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Tris(diethylamino)cyclotriboran sowie Konstitutionsisomerie zwischen cyclo ;‐ und closo ‐Hexakis(diethylamino)hexaboran(6)
Author(s) -
Baudler Marianne,
Rockstein Konrad,
Oehlert Wolfgang
Publication year - 1991
Publication title -
chemische berichte
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 0009-2940
DOI - 10.1002/cber.19911240526
Subject(s) - chemistry , tris , cyclohexane , boiling , medicinal chemistry , potassium , crystallization , octahedron , chemical stability , crystallography , organic chemistry , crystal structure , biochemistry
Tris(diethylamino)cyclotriborane and Constitutional Isomerism Between cyclo ;‐ and closo ‐Hexakis(diethylamino)hexaborane(6) The reaction of Et 2 NBCl 2 with potassium in boiling cyclohexane provides a mixture of aminopolyboranes, containing 20–25 mol‐% (BNEt 2 ) 3 ( 1 ), (BNEt 2 ) 4 ( 2 ), and cyclo ;‐(BNEt 2 ) 6 ( 3 ), respectively, as well as varying amounts of closo ;‐(BNEt 2 ) 6 ( 4 ). Whereas 1 and 3 have been highly enriched by means of HPLC, 4 has been isolated by column chromatography and crystallization. On standing in solution at room temperature, the cyclo ‐isomer 3 slowly rearranges to the closo ‐isomer 4 , while at elevated temperatures the reverse conversion occurs. Hence 4 , which is the first neutral B 6 compound with octahedral structure, has a relatively higher thermodynamic stability at normal conditions.