2.3. Single Crystal X-ray Diffraction The X-ray diffraction data for the single crystals rac-1–4, rac-6, (S)-4, and (R)-6 were collected on a Bruker KAPPA APEX II CCD automated four-circle diffractometer at 100(2) K: graphite monochromator, λ(Mo Kα) = 0.71073 Å, ω/ϕ-...