title: Carbon avoids hypercoordination in CB6(-), CB6(2-), and C2B5(-) planar carbon-boron clusters.
abstract: The structures and bonding of CB6-, C2B5-, and CB62- are investigated by photoelectron spectroscopy and ab initio calculations. It is shown that the global minimum structures for these systems are distorted heptacyclic structures. The previously reported hexacyclic structures with a hypercoordinate central carbon atom are found to be significantly higher in energy and were not populated under current experimental conditions. The reasons why carbon avoids hypercoordination in these planar carbon-boron clusters are explained through detailed chemical-bonding analyses.
authors.affiliation: Department of Chemistry and Biochemistry, Utah State University, 0300 Old Main Hill, Logan, Utah 84322, USA.
authors.forename: Boris B
authors.initials: BB
authors.lastname: Averkiev
authors.forename: Dmitry Yu
authors.initials: DY
authors.lastname: Zubarev
authors.forename: Lei-Ming
authors.initials: LM
authors.lastname: Wang
authors.forename: Wei
authors.initials: W
authors.lastname: Huang
authors.forename: Lai-Sheng
authors.initials: LS
authors.lastname: Wang
authors.forename: Alexander I
authors.initials: AI
authors.lastname: Boldyrev