Diamido tantalum(V) complexes derived from a diazamacrocycle

Abstract

The amido complexes [Ta{O(N)2}(CH2Ph)3], (1), [Ta{O(N)2}(µ-CHBu t){µ-O(NH)N}Li], (2), and [Ta{O(N)2}Cl3], (3), all featuring the dianionic diamido macrocycle [O(N)2] 2originating from O(NH)2 by deprotonation, O(NH)2 = 3,3-dimethyl-1,5-diaza-8-oxacyclodecane, have been prepared from Ta(CH2Ph)5, Ta(CH2 t Bu)3Cl2 and TaCl5 by alkanolysis, salt metathesis with Li2[O(N)2] and .Me3SiCl elimination with O(NSiMe3)2, respectively. Structural analyses revealed that in (1) the macrocycle is facially coordinated, while (2) contains one dianionic, facially coordinated macrocycle and one monoanionic macrocycle coordinating one lithium atom and metallated at one of the 3-methyl groups by the Ta.