SrSi₆N₈ — A Reduced Nitridosilicate with a Si—Si Bond.

Abstract

Structure D 2000 SrSi 6 N 8 -A Reduced Nitridosilicate with a Si-Si Bond. -Single crystals of the title compound are obtained from the reaction of Sr with Si(NH)2 at 1650°C (N2 atmosphere, tungsten crucible, r.f. furnace, 6.5 h). SrSi6N8 crystallizes in the orthorhombic space group Imm2 with Z = 2. The structure contains SiN4 tetrahedra as well as N3Si-SiN3 units with Si-Si single bonds of 235.2 pm lengths. The compound represents the first ternary silicate with a partially reduced silicate substructure in which Si is present in the oxidation states +3 and +4. -(STADLER, F.; OECKLER, O.; SENKER, J.; HOEPPE, H. A.; KROLL, P.; SCHNICK*, W.; Angew. Chem., Int. Ed. 44 (2005) 4, 567-570; Fachbereich Chem. Biochem.,

Luminescence and density functional theory (DFT) calculation of undoped nitridosilicate phosphors for light-emitting diodes

“…The frameworks of highly condensed SiN 4 tetrahedrons can be classified by the connections among those tetrahedrons and their arrangement. 24 It has an orthorhombic crystal structure with space group Imm2. Corner-sharing occurs when two, three, or four tetrahedrons are sharing one vertex, and edge-sharing occurs between pairs of tetrahedrons that share two vertices forming infinite chains.…”

SrSi6N8—A Reduced Nitridosilicate with a SiSi Bond

“…[23] SrSi 6 N 8 thus represents the first crystalline ternary silicate with a partially reduced silicate substructure in which Si is present in the oxidation states + iii and + iv. Recently, another silicate with Si in two oxidation states (+ iv and Ài) was reported, namely Cs 10 Si 7 O 9 .…”

Facile synthesis of the desired red phosphor Li2Ca2Mg2Si2N6:Eu2+ for high CRI white LEDs and plant growth LED device

“…The 29 Si solid‐state MAS nuclear magnetic resonance spectrum of Li 2 Ca 2 Mg 2 Si 2 N 6 :1.0%Eu 2+ was measured and presented in Figure . Mostly, the chemical shift of 29 Si is ranging from −40 to −60 ppm in nitrides . There is only one sharp peak observed at −55 ppm, in line with one crystallographic Si site in the structure of Li 2 Ca 2 Mg 2 Si 2 N 6 .…”

“…The narrow band red‐emitting nitridomagnesosilicate Li 2 (Ca 1− x Sr x ) 2 Mg 2 Si 2 N 6 :Eu 2+ ( x = 0‐0.06) was reported by Wolfgang Schnick group in 2017 based on the work of describing the structure of Li 2 Ca 2 Mg 2 Si 2 N 6 compound . Li 2 Ca 2 Mg 2 Si 2 N 6 :Eu 2+ shows red emission at 638 nm as well as FWHM of 62 nm under blue light irradiation, which is desirable for high CRI white LEDs . However, the preparation of this phosphor needs the rigorous preparation conditions, such as the sealed tantalum ampules into a silica glass tube, long reaction time more than 90 hours, dangerous raw materials including Si(NH) 2 and LiN 3 .…”