Synthesis, structure and physical properties of a new organic metal, (BEDO-TTF)4[C4N6]H2O

Abstract

A new organic metal based on the π-donor bis(ethylenedioxy)tetrathiafulvalene, (BEDO–TTF)₄ [C₄N₆ ]H₂O, has been isolated as the N,N′,N″-tricyanoguanidinate monohydrate salt. The crystal structure indicates strong two-dimensional (2D) behavior in the BEDO–TTF donor layer demonstrated by the close intermolecular C–H‥O, S‥S, and S‥O contacts. The N,N′,N″-tricyanoguanidinate dianions are puckered and form dimers through hydrogen bonding with two water molecules, resulting in an infinite sheet of dianions that complement the 2D nature of the BEDO–TTF donor layers. Four-probe resistance, tunnel diode oscillator, and EPR measurements indicate metallic behavior down to 8 K where a metal–semiconductor transition occurs. (BEDO–TTF)₄ [C₄N₆ ]H₂O crystallizes in the P space group with a=11.9628(2), b=14.1016(2), c=17.0830(2) Å, α=81.27(1), β=70.21(1), γ=77.04(1)°, V=2633.39(7) ų , Z=2.