Related Experiment Video
Updated: Jun 5, 2026

06:31
Preparation of SNS Cobalt(II) Pincer Model Complexes of Liver Alcohol Dehydrogenase
Published on: March 19, 2020
Diaqua-bis[2-(benzyl-oxy)acetato]cobalt(II)
Acta Crystallographica. Section E, Structure Reports Online
|January 5, 2011
Summary
Researchers characterized a cobalt(II) complex with benzyl-oxyacetate ligands. The crystal structure reveals a distorted octahedral cobalt(II) center, linked by hydrogen bonds and pi-pi stacking into a supramolecular assembly.
Area of Science:
- Coordination Chemistry
- Crystal Engineering
- Supramolecular Chemistry
Background:
- Metal-organic complexes offer diverse structural motifs and properties.
- Benzyl-oxyacetate ligands provide functional groups for coordination and intermolecular interactions.
- Understanding supramolecular assembly is crucial for designing advanced materials.
Purpose of the Study:
- To synthesize and characterize a novel mononuclear cobalt(II) complex.
- To elucidate the coordination environment and crystal packing of the complex.
- To investigate the intermolecular forces driving supramolecular structure formation.
Main Methods:
- Single-crystal X-ray diffraction was employed to determine the molecular and crystal structure.
- Analysis of bond lengths and coordination geometry around the cobalt(II) center.
- Identification and characterization of intermolecular hydrogen bonding and pi-pi stacking interactions.
Main Results:
- The mononuclear complex [Co(C(9)H(9)O(3))(2)(H(2)O)(2)] was synthesized and structurally characterized.
- Each cobalt(II) atom exhibits a hexa-coordinated, distorted octahedral geometry.
- Intermolecular hydrogen bonds and pi-pi stacking interactions link molecules into a supramolecular network.
Conclusions:
- The study successfully synthesized and characterized a novel cobalt(II) complex.
- The crystal structure highlights the role of both coordination and non-covalent interactions in supramolecular assembly.
- The findings contribute to the understanding of crystal engineering principles for metal-organic compounds.
Related Concept Videos
Colors and Magnetism
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
Valence Bond Theory
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
Coordination Compounds and Nomenclature
In most main group element compounds, the valence electrons of the isolated atoms combine to form chemical bonds that satisfy the octet rule. For instance, the four valence electrons of carbon overlap with electrons from four hydrogen atoms to form CH4. The one valence electron leaves sodium and adds to the seven valence electrons of chlorine to form the ionic formula unit NaCl (Figure 1a). Transition metals do not normally bond in this fashion. They primarily form coordinate covalent bonds, a...
Structural Isomerism
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...
Metal-Ligand Bonds
The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain coordination compounds. Ions of the metals, especially the transition metals, are likely to form complexes.
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
Formation of Complex Ions
A type of Lewis acid-base chemistry involves the formation of a complex ion (or a coordination complex) comprising a central atom, typically a transition metal cation, surrounded by ions or molecules called ligands. These ligands can be neutral molecules like H2O or NH3, or ions such as CN− or OH−. Often, the ligands act as Lewis bases, donating a pair of electrons to the central atom. These types of Lewis acid-base reactions are examples of a broad subdiscipline called coordination...

