Labile silver(I) complexes with benzisothiazolinone anion and phosphines: Synthesis, characterization and hydrogen storage application

Abstract

AbstractA silver complex was prepared with benzisothiazolinone ligand, which was used to prepare new phosphorus‐rich complexes with dppe and dppp. All complexes were diagnosed by FTIR, 1H‐NMR, 31P‐NMR, CHN, and molar conductivity. The results proved that phosphines were labile, therefore 31P‐NMR was measured by cryoprotection at different temperatures. As a promoted effort to obtain direct experimental proof for the dimeric and the labile nature of [Ag(bit)(diphos)]2 complexes in solution, the 31P{1H}‐NMR spectrum of mixed (dppe/dppp) ligand complexes was measured. It was anticipated that an exchange of phosphines occurred between [Ag(bit)(dppe)]2 and [Ag(bit)(dppp)]2 complexes. However, a distribution of the dppp and dppe should result, and complex with compositions of [Ag2(bit)2(dppe)(dppp)] will be formed. The phosphine‐containing complexes were used in hydrogen storage study. The results proved that hydrogen storage values were initially similar for [Ag(bit)(dppp)]2 and [Ag(bit)(dppe)]2, but increased significantly for [Ag(bit)(dppe)]2 at higher pressures to reach 4.35 wt% at 90 bar.