PALLADIUM(II) COMPLEX WITH TETRAHYDROBENZOXAZINOBENZOXOSINE: SYNTHESIS, ELECTRONIC AND MOLECULAR STRUCTURES

Interaction of the palladium(II) benzonitrile complex [Pd(PhCN) 2 Cl 2 ] with glyoxal-bis(2-hydroxy-3,5-di- tert -butylphenyl)imine (H 2 L) induces intramolecular rearrangement of H 2 L into the corresponding tetrahydrobenzoxazinobenzoxosine ( L′ ), and the coordination of the latter to Pd(II) leads to the formation of [Pd( L′ )Cl 2 ]·(CH 3 ) 2 CO ( 1· (CH 3 ) 2 CO). The crystal structure of this compound is determined by XRD. The Pd atom in the structure occurs in a square planar environment of two Cl atoms and two N atoms of the L′ ligand. Quantum chemical calculations within the density functional theory are conducted; the electronic structure of 1 is studied. The Pd–N and Pd–Cl bonds are shown to be intermediate type bonds. Orbitals of N–Pd–Cl three-center bonds are discovered using the NBO analysis. The formation of such three-center bonds can be represented as a result of the electron density donation from the orbitals of nitrogen lone pairs to the σ * orbitals of Pd–Cl bonds.