TY - JOUR
T1 - Synthesis, structures and luminescent properties of new heterobimetallic Zn-4f Schiff base complexes
AU - Lo, Wing Kit
AU - WONG, Rick W K
AU - Guo, Jianping
AU - WONG, Wai Yeung
AU - Li, King Fai
AU - CHEAH, Kok Wai
N1 - Funding Information:
Financial support from the Hong Kong Baptist University and the Hong Kong Research Grants Council (HKBU 2038/02P) is acknowledged.
PY - 2004/12/1
Y1 - 2004/12/1
N2 - New stable heterobimetallic Zn-Ln (Ln = La, Gd, Nd, Yb, Er) Schiff base complexes have been synthesized and characterized. The photophysical properties of these Schiff base complexes can be tuned by changing the electronic properties of the substituents. By extending the conjugation, both the absorption and emission bands of the complexes show bathochromic shifts. Energy transfer is observed from the triplet state of the Zn-Ln complex to the excited state of lanthanide metal (Ln = Nd, Er, Yb) which then emits in the NIR region. A series of new 3d-4f heterobimetallic Schiff base complexes of the general formula [Zn(μ-L2)Ln(NO3)3(H 2O)n] (Ln = La 1, Nd 2, Gd 3, Er 4 and Yb 5; n = 1 or 2; H2L2 = N,N′-bis(3-methoxy-5-p-tolylsalicylidene) ethylene-1,2-diamine) are synthesized and characterized. Complexes 1, 2, 4 and 5 are structurally characterized by X-ray crystallography. The photophysical properties of these complexes are also investigated. At room temperature, complexes 1-5 exhibit similar solution absorption and emission spectra in the UV-Vis region. Furthermore, compounds 2, 4 and 5 exhibit solution emission corresponding to the lanthanide(III) ion in the near-infrared region at room temperature. The triplet state emission of the 3d-4f bimetallic complexes without energy transfer is also determined through the photophysical study of complex 3.
AB - New stable heterobimetallic Zn-Ln (Ln = La, Gd, Nd, Yb, Er) Schiff base complexes have been synthesized and characterized. The photophysical properties of these Schiff base complexes can be tuned by changing the electronic properties of the substituents. By extending the conjugation, both the absorption and emission bands of the complexes show bathochromic shifts. Energy transfer is observed from the triplet state of the Zn-Ln complex to the excited state of lanthanide metal (Ln = Nd, Er, Yb) which then emits in the NIR region. A series of new 3d-4f heterobimetallic Schiff base complexes of the general formula [Zn(μ-L2)Ln(NO3)3(H 2O)n] (Ln = La 1, Nd 2, Gd 3, Er 4 and Yb 5; n = 1 or 2; H2L2 = N,N′-bis(3-methoxy-5-p-tolylsalicylidene) ethylene-1,2-diamine) are synthesized and characterized. Complexes 1, 2, 4 and 5 are structurally characterized by X-ray crystallography. The photophysical properties of these complexes are also investigated. At room temperature, complexes 1-5 exhibit similar solution absorption and emission spectra in the UV-Vis region. Furthermore, compounds 2, 4 and 5 exhibit solution emission corresponding to the lanthanide(III) ion in the near-infrared region at room temperature. The triplet state emission of the 3d-4f bimetallic complexes without energy transfer is also determined through the photophysical study of complex 3.
KW - Heterobimetallic complexes
KW - Lanthanide
KW - Luminescence
KW - Schiff bases
KW - Zinc
UR - http://www.scopus.com/inward/record.url?scp=9244223066&partnerID=8YFLogxK
U2 - 10.1016/j.ica.2004.06.041
DO - 10.1016/j.ica.2004.06.041
M3 - Journal article
AN - SCOPUS:9244223066
SN - 0020-1693
VL - 357
SP - 4510
EP - 4521
JO - Inorganica Chimica Acta
JF - Inorganica Chimica Acta
IS - 15
ER -