Diboryne

A diboryne in chemistry is a chemical compound containing a boron–boron triple bond. Such compounds are of fundamental importance in the study of chemical bonding, though only few have been reported. A diboryne stabilized by two carbon monoxide groups, (OC)B≡B(CO), was reported isolated in matrix isolation in 2002.{{cite journal|pmid=12405806|year=2002|last1=Zhou|first1=M|last2=Tsumori|first2=N|last3=Li|first3=Z|last4=Fan|first4=K|last5=Andrews|first5=L|last6=Xu|first6=Q|title=OCBBCO: A neutral molecule with some boron-boron triple bond character|volume=124|issue=44|pages=12936–7|journal=Journal of the American Chemical Society|doi=10.1021/ja026257+}} A diboryne stable at room temperature with two N-heterocyclic carbene (NHC) units was reported by Holger Braunschweig et al. in 2012.{{cite journal|doi=10.1126/science.1221138|title=Ambient-Temperature Isolation of a Compound with a Boron-Boron Triple Bond|year=2012|last1=Braunschweig|first1=H.|last2=Dewhurst|first2=R. D.|last3=Hammond|first3=K.|last4=Mies|first4=J.|last5=Radacki|first5=K.|last6=Vargas|first6=A.|journal=Science|volume=336|issue=6087|pages=1420–2|pmid=22700924|bibcode=2012Sci...336.1420B|s2cid=206540959}} In terms of qualitative molecular orbital theory, the B₂ molecule itself is expected to have a single bond, but with NHC ligands, the third excited state yields a triple bond.{{cite journal|doi=10.1002/chem.201101915|title=Structures and Stabilities of Group 13 Adducts...|year=2011|last1=Holzmann|first1=N.|last2=Stasch|first2=A.|last3=Jones|first3=C.|last4=Frenking|first4=G.|journal=Chemistry: A European Journal|volume=17|issue=1521–3765|pages=13517–13525|pmid=22038936}}