Supramolecular assemblies of tungsten complexes with unusual chelating groups

Metal complexes of ligands with eta(1)-O coordinated carbonyl moieties are well-known throughout the inorganic literature. However, metal complexes containing authentic acid chloride ligands have not previously been isolated. The synthesis and characterization of compounds with the formula W(X)Cl-3(OPh-2-COCl) (2) [X = O (2a), NC6H3-2,6-(CH3)(2) (2b), and Ph2C2 (2c)] are reported. The crystal structures of 2a and 2c were solved, showing the interaction of the acid chloride carbonyl moiety with the tungsten center. Complex 2c adopts a channelled structure having six-fold symmetric voids in the solid state. As was anticipated, the coordinated acid chloride of 2a reacts readily with nucleophiles to produce the ester WOCl3(OPh-2-COPrn) (3) and the amide WOCl3(OPh-2-CONHBut) (4a). A related amide complex WOCl3(OPh-(2)-CONH2) (4b), synthesized by the reaction of WOCl4 with salicylamide, displays an infinite-chain structure supported by hydrogen bonding between the amide group and the oxo ligand of an adjacent tungsten complex. The eta(1)-O coordinated nitro compounds W(X)Cl-3(OPh-2-NO2) (5) [X = O (5a), NC6H3-2,6-(CN3)(2) (5b), and Ph2C2 (5c)] have also been isolated and the crystal structure of 5c is reported. (C) 1998 Elsevier Science Ltd. All rights reserved.