Syntheses and Crystal Structures of Brominated Polyhedral Arsa‐ and Phosphaboranes. Issue 10 (24th April 2017)

• Record Type: Journal Article
• Authors: Keller, Willi; Einholz, Wolfgang; Rudolph, Daniel; Schleid, Thomas
• Is Part Of: Zeitschrift für anorganische und allgemeine Chemie. Volume 643:Issue 10(2017)
• Page Start: 664
• Page End: 668
• Publication Date: 2017-04-24
• Subjects: Perbrominated pnictogenaboranes; Heteroborane clusters; Arsaborane; Phosphaborane; Crystal structures; Chemistry, Inorganic -- Periodicals; Chemistry -- Periodicals; 540
• DOI: 10.1002/zaac.201700051
• Languages: English
• ISSNs: 0044-2313

Abstract

Abstract : The synthesis of the perbrominated arsaboranes closo ‐1, 2‐As2 B4 Br4 (1 ) and closo ‐1, 2‐As2 B10 Br10 (2 ) occurs by co‐pyrolysis of B2 Br4 and AsBr3 at 500 °C. Repeated fractionation of the sublimable products in vacuo yields both compounds in pure form. The X‐ray structure determination for orthorhombic closo ‐1, 2‐As2 B4 Br4 (1 ) [space group: Pbcn, a = 2345.48(17) pm, b = 627.31(4) pm, c = 1294.02(9) pm for Z = 8] and the corresponding phosphorus compound, monoclinic closo ‐1, 2‐P2 B4 Br4 (3 ) [space group: P 21 / n, a = 806.84(6) pm, b = 1247.96(9) pm, c = 974.91(7) pm, β = 90.493(3)° and Z = 4] confirmed that both1 and3, consistent with their 14‐skeletal electron counts, adopt octahedral structures distorted from regular by two arsenic or phosphorus atoms in the 1, 2‐positions. The shortest boron–boron bonds within the cluster frameworks are located between the boron atoms antipodal to the heteroatoms. Abstract :