TY - JOUR
T1 - Alignment of acentric MoO3F33- anions in a polar material
T2 - (Ag3MoO3F3)(Ag 3MoO4)Cl
AU - Maggard, Paul A.
AU - Nault, Tiffany S.
AU - Stern, Charlotte L.
AU - Poeppelmeier, Kenneth R.
N1 - Funding Information:
The authors gratefully acknowledge support from the National Science Foundation (NSF), Solid State Chemistry, (Award No. DMR-9727516), and made use of the Central Facilities supported by the MRSEC program of the National Science Foundation (Grant DMR-0076097) at the Materials Research Center of Northwestern University. T.S.N. thanks the NSF for summer undergraduate research support as part of the REU program at Northwestern University. The authors also thank Professor Shiv Halasyamani for help with the SHG measurements, and also Professor George Schatz for helpful comments concerning the dipole moment calculations.
PY - 2003/10
Y1 - 2003/10
N2 - (Ag3MoO3F3)(Ag3MoO 4)Cl was synthesized by hydro(solvato)thermal methods and characterized by single-crystal X-ray diffraction (P3m1, No. 156, Z=1, a=7.4488(6)Å, c=5.9190(7)Å). The transparent colorless crystals are comprised of chains of distorted fac-MoO3F33- octahedra and MoO42- tetrahedra anions, as suggested by the formulas Ag3MoO3F3 and Ag 3MoO4+, and are connected through Ag + cations in a polar alignment along the c-axis. One Cl- anion per formula unit serves as a charge balance and connects the two types of chains in a staggered fashion, offset by ∼1/2×c. In MoO 42-, the Mo atom displaces towards a single oxide vertex, and in MoO3F33-, the Mo displaces towards the three oxide ligands. The ordered oxide-fluoride ligands on the MoO 3F33- anion is important to prevent local inversion centers, while the polar organization is directed by the Cl - anion and interchain dipole-dipole interactions. The dipole moments of MoO3F33- and MoO4 2- align in the negative c-axis direction, to give a polar structure with no cancellation of the individual moments. The direction and magnitude of the dipole moments for MoO3F33- and MoO 42- were calculated from bond valence analyses and are 6. 1 and 1.9debye (10-18esucm) respectively, compared to 4.4debye for polar NbO6 octahedra in LiNbO3, and 4.5debye for polar TiO6 octahedra in KTiOPO4 (KTP).
AB - (Ag3MoO3F3)(Ag3MoO 4)Cl was synthesized by hydro(solvato)thermal methods and characterized by single-crystal X-ray diffraction (P3m1, No. 156, Z=1, a=7.4488(6)Å, c=5.9190(7)Å). The transparent colorless crystals are comprised of chains of distorted fac-MoO3F33- octahedra and MoO42- tetrahedra anions, as suggested by the formulas Ag3MoO3F3 and Ag 3MoO4+, and are connected through Ag + cations in a polar alignment along the c-axis. One Cl- anion per formula unit serves as a charge balance and connects the two types of chains in a staggered fashion, offset by ∼1/2×c. In MoO 42-, the Mo atom displaces towards a single oxide vertex, and in MoO3F33-, the Mo displaces towards the three oxide ligands. The ordered oxide-fluoride ligands on the MoO 3F33- anion is important to prevent local inversion centers, while the polar organization is directed by the Cl - anion and interchain dipole-dipole interactions. The dipole moments of MoO3F33- and MoO4 2- align in the negative c-axis direction, to give a polar structure with no cancellation of the individual moments. The direction and magnitude of the dipole moments for MoO3F33- and MoO 42- were calculated from bond valence analyses and are 6. 1 and 1.9debye (10-18esucm) respectively, compared to 4.4debye for polar NbO6 octahedra in LiNbO3, and 4.5debye for polar TiO6 octahedra in KTiOPO4 (KTP).
KW - Dipole moment calculation
KW - Metal oxyfluoride anions
KW - Polar compound
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U2 - 10.1016/S0022-4596(03)00090-2
DO - 10.1016/S0022-4596(03)00090-2
M3 - Article
AN - SCOPUS:0041326589
SN - 0022-4596
VL - 175
SP - 27
EP - 33
JO - Journal of Solid State Chemistry
JF - Journal of Solid State Chemistry
IS - 1
ER -