PCP Pincer Complexes of Titanium in the +3 and +4 Oxidation States

Benedek Stadler; Hilary H Y Meng; Sara Belazregue; Leah Webster; Alberto Collauto; Keelan M Byrne; Tobias Krämer; F Mark Chadwick

doi:10.1021/acs.organomet.2c00662

PCP Pincer Complexes of Titanium in the +3 and +4 Oxidation States

Organometallics. 2023 Mar 13;42(12):1278-1285. doi: 10.1021/acs.organomet.2c00662. eCollection 2023 Jun 26.

Authors

Benedek Stadler¹, Hilary H Y Meng¹, Sara Belazregue¹, Leah Webster¹, Alberto Collauto¹, Keelan M Byrne², Tobias Krämer², F Mark Chadwick¹

Affiliations

¹ Molecular Sciences Research Hub, Department of Chemistry, Imperial College London, 82 Wood Lane, London W12 0BZ, United Kingdom.
² Department of Chemistry, Maynooth University, Maynooth, Co. Kildare W23 F2H6, Ireland.

Abstract

Ti(IV) and Ti(III) complexes using the ^tBuPCP ligand have been synthesized (^tBuPCP = C₆H₃-2,6-(CH₂P^tBu₂)₂). The [^tBuPCP]Li synthon can be reacted with TiCl₄(THF)₂ to form (^tBuPCP)TiCl₃ (1) in limited yields due to significant reduction of the titanium synthon. The Ti(III) complex (^tBuPCP)TiCl₂ (2) has been further characterized. This can have half an equivalent of halide abstracted to form [{(^tBuPCP)TiCl}₂{μ-Cl}][B(C₆F₅)₄] (3) and can also be methylated, forming (^tBuPCP)TiMe₂ (4). All the Ti(III) complexes have been characterized using EPR and X-ray crystallography, giving insight into their electronic structures, which are further supported by DFT calculations.