Aurophilicity vs. thiophilicity: directing the crystalline supramolecular arrangement in luminescent gold compounds

• Published in: New journal of chemistry Vol. 42; no. 10; pp. 7845 - 7852
• Main Authors: Moreno-Alcántar, Guillermo, Romo-Islas, Guillermo, Flores-Álamo, Marcos, Torrens, Hugo
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 2018
• Subjects: Coordination compounds; Crystal structure; Crystallinity; Ethane; Fluorination; Gold; Gold compounds; Ligands; Photoluminescence; Solid state
• ISSN: 1144-0546; 1369-9261
• DOI: 10.1039/C7NJ04354F

Herein, we study the influence of the fluorination of thiolate ligand backbones over the solid state crystalline supramolecular arrangement in a series of seven new dinuclear fluorophenylthiolate gold( i ) coordination compounds. These compounds include the bridge ligand 1,2-bis(diphenylphosphine)ethane (dppe) and have the general formula [Au 2 (SR F ) 2 (μ-dppe)] with SR F = SC 6 F 5 ( 1 ); SC 6 HF 4 -4 ( 2 ); SC 6 H 3 F 2 -3,5 ( 3 ); SC 6 H 3 F 2 -2,4 ( 4 ); SC 6 H 4 (CF 3 )-2 ( 5 ); SC 6 H 4 F-3 ( 6 ) and SC 6 H 4 (CF 3 )-4 ( 7 ). By the analysis of X-ray crystalline structures, we found that the increase in the fluorination degree of the ligands reduces the incidence of aurophilic interactions and collaterally favours the formation of a secondary Au⋯S (thiophilic) interaction resulting in a rhomboidal planar (AuS) 2 unit. This latter synthon recurrently competes with the expected Au–Au contacts. All the analysed compounds show visible photoluminescence in the solid state, indicating an aggregation-induced emissive behaviour, i.e. both the aurophilic and thiophilic interactions promote the emission of light by this family of gold complexes.