To determine which complex has an inverse-spinel structure, let's first understand what an inverse-spinel structure entails.
In a spinel structure, the general formula is AB_2O_4. In the standard spinel arrangement, A^{2+} cations occupy one-eighth of the tetrahedral sites, while B^{3+} cations occupy half of the octahedral sites in a close-packed oxygen lattice.
In an inverse-spinel structure, half of the B^{3+} ions occupy the tetrahedral sites, and the remaining B^{3+} ions, along with the A^{2+} ions, occupy the octahedral sites.
Let's evaluate the given options:
- Co_3O_4: This compound has a normal spinel structure where Co^{2+} is in tetrahedral sites.
- Fe_3O_4: In this structure, half of the Fe^{3+} ions occupy tetrahedral sites, and the Fe^{2+} and remaining Fe^{3+} occupy octahedral sites, which fits the inverse-spinel format.
- MgAlO_4: This is also a normal spinel.
- Mn_3O_4: Possesses a normal spinel structure.
Based on this analysis, the correct answer is:
Fe_3O_4 is the complex with an inverse-spinel structure.
Important Questions from Coordination Chemistry
Consider the figure given below, where M is a metal and L is a monodentate ligand. The $\sigma$-bonding ligand group orbital (LGO) having same symmetry with $d_{z^2}$ orbital of M in the octahedral coordination geometry is
- Among the following, the compound with the lowest CO stretching frequency is
- The complex(es) that exhibit(s) optical isomerism is (are)
Among the given platinum(II) complexes, the one that is thermally the most unstable is
- According to Irving-Williams series, the number of d electrons for the first row transition metal (M) ion having the highest overall stability constant (log $\beta$) for $[M(EDTA)]^{2-}$ is ________
