Neodymium(III) molybdenum(VI) borate, NdBO₂MoO₄

Abstract

Single crystals of NdBO2MoO4 were obtained from a molybdenum oxide–boron oxide flux under an air atmosphere. The structure features double chains of edge- and face-sharing distorted [NdO10] bicapped square-anti­prisms, which are linked by rows of isolated [MoO4] tetra­hedra and by zigzag chains of corner-sharing [BO3] groups, all of them running along the b axis. The chains of [NdO10], chains of [BO3] and rows of [MoO4] groups are arranged in layers parallel to the bc plane.

Pr3Mo4B6O24(OH)3: High‐Pressure/High‐Temperature Synthesis of an Acentric Rare Earth Molybdenum Borate

“…In Pr 3 Mo 4 B 6 O 24 (OH) 3 , common features of high-pressure phases are observed. [24] Compared to the high-temperature phases in the realm of rare earth molybdenum borates LnMoBO 6 (Ln = La, Ce, Nd) [3,4] and Ln 2 MoB 2 O 9 (Ln = Pr), [8] we found an increase in the coordination numbers of the boron, molybdenum, and, compared to Pr 2 MoB 2 O 9 , also the praseodymium atoms, correlating with generally higher interatomic distances. In LnMoBO Furthermore, an increase in the bond lengths is observed, which is commonly found as a result of higher coordination numbers.…”

“…[3] Single-crystal data of NdMoBO 6 were determined in 2011 with similar unit cell parameters as CeMoBO 6 . [4] In the context of optical and thermal investigations of the above-mentioned compounds, a reversible first order phase transition between a high-temperature LaMoBO 6 and a low-temperature LaMoBO 6 was proposed [5] and the low-temperature phase of LaMoBO 6 subsequently was reported to crystallize in space group P2 1 (no. 4) with the unit cell parameters a = 10.2863(3) Å, b = 4.15790 (10) Å, c = 16.3390(5) Å, and β = 98.830(3)°.…”

“…[6] We assume that the different length of the c-axis and the deviation of the monoclinic angle β in references [1] and [6,7] result from the method of structure determination. However, it should be noted that the structures described in references, [1,3,4,6,7] despite different unit cell data, display a very high degree of similarity: in all the mentioned compounds with the sum formula LnMoBO 6 (Ln = LaÀ Nd), the rare earth atoms are ten-fold coordinated, forming double-chains of edge-sharing distorted bicapped square antiprisms. The double chains are connected via "zigzag"-chains of corner-sharing [BO 3 ] units and the molybdenum-centered polyhedron, which can either be described as an isolated distorted [MoO 4 ] tetrahedron or as a corner-sharing [MoO 5 ] trigonal bipyramid with four shorter and one very long MoÀ OÀ bond.…”

“…Minor distortions of the coordination spheres and the resulting slight deviations of the OÀ LaÀ O, OÀ MoÀ O, and especially the OÀ BÀ O angles are the main difference between the high and low-temperature LaMoBO 6 structures. [1,3,4,6,7] In the Ln 2 MoB 2 O 9 (Ln = Pr, Nd, SmÀ Tb) structure family, Pr 2 MoB 2 O 9 has been examined representatively for the rare earth pyroborate molybdates with single-crystal methods by Peter Held and Petra Becker. [8] The structure contains distorted square antiprismatic [PrO 8 ] units, nearly undistorted, isolated [MoO 4 ] tetrahedra, and isolated [B 2 O 5 ] units built up of two corner-sharing triangular [BO 3 ] units.…”

“…[8] The structure contains distorted square antiprismatic [PrO 8 ] units, nearly undistorted, isolated [MoO 4 ] tetrahedra, and isolated [B 2 O 5 ] units built up of two corner-sharing triangular [BO 3 ] units. [8] In the past years, the optical properties of rare earth molybdenum borates have been studied with special regard to their nonlinear optical (NLO) properties [4,6,7] and their use as host materials for activator ions in solid-state lighting technologies. [9,10] Highly interesting is the synthesis of a yellow phosphor through doping of LaMoBO 6 with Tb 3 + , Eu 3 + , and Bi 3 + with quantum yields of 92 % and emission peaks at 542 and 613 nm upon excitation with blue light.…”