Coordination diversity in palladium(II)-picolinamide ligand complexes: structural and quantum chemical studies

Debasish Das, Amsaveni Muruganantham, S. Kannan, Mukesh Kumar, Mahesh Sundararajan, M. K. Sureshkumar
2017 Figshare  
The separation of different metal ions can be successfully accomplished by using picolinamide-based ligands. We herein report the first X-ray structure of picolinamide-based ligands of the type C5H4NCONR2 (where R=iC3H7 (L1) and iC4H9 (L2)) and C5H4NCONHR (R=tC4H9 (L3)) with palladium(II) ion. We have synthesized and characterized the structures of two palladium complexes, [PdCl2(L1)2] (1) and [PdCl2L3] (3). In 1, ligand L1 forms a 2 : 1 complex with palladium(II) chloride, whereas in 3, the
more » ... hereas in 3, the ligand L3 forms a 1 : 1 complex. Further, in 1, the ligand L1 acts as a monodentate ligand and is bound only through pyridyl-N atom, whereas in 3, the ligand L3 acts as a bidentate chelating ligand and is bound through both the pyridyl-N and amido-O atoms to the Pd(II) center. Electronic structure calculations are carried out to understand the experimental coordination diversity in the Pd complexes. Our calculations clearly suggest that a combination of steric hindrance of the ligand and the electronic effect of metal ions may modulate the coordination preferences.
doi:10.6084/m9.figshare.4818064.v2 fatcat:yg6h55pms5dehgvebawhvrxffi