A series of dichlorocyclophosphazanes [{ClP(μ-NR)}2 ] containing chiral and achiral R groups was obtained from simple commercially available amines and PCl3 . Their condensation reactions with axially chiral biaryl diols yielded ansa-bridged chiral cyclophosphazane (CycloP) ligands. This highly modular methodology allows extensive elaboration of the ligand set, in which the chirality can be introduced at the diol bridge and/or the amido R group. This provides the possibility to observe match and mismatch effects in catalysis. A series of twenty CycloP ligands was synthesized and characterized by multinuclear NMR spectroscopy, HRMS, elemental analysis, and in selected cases, single-crystal X-ray diffraction. These studies show that all of the ditopic CycloP ligands are C2 symmetric, rendering their metal coordination sites symmetry equivalent. Two well-established enantioselective reactions were explored by using late-transition metal CycloP complexes as catalysts; the gold-catalyzed hydroamination of γ-allenyl sulfonamides and the asymmetric nickel-catalyzed three-component coupling of a diene and an aldehyde. The steric demands of the CycloP ligands have a subtle influence on the reactivity and selectivity observed in both reactions. Good enantiomeric ratios (e.r.) as high as 89:11 in the gold-catalyzed reaction and 92:8 in the nickel-catalyzed bis-homoallylation reaction were observed.

A series of chiral mono-, di-, and trinuclear gold(I) complexes have been prepared and used as precatalysts in the asymmetric cyclohydroamination of N-protected γ-allenyl sulfonamides. The stereodirecting ligands were mono-, di-, and tridentate 2,5-diphenylphospholanes, which possessed C(1), C(2), and C(3) symmetry, respectively, thereby rendering the catalytic sites in the di- and trinuclear complexes symmetry equivalent. The C(3)-symmetric trinuclear complex displayed the highest activity and enantioselectivity (up to 95 % ee), whilst its mono- and dinuclear counterparts exhibited considerably lower enantioselectivities and activities. A similar trend was observed in a series of mono-, di-, and trinuclear 2,5-dimethylphospholane gold(I) complexes. Aurophilic interactions were established from the solid-state structures of the trinuclear gold(I) complexes, thereby raising the question as to whether these secondary forces were responsible for the different catalytic behavior observed.

Aqueous hydrolysis of a series of cerium-containing polyoxotitanium cages gives Ce(III)-doped TiO 2 [TiO 2 (Ce)] or TiO 2 -supported Ce(III) 2 Ti 2 O 7 , depending on the starting Ti : Ce ratio of the precursor. TiO 2 -supported Ce 2 Ti 2 O 7 exhibits superior photocatalytic activity to the Ce-doped TiO 2 materials and unusual broadband absorption behaviour across the visible and near-infrared regions.

A series of κ 2 -(N,N)-coordinated bis(2-pyridylimino)isoindolato (BPI) complexes [Cp*Ir(BPI)Cl], which possess "three-legged piano-stool" structures, with the iridium atom being coordinated by the Cp* ligand 2 × N and Cl, were prepared via deprotonation of the BPIH ligands with either potassium hydride or LDA and subsequent reaction with [Cp*IrCl 2 ] 2 in THF. Cationic complexes [Cp*Ir(BPI)] + containing κ 3 -(N,N,N)-coordinated BPI ligands were prepared as well as complexes with bidentate-coordinated BPI ligands, where the chloride ligand was substituted by either neutral or anionic ligands. Substitution in the orthoposition of the PBI ligands led to the formation of cycloiridated κ 3 -(N,N,C) species. Upon substitution of the anionic ligand by triphenylphosphine, a product was obtained with a hitherto unobserved κ 2 -(N,N) coordination of oMe-BPI to the metal center via the deprotonated nitrogen atom of the isoindole unit and one of the imine nitrogen atoms of the BPI ligand. A series of (para-cymene) osmium half-sandwich complexes with analogous structures and reactivities to their isoelectronic Cp*Ir(BPI) congeners were also prepared. Finally, it has been demonstrated that both Ir and Os complexes are catalytically active in the transfer hydrogenation of various ketones and imines.

A new type of hybrid phosph(III)azane/NHC system is described in which a phosphazane P2N2 ring provides unique opportunities for modifying the electronic and steric character of these carbenes.