| Title: | Structural systematics and conformational analyses of a 3 × 3 isomer grid of nine N-(tolyl)pyridinecarboxamides and three chlorinated relatives |
| Authors: | Pavle Mocilac, John F. Gallagher, 2011 |
| Abstract: | A 3 × 3 isomer grid of nine N-(tolyl)pyridinecarboxamides (NxxM, x = para-/meta-/ortho-) integrating crystal structure analyses, ab initio calculations (gas phase and PCM-SMD solvated in CH2Cl2, H2O) and conformational studies is described. Three 5-Cl-NoxM derivatives (side-products from the NoxM syntheses) and NmpFM (a 50:50 mixture of NmpF and NmpM) are reported. The six NpxM/NmxM isomers aggregate via N–HN or N–HOC hydrogen bonds, whereas the six NoxM/5-Cl-NoxM structures exhibit intramolecular N–HN interactions influencing co-planarity. The NmmM isomer is isomorphous and isostructural with its bridge-flippedMmm isomer providing a rare case of isostructuralism between such isomers. Our objectives are to (a) understand correlations between the p-/m-/o-N/CH3 substituent permutations with solid state molecular conformations and supramolecular aggregation, (b) explain the influence of molecular conformation on inter/intramolecular interactions, (c) correlate physico-chemical properties and (d) compare and rationalise differences between crystal and calculated structures. |
| ICHEC Project: | Structural systematics of n x m isomer grids: comparison of structural data (from diffraction) with ab initio calculations |
| Publication: | CrystEngComm (2011), 13, pp. 5354-5366 |
| URL: | http://dx.doi.org/10.1039/c1ce05169e |
| Status: | Published |