The catalytic performance of the microporous Hb sieve supported K 2 CO 3 catalyst for the synthesis of dipropyl carbonates (DPC) by transesterification of dimethyl carbonate (DMC) with propyl alcohol was investigated at atmospheric pressure, and the optimized reaction conditions were acquired. The catalyst of Hb with 28% K 2 CO 3 -loading performed best, giving 94.4% conversion of DMC and 58.7% selectivity to DPC. An optimum reactant molar ratio n(propyl alcohol)/ n(DMC) existed for catalytic activity, which was about 3/1. The optimum reaction time was 10 h and the suitable reaction temperature was about 363 K considering various factors. The XRD results indicated that the structure of Hb was gradually deformed with the increase in the K 2 CO 3 loading. From nitrogen physisorption, it could be concluded that the improvement of the catalytic activities with the optimized K 2 CO 3 -loading about 28% can be ascribed to both enough active sites and preferable surface area and bigger pore diameter. There was no significant difference between the IR spectrums of K 2 CO 3 /Hb catalyst before and after a 10 h reaction, which was consistent with that K 2 CO 3 /Hb catalyst had excellent utility for repeated use. The possible mechanism of the transesterification reaction was also discussed.

The title compound, C29H37BrSi, was synthesized by the Sonogashira coupling of [(3,5-diethyl-4-ethynylphen­yl)ethyn­yl]triiso­propyl­silane with 4-bromo-1-iodo­benzene. In the structure, the two phenyl rings are nearly parallel to each other with a dihedral angle of 4.27 (4)°. In the crystal, π–π inter­actions between the terminal and central phenyl rings of adjacent mol­ecules link them in the a-axis direction [perpendicular distance = 3.5135 (14); centroid–centroid distance = 3.7393 (11) Å]. In addition, there are weak C—H⋯π inter­actions between the isopropyl H atoms and the phenyl rings of adjacent mol­ecules.