Don’t Monkey Around – What is a Banana Bond?

Chemistry, Education
A banana bond is not a typical chemical bond by any stretch of the imagination. It is a 3-center, 2-electron bond. The shape of this kind of bond resembles a banana, hence its name. Perhaps the simplest example of a banana bond is demonstrated between boron and hydrogen in the diborane molecule, B2H6. Elemental Atomic Orbitals We begin with a discussion of the much simpler, more typical 2-center, 2-electron single bond. When atoms form molecules, the atomic orbitals involved transform into molecular orbitals. Let's consider a very simple example. Say we want to form one C-H bond of the molecule methane (CH4). Now hydrogen atoms only have one electron. The single electron lies in the 1s2 orbital. That type of orbital possesses spherical symmetry. Unlike hydrogen, carbon has 12 electrons…
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On the Nature of the Chemical Bond

[caption id="attachment_3393" align="alignright" width="440"] Proline - Ball and Stick Model CCA 2.5 by Peter Murray-Rust.[/caption] Atoms combine to form molecules. Atom A approaches atom B and cohesively attaches to it. Molecule AB is held together by a chemical bond.¹ That bond is written A–B,  or in the case of multiple bonds, A=B, A≡B, etc. Factors in Bond Formation The primary bonding agency is electrostatic force. This is the force between electrical charges. A positive charge is due to a lack of one or more electrons, producing cations. A negative charge is due to an excess of electrons, producing anions. One of the simplest examples is the formation from sodium (Na) and chlorine (Cl) of ordinary table salt, sodium chloride (NaCl).² We write, Na – e⁻ → Na⁺ Cl + e⁻…
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