title: Janus POSS Based on Mixed [2:6] Octakis-Adduct Regioisomers.
abstract: A series of regioisomeric Janus-type polyhedral oligomeric silsesquioxanes (POSS) with multiple, mixed surface functional groups has been successfully synthesized based on the cubic T8 -POSS framework in two consecutive thiol-ene reactions. The first thiol-ene addition of β-mercaptoethanol leads to a statistical mixture of multi-adducts where the regioisomers of bis-adducts (ortho, meta, and para isomers) can be isolated at synthetically useful quantities by flash column chromatography. Then, the second thiol-ene reaction readily installs a variety of functional groups onto the remaining vinyl groups of each regioisomer, providing an easy access to precisely defined, hetero-bifunctional Janus POSS nano-building blocks. The configurations and structures of the products have been unambiguously proven by using (1) H, (13) C, and (29) Si NMR spectroscopy as well as MALDI-TOF mass spectrometry.
authors.affiliation: Key Laboratory of Polymer Chemistry & Physics of the Ministry of Education, Center for Soft Matter Science and Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, P.R. China.
authors.forename: Shuai-Yuan
authors.initials: SY
authors.lastname: Han
authors.affiliation: Key Laboratory of Polymer Chemistry & Physics of the Ministry of Education, Center for Soft Matter Science and Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, P.R. China.
authors.forename: Xiao-Man
authors.initials: XM
authors.lastname: Wang
authors.affiliation: Key Laboratory of Polymer Chemistry & Physics of the Ministry of Education, Center for Soft Matter Science and Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, P.R. China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Shao
authors.affiliation: Key Laboratory of Polymer Chemistry & Physics of the Ministry of Education, Center for Soft Matter Science and Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, P.R. China.
authors.forename: Qing-Yun
authors.initials: QY
authors.lastname: Guo
authors.affiliation: College of Polymer Science & Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, 610065, P.R. China.
authors.forename: Yiwen
authors.initials: Y
authors.lastname: Li
authors.affiliation: Key Laboratory of Polymer Chemistry & Physics of the Ministry of Education, Center for Soft Matter Science and Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, P.R. China. wenbin@pku.edu.cn.
authors.forename: Wen-Bin
authors.initials: WB
authors.lastname: Zhang
keywords: Janus silsesquioxanes; NMR spectroscopy; isomers; nanoparticles