摘要
在乙腈溶液中合成了三种镧系金属三氟甲基磺酸盐Ln(OTf)3(Ln=Ce,Dy)与四异丙基亚甲基双膦酸酯[L=(iPrO)2P(O)CH2P(O)(iPrO)2]配合物[CeL4](OTf)3.2H2O,[Dy(OTf)2L2(H2O)2](OTf)(CH3CN)和[DyL4](OTf)3.L.2H2O。荧光分析发现,[CeL4](OTf)3.2H2O在波长249和300 nm激发下,测得641 nm处有明显的发射峰,Dy3+的两种配合物中[Dy(OTf)2L2(H2O)2](OTf)(CH3CN)中有水参与配位,使得其发射和激发峰的强度均弱于没有水参与配位的[DyL4](OTf)3.L.2H2O。另外,通过元素分析,热重分析,红外光谱和核磁共振等手段对配合物进行了组成确定和光谱学表征,并初步确定了膦氧配体与稀土离子的配位模式。这三种配合物均是八配位模式,[CeL4](OTf)3.2H2O和[DyL4](OTf)3.L.2H2O呈现高的对称性,4个L配体作为双齿配体全部参与配位,而[Dy(OTf)2L2(H2O)2](OTf)(CH3CN)中Dy3+周围除两个L和两个OTf外,还有2个配位水。
Three rare-earth complexes （OTf）3·2H2O（L=tetraisopropylmethylene-diphosphonate,OTf=trifluoromethanesulfate）,[Dy（OTf）2L2（H2O）2]（OTf）（CH3CN） and （OTf）3·L·2H2O were prepared by the reaction of Ln（OTf）3（Ln=Ce,Dy） and（iPrO）2P（O）CH2P（O）（iPrO）2 in CH3CN.Their compositions were confirmed and their properties were characterized by elemental analysis,infrared spectra,1H and 31P NMR spectroscopy,fluorescence spectra and DTA-TGA.The data of elemental analysis of these complexes are in good agreement with the formula given above.In the infrared spectra of all these complexes,there are obvious shifts of some important absorption bands,such as the PO or S—O bands,illustrating that the ligands L or OTf ions were coordinated to the lanthanide ions.The signals in 1H NMR spectrum at approximately 1.2,2.4 and 4.5 have been assigned to the resonance of H atoms in the ligand L,and these signals in the spectrum of complexes are highfield shifted compared to that of free ligand due to the electron cloud of Ln—O band moving towards to P—O band.The sharp single peaks were found in the 31P NMR spectrum,and the chemical shifts are at 18.705 6 for free ligand L,18.543 5 for complex Ⅰ,18.273 1 for complex Ⅱ,and 18.489 4 for complex Ⅲ.The excitation and emission signals of Ce（Ⅲ） ion were in view of electric dipole transition from 4f15d1 to 4f7.The fluorescence spectroscopy shows that the excitation peak of （OTf）3·2H2O is at 249 and 300 nm,and a strong emission peak is at 641 nm.The existence of two coordination water molecules in [Dy（OTf）2L2（H2O）2]（OTf）（CH3CN） makes both the excitation and emission peaks weaker than that of （OTf）3·L·2H2O.The coordination model of rare-earth with diphosphonic ligand was also discussed.All of these complexes are eight-coordinated.The complexes （OTf）3·2H2O and [DyL4]（OTf）3·L·2H2O are highly-symmetrical,in which four bidentate ligands L are coordinated to Ce and Dy atoms respectively while the OTf ions an
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
2008年第11期2592-2595,共4页
Spectroscopy and Spectral Analysis
基金
国家自然科学基金项目(20206001)
国家教育部留学回国人员启动基金项目
北京市教委科技面上项目(KM20061002806)
北京市留学人员科技活动择优项目资助
关键词
稀土配合物
光谱表征
配位模式
Rare-earth complex,Spectra characterization,Coordination model
