Li₁₃Mn(SeO₃)₈: Lithium-Rich Transition Metal Selenite Containing Jahn–Teller Distortive Cations

Abstract

A novel lithium-rich transition metal selenite, LiMn(SeO), that is composed of a Jahn-Teller distortive cation, Mn, in the high spin d state, and a second-order Jahn-Teller (SOJT) distortive lone pair cation, Se, has been synthesized via hydrothermal and high temperature solid state reactions. The selenite is classified as a molecular compound consisting of MnO octahedra, SeO trigonal pyramids, and Li cations. Considering the Li-O interactions, the structure of LiMn(SeO) may be described as a pseudo-three-dimensional framework as well. The title compound is thermally stable up to 500 °C and starts decomposing above the temperature attributable to the volatilization of SeO. While the MnO octahedra in LiMn(SeO) exhibit six identical Mn-O bond distances at room temperature due to the dynamic Jahn-Teller effect, a clear elongation of two Mn-O bonds along a specific direction is observed at 100 K. A series of isostructural selenites with different transition metals, i.e., LiM(SeO) (M = Sc, Cr, and Fe), have been also successfully obtained in phase pure forms using similar synthetic methods. Magnetic properties, spectroscopic characterizations, and local dipole moments calculations for all the synthesized selenites are presented.

Li6M(SeO3)4 (M = Co, Ni, and Cd) and Li2Zn(SeO3)2: Selenites with Late Transition-Metal Cations

“…Li 6 M­(SeO 3 ) 4 (M = Co and Ni) are closely related with previously reported lithium-rich selenites Li 13 M­(SeO 3 ) 8 (M = Sc, Cr, Mn and Fe), although their stoichiometries are different. Specifically, as Li + cations in Li 13 M­(SeO 3 ) 8 are substituted by late transition metals, the oxidation state of the d-block transition metals in Li 6 M­(SeO 3 ) 4 was changed from +3 to +2 to make a charge balance.…”

“…Recently, we synthesized a series of lithium-rich transition-metal selenites, Li 13 M(SeO 3 ) 8 (M = Sc, Cr, Mn, and Fe), and reported their structures and properties. 39 Especially, Li 13 Mn(SeO 3 ) 8 revealed an interesting phase transition at low temperature due to the Jahn−Teller effect. Herein, we expand the selenite series using late transition metals such as Co, Ni, Zn, and Cd and successfully discovered four new selenites, namely, Li 6 Co(SeO 3 ) 4 , Li 6 Ni(SeO 3 ) 4 , Li 2 Zn(SeO 3 ) 2 , and Li 6 Cd(SeO 3 ) 4 .…”

“…For example, Li 5 Mn­(II) 4 ­Mn­(III)­(SeO 3 ) 8 , LiFe­(SeO 3 ) 2 , and Li 2 ­Co 3 (SeO 3 ) 4 exhibit magnetic properties, Li 6 (Mo 2 O 5 ) 3 ­(SeO 3 ) 6 reveals nonlinear optical (NLO) properties, Li 2 Cd 3 ­(SeO 3 ) 4 shows a transformation reaction, and LiSc­(SeO 3 ) 2 · x H 2 O 16 exhibits a reversible single-crystal-to-single-crystal transformation. Recently, we synthesized a series of lithium-rich transition-metal selenites, Li 13 M­(SeO 3 ) 8 (M = Sc, Cr, Mn, and Fe), and reported their structures and properties . Especially, Li 13 Mn­(SeO 3 ) 8 revealed an interesting phase transition at low temperature due to the Jahn–Teller effect.…”

The Power of Heterometalation through Lithium for Helix Chain-Based Noncentrosymmetric Metal–Organic Frameworks with Tunable Second-Harmonic Generation Effects

“…As an important component for the development of inorganic NLO materials such as LiBO 3 and LiNbO 3 , − lithium is first selected in our work. Taking the small radius and generally 4-coordinated tetrahedral geometry of Li + into account, − we speculate that the heterometalation of Li + and transition metal ions such as Zn 2+ , Co 2+ , and Cd 2+ should be an effective combination to eliminate the symmetry of organic ligand through the coordination process.…”