Novel Barium Beryllates Ba[Be2N2] and Ba3[Be5O8]: Syntheses, Crystal Structures and Bonding Properties

Abstract

AbstractBa[Be2N2] was prepared as a yellow‐green microcrystalline powder by reaction of Ba2N with Be3N2 under nitrogen atmosphere. The crystal structure Rietfeld refinements (space group I4/mcm, a = 566.46(5) pm, c = 839.42(9) pm, Rint = 4.73 %, Rprof = 9.16 %) reveal the compound to crystallize as an isotype of the nitridoberyllates A[Be2N2] (A = Ca, Sr) consisting of planar 4.82 nets $^{2}_{\infty}\rm [(Be_{2}N_{2})^{2-}]$ of mutually trigonal planar coordinated Be and N species. Averaged magnetic susceptibility values for the anion [(Be2N2)2−] determined from measurements on A[Be2N2] with A = Mg, Ca, Ba allow to derive a diamagnetic increment for N3− χdia = (−13±1stat.) · 10−6emu mol−1.Colorless Ba3[Be5O8] was first obtained as an oxidation product of Ba[Be2N2] in air. The crystal structure was solved and refined from single crystal X‐ray diffaction data (space group Pnma, a = 942.9(1) pm, b = 1163.47(7) pm, c = 742.1(1) pm, R1 = 2.99 %, wR2 = 7.15 %) and contains infinite rods of Be in trigonal planar, tetrahedral and 3 + 1 coordination by O. The crystal structure is discussed in context with other known oxoberyllates. Electronic structure calculations and electron localization function diagrams for both compounds support the classification as nitrido‐ and oxoberyllate, respectively.