Selective Formation of Mononuclear Palladium and Acetonitrile-Bridged Dinuclear Palladium Complexes Containing a Chiral Tridentate Ligand

Abstract

From the chiral Schiff base tridentate ligand L Ph , unusual acetonitrile-bridged dinuclear palladium complex 1 and organopalladium complex 1′ were synthesized selectively by using acetonitrile and ethanol, respectively. The chiral tridentate Schiff base ligand was bound to the palladium metal center with different chelation modes ([ONO] for 1 and [CNO] for 1′). Complex 1 constitutes the first example of dinuclear metal complexes connected only by a bridging acetonitrile, in which an exceptionally short CN bond distance [0.945( 12) Å] of bridged acetonitrile was observed. To study the influence of a phenyl group attached to an imine, the phenyl-free ligand L H was prepared and used. In that case, an acetonitrile bridge was not observed. Theoretical calculation studies supporting the formation of 1 and 1′ are favored. * sı Supporting InformationThe Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acs.inorgchem.1c03391.Experimental procedures, analytical data of the complexes with 1 H NMR, IR, and MS spectra of 1, 1′, and 2, X-ray crystallographic data for 1, 1′, and 2, and density functional theory calculations (PDF)Accession Codes CCDC 2043775, 2043777, and 2095625 contain the supplementary crystallographic data for this paper. These data can be obtained free of charge via www.ccdc.cam.ac.uk

Bis(2-hydroxy-2,3-dihydro-1H-inden-1-aminium) tetrachloridopalladate(II) hemihydrate

“…In particular, palladium complexes with chiral ligands has received increasing attention in asymmetric reactions (Uchikura et al, 2023). In this field, we have been interested in the synthesis of chiral palladium complexes and recently reported several palladium complexes with chiral tridentate ligands based on (1R,2S)-(+)-1-aminoindan-2-ol (Singh et al, 2022). During these studies, we unexpectedly isolated the title complex, (C 9 H 12 -NO) 2 [PdCl 4 ]•0.5H 2 O.…”