Oxazoles revisited: On the nature of binding of benzoxazole and 2-methylbenzoxazole with the zinc and palladium halidesOxazole Chemistry XXV. Electronic supplementary information (ESI) available: Alternative views of the molecules found in the unit cell of complex 7, DFT calculated energies for the various isomers of compounds 1-6 and detailed synthetic procedures for complexes 1-6. Additional cif files for the refined datasets for hypothetical O-bonded isomers of 1, 2, 4 and 6 are available fro

• Main Authors: Jones, Roderick C, Chojnacka, Maja W, Quail, J. Wilson, Gardiner, Michael G, Decken, Andreas, Yates, Brian F, Gossage, Robert A
• Format: Journal Article
• Language: English
• Published: 01.02.2011
• DOI: 10.1039/c0dt01266a
• ISSN: 1477-9226

A synthetic and structural (X-ray) investigation into the bonding modes of benzoxazole (box) and 2-methylbenzoxazole (Mebox) ligands with halide precursors of Zn and Pd has been undertaken to clarify earlier discrepancies concerning the nature of the bonding mode(s) of the two azoles. In four structurally characterised examples, all contain the title ligands in a κ 1 N bonding motif. Calculations at the density functional level ( dft ) of theory (B3LYP) confirm the ground state stability of this class of coordination for several hypothetical Pd and Zn (gas phase) compounds. The attempt to obtain suitable crystalline material of PdCl 2 (box) 2 ( i.e ., 5 ) leads to substantial complex degradation. One minor product of this process has been identified (X-ray) as the diarylformamidinato complex C 26 H 22 N 4 O 4 Pd, presumably formed via a complex combination of the decomposition products of both free box and 5 . Several examples of early benchmark benzoxazole complexes of Zn and Pd have been further characterised to confirm the κ 1 N bonding mode of the azole ligands.