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通过由2,2,6,6-四甲基哌啶-氮-氧化物(TEMPO)自由基修饰的三联吡啶配体与二价金属铂盐反应,合成得到一种新型的金属配合物,[Pt(terpy-TEMPO)Cl]Cl?H_2O?CH_3OH(terpy指2,2′:6′,2′′-三联吡啶)。此配合物由于TEMPO自由基的作用呈现高效率的光猝灭现象。X衍射单晶数据证实此配合物的分子结构信息。利用紫外、荧光及电子顺磁共振光谱等谱学手段探讨了该配合物的紫外吸收、发射及电子顺磁共振(EPR)光谱性质。[Pt(terpy-TEMPO)Cl]Cl?H_2O?CH_3OH的室温紫外吸收光谱表明,此配合物有两个典型的紫外吸收波段,强吸收段和次强吸收段,分别来源于配体到配体的跃迁(MLCT),金属到配体的跃迁(LLCT)。另外,[Pt(terpy-TEMPO)Cl]Cl?H_2O?CH_3OH的室温固体荧光光谱表明,TEMPO的单电子能有效地猝灭三联吡啶铂的荧光发射。我们对此猝灭机理进行了详细合理的阐述,并通过高斯09软件包对配合物的能隙和能带进行了量化计算,结果进一步证明配合物体系中的TEMPO单电子能极大的影响最高占有分子轨道(HOMO)与最低未占分子轨道(LUMO)之间的能级差,从理论上解释了三联吡啶铂配合物的光猝灭的光学性质与分子结构之间的关系。EPR结果表明,稳定自由基上接上金属配合物,不影响自由基A值和g值(A值指自由基超精细耦合常数,g值指自由基的g因子),但影响自由基转动、弛豫时间。
A novel metal complex was synthesized by reacting terpyridine ligand modified by 2,2,6,6-tetramethylpiperidine-nitrogen-oxide (TEMPO) with divalent metal platinum salt [ Pt (terpy-TEMPO) Cl] Cl-H 2 O-CH 3 OH (terpy refers to 2,2 ’: 6’, 2 "-terpyridine). This complex exhibits a high efficiency of light quenching due to the action of TEMPO free radicals. X-ray diffraction data confirm the molecular structure of this complex. The UV absorption, emission and electronic paramagnetic resonance (EPR) spectroscopic properties of the complexes were investigated by UV, fluorescence and electron paramagnetic resonance spectroscopy. The room-temperature ultraviolet absorption spectra of [Pt (terpy-TEMPO) Cl] Cl • H_2O • CH_3OH showed that this complex has two typical ultraviolet absorption bands, strong absorption bands and minor absorption bands, (MLCT), metal-to-ligand transition (LLCT). In addition, the room-temperature solid-state fluorescence spectra of [Pt (terpy-TEMPO) Cl] Cl-H_2O · CH_3OH showed that the single electron of TEMPO effectively quenched the fluorescence emission of terpyridylplatinum. We described the quenching mechanism in detail and reasonably, and calculated the energy gap and energy band of the complex through the Gaussian 09 software package. The results further prove that the TEMPO single electron in the complex system can greatly influence the maximum The energy level difference between HOMO and LUMO theoretically explains the relationship between optical properties and molecular structure of photodissociation of terpyridylplatinum complex. The results of EPR showed that the attachment of the metal complex to the stable free radical did not affect the free radical A value and g value (A value refers to free radical hyperfine coupling constant, g value refers to g factor of free radical) but affects the free radical rotation, Relaxation time.