Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

A new nonlinear optical borate, Na{sub 0.5}Pb{sub 2}[B{sub 5}O{sub 9}](OH){sub 1.5} . 0.5H{sub 2}O, from the orthorhombic hilgardite family

Journal Article · · Crystallography Reports
; ; ;  [1]
  1. Moscow State University, Department of Crystallography and Crystal Chemistry, Faculty of Geology (Russian Federation)
A new polar representative of the hilgardite structural family, Na{sub 0.5}Pb{sub 2}[B{sub 5}O{sub 9}](OH){sub 1.5} . 0.5H{sub 2}O (space group Pnn2), is synthesized under hydrothermal conditions. The crystal structure of the compound synthesized is similar to the structure of the previously studied polar compound Na{sub 0.5}Pb{sub 2}[B{sub 5}O{sub 9}]Cl(OH){sub 0.5} and is intermediate between the latter compound and the centrosymmetric hydrate Pb{sub 2}[B{sub 5}O{sub 9}](OH) . 0.5H{sub 2}O. The additional peak revealed in the electron density in the vicinity of the Pb(1) atom is attributed to the stereochemically active lone electron pair of this atom. The lone electron pair is oriented toward the two most distant oxygen atoms involved in the Pb(1) coordination environment, namely, O(7) and O(2), which are located in a boron-oxygen framework layer in the ac plane, not toward the (00{sub z}) channel occupied by water molecules. The nonequivalence in the stereochemical activity of two lead atoms [Pb(1) > Pb(2)] is similar to that observed in the nonlinear optical borate Pb{sub 2}[B{sub 4}O{sub 5}(OH){sub 4}](OH){sub 2} . H{sub 2}O related to BiB{sub 3}O{sub 6}.
OSTI ID:
21091485
Journal Information:
Crystallography Reports, Journal Name: Crystallography Reports Journal Issue: 3 Vol. 51; ISSN 1063-7745; ISSN CYSTE3
Country of Publication:
United States
Language:
English