STARK HOLE BURNING SPECTROSCOPY OF MODEL HEMES

本建议中所述的研究是对以下研究的继续： 固态生物学上重要的分子， 它们的电子激发态性质，光化学和动力学， 使用光学烧孔和斯塔克效应的组合。 当 吸收分子溶解在基质中，其电子光谱 由于局部环境的变化而不均匀地变宽。 如果激光器的带宽远小于非均匀带， 宽度是用来激发这些吸收剂，这是可能的燃烧， 光谱中的光洞 空穴是由光化学产生的， 瞬时存储或分子重定向。 由于孔的宽度是 通常以MHz为单位测量，当与斯塔克效应相结合时， 一种非常高分辨率的分子特性探针。 这项研究的长期目标是提取详细的兴奋 状态信息（例如，偶极矩、极化率、几何形状）， 用Stark烧孔法分离卟啉分子， 并扩展技术，使其可以用作高分辨率 生理学上更真实的生物分子探索 环境. 具体来说，我们打算继续研究简单的 正构烷烃晶体中的游离碱和金属卟啉 矩阵 然后将研究扩展到使用随机定向 玻璃杯里的卟啉 最后，我们将把斯塔克的烧孔法应用到更多的领域。 低温玻璃中的复杂生物分子（例如血红素）， 解决方案 该方法涉及单一混合（卟啉/正烷烃） 晶体和制造低温玻璃溶液。 样品 放置在电极之间并浸入液体N2或He中， 获得的吸收或发射光谱。 光学孔被烧毁， 用窄带激光扫描;斯塔克场被施加在DC或DC 或者根据需要进行脉冲。 随后的电场效应 然后与分子激发态性质和动力学有关。

The research described in this proposal is a continuation of a study of biologically important molecules in the solid state, with respect to their electronic excited state properties, photochemistry and dynamics, using a combination of optical hole-burning and the Stark effect. When an absorbing molecule is dissolved in a matrix, its electronic spectrum is inhomogeneously broadened due to variations in the local environments. If a laser which has a bandwidth much less than the inhomogeneous band width is used to excite these absorbers, it is possible to burn an optical hole in the spectrum. Holes result from photochemistry, transient storage or molecular reorientation. Since the hole widths are often measured in MHz, when coupled with the Stark effect, this becomes a very high resolution probe of molecular properties. The long-term objectives of this research are to extract detailed excited state information (e.g. dipole moments, polarizabilities, geometry) from isolated porphyrin molecules using Stark hole-burning method and develop and extend the techniques so that it can be used as a high resolution probe on biological molecules in more physiologically realistic environments. Specifically we intend to continue our study of simple free base and metalloporphyrins in well defined n-alkane crystal matrices. Then the study will be extended to use randomly oriented porphyrins in glasses. Finally, we will apply Stark hole-burning to more complex biological molecules (e.g. heme) in low temperature glasses and solutions. The methodology involves the growth of single mixed (porphyrin/n-alkane) crystals and making low temperature glass solutions. The sample is placed between electrodes and immersed in liquid N2 or He and an absorption or emission spectrum obtained. Optical holes are burned and scanned with a narrow band laser; the Stark field is applied either DC or pulsed depending on the need. The subsequent electric field effects are then related to molecular excited state properties and dynamics.