*2.3. Single-Crystal X-Ray Di*ff*raction Study*

Single crystals of **1**–**4** were selected under binocular, coated in oil-based cryoprotectant, and mounted on cryoloops. Diffraction data were collected using a Bruker Kappa Duo diffractometer (Bruker AXS, Madison, WI, USA) equipped with a CCD (charge-coupled device) Apex II detector operated with monochromated microfocused MoKα radiation (λ[MoKα] = 0.71073 Å) at 45 kV and 0.6 mA. Diffraction data were collected at room temperature with frame widths of 0.5◦ in ω and ϕ, and exposures of 40 to 120 s per frame. Diffraction data were integrated and corrected for polarization, background, and Lorentz effects. An empirical absorption correction based on spherical harmonics implemented in the SCALE3 ABSPACK algorithm was applied in the CrysAlisPro program [10]. The unit-cell parameters (Table 1) were refined using the least-squares techniques. The structure was solved by a dual-space algorithm and refined using the SHELX programs [11,12] incorporated in the OLEX2 program package [13]. The final models include coordinates and anisotropic displacement parameters for all non-H atoms. The H atoms of OH groups and H2O molecules were localized from difference Fourier maps and were included in the refinement with *U*iso(H) set to 1.5*U*eq(O) and O–H bond-length restraints to 0.95 Å. Selected bond lengths and angles are listed in Tables 2–4. Checking of the unit-cell parameters along with the results of the chemical analyses showed that the crystals of **2** were the cesium uranyl sulfate phase, which was reported previously [8]. Due to the small size and low quality of the crystals of **3**, refinement parameters were rather high, but the structural model was quite reliable.


**Table 1.** Crystallographic data for **1**, **3**, and **4**.


**Table 1.** *Cont.*

*R*<sup>1</sup> = Σ||*F*o| − |*F*c||/Σ|*F*o|; *wR*<sup>2</sup> = {Σ[*w*(*F*<sup>o</sup> <sup>2</sup> − *<sup>F</sup>*<sup>c</sup> 2) 2]/Σ[*w*(*F*<sup>o</sup> 2) 2]}1/2; *w* = 1/[σ2(*F*<sup>o</sup> 2) + (a*P*) <sup>2</sup> + b*P*], where *P* = (*F*<sup>o</sup> <sup>2</sup> + 2*F*<sup>c</sup> 2)/3; *s* = {Σ[*w*(*F*<sup>o</sup> <sup>2</sup> − *F*<sup>c</sup> 2)]/(*n* − *p*)}1/<sup>2</sup> where *n* is the number of reflections, and *p* is the number of refinement parameters.


**Table 2.** Selected bond lengths (Å) and angles (◦) in the structure of **1**.

\*-Coordination numbers (CN) at the 3.6 Å limit, for the average bond length value.

**Table 3.** Selected bond lengths (Å) and angles (◦) in the structure of **3**.



**Table 3.** *Cont.*

\*-Coordination numbers (CN) at the 3.6 Å limit, for the average bond length value.


\*-Coordination numbers (CN) at the 3.6 Å limit, for the average bond length value.

Supplementary crystallographic data (see online Supplementary Materials) for **1**, **3**, and **4** were deposited in the Inorganic Crystal Structure Database and could be obtained from Fachinformationszentrum Karlsruhe via https://www.ccdc.cam.ac.uk/structures/.

## **3. Results**
