Premium
Syntheses and Crystal Structures of Brominated Polyhedral Arsa‐ and Phosphaboranes
Author(s) -
Keller Willi,
Einholz Wolfgang,
Rudolph Daniel,
Schleid Thomas
Publication year - 2017
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.201700051
Subject(s) - monoclinic crystal system , orthorhombic crystal system , crystallography , boron , chemistry , heteroatom , octahedron , cluster (spacecraft) , group (periodic table) , crystal structure , phosphorus , organic chemistry , ring (chemistry) , computer science , programming language
The synthesis of the perbrominated arsaboranes closo ‐1,2‐As 2 B 4 Br 4 ( 1 ) and closo ‐1,2‐As 2 B 10 Br 10 ( 2 ) occurs by co‐pyrolysis of B 2 Br 4 and AsBr 3 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‐As 2 B 4 Br 4 ( 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‐P 2 B 4 Br 4 ( 3 ) [space group: P 2 1 / 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 both 1 and 3 , 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.