Carbonate encapsulation from dissolved atmospheric CO into a polyoxovanadate capsule.

An aqueous synthesis, involving the reduction of the VO anion in a mild alkaline pH in the presence of α-BiO, led to the formation of a fully reduced polyoxovanadate (POV) capsule, with CO anion encapsulation in its internal cavity, in the compound [Na(HO)][HVO(CO)]·3NH·10HO (1). This CO anion encapsulation, the source of which is absorbed aerial CO in the pertinent aqueous alkaline reaction mixture, occurs only in the presence of α-BiO. Compound 1 crystals, upon exposure to HCl acid vapor, exclude CO gas that can react with the Grignard reagent (PhMgBr) to form triphenylcarbinol and benzoic acid; during this solid-vapor interface reaction, compound 1 itself transforms into an amorphous material that includes the Cl anion but could not be characterized unambiguously. Thus, we have synthesized a chloride ion (Cl) encapsulated compound [Na(HO)][HVO(Cl)]·6HO (2) in a direct synthesis protocol, which has been characterized by crystallography as well as by other spectroscopic methods. Compounds 1 and 2, each having fifteen vanadium(iv) centers, exhibit interesting magnetism in their solid states. The temperature-dependent magnetic susceptibilities for compounds 1 and 2 have been recordred at 0.1 T in the temperature range of 3-300 K. The temperature-dependent magnetic susceptibilities of compounds 1 and 2 are shown in the form of χvs. T and their product χT vs. T plots.