We have discussed low and high spin complexes in class. We said that a large pai

Question

We have discussed low and high spin complexes in class. We said that a large pairing energy (P) and a small value of 10Dq favors the high spin case, while a low P and a large value of 10Dq favors the low spin case. In some compounds, there is a small energy difference between these two situations, and the complex can change its spin behavior with changes in temperature. With this information in mind, explain the following experimental results: At room temperature a 0.192 gram sample of Fe[HB(1-pyrazolyl)_3]_2 weighs the same in a magnetic field as it does out of the field (to three significant figures). However, in an identical magnetic field at 449K, a 0.192 gram sample of this material gains 0.015 grams over its zero field weight. (The ligand has a -1 charge and is a tridentate N-donor. The complex has octahedral geometry). In your explanation, be sure to show how the d-orbitals are filled with electrons in each case.

Explanation / Answer

Magnetic behaviour remain same at room temperature as well as 449K becouse ligand is N-donor which is strong field ligand which give low spin complex (all electron of iron(III) pair) at all temperature. Whereas weight of complex increases by 0.015g it is becouse of Hydride of boron(ligand) replace by -OH group.

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.