An Expected Calcium Carbido Borate Chloride: Ca9Cl8(BC2)2

Abstract

structure structure (solids and liquids) D 2000 -014The Nitrido Borates Ln 3 B 2 N 4 (Ln: La-Nd) and La 5 B 4 N 9 : Syntheses, Structures, and Properties.-The compounds Ln 3 B 2 N 4 with Ln: La, Ce, Pr, and Nd are prepared by reaction of LnN, Ln, and hexagonal BN in a CaCl 2 flux (1500 K, 4 d). The isotypic compounds crystallize in the space group Immm with Z = 2. The compounds, which can also be formulated as (Ln 3+ ) 3 (B 2 N 4 8− ) (e − ), contain the oxalate analogue B 2 N 4 8− and one electron in the conduction band, yielding temp.-independent paramagnetism for La 3 B 2 N 4 . La 5 B 4 N 9 or La 5 (BN 3 )(B 3 N 6 ), obtained as a by-product, crystallizes in space group Pbcm with Z = 4 and contains the carbonate analogue BN 3 6− together with the six-membered ring anion B 3 N 6 9− .

OnemoreCompound Containing the CBN4- Ion – Synthesis, Single-crystal Structure and Vibrational Spectra of Ca15(CBN)6(C2)2F2

“…The Raman spectrum of the extremely bent (BC 2 ) 5− anion in Ca 9 (BC 2 ) 2 Cl 8 [7] with C 2v symmetry and the Raman as well as the IR spectrum of the (CBN) 4− anion with C ∞v symmetry observed in Ca 15 (CBN) 6 (C 2 ) 2 F 2 exhibit all three modes ν sym , ν asym and δ (the modes are -not in accordance with the real symmetry -named in analogy to triatomic moieties with D ∞v symmetry) expected for a triatomic unit due to the decrease in symmetry. It is noteworthy that the antisymmetric stretching mode was not observed in the Raman spectrum of the compound Ca 5 (BC 2 )(C 2 )Cl 3 [6] despite its similarity to Ca 9 (BC 2 ) 2 Cl 8 [7] regarding the symmetry and coordination of the (BC 2 ) 5− moiety.…”

“…For comparison, the Raman spectra of the compounds Ca 5 (BC 2 )(C 2 )Cl 3 [6] and Ca 9 (BC 2 ) 2 Cl 8 [7] were recorded on single crystals in Mark capillaries sealed under a protective argon atmosphere (microscope laser Raman spectrometer: Jobin Yvon, 4 mW, excitation line at λ = 632.817 nm (HeNe laser), 100× magnification, 6 × 30 s accumulation time) since these had not been reported yet (Fig. 2).…”

“…It is noteworthy that the antisymmetric stretching mode was not observed in the Raman spectrum of the compound Ca 5 (BC 2 )(C 2 )Cl 3 [6] despite its similarity to Ca 9 (BC 2 ) 2 Cl 8 [7] regarding the symmetry and coordination of the (BC 2 ) 5− moiety. The only difference is the bending angle of the anion, which at 161.5 • for Ca 9 (BC 2 ) 2 Cl 8 deviates more from linearity than the angle of 164.0 • for Ca 5 (BC 2 )(C 2 )Cl 3 and therefore might be the reason for the different behavior.…”

“…For comparison, the linear (BN 2 ) 3− anion in Ca 3 (BN 2 ) 2 [4] is coordinated in a similar way, but the bases are orientated to each other in a prismatic way. If the anions are more bent as in Ca 3 (C 3 )Cl 2 [12], Ca 5 (BC 2 )(C 2 )Cl 3 [6] or Ca 9 (BC 2 ) 2 Cl 8 [7] (Table 1), the coordination sphere resembles very closely a bicapped trigonal prism. The possibility has already been discussed (e. g. for (CN 2 ) 2− [27] or for (BC 2 ) 5− [6]) that coordinative needs are responsible for the bending angle of the respective triatomic moiety, which does not take too much of an energetic effort and is possibly due to the low bending constants.…”

Calcium‐Based Sustainable Chemical Technologies for Total Carbon Recycling

“…[52] It was found that different polymorphic structures could coexist. [53] The phase transitions and ratios depend on the reaction temperature, size of the crystallites, proportions and type of reactants, [54] and purity of the sample. [55] In 2010, three new possible metastable structures were predicted to form at standard pressures (Figure 9d and e) and at high pressures ( Figure 9f).…”