Loren D. Durfee

The chemistry of sterically crowded aryloxide ligands—VII. Synthesis, structure and spectroscopic properties of some group 4 and group 5 metal derivatives of 2,6-diphenylphenoxide

Abstract A series of early transition metal organometallic derivatives containing the ancillary ligand 2,6-diphenylphenoxide (OAr-2,6Ph 2 ) have been synthesized. Compounds of stoichiometry Ti(OAr-2,6Ph 2 ) 2 (R) 2 (R = CH 3 , CH 2 SiMe 3 , CH 2 Ph and Ph) and Ti(OAr-2,6Ph) 3 (R) (R = CH 3 , CH 2 SiMe 3 ) are obtained by treating the corresponding homoleptic alkyl, TiR 4 , with the required amount of phenol, HOAr-2,6Ph 2 . For the Group 5 metals Nb and Ta, the methyl derivatives M(OAr-2,6Ph 2 ) 2 (CH 3 ) 3 and M(OAr-2,6Ph 2 ) 3 (CH 3 ) 2 are obtained via methylation of the corresponding chloro-aryloxides. Besides routine spectroscopic characterization the diphenyl Ti(OAr-2,6Ph 2 ) 2 (Ph) 2 and mono-alkyl Ti(OAr-2,6Ph 2 ) 3 (CH 2 SiMe 3 ) have been structurally characterized by X-ray diffraction techniques. Both molecules contain a pseudo-tetrahedral environment about the titanium atom with short 1.794(3)–1.806(2) A, TiO distances and large, 153–179°, TiOAr angles. The TiC distances appear normal for these types of compounds.