multicentre bond

A multicentre bond is a type of chemical bond where three or more atoms are linked together by a pair of delocalized electrons. This concept is particularly relevant in the study of electron-deficient compounds like boranes, where a single pair of electrons binds three atoms, forming a three-centre, two-electron (3c,2e) bond.1

These bonds are crucial for understanding the structures of various boron and hydrogen compounds, known as boranes and borohydride anions. The arrangement and number of these multicentre bonds, along with standard two-centre, two-electron bonds, dictate the overall structure of these molecules, which can form complex networks like frameworks (closo), nests (nido), or webs (arachno). These structural correlations are often described by Wade's rules.1