ASb(SO_(4))_(2)(A=Rb,Cs):Two short-wave UV antimony sulfates exhibiting large birefringence

Herein,two antimony sulfates,named RbSb(SO_(4))_(2)(1)and CsSb(SO_(4))_(2)(2),have been successfully synthesized with the introduction of Sb^(3+)cation with stereochemically active lone pairs(SCALP)into sulfates by the conventional hydrothermal method.Both two compounds endow short ultraviolet(UV)absorption edges(281 nm and 278 nm,respectively)and large birefringence(0.171@546 nm and 0.174@546 nm,respectively),which means that they are promising short-wave UV optical materials.Interestingly,though both of the two compounds exhibit similar 1D chained structures,and possess the same functional moieties including SbO4 seesaws and SO4 tetrahedral groups,they exhibit significantly opposite macroscopic symmetries,i.e.,compound 1 crystallizes in a centrosymmetric(CS)manner(P2_(1)/n)and compound 2 in a noncentrosymmetric(NCS)manner(P2_(1)2_(1)2_(1)),due to the size of cations[r(Rb+)=1.56 A˚,r(Cs+)=1.67 A˚]affects the orientation of SCALP of the adjacent Sb^(3+).

Two UV organic-inorganic hybrid antimony-based materials with superior optical performance derived from cation-anion synergetic interactions

Finding suitable strategies to effectively enhance the optical properties of materials are the goal being pursued by researchers.Herein,cation-anion synergetic interactions strategy was proposed to develop two novel organic-inorganic hybrid antimony-based optical materials,(C_(3)H_(5)N_(2))Sb F_(2)SO_(4)(I)and(C_(5)H_(6)N)Sb F_(2)SO_(4)(Ⅱ),which were obtained by introducing Sb^(3+)cation containing stereochemically active lone-pair(SCALP)and organicπ-conjugated cations into sulphate system.The synergistic interactions of the organicπ-conjugated cations,the inorganic[SbO_(2)F_(2)]^(3-)seesaw anions and the[SO_(4)]^(2-)distorted tetrahedra anions make their ultraviolet(UV)absorption edges approach 297 and 283 nm,respectively,and raise their birefringence up to 0.193@546 nm and 0.179@546 nm,respectively.Interestingly,although the two compounds have the same stoichiometric ratio and similar one-dimensional(1D)chain structure,they show opposite macroscopic symmetry,where the NCS compound(Ⅱ)exhibits a large secondharmonic generation(SHG)response(1.6 times that of KH_(2)PO_(4)).The two reported compounds are found to be promising UV optical materials in the experimental tests.