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+).

Recent advances on the synthesis of Sb(Ⅲ)-based inorganic ultraviolet nonlinear optical materials

Nonlinear optical(NLO)crystals are key components of solid-state lasers and widely used in civilian and military applications.A wide transmission range,a large second harmonic generation(SHG)effect and a suitable bire-fringence are important factors in determining a nonlinear material with excellent performance.Research on ultraviolet(UV)nonlinear optical materials has concentrated on borates,carbonates,and nitrates containing derivative groups,as well as phosphates and sulfates containing tetrahedral groups,as a result of the anionic group theory's influence.In addition,cations have a significant impact on NLO materials according to recent researches.The introduction of lone electron pair cations Sb(Ⅲ)has been proven to be an effective strategy by our group,which could modulate the crystal structures of NLO materials to regulate their linear and nonlinear optical properties.This paper presents a short review of the reported Sb(Ⅲ)-based UV-NLO materials.Also,it gives an overview of the role played by different synthetic methods in the synthesis process of Sb(Ⅲ)-based UV-NLO materials and how to solve the difficult problems including oxidation and hydrolysis.This work will offer some synthetic concepts for investigating the subsequent class of high-performance UV nonlinear materials.

Preface to Nonlinear Optical Crystals

Nonlinear optical(NLO)crystals are core materials in laser frequency-conversion technique,and the requirement on the laser wavelength varies from one application to another.Now,the commercial NLO crystals,e.g.,KDP,LBO,BBO,KTP,AgGaS_(2),ZnGeP_(2),et al.,have prevailed in ultraviolet(UV)/visible and near-/mid-infrared region for decades.

Preface to Nonlinear Optical Crystals

Nonlinear optical(NLO)crystals can efficiently convert the frequency of common solid-state laser with fixed or limited wavelengths.Since the first observation of second-harmonic generation(SHG)phenomenon in the early 1960s,they have played an increasing role in the fields of laser spectra,precision measurements,and quantum information,as well as industrial laser processing,and so on.However,it is still challenging to rationally design and synthesize new NLO crystals.

Biomimetic mineralization and cytocompatibility of nanorod hydroxyapatite/graphene oxide composites

Nanorod hydroxyapatite (NRHA)/graphene oxide (GO)composites with weight ratios of 0.4,1.5, and 5have been fabricated by a facile ultrasonic-assisted method at room temperature and atmospheric pressure. The chemical structure properties and morphology of the composites were characterized by field emission source scanning electron microscope,X-ray diffraction,transmission electron microscopy,and high-resolution transmission electron microscopy.The results indicate that the NRHA/ GO composites have an irregular surface with different degree wrinkles and are stable,and NRHA are well combined with GO.In addition,the biomimetic mineralization mechanism of hydroxyapatite on the NRHA/GO composites in simulated body fluid (SBF)is presented.The presence of a bone-like apatite layer on the composite surface indicate that the NRHA/GO composites facilitate the nucleation and growth of hydroxyapatite crystals in SBF for biomimetic mineralization.Moreover,the NRHA-1.5/GO composite and pure GO were cultured with MC3T3-E1cells to investigate the proliferation and adhesion of cells.In vitro cytocompatibility evaluation demonstrated that the NRHA/GO composite can act as a good template for the growth and adhesion of cells. Therefore,the NRHA/GO composite could be applied as a GO-based,free-template,non-toxic,and bioactive composite to substitute for a damaged or defect bone.