Fig. 3.

Molecular structures of complexes 1–4. Pale yellow colored (orange colored) crystals suitable for scXRD and with spectroscopic data in agreement with an assignment as 1 and 2 (3 and 4) were isolated from batches of reactions according to Eq. 1 (Eq. 2). However, the respective nitrogen position was never crystallographically distinguishable from the carbon positions. Therefore, only one set of molecular structures is shown: 1 and 3 (left) and 2 and 4 (right). Inclusion of a disordered nitrogen atom into the refinement did only slightly change the agreement factors (Supplementary Figures 70 and 72). Nevertheless, the average bond lengths are about 3 pm shorter for 3 and 4, which agrees with the (calculated) shorter Cr–N bond length and the observed smaller unit cell volumes. Only crystallographically independent atoms were labeled; ellipsoids are shown at 50% probability level. See Table 3 for information on metric data