Structural, vibrational and dielectric properties of new potassium hydrogen sulfate arsenate: K4(SO4)(HSO4)2(H3AsO4) Review Article

A new compound, K4(SO4)(HSO4)2(H3AsO4) was synthesized from water solution of KHSO4/K3H(SO4)2/H3AsO4. This compound crystallizes in the triclinic system with space group P1¯ and cell parameters: a=8.9076(2) Å, b=10.1258(2) Å, c=10.6785(3) Å; α=72.5250(14)°, β=66.3990(13)°, γ=65.5159(13)°, V=792.74(3) Å3, Z=2 and ρcal=2.466 g cm−3. The refinement of 3760 observed reflections (I>2σ(I)) leads to R1=0.0394 and wR2=0.0755. The structure is characterized by SO42−, HSO4− and H3AsO4 tetrahedra connected by hydrogen bridge to form two types of dimer (H(16)S(3)O4−⋯S(1)O42− and H(12)S(2)O4−⋯H3AsO4). These dimers are interconnected along the [1¯ 1 0] direction by the hydrogen bonds O(3)–H(3)⋯O(6). They are also linked by the hydrogen bridge assured by the hydrogen atoms H(2), H(3) and H(4) of the H3AsO4 group to build the chain S(1)O4⋯H3AsO4 which are parallel to the “a” direction. The potassium cations are coordinated by eight oxygen atoms with K–O distance ranging from 2.678(2) to 3.354(2) Å.