Highly active reduced graphene oxide supported Ni nanoparticles for C-S coupling reactions

Abstract

Air-stable Ni nanoparticles (with particle size ∼ 11 nm) supported on reduced graphene oxide [Ni(0)@RGO] was prepared by a simple and easy procedure. We previously described the Kumada-Corriu C-C cross-coupling reaction between iodo-arenes and Grignard reagents with Ni(0)RGO as a stable and efficient catalyst. This Ni(0)RGO catalyst gave an excellent yield (92%) and good recyclability (up to the 5^th cycle). This communication confirms that the catalyst shows superior efficacy for the C-S coupling reaction, similar to that for the Kumada-Corriu C-C cross-coupling reaction. A catalytic experiment with the Ni(0)@RGO recycled material was also performed. HRTEM study of the reused material after the C-S coupling reaction confirmed the retention of the original (fresh) catalyst structure. It is reusable up to the 7^th cycle without any activity loss.

Fig. 1. XPS spectrum of the Ni 2p region of the Ni(0)@RGO material.

Fig. 2. Optimisation of reaction time using the Ni(0)@RGO material.

Fig. 3. Effect of different reaction temperatures on the C–S coupling reaction with the Ni(0)@RGO material.

Fig. 4. Reusability result of the Ni(0)@RGO material for the C–S coupling reaction.

Scheme 1. Schematic presentation of the C–S coupling reaction.

Fig. 5. HRTEM study of the Ni(0)@RGO material after the first run of the C–S coupling reaction.