Darstellung und Struktur von Bromoarsenaten(III) organischer Stickstoffbasen / Preparation and Structures of Bromoarsenates(III) of Organic Nitrogen Bases

Abstract

<jats:p>N-methylanilinium-tetrabromoarsenate(III) (1). pyridinium-tetrabromoarsenate(III) (2), and tris-pyridinium-nonabromo-diarsenate(III) (3) habe been prepared and their structures deter­mined by X-ray structural analysis. 1 contains discrete As<jats:sub>2</jats:sub>Br<jats:sub>8</jats:sub><jats:sup>2-</jats:sup> anions with C<jats:sub>i</jats:sub> symmetry, 2 infinite (AsBr<jats:sub>4</jats:sub><jats:sup>-</jats:sup>)<jats:sub>n</jats:sub> chains and 3 discrete As<jats:sub>2</jats:sub>Br<jats:sub>9</jats:sub><jats:sup>3-</jats:sup> anions. Pseudo-octahedral coordination is ob­served for the As atoms in 1. The bridging As-Br bonds in As<jats:sub>2</jats:sub>Br<jats:sub>9</jats:sub><jats:sup>3-</jats:sup> are markedly stronger than the analogous As-Cl bonds in the tris-pyridinium salt of As<jats:sub>2</jats:sub>Cl<jats:sub>9</jats:sub><jats:sup>3-</jats:sup>.</jats:p>

Tetrachloro- and Tetrabromoarsonium(V) Cations: Raman and 75As, 19F NMR Spectroscopic Characterization and X-ray Crystal Structures of [AsCl4][As(OTeF5)6] and [AsBr4][AsF(OTeF5)5]

“…The two crystallographically independent AsBr 4 + cations have the expected tetrahedral geometry, with the Br-As-Br angles close to the ideal tetrahedral value (range: 107.53(6)-110.70(7)°). All the As V -Br bond lengths are equal within 3σ, ranging from 2.225(2) to 2.236(2) Å, and are in excellent agreement with our previous empirically predicted value of 2.221 Å 30 in this paper is presently the only As V -Br bond length known, and as expected, it is shorter than the terminal As III -Br bond lengths observed in AsBr 3 (2.322(1) Å), 62 As 2 Br 8 2-(2.347(1)-2.387(1) Å), 63 and [AsBr 4 -] n (2.393(1) Å). 63 The central As V atom in the AsF(OTeF 5 ) 5anion is coordinated to five crystallographically nonequivalent OTeF 5 groups and to a fluorine atom so that the gross geometry can be described as a pseudo-octahedron in which all the OTeF 5 groups of the anion have the pseudo-octahedral geometry observed in other OTeF 5 compounds (vide supra).…”

“…All the As V -Br bond lengths are equal within 3σ, ranging from 2.225(2) to 2.236(2) Å, and are in excellent agreement with our previous empirically predicted value of 2.221 Å 30 in this paper is presently the only As V -Br bond length known, and as expected, it is shorter than the terminal As III -Br bond lengths observed in AsBr 3 (2.322(1) Å), 62 As 2 Br 8 2-(2.347(1)-2.387(1) Å), 63 and [AsBr 4 -] n (2.393(1) Å). 63 The central As V atom in the AsF(OTeF 5 ) 5anion is coordinated to five crystallographically nonequivalent OTeF 5 groups and to a fluorine atom so that the gross geometry can be described as a pseudo-octahedron in which all the OTeF 5 groups of the anion have the pseudo-octahedral geometry observed in other OTeF 5 compounds (vide supra). The As V -O (av 1.805(9) Å), Te VI -O (av 1.849(8) Å), and Te VI -F (av 1.827(9) Å) bond lengths are identical to those observed in As(OTeF 5 ) 6 -(vide supra and Supporting Information), and the unique As V -F (1.721(6) and 1.734(6) Å) bond length is equal, within 3σ, to the As V -F bond length in the AsF 6anion.…”

“…All the As V −Br bond lengths are equal within 3σ, ranging from 2.225(2) to 2.236(2) Å, and are in excellent agreement with our previous empirically predicted value of 2.221 Å 30 and theoretical values (see Computational Results). The As V −Br bond length reported in this paper is presently the only As V −Br bond length known, and as expected, it is shorter than the terminal As III −Br bond lengths observed in AsBr 3 (2.322(1) Å), As 2 Br 8 2- (2.347(1)−2.387(1) Å), and [AsBr 4 - ] n (2.393(1) Å) 4 Geometries of the (a) AsBr 4 + cation and (b) AsF(OTeF 5 ) 5 - anion in [AsBr 4 ][AsF(OTeF 5 ) 5 ] with thermal ellipsoids shown at the 50% probability level.…”

Zur Strukturchemie der Alkyl- und Arylhalogenoarsenate(III), [Me2As2Cl5]-, [RAsCl3]-, [R2As2Br6]2- (R = Me, Et, Ph) und [Ph2AsX2]- (X = Cl, Br)

“…Bindungsla È ngen und -winkel: As(1)±Cl(12) 2.249(2), As(1)±Cl(3) 3.019(2), As(1)±Cl (14) 2.236(2), As(1)±C(11) 1.942(8), As(2)±Cl(22) 2.267(2), As(2)±Cl(3) 2.852(2), As(2)±Cl(24) 2.324(2), As(2)±C(21) 1.939(6) A Ê ; Cl(3)±As(1)±Cl (14) 167.03(7), Cl(3)±As(2)±Cl(24) 174.10(6), Cl(12)±As(1)±C (11) 97.5(3), Cl (22)±As (2)±C (21) 94.8(2), As(1)±Cl (3)±As (2) 129.80(6)° terscheiden sich die trans-sta È ndigen axialen As±Cl-Bindungsla È ngen nur geringfu È gig. Fu È r 2 betragen die As(1)±Cl(3)-und As(1)±Cl (4) 2± beobachtet [15]. Die Summe der van der Waals-Absta È nde fu È r As und Br betra È gt 3.70 A Ê [12].…”

Crystal Structure, Thermal and Electric Behaviour of [(CH3)2NH2]3[As2Cl9] and [(CH3)2NH2][AsOCl2]

“…The crystal structure of them consist of alternating layers of single metal halide (MX 4 2Ϫ ) perovskite sheets and organic ammonium cation (A ϩ ) bilayers. The crystal structure of halogenoarsenate(III) with different organic cations (alkylammonium, cyclic or aromatic) are reported [6,7,8]. The perovskite type oxides containing alkylammonium cations deserve also special attention [3].…”