[Zurück]

S. Asadizadeh, M. Sohrabi, K. Mereiter, H. Farrokhpour, S. Meghdadi, M. Amirnasr:
"Novel octanuclear copper(I) clusters [Cu₈{(N)-(μ₄-S)}₄(μ₃-I)₂I₂(PPh₃)₂] produced via reductive S-S bond cleavage of disulfide Schiff base ligands and their use as efficient heterogeneous catalysts in CuAAC click reaction";
Molecular Catalysis, 524 (2022), S. 112290-1 - 112290-15.

Thiol/disulfide interconversion, catalyzed by metal ions and enzymes, is a fundamental transformation and plays important roles in biological systems. The thiolates, produced in these reactions, are particularly versatile sulfur-containing ligands that can bind to metals or group of metals via a variety of modes and this versatility can lead to the formation of polymeric chains and metal clusters with high nuclearity. Herein, we report the facile one pot synthesis of novel octanuclear copper(I) complexes, [Cu₈{(N)-(μ₄-S)}₄(μ₃-I)₂I₂(PPh₃)₂] (1-5), by the reaction of copper(I) iodide and disulfide Schiff base molecules (R-CH=N−Ph−S−S−Ph-N=CH-R, RMePh = 4-MePh (SB¹), R^MeOPh = 4-MeOPh (SB²), R^MeSPh = 4-MeSPh (SB³), R^BrPh = 4-BrPh (SB⁴), and RFur = 2-furan (SB⁵)) in the presence of PPh3 in dichloromethane-acetonitrile or chloroform-acetonitrile solution under ambient conditions. Single-crystal X-ray structure analyses of these clusters confirm the presence of Cu8S₄I₄ core stabilized by the chelating Schiff base thiolate fragment R-CH=N−Ph−S^- produced by the reductive cleavage of disulfide bond, I^-, and PPh3. DFT calculations have been performed to describe a speculative mechanism of cluster formation. The octanuclear clusters [Cu₈{(N)-(μ₄-S)}4(μ₃-I)₂I₂(PPh₃)₂] (1-5) have been exploited as efficient heterogeneous catalysts for the green synthesis of 1,2,3-triazoles from NaN₃, alkyl halides, and alkyne derivatives (CuAAC reaction) under mild conditions.

Novel octanuclear Cu(I) clusters; Crystal structures; Heterogeneous catalysis; CuAAC click reaction; Synthesis of 1,2,3-triazoles

http://dx.doi.org/10.1016/j.mcat.2022.112290