Speaker
Samuel Tetteh,
(1 Department of Chemistry, School of Physical Sciences, College of Agriculture and Natural Sciences, University of Cape Coast, Cape Coast, Ghana)
Description
Dioxygen, a readily available raw material for most oxidation processes, has been the
focus of research in inorganic chemistry, material science and catalysis in recent times. The
molecule undergoes multielectron reduction reactions and is used in proton exchange membrane
(PEM) fuel cell to generate electrical energy. Triplet oxygen is also used in combination with
photosensitizers and visible light to generate singlet oxygen which is employed in photodynamic
therapy (PDT). Other areas of research include the study of biochemical systems such as oxygen
transport and electron transport using dioxygen complexes of transition metals such as iron and
copper in combination with porphyrins. Recently, vanadium(IV)/(V)-dioxygen complexes are
being explored as insulin mimetics to lower blood sugar levels. In most of thes studies, FTIR
data on increased bond lengths of the coordinated O 2 is largely explained by the donation of π-
electrons from metal d-orbitals into empty π* ligand orbitals.
A search in the CSD version 5.39 (November) + 1 update using the ConQuest version
1.20 software revealed 250 first row tranistion metal complexes with terminal dioxygen ligands.
These crystal structures were then analysed using mercury 3.10 software of the CCDC.
Statistical analysis show strong correlation between O-O bond lengths and O-M-O bond angles.
DFT analyses of a vanadium (V)-dioxygen complex (refcode: VEMRUA) and its optimised
analogues reveal possible σ-donor, π-donor weakening of the O-O bond and not the usual σ-
donor, π-acceptor model used in explaining this phenomenon.
Primary author
Samuel Tetteh,
(1 Department of Chemistry, School of Physical Sciences, College of Agriculture and Natural Sciences, University of Cape Coast, Cape Coast, Ghana)
