Probing the electronic structure and aromaticity in W3F3+/−, W3F3X (X = Li, Na, K), AND W3F3Y+ (Y = Be, Mg, Ca) clusters

Abstract

The equilibrium geometries, electronic properties, and aromaticity of tungsten low-fluoride W₃F₃^+/− clusters and their half-sandwich-type W₃F₃X (X = Li, Na, K) and W₃F₃Y⁺ (Y = Be, Mg, Ca) complexes are investigated by density functional theory (DFT) methods. The calculations reveal three types of the d bonding interaction existing in the planar regular hexagonal W₃F₃⁺ (D_3h, ¹A′₁) cation, W₃F₃⁻ (D_3h, ³A′₁) anion, and W₃F₃X (C_s, ³A″) (X = Li, Na, K), W₃F₃Y⁺ (C_s, ³A″) (Y = Be, Mg, Ca) complexes. The δ aromaticity is revealed in the W₃F₃⁺ (D_3h, ¹A′₁) cation, while the W₃F₃⁻ (D_3h, ³A″₁) anion possesses partial δ aromaticity. They have two delocalized δ electrons, satisfying the (4n+2) Hückel electron counting rule.