# Characterization of the Titanium(III) Tris(alkyl) Ti{CH(SiMe3)2}3 and its Conversion to a Dimeric Alkyl‐Bridged Titanium(IV) Species

## TL;DR

Scientists synthesized a rare titanium(III) compound and observed its conversion to a titanium(IV) dimer through chemical reactions.

## Contribution

The synthesis and characterization of a rare titanium(III) tris(alkyl) compound and its transformation into a dimeric titanium(IV) species.

## Key findings

- Ti{CH(SiMe3)2}3 was synthesized in 32% yield and crystallized as blue needles.
- X-ray crystallography revealed a trigonal pyramidal geometry around titanium.
- The compound converts to a dimeric Ti(IV) complex via intramolecular C−H activation.

## Abstract

The reaction of three equivalents of LiCH(SiMe3)2 with TiCl3(NMe3)2 afforded the rare homoleptic Ti(III) alkyl Ti{CH(SiMe3)2}3 (1) which crystallized as blue needles in 32 % yield. Single crystal X‐Ray data for 1 showed a trigonal pyramidal coordination geometry around titanium, which could be ascribed to weak interactions between the C−H bonds and the Ti(III) atom based on computational results. X‐band EPR spectroscopy gives spectral parameters consistent with the proposed Ti(III) formulation. Solutions of 1 are unstable at room temperature owing to intramolecular C−H activation that gave a dimeric Ti(IV) complex [{(Me3Si)2HC}Ti{μ‐CHSiMe2CHSiMe3}]2 (2).

The trigonal pyramidal titanium(III) trialkyl is synthesized in moderate, reproducible yield via the reaction of three equivalents of Li{CH(SiMe3)2} with TiCl3(NMe3)2 in hexanes. The use of the latter solvent is a key feature for the success of the synthetic route. Ti{CH(SiMe3)2}3 is characterized by X‐ray crystallography, EPR and electronic spectroscopy.