Synthesis and Reactivity of titanium ‘POCOP’ pincer complexes

21 July 2022, Version 1
This content is a preprint and has not undergone peer review at the time of posting.


The ‘POCOP’ pincer ligand, [2,6-(R2PO)2C6H3], has been attached to titanium in both Ti(III) and Ti(IV) complexes for the first time. Using a lithium-halogen exchange route [2.6-(R2O)2C6H3]Li ([RPOCOP]Li) can be synthesised. Both the iso-propyl and tert-butyl derivatives can be made, but only the latter isolated. These can be reacted with the Ti(III) and Ti(IV) synthons to make [tBuPOCOP]TiCl2 (1), [tBuPOCOP]TiCl3 (2) and {[iPrPOCOP]TiCl2(µ-Cl)}2 (4). In the presence of Ti(IV), THF and [RPOCOP]Li an unprecedented ligand rearrangement occurs. 1 can be derivatised with alkylating agents to make bis-methyl, phenyl and neopentyl complexes. The last of these can activate H2 to make a rare example of a titanium hydride chloride, with the metal pincer fragment staying attached. This opens the door for this archetypical pincer ligand to be used with early transition metals.


Pincer Ligands

Supplementary materials

Supplementary Materials for Synthesis and Reactivity of Ti POCOP complexes
Contains experimental details, spectra and DFT details


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