ChemInform Abstract: Tris(diethylamino)cyclotriborane and Constitutional Isomerism Between cyclo‐ and closo‐Hexakis(diethylamino)hexaborane(6).

Abstract

Tris(diethy1amino)cyclotriborane and Constitutional Isomerism Between cyclo-and closo-Hexakis(diethylamino)hexaborane(6)The reaction of EtzNBClz with potassium in boiling cyclohex-crystallization. On standing in solution at room temperature, ane provides a mixture of aminopolyboranes, containing the cyclo-isomer 3 slowly rearranges to the closo-isomer 4, 20-25 mol-% (BNEt& (l), (BNEt& (2), and cyclo- (BNEt& (3), while at elevated temperatures the reverse conversion occurs. respectively, as well as varying amounts of closo-(BNEt& (4). Hence 4, which is the first neutral B6 compound with octa-Whereas l and 3 have been highly enriched by means of hedral structure, has a relatively higher thermodynamic sta-HPLC, 4 has been isolated by column chromatography and bility at normal conditions.

Synthesis and Applications of Perfunctionalized Boron Clusters

“…Prior to our involvement, the only non-halogen containing perfunctionalized six-membered closo -boron clusters were the neutral hypercloso -B 6 (NEt 2 ) 6 , 41,42 with Berndt and co-workers also disclosing the synthesis and structure of the dimethyl analogue, hypercloso -B 6 (NMe 2 ) 6 . 43 Given our interest in the development of chemistry and applications of perfunctionalized boron clusters, 44–46 we reexamined the reactivity of the closo -[B 6 H 7 ] 1− anion.…”

Metal-Free Peralkylation of the closo-Hexaborate Anion

“…While the homo- and heteroleptic perhalogenation (Cl, Br, I) of B 6 H 6 2– has been reported, 1a , b are the first molecules of their type in which carbon -based substituents are bound to each vertex of the hexaborate cage. Indeed, the only other reports of perfunctionalized hexaborate clusters are the charge-neutral B 6 (NR 2 ) 6 species (R = Me, Et) . In contrast to 1a , b , the B 6 (NR 2 ) 6 clusters irreversibly open into cyclic constitutional isomers on heating.…”