Related Experiment Video
Updated: Mar 6, 2026
04:51
Author Spotlight: Functionalizing Metal-Organic Frameworks: Advancements, Challenges, and the Power of Post-Synthetic Ligand Exchange
Published on: June 23, 2023
4.3K
5-(2-Pyridil)-1H-tetrazole complexes with Mo(iv) and W(iv) cyanides
A Mrowiec1, A Jurowska1, M Hodorowicz1
1Jagiellonian University in Kraków, Faculty of Chemistry, 30-060 Kraków, R. Ingardena 3, Poland. szklarze@chemia.uj.edu.pl.
Dalton Transactions (Cambridge, England : 2003)
|March 9, 2017
Summary
Two new metal complexes featuring a tetrazole ligand derived from 2-cyanopyridine were synthesized and characterized. Structural analysis revealed coordination isomers, with pyridine nitrogen positioning influenced by similar pK values.
Area of Science:
- Inorganic Chemistry
- Coordination Chemistry
- Materials Science
Background:
- Tetrazole ligands are versatile building blocks in coordination chemistry.
- Molybdenum and Tungsten oxycyanide complexes offer unique electronic and structural properties.
Purpose of the Study:
- Synthesize and characterize novel tetrazole-based molybdenum and tungsten complexes.
- Investigate the coordination behavior and structural isomerism of these new compounds.
- Explore the influence of ligand properties on complex stability.
Main Methods:
- Reaction of 2-cyanopyridine-derived tetrazole ligand with K3Na[Mo(CN)4O2]·6H2O and K3Na[W(CN)4O2]·6H2O.
- Isolation and characterization using elemental analysis, IR, UV-Vis spectroscopy, cyclic voltammetry, and thermogravimetric analysis (TGA/DTG).
- Single crystal X-ray diffraction for detailed structural elucidation.
Main Results:
- Two new complexes, (PPh4)2[Mo(CN)3O(pdt)]·2H2O (1) and (PPh4)2[W(CN)3O(pdt)]·3H2O (2), were successfully synthesized.
- X-ray crystallography revealed the presence of two coordination isomers within the same crystal lattice.
- The pyridine nitrogen atom was observed in both trans and cis positions relative to the M=O bond, attributed to similar pK values of pyridine and tetrazole nitrogens.
- Thermogravimetric analysis indicated enhanced stability of the tetrazole ligand upon coordination.
Conclusions:
- The study successfully synthesized and characterized novel molybdenum and tungsten tetrazole complexes.
- The formation of coordination isomers highlights the nuanced coordination preferences of the ligand.
- The findings provide insights into the electronic and structural factors governing the coordination of tetrazole ligands to metal centers.
Related Concept Videos
02:42Valence Bond Theory
11.4K
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...
11.4K
02:57Coordination Number and Geometry
19.4K
For transition metal complexes, the coordination number determines the geometry around the central metal ion. Table 1 compares coordination numbers to molecular geometry. The most common structures of the complexes in coordination compounds are octahedral, tetrahedral, and square planar.
19.4K
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
49.2K
Tetrahedral Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
49.2K
03:02Colors and Magnetism
14.4K
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...
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...
14.4K
02:34Structural Isomerism
22.3K
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...
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...
22.3K
01:20Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions
2.6K
Arenediazonium substitution reactions occur when the diazonium group is substituted by various functional groups such as halides, hydroxyl, nitrile, etc. For instance, arenediazonium salts react with copper(I) salts of chloride, bromide, or cyanide to form corresponding aryl chlorides, bromides, and nitriles. These reactions are named Sandmeyer reactions. Although the mechanism of this reaction is complicated, as illustrated in Figure 1, they are believed to progress via an aryl copper...
2.6K