Pyrrolyl-based pincer complexes of iron – Synthesis and electronic structure

High-spin iron(II) compounds with the pyrrolyl-derived tBuPNP pincer ligand scaffold have been prepared. These complexes exhibit significant zero-field splitting. In addition, slow paramagnetic relaxation for [(tBuPNP)FeN(SiMe3)2] is observed by zero-field 57Fe Mössbauer spectroscopy. Reaction of [(tBuPNP)FeCl] with adamantyl azide gives [(tBuPNPN3Adamantyl)FeCl], implying labile coordination of a phosphine sidearm.