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Double‐CO 3 2− Centered [Co II 5 ] Wheel and Modeling of Its Magnetic Properties
Author(s) -
Sarkar Mrinal,
Aromí Guillem,
Cano Joan,
Bertolasi Valerio,
Ray Debashis
Publication year - 2010
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201001418
Subject(s) - crystallography , ion , crystal structure , magnetization , cluster (spacecraft) , chemistry , metal , materials science , atomic physics , physics , magnetic field , organic chemistry , quantum mechanics , computer science , programming language
A high‐spin Co II cluster with a rare pentagonal molecular structure and formula [Co 5 (CO 3 ) 2 (bpp) 5 ]ClO 4 ( 1 ; Hbpp is 2,6‐bis(phenyliminomethyl)‐4‐methylphenolate) has been synthesized and characterized by single‐crystal X‐ray diffraction. This topology arises from fusing five [Co 2 (bpp)] moieties in a cyclic manner around two CO 3 2− central ligands, resulting in propeller‐like configuration. The irregular coordination of the carbonate ions to the metal centers results in a combination of coordination numbers (CNs) of the Co II ions of five and six. The bulk magnetization of this complicated magnetically exchanged system has been modeled successfully by employing a matrix diagonalization technique. For this, the combination of S =3/2 ions (CN=5) with ions exhibiting strong spin‐orbit coupling (CN=6) has been considered and a perturbative approach to handle the data in the whole studied range of temperatures (2–300 K) yielding parameters of g and D (for the five‐coordinate Co II ions), of A , κ , λ , and Δ (for the metals with spin‐orbit coupling) and of the exchange constants J . The agreement with results from DFT calculations, also presented here, is remarkable.