A high-spin CoII cluster with a rare pentagonal molecular structure and formula [Co5(CO3)2(bpp)5]ClO4 (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 [Co2(bpp)] moieties ina cyclic manner around two CO3 2- cen-tral ligands, resulting in propeller-likeconfiguration. The irregular coordination of the carbonate ions to the metalcenters results in a combination of co-ordination numbers (CNs) of the CoIIions of five and six. The bulk magneti- zation of this complicated magneticallyexchanged system has been modeledsuccessfully 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 consideredand a perturbative approach to handlethe data in the whole studied range oftemperatures (2–300 K) yielding parameters of g and D (for the five-coordinate CoII ions), of A, k, l, and D (forthe metals with spin-orbit coupling) and of the exchange constants J.Theagreement with results from DFT cal- culations, also presented here, is remarkable.
Double-CO3 2- Centered [CoII 5] Wheel and Modeling of Its Magnetic Properties
BERTOLASI, Valerio;
2010
Abstract
A high-spin CoII cluster with a rare pentagonal molecular structure and formula [Co5(CO3)2(bpp)5]ClO4 (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 [Co2(bpp)] moieties ina cyclic manner around two CO3 2- cen-tral ligands, resulting in propeller-likeconfiguration. The irregular coordination of the carbonate ions to the metalcenters results in a combination of co-ordination numbers (CNs) of the CoIIions of five and six. The bulk magneti- zation of this complicated magneticallyexchanged system has been modeledsuccessfully 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 consideredand a perturbative approach to handlethe data in the whole studied range oftemperatures (2–300 K) yielding parameters of g and D (for the five-coordinate CoII ions), of A, k, l, and D (forthe metals with spin-orbit coupling) and of the exchange constants J.Theagreement with results from DFT cal- culations, also presented here, is remarkable.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
