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Reactions of 13‐Vertex Carboranes with Strong Bases: Synthesis and Structural Characterization of Carborane Monoanions with exo ‐π Bonding
Author(s) -
Zheng Fangrui,
Zhang Jian,
Fu Xiaodu,
Xie Zuowei
Publication year - 2013
Publication title -
chemistry – an asian journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.18
H-Index - 106
eISSN - 1861-471X
pISSN - 1861-4728
DOI - 10.1002/asia.201300240
Subject(s) - carborane , delocalized electron , vicinal , vertex (graph theory) , crystallography , chemistry , atom (system on chip) , cage , carbon atom , computational chemistry , stereochemistry , combinatorics , organic chemistry , ring (chemistry) , mathematics , graph , computer science , embedded system
Several monoanions of 13‐vertex carboranes were prepared in high yields from the reactions of C,C′‐linked 13‐vertex carboranes with t BuOK or NaH in dry THF at room temperature. These monoanions were characterized by various spectroscopic methods, elemental analysis, and single‐crystal X‐ray diffraction. The results showed substantial double‐bond character between the cage‐carbon atom and the exo vicinal carbon atom, thus leading to charge delocalization into the cage. As a result, the atomatom distances within the cage were elongated, with one broken CB bond. However, the cage geometry of the monoanions remained very similar to that of their corresponding neutral 13‐vertex closo ‐carboranes. These monoanions represent the first examples of 13‐vertex carboranes with exo ‐π bonding to hypercarbon atoms.