## 2 Results and Discussion
### Structural Aspects
The hydrogen bonding between amine groups links mononuclear complexes of the same sheet (Figure 4). Each counter anion forms N-H\(\cdots\)F hydrogen bonds with several mononuclear species, generating links between complexes of the same sheet and complexes corresponding to different double planes. Although the hydrogen atoms of coordinated H\({}_{2}\)O were not located, interatomic distances between oxygen atoms of the water molecules of the sheet and the lone pair of the amine groups, corresponding to a further sheet of the same double plane, indicate the possible existence of hydrogen bonding between these ligands (predicted by the Mercury [28] software). Such hydrogen bonding was proposed by [PERSON] _et al_. [24] to explain the double sheet structure. The crystal packing in **III** and **IV** is made of parallel Cu(II) chains, between which non-coordinated counter anions and water molecules are located (Figures 3 and 5). The Cu\(\cdots\)Cu distances in **III** are 3.6532(16) A, while the same separations in **IV** are insignificantly shortened to 3.5994(16) and 3.6106(16) A (Table 1), which was expected since no change of the first coordination sphere is noticed between **III** and **IV**. These values are about 0.08-0.14 A longer than those for the similar Cu(II) chains, containing \(\mu_{2}\)-\(O\) or \(\mu_{2}\)-\(N\) bridging atoms, [11, 12, 13] but significantly shorter than the Cu\(\cdots\)Cu distances in the Cu(II) chains with three \(\mu_{2}\)-1,2,4-triazole derivatives [27, 29]. A shorter Cu\(\cdots\)Cu distance of 3.40 A is found when only one \(\mu_{2}\)-\(N_{1}\),\(N_{2}\)-1,2,4-triazole is bridging as observed for [Cu(Htrz)Cl\({}_{2}\)] [26]. The dihedral angles, formed by the \(\mu_{2}\)-NH\({}_{2}\)trz ligands linking two neighboring Cu(II) atoms, are about 5\({}^{\circ}\) and 12\({}^{\circ}\) in **III**. The former angle in **IV** is significantly reduced and of 0-2\({}^{\circ}\), while the latter angle is very similar, 12-14\({}^{\circ}\). These values are in a range characteristic for similar Cu(II) chains [12, 13, 14]. However, incorporation of the third \(\mu_{2}\)-1,2,4-triazole derivative into the Cu(II) chain leads to a significant increase of the third dihedral angle, which might be explained by steric demands [27, 29]. The presence of the amine groups, chloride ions and water molecules favors hydrogen bonding (Table S2 in Supplementary Information). Each chain is linked to a further two chains by the N-H\(\cdots\)Cl(coordinated) and N-H\(\cdots\)Cl(non-coordinated) \(\cdots\)H-N hydrogen bonding. Moreover, the N-H\(\cdots\)Cl\(\cdots\)H-O-H\(\cdots\)Cl\(\cdots\)H-N hydrogen bonds create connections to four neighboring chains. Thus, each chain is hydrogen bonded to six others in the structure of **III**. The crystal packing of **IV** consists of a dense hydrogen bonding network, which links neighboring chains (Table S2 in Supplementary Information). Parallel chains are linked by the multiples N-H\(\cdots\)Cl and N-H\(\cdots\)N hydrogen bonds. The N-H\(\cdots\)O-H\(\cdots\)F-Si-F\(\cdots\)H-N and N-H\(\cdots\)F-Si-F\(\cdots\)H-N hydrogen bonds connect the NH\({}_{2}\)trz ligands throughout the whole network. Finally, rows of the SiF\({}_{6}^{2-}\) anions are bound by F\(\cdots\)H-O-H\(\cdots\)F hydrogen bonding. As a result of dense hydrogen bonding network is observed. In **III**, voids between metal-containing chains are occupied by water-chloride \(\{\)[Cl(H\({}_{2}\)O)]\({}^{-}\}_{n}\) supramolecular chains propagated by hydrogen bonds in a meander-like manner (Figure 6, Table S2 in Supplementary Information). These clusters are connected to cationic chains through hydrogen bonds formed between non-coordinated chloride ions and one of the NH\({}_{2}\) hydrogen atoms of the NH\({}_{2}\)trz ligands (marked by red dash lines in Figure 6, Table S2 in Supplementary Information). Similar  
Figure 4: Thermal ellipsoid (50%) plot of **II** along the \(b\) axis.