Hydrolysis, polycondensation, and catalytic properties of Ru(II) complex of 3-4,5-dihydroimidazol-1-ylpropyltriethoxysilane

The preparation and measurements of some properties of organic-inorganic hy brid materials derived from Ru(II)-3-4,5-dihyroimidazol-1-yl-propyltriethox ysilane inside a polysiloxane network have been achieved. The hydrolysis an d polycondensation of Ru(II)-3-4,5-dihyroimidazol-1-yl-propyltriethoxysilan e were performed in different experimental conditions, producing a new orga nic-inorganic silica. The alkoxysilyl groups available were used for the co nstruction of inorganic backbone by the sal-gel process, and the imidazole group was found suitable for incorporating Ru(II) by coordination. The coor dination of metal complex is retained because there is no leaching from the metal complex containing gels. To ensure sufficient catalytic properties, a series of hybrid materials from tetraethoxysilane was prepared. These mat erials were identified and catalytic activities were tested for cyclization of (Z)-3-methylpent-2-en-4-yn-1-ol to 2,3-dimethylfuran. Heterogeneous Ru( II) catalyst can also be recycled and reused without significant loss of se lectivity or activity. (C) 2001 John Wiley & Sons, Inc.