Synthesis, characterizations and luminescent properties of three novel aryl amide type ligands and their lanthanide complexes.
Three new aryl amide type ligands, N-(phenyl)-2-(quinolin-8-yloxy)acetamide (L(1)), N-(benzyl)-2-(quinolin-8-yloxy)acetamide (L(2)) and N-(naphthalene-1-yl)-2-(quinolin-8-yloxy)acetamide (L(3)) were synthesized. With these ligands, three series of lanthanide(III) complexes were prepared: [Ln(L(1))(2)(NO(3))(2)]NO(3), [Ln(L(2))(2)(NO(3))(2)(H(2)O)(2)]NO(3).H(2)O and [Ln(L(3))(2)(NO(3))(2)(H(2)O)(2)]NO(3).H(2)O (Ln=La, Sm, Eu, Gd). The complexes were characterized by the elemental analyses, molar conductivity, (1)H NMR spectra, IR spectra and TG-DTA. The fluorescence properties of complexes in the solid state and the triplet state energies of the ligands were studied in detail, respectively. It was found that the Eu(III) complexes have bright red fluorescence in solid state. The energies of excited triplet state for the three ligands are 20325 cm(-1) (L(3)), 21053 cm(-1) (L(2)) and 22831 cm(-1) (L(1)), respectively. All the three ligands sensitize Eu(III) strongly and the order of the emission intensity for the Eu(III) complexes with the three ligands is L(3)>L(2)>L(1). It can be explained by the relative energy gap between the lowest triplet energy level of the ligand (T) and (5)D(1) of Eu(III). This means that the triplet energy level of the ligand is the chief factor, which dominates Eu(III) complexes luminescence.
Wu
Wei-Na
WN
Department of Chemistry, Lanzhou University, Lanzhou 730000, PR China.
Yuan
Wen-Bing
WB
Tang
Ning
N
Yang
Ru-Dong
RD
Yan
Lan
L
Xu
Zi-Hua
ZH
D000081:Acetamides / Q000138:chemical synthesis / Q000737:chemistry*; D001593:Benzyl Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D005453:Fluorescence; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D008024:Ligands; D009281:Naphthalenes / Q000138:chemical synthesis / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D011804:Quinolines / Q000138:chemical synthesis / Q000737:chemistry*; D013057:Spectrum Analysis
D000081:Acetamides; D001593:Benzyl Compounds; D028581:Lanthanoid Series Elements; D008024:Ligands; C517367:N-(benzyl)-2-(quinolin-8-yloxy)acetamide; C517369:N-(naphthalene-1-yl)-2-(quinolin-8-yloxy)acetamide; C517368:N-(phenyl)-2-(quinolin-8-yloxy)acetamide; D009281:Naphthalenes; D009942:Organometallic Compounds; D011804:Quinolines