Resonance Raman Investigation of the Au(I)−Au(I) Interaction of the ¹[dσ*pσ] Excited State of Au₂(dcpm)₂(ClO₄)₂ (dcpm = Bis(dicyclohexylphosphine)methane)

Abstract

We present a resonance Raman investigation of the lowest energy dipole-allowed absorption band of [Au 2 (dcpm) 2 ](ClO 4 ) 2 (dcpm ) bis(dicyclohexylphosphine)methane). The resonance Raman spectra provide the first experimental proof of the 5dσ* f 6pσ electronic transition in dinuclear gold(I)-phosphine compounds. A resonance Raman intensity analysis of the spectra allows estimation of the structural changes of the [dσ*pσ] excited states relative to the ground state.

Remarkable Luminescence Behaviors and Structural Variations of Two-Coordinate Gold(I) Complexes

“…The lowest energy dipole-allowed absorption band of [Au 2 (dcpm) 2 ](ClO 4 ) 2 at 297 nm has been investigated by resonance Raman spectroscopy [61]. The characteristics of the spectrum are fully in accord with the assignment of the absorption band as transition from a filled 5d z 2 (σ * ) orbital to an empty 6p z (σ ) orbital.…”

A Review of Luminescent Anionic Nano System: d10 Metallocyanide Excimers and Exciplexes in Alkali Halide Hosts

“…Closed-shell heavy metals used to be considered as repelling each other due to the fully occupied valence orbitals. However, in the study of inorganic and organometallic compounds, experimental results have presented evidence of interaction between closed-shell metals [16,17,18,19,20,21,22,23,24,25]. The strength of these bonds is weaker than ionic (700–4000 kJ/mol) and covalent bonds (200–1000 kJ/mol) but stronger than a van der Waals bond (<5 kJ/mol), and they are about the energy of hydrogen bonds (10–40 kJ/mol) [26].…”

Theoretical studies on metal–metal interaction and luminescence of a dinuclear [AuS2PH2]2 complex

“…Since the presence of a bridging ligand facilitates the intramolecular interaction [11,15], the Au complexes with the closed type of eight-membered ring conformation can serve as an ideal model for the investigation on the relationship between spectroscopic properties and aurophilicity [1,4,25] of the luminescence and aurophilicity of Au complexes. Second, the studies provide the support in theory for experimental observations, especially for the existing and/or potential [21,[28][29][30][31] applications of Au complexes. So far, the existing and/or potential applications of the Au thiolates such as optical materials [28], photocatalysts [29], biosensors [30], and molecular pharmacology [31] have also intrigued many researchers.…”

“…Withal, the spectra of the excited states for such Au complexes have been discussed in some degree. The emission of several dinuclear phosphine Au complexes is assigned to metal-centered charge transfer (MCCT) transitions [21,22]. In several dinuclear Au thiolate complexes, however, the emission is attributed to the Au to thiolate or sulfur charge transfer (MLCT) transition [23,24].…”