New Co-II members of the family of multifunctional materials of general formula [DAMS]4[M2Co(C2O4)(6)]center dot 2DAMBA center dot 2H(2)O (M-III = Rh, Fe, Cr; DAMBA = para-dimethylaminobenzaldehyde and [DAMS(+) = trans-4-(4-dimethylaminostyryl)-1-methylpyridinium) have been isolated and characterized. Such new hybrid mixed metal oxalates are isostructural with the previously investigated containing Zn-II, Mn-II, and Ni-II. This allows to preserve the exceptional second harmonic generation (SHG) activity, due to both the large molecular quadratic hyperpolarizability of [DAMS(+)] and the efficiency of the crystalline network which organizes [DAMS(+)] into head-to-tail arranged J-type aggregates, and to further tune the magnetic properties. In particular, the magnetic data of the Rh-III derivative demonstrate that high spin octacoordinated Co-II centers behave very similarly to the hexacoordinated Co-II ones, being dominated by a large orbital contribution. The Cr-III derivative is characterized by ferromagnetic Cr-III-Co-II interactions. Most relevantly, the Fe-III compound is characterized by a moderate antiferromagnetic interaction between Fe-III and Co-II, resulting in a ferrimagnetic like structure. Its low temperature dynamic magnetic properties were found to follow a thermally activated behavior (tau(0) = 8.6 x 10(-11) s and Delta E = 21.4 K) and make this a candidate for the second oxalate-based single chain magnet (SCM) reported up to date, a property which in this case is coupled to the second order non linear optical (NLO) ones.
Slow Relaxation of the Magnetization in Non-Linear Optical Active Layered Mixed Metal Oxalate Chains / E. Cariati, R. Ugo, G. Santoro, E. Tordin, L. Sorace, A. Caneschi, A. Sironi, P. Macchi, N.P. Casati. - In: INORGANIC CHEMISTRY. - ISSN 0020-1669. - 49:23(2010 Dec), pp. 10894-10901.
|Titolo:||Slow Relaxation of the Magnetization in Non-Linear Optical Active Layered Mixed Metal Oxalate Chains|
CARIATI, ELENA (Primo)
UGO, RENATO (Secondo)
MACCHI, PIERO (Penultimo)
CASATI, NICOLA PIETRO MARIA (Ultimo)
|Parole Chiave:||Spin cobalt(II) complexes ; inorganic-organic hybrid ; structural-characterization ; 2nd-harmonic generation ; molecular materials ; trimeric clusters ; magnet behavior ; NLO properties ; ligand ; family|
|Settore Scientifico Disciplinare:||Settore CHIM/03 - Chimica Generale e Inorganica|
|Data di pubblicazione:||dic-2010|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1021/ic1013076|
|Appare nelle tipologie:||01 - Articolo su periodico|