Bi₂Te₂O₆(NO₃)₂(OH)₂(H₂O): A layered bismuth tellurium nitrate hydroxide with multiple noncentrosymmetric chromophores

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>Crystals of a novel bismuth tellurium nitrate hydroxide, Bi<SUB>2</SUB>Te<SUB>2</SUB>O<SUB>6</SUB>(NO<SUB>3</SUB>)<SUB>2</SUB>(OH)<SUB>2</SUB>(H<SUB>2</SUB>O), with noncentrosymmetric (NCS) structure have been grown in high yield through a hydrothermal reaction using TeO<SUB>2</SUB>, Bi(NO<SUB>3</SUB>)<SUB>3</SUB>·5H<SUB>2</SUB>O, and HNO<SUB>3</SUB> as reagents. Bi<SUB>2</SUB>Te<SUB>2</SUB>O<SUB>6</SUB>(NO<SUB>3</SUB>)<SUB>2</SUB>(OH)<SUB>2</SUB>(H<SUB>2</SUB>O) exhibits a layered structure consisting of polyhedra with second-order Jahn-Teller (SOJT) distortive cations, i.e., BiO<SUB>5</SUB>, BiO<SUB>7</SUB>, Te<SUP>4+</SUP>O<SUB>3</SUB>, and Te<SUP>6+</SUP>O<SUB>6</SUB>, as well as anionic π-delocalized NO<SUB>3</SUB> <SUP>−</SUP> groups. Infrared spectral data not only show all of the vibrations for the constituting bonds, but confirm the existence of -OH groups in the framework of the title compound. UV–vis diffuse reflectance spectrum indicates that Bi<SUB>2</SUB>Te<SUB>2</SUB>O<SUB>6</SUB>(NO<SUB>3</SUB>)<SUB>2</SUB>(OH)<SUB>2</SUB>(H<SUB>2</SUB>O) reveals a band gap of ca. 4.0 eV. Thermogravimetric analysis along with powder X-ray diffraction measurements at different temperatures suggest that the crystallinity of Bi<SUB>2</SUB>Te<SUB>2</SUB>O<SUB>6</SUB>(NO<SUB>3</SUB>)<SUB>2</SUB>(OH)<SUB>2</SUB>(H<SUB>2</SUB>O) is maintained up to ca. 400 °C. Powder second-harmonic generation (SHG) measurements using 1064 nm radiation reveal that Bi<SUB>2</SUB>Te<SUB>2</SUB>O<SUB>6</SUB>(NO<SUB>3</SUB>)<SUB>2</SUB>(OH)<SUB>2</SUB>(H<SUB>2</SUB>O) has SHG efficiency of ca. 20 times that of α-SiO<SUB>2</SUB> and is phase-matchable (Type-I). Local dipole moment calculations for the polyhedra of SOJT distortive cations in Bi<SUB>2</SUB>Te<SUB>2</SUB>O<SUB>6</SUB>(NO<SUB>3</SUB>)<SUB>2</SUB>(OH)<SUB>2</SUB>(H<SUB>2</SUB>O) are also presented.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A noncentrosymmetric bismuth tellurium nitrate hydroxide, Bi<SUB>2</SUB>Te<SUB>2</SUB>O<SUB>6</SUB>(NO<SUB>3</SUB>)<SUB>2</SUB>(OH)<SUB>2</SUB>(H<SUB>2</SUB>O) has been synthesized in high yield. </LI> <LI> The layered material contains multiple noncentrosymmetric chromophores. </LI> <LI> Bi<SUB>2</SUB>Te<SUB>2</SUB>O<SUB>6</SUB>(NO<SUB>3</SUB>)<SUB>2</SUB>(OH)<SUB>2</SUB>(H<SUB>2</SUB>O) has SHG efficiency of ca. 20 times that of α-SiO<SUB>2</SUB> and is phase-matchable. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Bi<SUB>2</SUB>Te<SUB>2</SUB>O<SUB>6</SUB>(NO<SUB>3</SUB>)<SUB>2</SUB>(OH)<SUB>2</SUB>(H<SUB>2</SUB>O), a novel layered material consisting of polyhedra of second-order Jahn-Teller distortive cations, BiO<SUB>5</SUB>, BiO<SUB>7</SUB>, Te<SUP>4+</SUP>O<SUB>3</SUB>, and Te<SUP>6+</SUP>O<SUB>6</SUB>, as well as π-delocalized NO<SUB>3</SUB> groups has SHG efficiency of ca. 20 times that of α-SiO<SUB>2</SUB>.</P> <P>[DISPLAY OMISSION]</P>