Tellurium Precursor for Nanocrystal Synthesis: Tris(dimethylamino)phosphine Telluride

Preparations of CdTe quantum platelets, magic-size (CdTe)₁₃ nanoclusters, and CdTe quantum wires are described using (Me₂N)₃PTe (with (Me₂N)₃P) as a Te precursor. The (Me₂N)₃PTe/(Me₂N)₃P precursor mixture is shown to be more reactive than mixtures of trialkylphosphine tellurides and the corresponding trialkylphosphines, R₃PTe/R₃P, which are commonly employed in nanocrystal syntheses. For syntheses conducted in primary amine solvents, (Me₂N)₃PTe and (Me₂N)₃P undergo a transamination reaction, affording (Me₂N) _x(RHN)_{3- x}PTe and (Me₂N) _x(RHN)_{3- x}P (R = n-octyl or oleyl). The transaminated (Me₂N) _x(RHN)_{3- x}PTe derivatives are shown to be the likely Te precursors under those conditions. The enhanced reactivities of the tris(amino)phosphine tellurides are ascribed to increased nucleophilicity due to the amino-N lone pairs.