Table 2. Comparative geometrical parameters (Å, °) for free and coordinated N,O-bidendate (N,O-bid) compounds.
| Parameters | (I) | (II) | (III) | (IV) |
|---|---|---|---|---|
| C111—N11 | 1.422 (2) | 1.521 (4)/1.463 (3) | 1.440 (4) | - |
| C2—N11 | 1.345 (2) | 1.320 (4) | 1.319 (4) | 1.303 (6) |
| C4—O12 | 1.257 (2) | 1.290 (3) | 1.291 (4) | 1.281 (6) |
| C2—C3 | 1.383 (3) | 1.410 (4) | 1.423 (4) | 1.396 (7) |
| C3—C4 | 1.420 (2) | 1.365 (3) | 1.382 (3) | 1.388 (9) |
| O12⋯N11 | 2.635 (2) | 2.885 (3) | 2.886 (3) | 2.826 (6) |
| N11—C2—C4—O12 | −0.5 (1) | 4.1 (2) | −2.6 (2) | 1.2 (4) |
| Dihedral angle | 49.53 (5) | 87.47 (4)/89.36 (8) | 85.58 (8) | - |
Notes: (I) This work; (II) N,O-bid = 4-(2,3-dimethyl phenylamino)pent-3-en-2-onato (Venter et al., 2009a ▶); (III) N,O-bid = 4-(2,6-dimethyl phenylamino)pent-3-en-2-onato (Venter et al., 2009b ▶). (IV) N,O-bid = 4-amino-pent-3-en-2-onato (Damoense et al., 1994 ▶). The dihedral angle is defined as the torsion angle between the N–C–C–C–O plane and the benzene ring. A positive angle denotes a clockwise rotation.