Unsymmetrische BN₂ ^3--Ionen in den Strukturen von Ca₂ClBN₂ und Sr₂ClBN₂ / Unsymmetric BN₂ ^3--Ions in the Structures of Ca₂ClBN₂ and Sr₂ClBN₂

Abstract

The new compounds Ca2ClBN2 (1) and Sr2ClBN2 (2) were prepared from the respective metal, its dihalide and h-BN in sealed tantalum ampoules at 1200 °C. The crystals obtained were transparent yellow (1) and blue (2), respectively. The crystal structures were determined from single crystal X-ray data. Ca2ClBN2 and Sr2ClBN2 are isotypic and crystallize in the orthorhombic space group Pnma (No. 62), Z = 4 (Ca2ClBN 2: a = 1166.7(2), b = 390.26(4), c = 899.8(1) pm, R 1 = 0.043, wR2 = 0.115 for 554 independent reflections; Sr-,C1BNT: a = 1242.8(1), b = 416.75(4), c = 920.8(1) pm, R\ = 0.031, wR2 = 0.054 for 6 6 2 'independent reflections).The structures contain two different layers of M 2+, C P and BN23~ alternating along the[010] direction. The bond angles N-B-N are 177.2(4)° for (1) and 176,6(5)° for (2), the bond distances of the BN23_ ions are dB_ N] = 134.6(5) pm for (1), 136,3(7) pm for (2) and dg_N2 = 132.4(5) pm for (1) and 131,3(7) pm for (2). The unsymmetric structure of the BN23~ ion, as is manifested particularly in the Sr compound (2), is caused by the coordination of N 1 to four cations while N2 is coordinated only to three.

Synthesis and crystal structure of Ba26B12Si5N27 containing [Si2] dumbbells

“…2 The bond lengths of the B-N and the angles of N-B-N are in the ranges of 1.317(11)-1.331(10) Å and 174.7(7)-178.4 (14)°, respectively. These values agree with those reported for the compounds containing [BN 2 ] 3-[2, [3][4][5][6][7][8][9][10][11][12][13]. As shown in Fig.…”

“…Na and La were not detected by EPMA in the crystals. The atomic ratio of B:N:Si:Ba having the highest Si ratio among the results of elemental analysis was 17.5(7):38.0(2):6.3(4):38.1 (6). The content of Si tended to decrease by surface oxidation or hydration.…”

“…The [BN 2 ] 3-groups composed of central boron atoms linearly or almost linearly coordinated by two nitrogen atoms are isoelectronic to CO 2 . Multinary compounds have also been prepared by combining alkaline-earth cations AE 2 þ ¼Mg 2 þ , Ca 2 þ , Sr 2 þ , Ba 2 þ and [BN 2 ] 3-with N 3-(Ca 3 [BN 2 ]N) [3], O 2-(Ba 4 [BN 2 ] 2 O) [4], H À (Ca 2 [BN 2 ]H) [5], and halogen anions X -¼F -, Cl -, I -, Br -(AE 2 [BN 2 ]X [6][7][8][9][10][11][12], Ba 3 [BN 2 ] 5 F [13], Mg 8 [BN 2 ] 5 I [9]). Ba 3 Ge 2 N 2 [14] and Sr 3 Ge 2 N 2 [15] contain nitridogermanide anions [GeN 2 ] 4-and one-dimensional trans chains of Zintl polyanions 1 1 [Ge 2-].…”

Ca5Cl3(C2)(CBC): eine Verbindung mit Schichtstruktur und einer ungewöhnlichen Anionenkombination

“…Ca 5 Cl 3 (C 2 )(CBC): eine Verbindung mit Schichtstruktur und einer ungewöhnlichen Anionenkombination** Olaf Reckeweg und Hans-Jürgen Meyer* Berichte über ¹Calciummonochloridª [1] waren vor einigen Jahren für uns der Anlaû, Reaktionen in und mit Calciumchloridschmelzen zu untersuchen. Die farblosen Präparate von ¹Calciummonochloridª stellten sich als CaHCl, [2] die roten als Ca 3 Cl 2 C 3 [3] heraus.…”

“…Bei Reaktionen von Calcium mit den Elementen Bor, Kohlenstoff und Stickstoff in bestimmten Kombinationen in Calciumchloridschmelzen entstehen Verbindungen wie Ca 3 Cl 2 CBN mit CBN 4À -Ionen, [4] Ca 2 ClBN 2 [5] und Sr 3 (BN 2 ) 2 [6] mit BN 3À 2 -Ionen oder die Titelverbindung Ca 5 Cl 3 (C 2 )(CBC). [7] Bei Versuchen zur Herstellung von ¹Ca 4 Cl 3 BC 2 ª aus einer Calciumchloridschmelze entstand die neue Verbindung Ca 5 Cl 3 (C 2 )(CBC), die Acetylid-und Dicarbidoborat-Ionen enthält. Ein charakteristisches Merkmal der Struktur von Ca 5 Cl 3 (C 2 )(CBC) sind gewellte Schichten mit der Abfolge Cl-Ca-Ca.…”