2.3.1. Single Crystal X-ray Diffraction (SXRD)

The crystal structures were determined with a Bruker APEX-II CCD diffractometer using graphite monochromatic Mo-Kα radiation (λ = 0.71073 Å) at 296K. Frame integration was performed using SAINT (version 7.68A) [19]. The resulting raw data were scaled and the absorption was corrected using a multi-scan averaging of symmetry-equivalent data by SADABS [20]. The structure was solved by the direct method with the olex2 software and then refined via full-matrix least-squares procedures using SHELXL-2014 on F2 with anisotropic displacement parameters (ADPs) for non-hydrogen atoms [21,22]. The H atoms were located in idealized difference Fourier maps and refined as riding models with isotropic thermal parameters (Uiso(H) = 1.2 Ueq(C), Uiso(H) = 1.2 Ueq(N), and Uiso(H) = 1.5 Ueq(O)).

Diamond [23] (version 4.6.3, Crystal Impact GbR, Bonn, Germany) was used for preparing crystal packing diagrams.
