Naslov
Vibrational study of the Fe(phen)2(NCS)2 spin- crossover complex by density-functional calculations

Autori
Baranović, Goran ; Babić, Darko

Izvornik
Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy (1386-1425) 60 (2004), 5; 1013-1025

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
spin-crossover; vibrational spectroscopy; density functional

Sažetak
The geometries and vibrational frequencies of an iron(II) spin-crossover complex Fe(phen)2(NCS)2 in the low- and high-spin state have been calculated using DFT (BP86 functional with 6-311G* + Wachters+f, 6-31G* and LANL2DZ basis sets). A redundancy-free set of internal coordinates has been defined and used to obtain a valence force field. The use of the symmetry coordinates of a perfect octahedron as internal coordinates for the FeN6 framework of the complex has enabled the description of the stretching-bending couplings. A comparison of the force constants of free ligands with the corresponding constants of the two spin states has provided a basis for the discussion of the changes in electronic charge distribution in the complex. By use of the generalized harmonic mode scrambling it is shown that in the low-lying normal vibrations of the complex, the ligands participate as almost rigid units. Energies of these modes are close to the oscillators describing the interaction of the complex with the surrounding molecules in the solid phase.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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