| Full text | |
| Author(s): Show less - |
Bibi, Naheed
[1]
;
Ratier de Arruda, Eduardo Guimaraes
[1]
;
Domingo, Alex
[2]
;
Oliveira, Aline Alves
[3]
;
Galuppo, Carolina
[1]
;
Phung, Quan Manh
;
Orra, Naima Mohammed
[1]
;
Beron, Fanny
[4]
;
Paesano, Jr., Andrea
[3]
;
Pierloot, Kristine
[5]
;
Barboza Formiga, Andre Luiz
[1]
Total Authors: 11
|
| Affiliation: | [1] Univ Estadual Campinas, UNICAMP, Inst Chem, POB 6154, BR-13083970 Campinas, SP - Brazil
[2] Katholieke Univ Leuven, Dept Chem, Celestijnenlaan 200F, B-3001 Leuven - Belgium
[3] Univ Estadual Maringa, Maringa, Parana - Brazil
[4] Univ Estadual Campinas, UNICAMP, Inst Phys Gleb Wataghin, Rua Sergio Buarque de Holanda 777, BR-13083859 Campinas, SP - Brazil
[5] Quan Manh Phung, Katholieke Univ Leuven, Dept Chem, Celestijnenlaan 200F, B-3001 Leuven - Belgium
Total Affiliations: 5
|
| Document type: | Journal article |
| Source: | Inorganic Chemistry; v. 57, n. 23, p. 14603-14616, DEC 3 2018. |
| Web of Science Citations: | 6 |
| Abstract | |
The iron(II) complexes of two structural isomers of 2-(1H-imidazol-2-yl)diazine reveal how ligand design can be a successful strategy to control the electronic and magnetic properties of complexes by fine-tuning their ligand field. The two isomers only differ in the position of a single diazinic nitrogen atom, having either a pyrazine (Z) or a pyrimidine (M) moiety. However, {[}Fe(M)(3)](ClO4)(2) is a spin-crossover complex with a spin transition at 241 K, whereas {[}Fe(Z)(3)](ClO4)(2) has a stable magnetic behavior between 2 and 300 K. This is corroborated by temperature-dependent Mossbauer spectra showing the presence of a quintet and a singlet state in equilibrium. The temperature-dependent single crystal X-ray diffraction results relate the spin-crossover observed in {[}Fe(M)(3)](ClO4)(2) to changes in the bond distances and angles of the coordination sphere of iron(II), hinting at a stronger sigma donation of ligand Z in comparison to ligand M. The UV/vis spectra of both complexes are solved by means of the multiconfigurational wave-function-based method CASPT2 and confirm their different spin multiplicities at room temperature, as observed in the Mossbauer spectra. Calculations show larger stabilization of the singlet state in {[}Fe(Z)(3)](2+) than in {[}Fe(M)(3)](2+), stemming from the slightly stronger ligand field of the former (506 cm(-1) in the singlet). This relatively weak effect is indeed capable of changing the spin multiplicity of the complexes and causes the appearance of the spin transition in the M complex. (AU) | |
| FAPESP's process: | 14/50906-9 - INCT 2014: in Functional Complex Materials |
| Grantee: | Fernando Galembeck |
| Support Opportunities: | Research Projects - Thematic Grants |