Nevonen Dustin E, Wagner Jenna C, Brückner Christian, Ziegler Christopher J, Nemykin Victor N
Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States.
Department of Chemistry, University of Akron, Akron, Ohio 44325-3601, United States.
J Phys Chem Lett. 2023 Aug 24;14(33):7382-7388. doi: 10.1021/acs.jpclett.3c01658. Epub 2023 Aug 11.
We report a systematic investigation of a series of Ag(II) and Ag(III) complexes of porphyrins and their analogues using UV-vis magnetic circular dichroism (MCD) spectroscopies and theoretical calculations. Ag(II) and Ag(III) octaethyl- and tetraarylporphyrins show the usual sign sequence in the Q-band region (i.e., negative to positive intensities with increasing energy) of their MCD spectra, indicative of the ΔHOMO > ΔLUMO relationship (ΔHOMO is the energy difference between Michl's and orbitals, and ΔLUMO is the energy difference between Michl's and - pair of MOs). In contrast, Ag(II) complexes of β,β'-pyrrole-modified porphyrins (with an effective chlorin-type π-system) and Ag(III) corroles have sign reverse features in the MCD spectra of their Q-band region (ΔHOMO < ΔLUMO relationships). The Ag(III) complex of N-confused porphyrin shows the ΔHOMO > ΔLUMO relationship in the neutral state and the ΔHOMO < ΔLUMO relationship in the protonated form.
我们报告了一项使用紫外可见磁圆二色性（MCD）光谱和理论计算对一系列卟啉及其类似物的Ag（II）和Ag（III）配合物进行的系统研究。Ag（II）和Ag（III）的八乙基卟啉和四芳基卟啉在其MCD光谱的Q带区域显示出通常的符号序列（即随着能量增加，强度从负到正），这表明ΔHOMO>ΔLUMO关系（ΔHOMO是米氏 和 轨道之间的能量差，ΔLUMO是米氏 和 - 对分子轨道之间的能量差）。相比之下，β，β'-吡咯修饰的卟啉（具有有效的二氢卟酚型π体系）的Ag（II）配合物和Ag（III）咕啉在其Q带区域的MCD光谱中具有符号反转特征（ΔHOMO <ΔLUMO关系）。N-混杂卟啉的Ag（III）配合物在中性状态下显示出ΔHOMO>ΔLUMO关系，在质子化形式下显示出ΔHOMO <ΔLUMO关系。
