2.2.1. X-Ray Crystallography

Single crystal X-ray diffraction data were collected on a Bruker D8 QUEST CMOS system equipped with a TRIUMPH curved-crystal monochromator and a fine-focus X-ray tube with graphite monochromated Mo-Kα radiation (λ = 0.71073 Å) at ambient or low temperature using the APEX3 or APEX2 suite [16]. Crystal data, data collection and structure refinement details are listed in Supplementary Material (Table S1). Frames were integrated with the Bruker SAINT software package using a narrow-frame algorithm. Absorption effects were corrected using the multi-scan method (SADABS) [17]. Structures were solved by intrinsic phasing methods with ShelXT [18] and refined with ShelXL [19] using full-matrix least-squares minimization using Olex2 [20]. All non-hydrogen atoms were refined anisotropically. H atoms were included in calculated positions riding on the C atoms to which they are bonded, with C–H = 0.93 Å and *U*iso(H) = 1.2 *U*eq(C). Electron densities of poorly ordered lattice solvent molecules could not be modeled satisfactorily, and they were removed by using the SQUEEZE routine in PLATON [21]. In (**1**), the C47 and C48 atoms were constrained to have equivalent atomic displacement parameters and the relatively large thermal ellipsoids of C atoms of one of the phenyl rings (C46–C51) were restrained with enhanced rigid bond restraint [22].
