3.2. Single-Crystal X-ray Diffraction

The diffraction data of suitable single crystals of studied lanthanide(III) complexes were collected on a Rigaku SuperNova (dual source) four circle diffractometer equipped with an Eos CCD detector (Oxford, UK). The measurements were performed using a mirror-monochromated Mo Kα radiation (λ = 0.71073 Å) from a microfocus Mova X-ray source. All the required procedures including data collection, data reduction and multi-scan absorption correction were performed using CrysAlis PRO software (version 1.171.38.41, Oxford, UK). The structures were solved by direct methods and refined by the full matrix least-squares technique on F² data. All non-hydrogen atoms, with only a few exceptions for disordered perchlorate ions, were refined anisotropically while the hydrogen atoms were inserted in calculated positions or in those from the Fourier matrix and refined isotropically using standard parameters. All calculations were performed with the use of the OLEX2 crystallographic software [81] equipped with SHELX programs [82]. A MERCURY program [83] was applied for a graphical representation of the crystal structures. Selected crystallographic parameters and refinement details for the l-alanine complexes obtained from measurements at 100 K are listed in Table 1 and Table 2, while for the related d-alanine compounds in Tables S1 and S2. Additional crystallographic data obtained from measurements at ambient temperature (292 K) are collected in Table S6.