The present invention provides asymmetric bidentate silane reagents from modifying the surface of liquid chromatography supports, the supports and methods of making and using the same. When bonded to the surface of a support material, the resulting modified support material provides improved properties, such as better separations and more stable support materials, especially when used in liquid chromatography. These bidentate silanes have the general structure: R.sub.1 SiMe(NMe.sub.2)--(CH.sub.2).sub.n --SiMeR.sub.2 (NMe.sub.2). R.sub.1 is an alkyl group having from 1 to 30 carbon atoms, and R.sub.2 is an alkyl group having from 8 to 18 carbon atoms. R.sub.1 is a different alkyl group than R.sub.2. Me is a methyl group, and n has a value 2 or 3. In certain embodiments, R.sub.2 includes at least one functional group. When reacted with a silica surface, the resulting modified surface has a structure: PSiO--\x9bR.sub.1 SiMe--(CH.sub.2).sub.n --SiMeR!--OSiP. PSiO is a surface reacted silica.
本发明提供了通过改性
液相色谱支撑材料表面制备的不对称双齿
硅烷试剂、支撑材料及其制备和使用方法。当与支撑材料表面键合时,所得到的改性支撑材料具有改善的性能,例如更好的分离和更稳定的支撑材料,特别是在
液相色谱中使用时。这些双齿
硅烷试剂具有以下一般结构:R.sub.1 SiMe(NMe.sub.2)--(CH.sub.2).sub.n --SiMeR.sub.2 (NMe.sub.2)。其中,R.sub.1是具有1至30个碳原子的烷基,R.sub.2是具有8至18个碳原子的烷基,R.sub.1与R.sub.2是不同的烷基,Me是甲基基团,n的值为2或3。在某些实施例中,R.sub.2包括至少一个功能基团。当与
二氧化硅表面反应时,所得到的改性表面具有以下结构:PSiO--\x9bR.sub.1 SiMe--(CH.sub.2).sub.n --SiMeR!--OSiP。其中,PSiO是表面反应的
二氧化硅。