Functionalized Silicone Nanospheres: Synthesis, Transition Metal Immobilization, and Catalytic Applications

被引:25
作者
Bradley, Christopher A.
Yuhas, Benjamin D.
McMurdo, Meredith J.
Tilley, T. Don [1 ]
机构
[1] Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA
基金
美国能源部;
关键词
MESOPOROUS SILICA; POLY(ORGANOSILOXANE) MICROGELS; COOPERATIVE CATALYSIS; THERMAL-DECOMPOSITION; METALLOCENE CATALYSTS; SURFACE MODIFICATION; MOLECULAR PRECURSOR; SUPPORT MATERIALS; CLICK CHEMISTRY; ACID;
D O I
10.1021/cm8018154
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
Silicone nanospheres containing a variety of functional groups (pyridines, phosphines, thiols, amines, etc.) have been prepared by emulsion copolymerization of methyltrimethoxysilane, MeSi(OMe)(3), and the functionalized monomer of interest, RSi(OMe)(3). This procedure provides a reproducible synthesis of spherical particles in the 12-28 nm size regime as determined by transmission electron microscopy (TEM). The presence of the functional groups is supported by a combination of spectroscopic methods including DRUV-vis, DRIFTS, and NMR spectroscopy. Comonomer dispersity within the nanospheres was probed using elemental mapping techniques, and these support a homogeneous distribution of functional groups within the particles. Palladium(0) immobilization on phosphine-substituted nanospheres also results in a random distribution of the transition metal throughout the particles. Nanospheres containing multiple acid/base functionalities were also prepared, and these demonstrate functional group cooperativity based on enhanced conversions in the base-catalyzed Henry reaction, relative to nanosphere catalysts containing only basic groups. The diversity of functional groups that may be incorporated into the spheres suggests that these materials hold considerable promise as ligand supports and catalysts.
引用
收藏
页码:174 / 185
页数:12
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