Fluoromanganese(III) complex of phenanthroline. Distortion isomers of Mn(phen)F3(H2O) stabilised by intermolecular interactions – Crystal structures, electronic spectra and DFT calculations

Crystals of Mn(phen)F3(H2O) and its monohydrate which cocrystallise from solution contain distortion isomers of the Mn(III) fluoro complex. Intermolecular H-bonding involving the coordinated fluoride ions and water molecules influence the Mn–F distances. This has an indirect effect on the axial bond lengths which are already weakened by a static Jahn–Teller effect. Electronic spectral band positions are compared with predictions of density functional theory. It is found that the lowest energy transition is in poor agreement, while the higher energy transitions are in fair agreement with the calculation for the isolated molecule. The packing of the Mn(III) complex molecules are very similar in the two crystals leading to the formation of channels which are occupied by water molecules in the hydrate.