330(13)–2.0217(14) Å and 1.9102(11)–2.2431(13) Å, respectively. The introduction of bdc− into **2** results in a linkage reduction of the asymmetric unit; compared with **1**, the asymmetric unit of **2** behaves as a three-connective node to link the neighboring units, further forming a "ladder-shaped" 1D chain extending in the crystal *b* direction (Figure 4b). The 1D chain was found arrayed in the crystal *a* direction through the neighboring chain interaction of the H-bond (O−H···O) and π-π stacking interactions; the former exist between the carboxylic and carboxylate groups with a D-A distance 2.5770(16) Å [28], while the latter is formed between pyridine rings with a center–center distance of 4.38 Å [29]. The inter-chain interactions afford the orderly array of 1D chains, and further give birth to 2D supermolecular layers with a thickness of ca. 7.9 Å (Figure 4c). The final 3D structure of **2** is furnished by the stacking of the 2D supermolecular layers through the neighboring layer interaction of π-π stacking within the pyridine rings as well as the benzene rings; the center–center distances are 3.77 and 3.75 Å [29], respectively (Figure 4d).

**Figure 4.** Asymmetric unit of **2** (**a**); the 1D "ladder-shaped" chain structure in **2,** as well as the linking mode of the nodes (**b**); a 2D supermolecular layer is formed by the orderly array of the 1D chain (**c**); the 3D structure of **2** (**d**). Some H atoms are omitted for clarity.

#### *3.2. X-ray Diffraction Patterns*

The PXRD (powder X-ray diffraction) patterns of complexes **1** and **2** were measured with crystalline samples at room temperature. As is shown in Figure 5, the experimentally determined PXRD patterns and the simulated ones from the SCXRD analyses are in accordance in general, suggesting their phase homogeneity.

**Figure 5.** The experimental and simulated PXRD patterns for **1** (**a**) and **2** (**b**).
