Tailored metal-organic frameworks: new catalysts for the mild and selective oxidation of alkanes

Abstract

As main components of natural gas and oil, alkanes are rather inert compounds for a broad synthetic use. Thus, they are mainly utilized as fossil fuels or converted, via different power-consuming processes into olefins that are common and more reactive species in large-tonnage organic synthesis. Therefore, the development of new mild and efficient protocols for the functionalization of alkanes, toward the direct and selective synthesis of added value oxidation products, constitutes a challenge to modern chemistry. This challenge can potentially be overcome via the design and application of tailored or intelligent MOF catalysts, which are still rarely used in alkane oxidation but represent a considerable potential owing to their intrinsic characteristics.Hence, this proposal aims to apply a series of newly designed copper(II) based metal-organic frameworks (MOFs) bearing aminoalcohol and polycarboxylate blocks as tailored catalysts for the selective and direct oxidation of alkanes into desirable industrially important oxidation products. The key objectives are focused on (1) the application of MOFs as catalysts for the mild and selective oxidation of different C5-C9 alkanes (including linear, branched and cyclic hydrocarbons) to the corresponding alcohols and ketones, with an emphasis on the development of bond-, regio- and stereoselective processes, (2) the optimization of the most efficient catalytic systems, and (3) the investigation of mechanism.The innovative character of this proposal with respect to prior state-of-the-art consists in the parallel implementation of several concepts for a tailored MOF catalyst. These include: (A) the incorporation of highly active co-catalysts (N-heteroaromatic carboxylic acids) as building blocks into the structures of MOFs that also comprise copper(II) centers with a recognized potential in oxidation catalysis, (B) the selective catalytic transformations in the confined channels of MOFs hosting substrate or oxidant molecules, and (C) the potential of tuning the catalyst by external stimuli or post-synthetic modification.It is planned that Prof. A. Kirillov will spend three months at the UFABC as a Visiting Researcher, contributing to the development of the general CAPES A017_2013 project ("Green catalysis in the oxidation of natural products - production of renewable raw materials for the chemical industry"), linked to this proposal. Visiting Researcher will be responsible for the planning, execution and supervision of catalytic studies using MOFs catalysts, which would be synthesized and fully characterized by his research team at the IST/ULisboa.Apart from developing this proposal on MOFs, Prof. A. Kirillov will also participate in a variety of other research and educational activities at the UFABC. These would include: (i) lecturing a course entitled "Metal-organic Frameworks: a New Class of Materials" to students within the Post-graduation Program in Science and Technology/Chemistry, (ii) delivering a lecture summarizing the research developed by the Visiting Researcher including recent results that would be obtained at the UFABC, (iii) participating in research group meetings, (iv) taking part in the MSc and/or PhD thesis commissions, and (v) collaborating on the management of the general project, including the planning of research activities, supervision of students, and preparation of reports and research papers.It is expected that the visit of Prof. A. Kirillov would not only complement, diversify and strengthen the research output of the CAPES A017_2013 project, but would also intensify the existing and create new international collaborations, thus contributing to both the scientific and pedagogical cooperation between the UFABC and IST/ULisboa. (AU)