TY - JOUR
T1 - Structure of cyano-bridged Eu(III)-Co(III) bimetallic assembly and its application to photophysical verification of photomagnetic phenomenon
AU - Akitsu, T.
AU - Einaga, Y.
N1 - Funding Information:
Acknowledgements. This work was supported by the Grant-in-Aid for the 21st Century COE Orogram “KEIO Life Conjugate Chemistry” from the Ministry of Education, Culture, Sports, Science, and Technology, Research Foundation for Opto-Science and Technology, and Mizuho Foundation for the Promotion of Science. The authors also thank Dr. Isamu Oguro (Institute for Solid State Physics, the University of Tokyo) for the measurements on the SQUID apparatus.
PY - 2007/6
Y1 - 2007/6
N2 - New crystal structure of Eu(DMF)4(H2O) 3Co(CN)6•H2O (DMF = N,N′- dimethylformamide) (Eu-Co) has been determined to be monoclinic, P2(1)/n, a = 19.796(12) Å, b = 8.862(11) Å, c = 17.525(10) Å, β = 96.26(5)°, V = 3056(5) Å3, Z = 4. The Eu(III) ion adopts an antiprismatic eight-coordination and forms a cyano bridge with r(Eu-N) = 2.496(7) Å and Θ(Eu-N-C) = 165.7(7)° to the Co(III) ion. The complex exhibits some common features with the Eu-Fe complex. Diffuse reflectance electronic spectra and magnetic susceptibility of Eu-Cr, Eu-Mn, Eu-Fe, and Eu-Co complexes were compared. By substituting the metal ions, both electronic and structural features affected the charge transfer bands and superexchange interactions concerning cyanide ligands. In addition, only Eu-Co exhibited 5 D 0 → 7 F 2 and 5 D 0 → 7 F 1 luminescence bands at 16300 cm-1 and 16900 cm-1, respectively at 298 K (λex = 360 nm (27000 cm-1)), because quenching by cyano-bridged ions did not prevent Eu(III) ion from exhibiting emission. Thus, only Eu-Co may be suitable for verification of an assumption of mechanism concerning drastic photoinduced magnetic changes for Nd-Fe. Merely small decrease of magnetization was observed for Eu-Co after UV light irradiation at 2.0 K. This result was attributed to slight structural changes around cyano bridges without transitions of spin states.
AB - New crystal structure of Eu(DMF)4(H2O) 3Co(CN)6•H2O (DMF = N,N′- dimethylformamide) (Eu-Co) has been determined to be monoclinic, P2(1)/n, a = 19.796(12) Å, b = 8.862(11) Å, c = 17.525(10) Å, β = 96.26(5)°, V = 3056(5) Å3, Z = 4. The Eu(III) ion adopts an antiprismatic eight-coordination and forms a cyano bridge with r(Eu-N) = 2.496(7) Å and Θ(Eu-N-C) = 165.7(7)° to the Co(III) ion. The complex exhibits some common features with the Eu-Fe complex. Diffuse reflectance electronic spectra and magnetic susceptibility of Eu-Cr, Eu-Mn, Eu-Fe, and Eu-Co complexes were compared. By substituting the metal ions, both electronic and structural features affected the charge transfer bands and superexchange interactions concerning cyanide ligands. In addition, only Eu-Co exhibited 5 D 0 → 7 F 2 and 5 D 0 → 7 F 1 luminescence bands at 16300 cm-1 and 16900 cm-1, respectively at 298 K (λex = 360 nm (27000 cm-1)), because quenching by cyano-bridged ions did not prevent Eu(III) ion from exhibiting emission. Thus, only Eu-Co may be suitable for verification of an assumption of mechanism concerning drastic photoinduced magnetic changes for Nd-Fe. Merely small decrease of magnetization was observed for Eu-Co after UV light irradiation at 2.0 K. This result was attributed to slight structural changes around cyano bridges without transitions of spin states.
KW - Cobalt(III)
KW - Crystal structure
KW - Europium(III)
KW - Magnetism
KW - Spectroscopy
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U2 - 10.2478/s11696-007-0019-2
DO - 10.2478/s11696-007-0019-2
M3 - Article
AN - SCOPUS:34248398535
VL - 61
SP - 194
EP - 198
JO - Chemical Papers
JF - Chemical Papers
SN - 0366-6352
IS - 3
ER -