Phosphorus(III and V)– and arsenic(III)–nitrogen metallacycles derived from the bulky arylamido ligand NHAr (Ar = C6H2But3-2,4,6); X-ray structures of ArNPN(Ar)AIMe2 and PAr(NHAr)2

Abstract

In its co-ordination chemistry P(NAr)(NHAr)(Ar = C₆H₂Bu^t₃-2,4,6)(1a) behaves either as (i) a source of its conjugate base yielding Ar[graphic ommitted]L_n(2)[ML_n= AIMe₂, from (AIMe₃)₂] and (3)(ML_n= Li, from LiBuⁿ), or (ii) as a neutral hydrido-P^V ligand in [[graphic ommitted])₂PH}], but the arsa(III)azene (1b)[the As analogue of (1a)] undergoes facile As–NHAr bond-scission with (AIMe₃)₂; whereas (1b) is obtained from 2Li(NHAr)+ AsCl₃ in OEt₂ at 20 °C, prolonged reflux in PhMe of the same reagents furnishes a cyclometallated product; <P–N> in (2)[1.617(4)Å] is intermediate between the PN and P–N bond lengths in (1a), and is significantly shorter than the 1.74(1)Å for <P–N> in PAr(NHAr)₂[obtained from PArCl₂+ 2Li(NHAr)].