CAS: Ultrafast Spectroscopy and Photoisomerization of Iron Sulfoxide Complexes

在化学部（CHE）的化学结构，动力学机制-B（CSDM-B）计划和刺激竞争研究的既定计划（EPSCoR）的支持下，新墨西哥州大学的Jeffrey Rack教授正在开发具有有趣的光谱和磁光特性的新型铁络合物。本研究的目的是设计具有光活性的亚砜类铁配合物。该项目位于有机，无机和物理化学的界面，适合于各级经验的科学家的教育。新墨西哥州的大学是一个占多数的少数民族机构和机架研究小组是工作，以提供教育和培训的学生在科学代表性不足的最高水平，并将继续这样做，根据这个奖项。涉及高中和初中化学教师培训的外联活动是研究项目的一部分。拟议的工作详细说明了一项研究计划，以创造光活性铁聚吡啶亚砜络合物。这项工作的目标是发现，如果光引发的亚砜异构化可以支持铁中心的方式类似于相关的钌配合物。在钌配合物中，3 MLCT激发促使瞬时Ru 3+形成，这诱导了亚砜从S-键合到O-键合的激发态异构化。Rack教授和他的研究团队的目标是在铁上重现这种光化学反应，目的是用O键配位模式稳定高或中等自旋状态。有两个主要的挑战，必须满足观察这种化学对铁：3 MCLT（金属到配体电荷转移）状态的铁是罕见的，由于primogenic效应和亚砜异构化的铁还没有报道。初步结果提供的证据表明，这些挑战是可以克服的，并且可以实现在铁上实现S-到O-亚砜键合的目标。 如果成功的话，实现这种中至高自旋态Fe-亚砜络合物的能力将是该领域的重大进步，因为这将使该化学进入地球丰富的过渡金属空间的领域，该奖项反映了NSF的法定使命，并通过使用基金会的智力价值进行评估，被认为值得支持和更广泛的影响审查标准。

With support from the Chemical Structure, Dynamics & Mechanisms-B (CSDM-B) Program of the Chemistry Division (CHE), and the Established Program to Stimulate Competitive Research (EPSCoR), Professor Jeffrey Rack of the University of New Mexico is developing new classes of iron complexes with interesting spectroscopic and magneto-optical properties. The goal of this research is to design new photoactive iron complexes with sulfoxide ligands. The project lies at the interface of organic, inorganic, and physical chemistry, and is appropriate for education of scientists at all levels of experience. The University of New Mexico is a majority minority institution and the Rack research group is works to provide the highest level of education and training for students underrepresented in science and will continue to do so under this award. Outreach activities involving the training of high school and middle chemistry teachers is part of the research project. The proposed work details a research plan to create photoactive iron polypyridine sulfoxide complexes. The goal of this work is to discover if phototriggered sulfoxide isomerization can be supported on iron centers in a fashion similar to that on related ruthenium complexes. In ruthenium complexes, 3MLCT excitation prompts transient Ru3+ formation, which induces excited state isomerization of the sulfoxide from S-bonded to O-bonded. Professor Rack and his research team aim to reproduce this photochemistry on iron with the objective of stabilizing high or intermediate spin states with the O-bonded coordination mode. There are two major challenges that must be met to observe this chemistry on iron: 3MCLT (metal-to-ligand charge-transfer) states on iron are rare due to the primogenic effect and sulfoxide isomerization on iron has not been reported. Preliminary results provide evidence that these challenges can be overcome and that the goal of achieving S- to O-sulfoxide bonding on iron can be achieved. If successful, the ability to achieve such intermediate to high spin state Fe-sulfoxide complexes would be a significant advance for the field as this would bring this chemistry into the realm of earth abundant transition metal space, and open up an important new avenue of exploration for organometallic chemists.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.