%0 Generic
%A Holland, Michael
%A Donakowski, Martin D.
%A Pozzi, Eric A.
%A Rasmussen, Andrew M.
%A Tran, Thanh Thao
%A Pease-Dodson, Shannon E.
%A Halasyamani, P. Shiv
%A Seideman, Tamar
%A Duyne, Richard
P. Van
%A Poeppelmeier, Kenneth R.
%D 2014
%T Polar Alignment of Λ‑Shaped Basic Building
Units within Transition Metal Oxide Fluoride Materials
%U https://acs.figshare.com/articles/dataset/Polar_Alignment_of_Shaped_Basic_Building_Units_within_Transition_Metal_Oxide_Fluoride_Materials/2335618
%R 10.1021/ic402177j.s006
%2 https://acs.figshare.com/ndownloader/files/3973234
%K bimetallic BBUs
%K compound
%K Transition Metal Oxide Fluoride MaterialsA series
%K Basic Building Units
%K transition metal polyhedral BBUs
%K metal oxide fluoride BBUs
%K F 2Cl Br
%X A series
of pseudosymmetrical structures of formula K10(M2OnF11–n)3X (M = V and Nb, n = 2, X = (F2Cl)1/3, Br, Br4/2,I4/2; M
= Mo, n = 4, X = Cl, Br4/2, I4/2) illustrates generation of polar structures with the use of Λ-shaped
basic building units (BBUs). For a compound to belong to a polar space
group, dipole moments of individual species must be partially aligned.
Incorporation of d0 early transition metal polyhedral BBUs
into structures is a common method to create polar structures, owing
to the second-order Jahn–Teller distortion these polyhedra
contain. Less attention has been spent examining how to align the
polar moments of BBUs. To address alignment, we present a study on
previously reported bimetallic BBUs and synthesized compounds K10(M2OnF11–n)3X. These materials differ in their (non)centrosymmetry
despite chemical and structural similarities. The vanadium compounds
are centrosymmetric (space groups P3̅m1 or C2/m) while the
niobium and molybdenum heterotypes are noncentrosymmetric (Pmn21). The difference in symmetry occurs owing
to the presence of linear, bimetallic BBUs or Λ-shaped bimetallic
BBUs and related packing effects. These Λ-shaped BBUs form as
a consequence of the coordination environment around the bridging
anion of the metal oxide fluoride BBUs.
%I ACS Publications