First Principles Electronic Structure Study of Lanthanide-(III) complexes with pyridine-2,6-dicarboxamide on Au(111) substrate*

Development of complex metallo-supramolecular has been heavily imbalanced towards transition metal-based systems, and there is a smaller sub-section made up of rare-earth-based assemblies that have been the focal point for some research groups. In particular, europium (III) and lanthanide (III) complexes have attracted attention due to their well-defined luminescence properties, including hypersensitivity to the coordination environment, narrow bandwidth and millisecond luminescence decay times. In this regard, motivated by experiments, we have performed density functional theory (DFT) calculations on [La(pcam)₃]³⁺ deposited on the Au(111) surface to understand its electronic structure and charge transfer analysis between molecule and Au(111) substrate. Obtained DFT energy bandgap is ca. 3.8 eV, in agreement with the value ~3.5 eV obtained from STM experiments. Slight discrepancies in the energy bandgap might be due to the anion trapped with the molecule or might be due to an approximation in DFT. In this presentation, with the aid of different DFT methods, we will discuss the electronic structure and charge transfer analysis for both single and dimer [La(pcam)₃]³⁺ molecules with and without trapped triflate counter anions, [CF₃SO₃]^-1, on an Au(111) substrate based on Bader charge analysis.