Further Representatives of the Type RE₃[Si₅N₉O] (RE = Dy–Er, Yb)

Abstract

The isotypic series of the oxonitridosilicates RE 3 [Si 5 N 9 O] (RE = Dy-Er, Yb) was synthesized via solid-state reactions at high temperatures using a radio-frequency furnace. The crystal structures were solved and refined from single-crystal X-ray diffraction and powder X-ray diffraction data. Further characterizations were performed using vibrational spectroscopy (IR and Raman), REM-EDX measurements, lattice energy calculations (MAPLE), charge distribution (CHARDI), and bondvalence sum calculations (BVS). The compounds RE 3 [Si 5 N 9 O] (RE = Dy-Er, Yb) crystallize in the orthorhombic space group [a] 731 Pbcm (no. 57) (Z = 4) with the following lattice parameters: Dy 3 [Si 5 N 9 O]: a = 4.9865(3), b = 16.1633(9), and c = 10.6651(6) Å; Ho 3 [Si 5 N 9 O]: a = 4.9758(3), b = 16.1332(7), and c = 10.6312(5) Å; Er 3 [Si 5 N 9 O]: a = 4.9682(2), b = 16.1029(5), and c = 10.5995(3) Å; Yb 3 [Si 5 N 9 O]: a = 4.9473(2), b = 16.0622(5), and c = 10.5431(4) Å.The four isotypic compounds consist of a network of corner sharing SiN 4 and SiN 3 O tetrahedra. N [2] and N [3] interconnecting nitrogen atoms build five-membered rings, hosting the rare earth cations.These structural properties lead to rigid arrangements, which make nitrogen-containing silicates interesting compounds for hosting activator ions towards luminescent materials for the application in pc-LEDs, e.g., in M 3 [Si 6 N 2 O 12 ]:Eu 2+ (M = Ba, Sr), [13] Ba 2 [Si 5 N 8 ]:Eu 2+ , [14] Sr[Mg 3 SiN 4 ]:Eu 2+ , [15] Lu 4 Ba 2 [Si 9 N 16 O]O:Eu 2+ , and Y 4 Ba 2 [Si 9 N 16 O]O:Eu 2+ . [12] A large number of oxonitridosilicates also form structures solely with rare earth cations, such as

Structure Elucidation of Complex Endotaxially Intergrown Lanthanum Barium Oxonitridosilicate Oxides by Combination of Microfocused Synchrotron Radiation and Transmission Electron Microscopy

“…For all three compounds discussed, interatomic distances within the Si−N/O tetrahedra, O−La/Ba and O−La/Sr distances as well as the cation coordination polyhedra with the corresponding distances are listed in Tables S15–18 and agree well with those reported for other (oxo‐)nitridosilicates. [ 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 ]…”