Synthesis of two new Mo(II) organometallic catalysts immobilized on POSS for application in olefin oxidation reactions

Abstract

The purpose of this work was the preparation and characterization of two new catalysts POSS-ATZAc-[Mo(h 3-C 3 H 5)Br(CO) 2 ] (POSS-Mo-I) and POSS-ATZAc-[Mo(CO) 3 Br 2 ] (POSS-Mo-II). The new heterogeneous catalysts were characterized by several techniques and used as catalysts for the epoxidation of olefins, presenting high catalytic activity. To study and optimize the syntheses of the heterogeneous catalysts, immobilization experiments of the [Mo(h 3-C 3 H 5)Br(CO) 2 (NCMe) 2 ] and [Mo(CO) 3 Br 2 (NCMe) 2 ] organometallic complexes on the modified polyhedral oligomeric silsesquioxane were performed. The sorption properties of the modified silsesquioxane showed to be dependent of the contact time, concentration and temperature. Catalysts were tested in the epoxidation of six olefins and compared with homogeneous species [Mo(h 3-C 3 H 5)Br(CO) 2 (ATZAc)] (Mo-I) and [Mo(CO) 3 Br 2 (ATZAc)] (Mo-II). To the best of our knowledge, this paper is the first that has reported the preparation and characterization of two new heterogeneous catalysts, as well as the comparison with homogeneous species for catalytic epoxidation of olefins.

Silsesquioxane Derivatives as Functional Additives for Preparation of Polyethylene-Based Composites: A Case of Trisilanol Melt-Condensation

“…Its characteristics are M w = 66,000, MFR (190 °C; 2.16 kg) = 2 g/10 min, T m = 112 °C and density 0.921 g/cm 3 . Silsesquioxanes were prepared according to the literature procedures [ 56 , 57 , 58 , 59 ]. i Bu 7 SSQ-Vi was synthesised according to the procedure for the synthesis of i Bu 7 SSQ-Cl.…”

Silsesquioxane-Doped Electrospun Nanofibrillar Membranes for Separation Systems

“…Limonene-substituted spherosilicate (SS-Limomene) was prepared according to the previous report [41]. Silsesquioxane additives were prepared according to literature reports: hepta(isobutyl)trisilanolheptasilsesquioxane (iBu 7 SSQ-3OH) [42], octakis(3-chloropropyl) octasilsesquioxane (SSQ-8Cl) [43], and Ethoxyheptaisobutyloctasilsesquioxane (iBu 7 SSQ-OEt) [44]. All the obtained compounds were subjected to NMR and FT-IR spectroscopy and the results were compared with the literature data to confirm their structure and purity.…”

An engineered POSS drug delivery system for copper(ii) anticancer metallodrugs in a selective application toward melanoma cells

“…30,46 Similarly, the preparation of octa[3-amino-1,2,4-triazole-5-carboxylic acid) propyl] silsesquioxane (POSS-atzac) was first reported in our previous study. 47 However, a new synthesis of POSS-atzac was performed again with modification in order to obtain a compound with six units of the 3-amino-1,2,4-triazole-5-carboxylic acid ligand bonded to the POSS-Cl surface.…”