Carboxylate versus imidobenzoate bonding for anthranilic acid derivatives.: Crystal structures of [W(η-C5Me5)Cl3(η2-O2CC6H4NH2-2)] and [ReCl(OEt)(PPh3)2 (NC6H4CO2)]

The paramagnetic complex [W(eta -C5Me5)Cl-3 (eta (2)-O2CC6H4NH-2)] (1) has been obtained by reaction of [W(eta -C5Me5)Cl-4] with anthranilic acid [1,2-(NH2)(CO2H)C6H4]; the X-ray crystal structure shows a pseudo-octahedral geometry with a mer arrangement of chlorines and a symmetrically chelating carboxylate group containing a pendant non-coordinated NH2 group. Contrastingly, [ReCl(OEt) (PPh3)(2)(NC6H4CO2)] (2), the product of the reaction between [ReOCl3(PPh3)(2)] and anthranilic acid contains pseudooctahedral rhenium with a chelating imidobenzoate ligand and trans-phosphines which are mutually cir to the bent imido function [Re-N(1)-C(1) = 143.5(3)degrees]. The carboxylate group of the chelating ligand is trans to a chloride with the remaining site (trans to the imido function) occupied by an ethoxide ligand. (C) 2001 Elsevier Science B.V. All rights reserved.