当前位置: X-MOL 学术J. Phys. Chem. A › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Diboron Porphyrins: The Raman Signature of the In-Plane Tetragonal Elongation of the Macrocycle
The Journal of Physical Chemistry A ( IF 2.7 ) Pub Date : 2018-05-10 00:00:00 , DOI: 10.1021/acs.jpca.8b01925
Nina I. Novikova 1, 2, 3 , Alvie S. V. Lo 2, 3, 4 , Keith C. Gordon 2, 3, 4 , Penelope J. Brothers 1, 2 , M. Cather Simpson 1, 2, 3, 5
Affiliation  

We describe an unusual in-plane type of porphyrin core distortion, tetragonal elongation (TE), observed experimentally in diboron porphyrins. The vibrational spectra of several of these complexes exhibit shifts that we have assigned to this TE distortion by comparing experimental spectra with DFT computational findings. The influence of TE in porphyrin systems was isolated using DFT analysis of the well-known model compounds Ni(II)porphine and Zn(II)porphine, with the macrocycle ring constrained to eliminate the influence of out-of-plane (OOP) distortions. A significant down-shift in frequencies was observed for porphyrin normal vibrational modes, particularly the in-plane A1g/B1g modes that are dominated by contributions from stretching and bending of Cα–Cm coordinates. In contrast, TE had little effect on the v(Pyrhalfring) and δ(Pyrdef) modes, though the lowered symmetry of the system resulted in significant splitting of the B2u and B3u modes. The impact of the TE distortion upon the diboron porphyrin vibrational spectrum was probed experimentally using Raman spectroscopy of B2O2(BCl3)2(TTP), B2OF2(TTP), and B2OPhOH2(TTP) (TTP = 5,10,15,20-(tetra-p-tolyl)porphyrin). Comparing the experimentally obtained spectral signatures to the computational findings allowed us to assign the large shifts observed for the v2 and v3 modes to the TE distortion in diboron porphyrins.

中文翻译:

Diboron卟啉:大环的平面四边形伸长的拉曼特征

我们描述了一种异常的平面类型的卟啉核心畸变,四方伸长率(TE),在二硼化卟啉中进行了实验观察。通过将实验光谱与DFT计算结果进行比较,这些配合物中的几种的振动光谱显示出我们指定为这种TE变形的位移。使用DFT分析著名模型化合物Ni(II)porphine和Zn(II)porphine来分离TE在卟啉体系中的影响,并通过大环环的约束消除了面外(OOP)畸变的影响。观察到卟啉简正振动模式,特别是在面内阿在频率甲显著降档1克/ B 1克由捐款从拉伸和C的弯曲为主模式α -Cm座标。相比之下,TE对v(Pyr halfring)和δ(Pyr def)模几乎没有影响,尽管系统的对称性降低导致B 2u和B 3u模明显分裂。使用B 2 O 2(BCl 32(TTP),B 2 OF 2(TTP)和B 2 OPhOH 2(TTP)(TTP)的拉曼光谱法,实验研究了TE畸变对二硼卟啉振动谱的影响。= 5,10,15,20-(tetra- p-甲苯基)卟啉)。将实验获得的光谱特征与计算结果进行比较,使我们能够将针对v 2和v 3模式观察到的大位移分配给二硼卟啉中的TE畸变。
更新日期:2018-05-10
down
wechat
bug