Analysis of the Stereoisomers (cis, trans) of Polyhedral Oligomeric Silsesquioxane Compounds by UHPSFC-QTof MS

Abstract

Polyhedral oligomeric silsesquioxanes (POSSs) are a class of important hybrid inorganic/organic materials. When POSSs are used as the building block in polymerization, the materials show superior performance over their organic counterparts in many areas due to the special Si–O cage structure. However, the stereoisomers (cis, trans) of polyhedral oligomeric silsesquioxane (POSS) show some differences in improving polymer property and it is difficult to get the pure stereoisomer by synthesis. Therefore, a method is required to separate and purify the mixture of POSSs. In this study, the isomers of POSS compounds and the impurities were separated by ultra-high performance supercritical fluid chromatography coupled quadrupole time-of-flight mass spectrometry (UHPSFC-QTof MS). To separate the isomers of POSS, the crucial parameters of UHPSFC-QTof MS were investigated. Under the optimal conditions, the isomers of product and impurities were separated in 4 min. On account of exact mass measurement, some impurities were identified. This is the first study on the analysis of isomers of POSS using UHPSFC-QTof MS. Based on this analysis method, it is helpful to optimize the conditions of synthesis.