Coordination of Palladium with Polydentate Non‐planar Ligands with Competitive Donors (Oxygen and Double Bonds). Role of Stereochemistry

Abstract

Palladium (II) complexes of three polydentate non‐planar bicyclo[4.4.0]decane ligands with at least one double bond and bridgehead cis‐substituents CH2OH or CH2OCH2 were prepared in order to investigate the role of stereochemistry and donor nucleophilicity in the Pd coordination. All ligands and their corresponding complexes were characterized using NMR, solid‐state NMR (ssNMR), HR‐MS, ATR‐IR, DSC‐TGA. For ligand cis‐1,4,5,8‐tetrahydro‐naphthalene‐4a,8a‐diyl‐dimethanol (L2) the X‐ray structure corresponded to the DFT optimised structure. The HR‐MS and thermal analysis data confirmed a complexation ratio: ligand/PdCl2 of 1/1. The experimental data as well as the computations are consistent with the structures proposed based on 13C‐ssNMR, namely palladium coordinates with one double bond and an oxygen atom for ligands with CH2OH groups and with both double bonds for the ligand with an etheric bridge, showing the prevalence of stereochemistry over donor nucleophilicity for such non‐planar ligands.