Generation of Tp*2U(N3) from a family of new uranium(III) alkyl complexes

Abstract

A new family of uranium(III) benzyl species supported by bulky hydrotris(3,5-dimethylpyrazolyl)borate (Tp*) ligands has been synthesized and characterized. These derivatives were synthesized by treating Tp*2UI (1-I) with various benzylpotassium salts to afford Tp*2U(CH2-para-isopropylphenyl) (1-p-iPr), Tp*2U(CH2-para-tert-butylphenyl) (1-p-tBu), Tp*2U(CH2-meta-methoxyphenyl) (1-m-OMe), and Tp*2U(CH2-ortho-picolyl) (1-o-Picolyl). Along with previously reported Tp*2U(CH2Ph) (1-CH2Ph), these uranium alkyl complexes can be treated with an equivalent of Me3SiN3 to yield Tp*2UN3 (2-N3), releasing an equivalent of the corresponding benzyltrimethylsilane. All compounds were characterized by multinuclear NMR, IR, and electronic absorption spectroscopies as well as X-ray crystallography.