Alkoxy Substituted Brominated closo-Dodecaborates with Functionalized Aliphatic Spacers

The utilization of dodecaborate boron clusters, [B12X12]2- (X = Cl, Br, or I), as membrane carriers has been demonstrated recently, and their activity is known to be due to their superchaotropic nature. In this work, the mono-alkylation of [B12Br11OH]2- to functionalize it with an aliphatic spacer was developed with a view to expanding the known chemical space of membrane carriers based on [B12Br12]2-. A new and improved facile route for the preparation of [B12Br11OH]2-, which is an important precursor to other [B12Br11OR]2- species, is reported. Various alkoxylated [B12Br11O(CH2)5Z]2- (Z = OH, N(CO)2C6H4, CN and N3) derivatives were prepared via a divergent synthesis based on [B12Br11O(CH2)5Br]2-. One of the newly synthesized compounds was utilized as a membrane carrier, and its impact on cell viability was examined.