TITLE:
Introducing an Extended Covalent Bond between Oxygen Atoms with an OXO-Shape in Ions and Molecules: Compatibility with the Even-Odd and the Isoelectronicity Rules
AUTHORS:
Geoffroy Auvert, Marine Auvert
KEYWORDS:
Elongated Bond, Covalent Bond, Even-Odd, Double Bond, Isoelectronicity, Rules, Chemistry, Ions, Molecule
JOURNAL NAME:
Open Journal of Physical Chemistry,
Vol.6 No.3,
August
16,
2016
ABSTRACT: Building on the recent success of the even-odd rule, the present paper explores
its implications by studying the very specific case of OXO compounds. These compounds
are usually represented with double bonds linking two oxygen atoms to a central
atom—as in carbon dioxyde—yet can sometimes be drawn in a triangular structure,
such as in calcium dioxyde. Measurement data moreover indicate that most OXO compounds
have an angle around 120° between oxygen atoms, although that seems
incompatible with triangular representations. The aim here is to unify these
commonly admitted representations by linking oxygen atoms through a single bond
that is longer than usual covalent bonds: an “elongated bond”. This elongated
bond has the interesting effect of suppressing the need for double bonds
between oxygen and the central atom. The elongated bond concept is applied to
about a hundred of molecules and ions and methodically compared to classical
representations. It is shown that this new representation, associated to the
even-odd rule, is compatible with all studied compounds and can be used in
place of their classical drawings. Its usage greatly simplifies complex
concepts like resonance and separated charges in gases. Elongated bonds are
also shown to be practicable with the isoelectronic rule as well as isomers,
and throughout chemical reactions. This study of an especially long and wide
angle bond confirms the versatility of the even-odd rule: it is not limited to
compounds with short covalent bonds and can include OO covalent bond lengths of
more than 200 pm and with OXO angles above 90°.