%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 Pm1 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