Synthesis, characterization, crystal structure, Hirshfeld surface analysis, and theoretical study on a N-heterocyclic carbene salt and two NHC–palladium complexes

Abstract

An N-ethylphthalimide functionalized 1,3-dialkylbenzimidazolium salt has been synthesized and characterized by elemental analysis, FTIR, ¹H NMR, and ¹³C NMR spectroscopy. Crystal structures of the salt and two palladium complexes were determined by single-crystal X-ray diffraction studies. Theoretical calculations were obtained by density functional theory (DFT) methods at the HSEh1PBE/SDD level of theory. Structural parameters of the compounds are well represented by DFT calculations. Noncovalent interactions in the compounds have also been studied through two-dimensional fingerprint plots based on Hirshfeld surface analysis. Frontier molecular orbitals (HOMO-LUMO) and their energy gap were determined to explore the stability of the molecules. The large HOMO-LUMO energy gaps point out a high kinetic stability of the compounds in their electron transfer.

Graphical Abstract

Keywords:

• N-Heterocyclic carbene
• PEPPSI complex
• palladium
• X-ray crystallography
• DFT

Disclosure statement

No potential conflict of interest was reported by the authors.

Acknowledgment

We also acknowledge Amasya University, Turkey, for accessing to GaussView 5.0 and Gaussian 09W program packages.

Additional information

Funding

This work was financially supported by the İnönü University Research Fund (İÜ-BAP, Project No: 2015/41) and Technological and Scientific Research Council of Turkey TÜBİTAK (Project No: 117R010). This study was further supported by Ondokuz Mayıs University (Project No: PYO.FEN.1906.19.001).