Influence of Relativistic Effects on Assembled Structures of V-Shaped Bispyridine Molecules on M(111) Surfaces Where M = Cu, Ag, Au

Abstract

The self-assembly behavior of a V-shaped bispyridine, 1,3-bi(4-pyridyl)benzene (BPyB), was studied by scanning tunneling microscopy on the (111) surfaces of Cu, Ag, and Au. BPyB molecules coordinately bonded with active Cu adatoms on Cu(111) in the form of complete polygonal rings at low coverages. On Ag(111), BPyB molecules aggregated into two-dimensional islands by relatively weak intermolecular hydrogen bonds. The coexistence of hydrogen bonds and coordination interaction was observed on the BPyB-covered Au(111) substrate. Density functional theory calculations of the metal-molecule binding energy and Monte Carlo simulations were performed to help understand the forming mechanism of molecular superstructures on the surfaces. In particular, the comprehensive orbital composition analysis interprets the observed metal-organic complexes and reveals the importance of relativistic effects for the extraordinary activity of gold adatoms. The relativistic effects cause the energy stability of the Au 6s atomic orbital and decrease the energy separation between the Au 6s and 5d orbitals. The enhanced sd hybridization strengthens the N-Au-N bond in BPyB-Au-BPyB complexes.

Modelling of electronic and optical properties of Cu2SnS3 quantum dots for optoelectronics applications

“…QDs are used for the preparation of sensors with multidimensional response signals and narrow band luminescent emission and they offer high resistance to photodegradation. They have found delicate applications in various optoelectronic devices * E-mail: irshad_bcet@yahoo.co.in such as light emitting diodes (LEDs), laser diodes (LDs) [4][5][6], photovoltaics [2,7,8] and photodiodes (PDs) [9][10][11].…”

Mixed‐valence Compounds: AuO2 and AuS

“…Coinage metals, especially for Au, hold unique position in transition metals. The relativistic expansion of Au 5d orbital makes it exhibit several oxidation states in its compounds ,,. Thus, much attention has been paid to find mixed‐valence coinage metal compounds ,.…”

On-surface isostructural transformation from a hydrogen-bonded network to a coordination network for tuning the pore size and guest recognition

“…3). [43][44][45] It should be noted that H 3 btim hydrogen-bonded network 46 Moreover, the reverse transformation from the coordination to H-bonded networks was not observed, being consistent with the irreversible dehydrogenation process. Nevertheless, samples with both structures coexisting on the surface can be prepared by secondary deposition of molecules on the surface with [Ag 3 (btim)] (Fig.…”