Selective Oxidation of Nonrefractory and Refractory Sulfides by Cyclopentadienyl Molybdenum Acetylide Complexes as Effic
- PDF / 545,366 Bytes
- 9 Pages / 595.276 x 790.866 pts Page_size
- 13 Downloads / 196 Views
Selective Oxidation of Nonrefractory and Refractory Sulfides by Cyclopentadienyl Molybdenum Acetylide Complexes as Efficient Catalysts Macchindra G. Chandgude • Ankush V. Biradar Trupti V. Kotbagi • Vedavati G. Puranik • Mohan K. Dongare • Shubhangi B. Umbarkar
•
Received: 31 May 2011 / Accepted: 23 August 2012 / Published online: 19 September 2012 Ó Springer Science+Business Media, LLC 2012
Abstract The synthesis and catalytic properties of molybdenum acetylide complexes CpMo(CO)3(–C:CR), R = Ph(1), C6H4–p-CF3 (2) and C6H4–p-CH3 (3) has been studied. The molybdenum acetylide complexes were synthesized from CpMo(CO)3Cl and aryl acetylenes via Stephens–Castro coupling reaction. These complexes were characterized by single crystal X-ray diffraction analysis, FTIR and 1H NMR spectroscopy. These complexes on treatment with hydrogen peroxide, formed corresponding molybdenum oxo-peroxo species. These in situ formed oxo-peroxo species were found very active (up to 100 % conversion) and selective (up to 100 %) oxidation catalysts for various refractory and nonrefractory sulfides. Interestingly, even though the molybdenum acetylide complexes are homogeneous, they could be recycled very efficiently by extracting the catalytically active molybdenum oxoperoxo species in aqueous phase. Keywords Homogeneous catalysis Molybdenum acetylide Refractory sulfide oxidation Oxo-peroxo species
Electronic supplementary material The online version of this article (doi: 10.1007/s10562-012-0898-x) contains supplementary material, which is available to authorized users. M. G. Chandgude A. V. Biradar T. V. Kotbagi M. K. Dongare S. B. Umbarkar (&) Catalysis Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India e-mail: [email protected] V. G. Puranik Centre for Material Characterization, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India
123
1 Introduction Sulfur (S) is an essential element in the life processes of all living things including micro-organisms, higher plants, animals, and humans. Sulfur plays a major role in the formation of the proteins that are essential to sustain life in all biological organisms [1]. However, it is one of the major problems in fuel that causes air pollution leading to acid rains. Moreover, it poisons the catalyst in catalytic convertor [2]. In order to control the pollution, Environmental Protection Agency (EPA) has enforced stringent regulation for substantial reduction in the total sulfur content of gasoline and diesel fuel [3, 4]. Hence it is of great importance to develop effective ways to remove sulphur impurities from the fuel [5]. Commercially, these impurities are removed by hydrodesulfurization (HDS), which is a highly efficient process till date for removing nonrefractory sulfides, although not very effective for refractory sulfides [6]. An alternative route for removing refractory sulfides is oxidative desulfurization (ODS) process [7, 8]. Researchers worldwide have shown the use of heterogeneous Co–Mo or Co–Ni catalysts
Data Loading...