5 research outputs found
From Borapyramidane to Borole Dianion
No full textNonclassical
pyramidanes with their inverted tetrahedral configuration
of the apical atom are among the most challenging synthetic targets
in cluster chemistry. In this Communication, we report on the synthesis
and structure of the first representative of pyramidal compounds with
the group 13 element at the apex, namely, chloroborapyramidane <b>2</b>. Reduction of <b>2</b> with excess of lithium metal
unexpectedly produced the cage-opening product, borole dianion derivative <b>{3</b><sup><b>2–</b></sup><b>·[LiÂ(thf)</b><sup><b>+</b></sup><b>]</b><sub><b>2</b></sub><b>}</b>, a 6Ï€-electron aromatic system
From Borapyramidane to Borole Dianion
No full textNonclassical
pyramidanes with their inverted tetrahedral configuration
of the apical atom are among the most challenging synthetic targets
in cluster chemistry. In this Communication, we report on the synthesis
and structure of the first representative of pyramidal compounds with
the group 13 element at the apex, namely, chloroborapyramidane <b>2</b>. Reduction of <b>2</b> with excess of lithium metal
unexpectedly produced the cage-opening product, borole dianion derivative <b>{3</b><sup><b>2–</b></sup><b>·[LiÂ(thf)</b><sup><b>+</b></sup><b>]</b><sub><b>2</b></sub><b>}</b>, a 6Ï€-electron aromatic system
From Borapyramidane to Borole Dianion
No full textNonclassical
pyramidanes with their inverted tetrahedral configuration
of the apical atom are among the most challenging synthetic targets
in cluster chemistry. In this Communication, we report on the synthesis
and structure of the first representative of pyramidal compounds with
the group 13 element at the apex, namely, chloroborapyramidane <b>2</b>. Reduction of <b>2</b> with excess of lithium metal
unexpectedly produced the cage-opening product, borole dianion derivative <b>{3</b><sup><b>2–</b></sup><b>·[LiÂ(thf)</b><sup><b>+</b></sup><b>]</b><sub><b>2</b></sub><b>}</b>, a 6Ï€-electron aromatic system
From Borapyramidane to Borole Dianion
No full textNonclassical
pyramidanes with their inverted tetrahedral configuration
of the apical atom are among the most challenging synthetic targets
in cluster chemistry. In this Communication, we report on the synthesis
and structure of the first representative of pyramidal compounds with
the group 13 element at the apex, namely, chloroborapyramidane <b>2</b>. Reduction of <b>2</b> with excess of lithium metal
unexpectedly produced the cage-opening product, borole dianion derivative <b>{3</b><sup><b>2–</b></sup><b>·[LiÂ(thf)</b><sup><b>+</b></sup><b>]</b><sub><b>2</b></sub><b>}</b>, a 6Ï€-electron aromatic system
Pyramidanes: The Covalent Form of the Ionic Compounds
No full textPyramidane and its derivatives are
among the most desirable synthetic
chemistry targets, whose appealing square-pyramidal design, fascinating
nonclassical structure, and unusual bonding features have attracted
the permanently growing interest of organic chemists for decades.
Although they have been comprehensively approached on theoretical
grounds, no member of the pyramidane family was experimentally realized
until very recently, thus remaining one of the biggest synthetic challenges
for experimental pursuits. In this paper, we report on a series of
stable hybrid pyramidanes of group 14 elements, featuring germanium,
tin, or lead at the apex of the square pyramid, capping the four-membered-ring
base made of carbon, silicon, or germanium atoms. On the basis of
the experimental results (X-ray diffraction and NMR and Mössbauer
spectroscopy) and computational studies at the B3LYP/Def2TZVP level
of theory (MO, NBO, NRT, and AIM), an extraordinarily high degree
of ionicity of the pyramidal apex-to-base bonds was attributed to
the overall structure of these nonclassical covalent compounds
