Nickel and iridium pincer complexes with saturated frameworks - synthesis and reactivity

Sammanfattning: As the tridentate chelate complexes referred to as pincer complexes have expanded their scope as homogeneous catalysts, there is an increased interest in electronic and steric fine-tuning of such complexes. One accessible variable in this aspect is the hybridisation of any coordinated carbon atoms. This thesis describes the synthesis of bis(phosphine) and bis(phosphinite) PCP pincer complexes with nickel and iridium. The studied pincer ligands have all-aliphatic backbones based on a linear alkyl or a cyclohexyl moiety. The presented families of new pincer complexes have been investigated with aspect to their coordination chemistry and stability. The reactivity of POCOP-supported nickel complexes towards carbon dioxide and carbon monoxide has been studied. Further, iridium pincer complexes with saturated frameworks have been evaluated as catalysts for alkane dehydrogenation reactions. The work also include indications of an unusual C(sp3)–C(sp3) reductive elimination at an iridium(III) centre, resulting in a net methyl migration from the metal to the ligand backbone.