Different Hemi-Salen/Salan Ligand Containing Binuclear Boron-Fluoride Complexes: Synthesis, Spectroscopy, Fluorescence Properties, and Catalysis

ABSTRACT

A family of hemi-salen (L₁H–L₆H) and hemi-salan (L_1aH–L_2aH) ligands-based N,O-chelated binuclear boron-fluoride [L_n(BF₂)₂] (n = L₁–L₆ or L_1a–L_2a) complexes have been prepared and characterized by a variety of spectroscopic techniques (¹H, ¹³C and ¹⁹F NMR, FT-IR, UV-Vis, LC-MS, and fluorescence spectra) and elemental analysis. All of the binuclear boron-fluoride complexes exhibit strong absorption bands due to S₀→S₁ transitions and strong fluorescence properties were observed at room temperature in the solution. The binuclear boron complexes containing two naphthyl groups are significantly red-shifted in comparison with the other binuclear boron-fluoride complexes. After the structures are characterized, these hemi-salen and salan ligand-based N, O-chelated binuclear boron-fluoride complexes were utilized to the transfer hydrogenation of the different acetophenone derivatives conversion to 1-phenylethanol derivatives as catalysts.

KEYWORDS:

• Boron complexes
• catalysis
• fluorescence
• synthesis
• spectroscopy

Funding

This work was supported by the Chemistry Department of Harran University, Sanliurfa, Turkey.