Structural parameters of the experimentally determined crystal structures (index cryst) of [Fe(pypypyr)2]·solvent and [Zn(pypypyr)2]·DCM as well as DFT-calculated structures (index calc) of the iron(ii) complex (LS and HS). Given are the Fe–N bond lengths d (py,o: outer pyridine; py,c: central pyridine; pyr: pyrrole), the sum of the deviation from the average bond length ζ, the trans-Npy,c–Fe–Npy,c′ angle φ, the angle θ between the two ligand planes determined by a least-squares method, the sum of the deviation of the cis-N–Fe–N angles from 90° Σ and the trigonal distortion parameter Θ. The differences between the calculated Fe(ii) structures are given in the column Δcalc, whereas the differences between the Fe(ii) and Zn(ii) crystal structures are given in column Δcryst. All bond lengths are given as the average between the two ligands. The only noteworthy deviations from the average are found for dpy,o in the zinc(ii) structure (±0.03 Å).
| LScryst | LScalc | HScalc | Zncryst | Δcalc | Δcryst | |
|---|---|---|---|---|---|---|
| d py,c/Å | 1.89 | 1.91 | 2.16 | 2.13 | 0.25 | 0.24 |
| d py,o/Å | 1.97 | 1.99 | 2.30 | 2.34 | 0.31 | 0.38 |
| d pyr/Å | 1.96 | 1.97 | 2.10 | 2.07 | 0.13 | 0.11 |
| ζ/Å | 0.22 | 0.17 | 0.46 | 0.65 | 0.29 | 0.43 |
| ξ/° | 35.8 | 35.6 | 62.9 | 64.1 | 27.3 | 28.3 |
| φ/° | 179.1 | 179.3 | 155.6 | 167.3 | −23.7 | −11.8 |
| θ/° | 89.7 | 84.7 | 86.6 | 80.2 | 1.9 | −9.5 |
| Σ/° | 77.3 | 79.4 | 143.0 | 141.7 | 64.7 | 64.4 |
| Θ/° | 255.5 | 256.3 | 527.7 | 484.5 | 271.4 | 229.0 |