TY - JOUR
T1 - Highly luminescent Eu(III) complexes with 2,4,6-tri(2-pyridyl)-1,3,5-triazine ligand
T2 - Synthesis, structural characterization, and photoluminescence studies
AU - De Silva, Channa R.
AU - Wang, Ruiyao
AU - Zheng, Zhiping
N1 - Funding Information:
This work was supported by NSF CAREER Grant No. CHE-0238790. Acknowledgment is also made to the Donors of The Petroleum Research Fund, administered by the American Chemical Society, for partial support of this research. We thank Professor K. Miranda for the use of fluorometer. The CCD-based X-ray diffractometer was purchased through an NSF Grant (CHE-96103474, USA).
PY - 2006/12/4
Y1 - 2006/12/4
N2 - Two new Eu(III) complexes featuring 1,1,1,5,5,5-hexafluoro-2,4-pentanedionate (hfac) and a rigid Lewis base ligand 2,4,6-tri(2-pyridyl)-1,3,5-triazine (tptz), [Eu (hfac)2 (H2 O) (EtOH) (tptz)] [CF3 CO2-] (1) and Eu(hfac)3(tptz) (2), were synthesized. Their structures were established by single crystal X-ray diffraction. The europium ion in each of these complexes is nona-coordinate with six oxygen and three nitrogen atoms forming a coordination polyhedron best describable as a monocapped square antiprism. The difference in the composition and structure between these two complexes is caused by simply reversing the order of ligand (hfac and tptz) addition during the complex synthesis, and is rationalized in terms of the structural and electronic properties of the ligands and the overall steric bulk of the coordination sphere. Both complexes display characteristic Eu(III)-originated red emission upon UV excitation. The high quantum yields observed, 52% (1) and 60% (2), are rationalized in terms of the strong absorptions of both hfac and tptz ligands near the excitation wavelength (295 nm), an interpretation consistent with the well-established mechanism of ligand-mediated energy transfer for lanthanide-based light emission.
AB - Two new Eu(III) complexes featuring 1,1,1,5,5,5-hexafluoro-2,4-pentanedionate (hfac) and a rigid Lewis base ligand 2,4,6-tri(2-pyridyl)-1,3,5-triazine (tptz), [Eu (hfac)2 (H2 O) (EtOH) (tptz)] [CF3 CO2-] (1) and Eu(hfac)3(tptz) (2), were synthesized. Their structures were established by single crystal X-ray diffraction. The europium ion in each of these complexes is nona-coordinate with six oxygen and three nitrogen atoms forming a coordination polyhedron best describable as a monocapped square antiprism. The difference in the composition and structure between these two complexes is caused by simply reversing the order of ligand (hfac and tptz) addition during the complex synthesis, and is rationalized in terms of the structural and electronic properties of the ligands and the overall steric bulk of the coordination sphere. Both complexes display characteristic Eu(III)-originated red emission upon UV excitation. The high quantum yields observed, 52% (1) and 60% (2), are rationalized in terms of the strong absorptions of both hfac and tptz ligands near the excitation wavelength (295 nm), an interpretation consistent with the well-established mechanism of ligand-mediated energy transfer for lanthanide-based light emission.
KW - 2,4,6-Tri(2-pyridyl)-1,3,5-triazine
KW - Absorption
KW - Crystal structures
KW - Europium complexes
KW - Photoluminescence
KW - Synthesis
UR - http://www.scopus.com/inward/record.url?scp=33750818429&partnerID=8YFLogxK
U2 - 10.1016/j.poly.2006.06.032
DO - 10.1016/j.poly.2006.06.032
M3 - Article
AN - SCOPUS:33750818429
SN - 0277-5387
VL - 25
SP - 3449
EP - 3455
JO - Polyhedron
JF - Polyhedron
IS - 17
ER -