Related Experiment Video
Updated: Jun 28, 2026

09:02
Manganese Oxide Nanoparticle Synthesis by Thermal Decomposition of Manganese(II) Acetylacetonate
Published on: June 18, 2020
Stability constants of manganese(II) bromide complexes
1Department of Chemistry Brunel University London, W.3, U.K.
Talanta
|November 1, 1968
Summary
Researchers used Manganese-54 tracer to study manganese(II) bromide complexes. Cation-exchange chromatography determined stability constants for these complexes in solution at 20 degrees Celsius.
Area of Science:
- Inorganic Chemistry
- Radiochemistry
- Solution Chemistry
Background:
- Manganese(II) bromide solutions can form various complexes.
- Understanding complex stability is crucial for chemical processes.
Purpose of the Study:
- To investigate the formation and stability of manganese(II) bromide complexes.
- To determine the stability constants (beta(j)) for these complexes.
Main Methods:
- Utilized Manganese-54 as a radioactive tracer.
- Employed cation-exchange chromatography for separation and analysis.
- Maintained constant ionic strength (0.691M) using perchloric acid.
Main Results:
- Obtained values for the stability constants beta(j) = [MnBr((2-j)+)(j)]/[Mn(2+)][Br(-)](j).
- The study provides quantitative data on complex formation.
Conclusions:
- The stability constants determined are valid for the specified conditions (20 degrees C, 0.691M ionic strength).
- This research contributes to the understanding of complexation behavior in manganese-bromide systems.
Related Concept Videos
Complexation Equilibria: Factors Influencing Stability of Complexes
In complexation reactions, metal cations are the electron pair acceptors, and the ligands are the electron pair donors. The stability of the metal complexes depends primarily on the complexing ability of the central metal ion and the nature of the ligands. Generally, the complexing ability of the metal ion depends on the size and charge of the ion. As the metal ion size increases, the stability of the metal complexes decreases, provided that the valency of the metal ion and the ligands remain...
Complexation Equilibria: Overview
Complexation reactions take place when dative or coordinate covalent bonds form between metal ions and ligands. The compounds formed in these reactions are called coordination compounds. The number of bonds formed between the metal ion and the ligands is called its coordination number. Generally, most metal ions in an aqueous solution are solvated by water molecules and thus exist as aqua complexes.
The equilibrium constant of the complexation reaction is represented as the formation constant...
The equilibrium constant of the complexation reaction is represented as the formation constant...
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...
Properties of Transition Metals
Transition metals are defined as those elements that have partially filled d orbitals. As shown in Figure 1, the d-block elements in groups 3–12 are transition elements. The f-block elements, also called inner transition metals (the lanthanides and actinides), also meet this criterion because the d orbital is partially occupied before the f orbitals.
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...

