TRANSIENT ABSORPTION SPECTROSCOPY OF POLYGERMANE COPOLYMER

聚锗烷共聚物的瞬态吸收光谱

• 批准号: 6328040
• 负责人: D BERRY
• 金额: $ 0.27万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-08-01 至 2001-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6328040
• 关键词: biological products; biomaterials; biomedical resource; immunology; infection; inflammation; lymphatic system; nanotechnology; nucleic acids; proteins; virus

In an investigation of the electronic properties of a series of copolymers, poly[methylphenyl-co-methyl-4-(dimethylamino)phenylgermane] and the corresponding homopolymers, the copolymers containing 5%, 25%, and 50% dimethylaminophenyl units show a broad emission peak at ~500 nm. This is in addition to contributions from a sharp emission peak at ~375 nm exhibited by the phenyl homopolymer and a broader peak at ~420 nm found in the emission of the dimethylaminophenyl homopolymer. In an investigation of an analogous series of polysilane copolymers, Hochstrasser and Miller observed a broad emission peak at ~420 nm, which they attributed to a "self-trapped exciton", or an excitation which is localized on ~1 dimethylaniline unit. Furthermore, literature reports of the emission spectrum of poly(phenylmethylsilane) indicate the presence of two peaks a sharp peak at ~355nm and a broader peak at ~400-500 nm. The origin of the latter peak is controversial, and has been propose d to be due to phosphorescence, impurities generated during polymerization or during photolysis, or a charge transfer state between the polymer backbone and pendant groups. Our goal is to determine the origin of the broad emission peak which we are observing at ~500 nm. It seems likely that it is due to a "self-trapped" exciton as postulated by Hochstrasser et al. However, it is necessary to rule out the possibility of phosphorescence, and transient absorption spectroscopy is a relatively quick method to detect long lived species which may be responsible for phosphorescence.

在一系列的电子性质的研究中， 共聚物， 聚[甲基苯基-co-甲基-4-（二甲氨基）苯基锗烷]和 相应的均聚物，含有5%、25%和50%的共聚物， 二甲基氨基苯基单元在~500 nm处显示宽发射峰。 这 除了来自约375 nm处的尖锐发射峰的贡献之外 在约420 nm处出现较宽的峰 在二甲基氨基苯基均聚物的发射中发现。 中 研究了类似系列的聚硅烷共聚物， Hochstrasser和米勒在~420 nm处观察到宽发射峰， 他们将其归因于“自陷激子”，或激发 其位于~1个二甲基苯胺单元上。 此外，委员会认为， 文献报道的发射光谱 聚（苯基甲基硅烷）表明存在两个峰 在~ 355 nm处有一个峰，在~400-500 nm处有一个较宽的峰。 的起源 后一个峰值是有争议的，并已被提出是由于 磷光，在聚合期间或在聚合期间产生的杂质， 光解，或聚合物主链之间的电荷转移状态 和侧基。 我们的目标是确定 我们在~500 nm处观察到的发射峰。 很可能 这是由于Hochstrasser等人假设的“自陷”激子 al.但是，有必要排除以下可能性： 磷光，和瞬态吸收光谱是一个相对 快速检测长寿物种的方法， 磷光