Department of Chemistry, Bilkent University, 06800, Ankara, Turkey.
J Am Chem Soc. 2011 Nov 2;133(43):17454-62. doi: 10.1021/ja2074246. Epub 2011 Oct 7.
Periodic mesoporous hydridosilica, PMHS, is shown for the first time to function as both a host and a mild reducing agent toward noble metal ions. In this archetypical study, PMHS microspheres react with aqueous Ag(I) solutions to form Ag(0) nanoparticles housed in different pore locations of the mesostructure. The dominant reductive nucleation and growth process involves SiH groups located within the pore walls and yields molecular scale Ag(0) nanoclusters trapped and stabilized in the pore walls of the PMHS microspheres that emit orange-red photoluminescence. Lesser processes initiated with pore surface SiH groups produce some larger spherical and worm-shaped Ag(0) nanoparticles within the pore voids and on the outer surfaces of the PMHS microspheres. The intrinsic reducing power demonstrated in this work for the pore walls of PMHS speaks well for a new genre of chemistry that benefits from the mesoscopic confinement of Si-H groups.
首次表明，周期性介孔硅氢化物（PMHS）既可用作贵金属离子的主体，又可用作温和的还原剂。在这项典型的研究中，PMHS 微球与含水的 Ag（I）溶液反应，在介孔结构的不同孔位置形成 Ag（0）纳米颗粒。主要的还原成核和生长过程涉及位于孔壁内的 SiH 基团，并产生分子尺度的 Ag（0）纳米团簇，这些团簇被困在 PMHS 微球的孔壁内并稳定下来，发出橙红色的光致发光。由孔表面 SiH 基团引发的较小过程在孔空隙和 PMHS 微球的外表面内产生一些较大的球形和蠕虫形 Ag（0）纳米颗粒。这项工作中 PMHS 孔壁表现出的内在还原能力很好地证明了一种新的化学类型，它受益于 Si-H 基团的介观限制。
