利用低频拉曼光谱识别Ni(II)-中四苯基卟啉的非平面形变  

Use of Low Frequency Raman Bands to Identify Non-planar Deformation of Ni(II)Meso-tetraphenylporphyrin Induced by Axial Ligands

作　　者：王申浩 Muhammad Muhammad 黄青[1,2] Shen-hao Wang;Muhammad Muhammad;Qing Huang(CAS Key Laboratory of High Magnetic Field and Ion Beam Physical Biology,Hefei Institutes of Physical Science,Institute of Intelligent Machines,Chinese Academy of Sciences,Hefei 230031,China;Science Island Branch of Graduate School,University of Science and Technology of China,Hefei 230026,China)

机构地区：[1]中国科学院合肥物质科学研究院,中国科学院强磁场与离子束物理生物学重点实验室,合肥230031 [2]中国科学技术大学研究生院科学岛分院,合肥230026

出　　处：《Chinese Journal of Chemical Physics》2023年第1期57-65,I0002,共10页化学物理学报（英文）

基　　金：This work was supported by the National Natural Science Foundation of China(No.11674096 and No.11635013).

摘　　要：金属卟啉蛋白中卟啉环的非平面形变具有重要的功能相关性.本文采用密度泛函理论、简正坐标结构分解法和拉曼光谱研究了Ni(II)-中四苯基卟啉在不同配位数下的非平面形变与低频拉曼光谱之间的关系.结果表明,四配位的四苯基卟啉晶体存在两种主要的非平面形变:折皱形和鞍形.通过密度泛函理论计算,四苯基卟啉的折皱形和鞍形形变大小分别为1.473Å和0.493Å.利用低频拉曼特征峰(γ12,γ13)和(γ16,γ17)可分别识别出折皱形和鞍形形变.当四配位的四苯基卟啉转化为六配位的双(吡咯烷)时,卟啉环的非平面形变几乎消失,通过采用密度泛函理论计算估计鞍形的非平面变形仅为0.213A左右.实验.上可以利用低频拉曼光谱的特征峰来识别超过0.25 A的鞍形形变.It is important to identify non-planar deformations of porphyrin macrocycle in metallo-porphyrin proteins due to their functional relevance.The relationship between non-planar deformations of porphyrin macrocycle and low frequency Raman spectral bands of Ni(II)meso-tetraphenyl porphyrin(NiTPP),with different coordination numbers,was studied by density functional theory(DFT),normal coordinate structural decomposition method and Raman experiments.The results show that the crystal of four-coordinate NiTPP has two major kinds of non-planar deformations:ruffling and saddling.The non-planar deformations of ruffling and saddling for NiTPP are 1.473Åand 0.493Ådetermined by DFT calculation.The ruffling and saddling deformations can be identified by using the low frequency Raman characteristic peaks(γ12,γ13)and(γ16,γ17),respectively.When four-coordinate NiTPP is transformed to the six-coordinate bis(pyrrolidine)NiTPP(NiTPP(Pyr)2),the large non-planar distortion of the porphyrin macrocycle almost disappears,with the non-planar deformation of saddling only about 0.213Åestimated by DFT calculation.Experimentally,we can make use of the characteristic peaks of low frequency Raman spectra to identify the saddling deformation beyond 0.25Å.

关 键 词：卟啉 非平面形变 拉曼光谱 简正坐标结构分解 密度泛函理论 配体 

分 类 号：O641.4[理学—物理化学]