Charge Transfer Salts Based on Polyoxometalates and Seleno-Substituted Organic Donors. Synthesis, Structure, and Magnetic Properties of (BEST)3H[PMo12O40]·CH3CN·CH2Cl2 (BEST = Bis(ethylenediseleno)tetrathiafulvalene)

Electrochemical oxidation of the tetrathiafulvalene (TTF) type organic donor bis(ethylenediseleno)tetrathiafulvalene (BEST) in the presence of the Keggin polyoxometalate [PMo12O40]3- affords the radical salt formulated as (BEST)3H[PMo12O40] (crystal data:  triclinic, space group P1 with a = 13.056(1) A, b = 13.957(1) A, c = 22.302(3) A, α = 97.019(9)°, β = 94.17(1)°, γ = 95.847(9)°, and Z = 2). This is the first salt of a selenium-containing donor with a polyoxometalate cluster. The structure of this organic/inorganic hybrid consists of layers of the organic donors that alternate with polyoxometalate layers in the c direction. The organic molecules, which are completely ionized, form two ty…