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首页> 外文期刊>Chemistry: A European journal >Synthesis,Spectroscopy,and Electrochemistry of Tetra-tert-butylated Tetraazaporphyrins,Phthalocyanines,Naphthalocyanines,and Anthracocyanines,together with Molecular Orbital Calculations
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Synthesis,Spectroscopy,and Electrochemistry of Tetra-tert-butylated Tetraazaporphyrins,Phthalocyanines,Naphthalocyanines,and Anthracocyanines,together with Molecular Orbital Calculations

机译：四叔丁基化四唑氏，酞菁，萘酞菁和蒽氰胺的合成，光谱学和电化学与分子轨道计算

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摘要

Tetraazaporphyrins(TAPs),phthalocyanines(Pcs),naphthalocya-nines(Ncs),and anthracocyanines(Acs)with four tert-butyl groups attached at similar positions have been synthesized,and their electronic absorption,magnetic circular dichroism(MCD),IR,and voltammetric properties were studied and interpreted with the help of quantum-mechanical calculations.Through the preparation of a series of compounds with the same number of the same substituent,the effects of the increase in the size of the ring system were clearly derived.The main results may be summarized as follows.1)The Q band shifts to longer wavelength and its intensity increases,but with decreasing degree of change with increasing molecular size.If the size of the effect of benzene directly fused to the TAP skeleton is set at unity,the effects of the second and third benzene units are roughly 0.8 and 0.5,respectively.2)The splitting of the Q bands in metal-free compounds decreases with increasing molecular size,so that the Q bands of H_2Nc and H_2Ac appear as single bands.3)The magnitude of the orbital angular momentum of the excited state of the ligand decreases with increasing molecular size.4)Interestingly,the ring current,as judged from the positions of pyrrole proton signals in the 'H NMR spectrum,appears to decrease with increasing molecular size.5)The first reduction potential becomes less negative,but only slightly,whereas the first oxidation potential shows a marked shift to less positive values with increasing molecular size,indicating that the HOMO destabilizes significantly as the molecule becomes larger.6)In 5),the extent of the HOMO destabilization with molecular size differs depending on the central metal,so metals producing smaller destabilization effects can allow larger macrocycles.Of the metals studied,the most effective is cobalt,and the practical size limit is represented by the Acs.7)The IR spectra become simpler the larger the molecule,and the main bands were assigned by DFT calculations.8)The trend in experimentally determined redox potentials and electronic absorption and MCD spectra were reasonably reproduced by MO calculations using the ZINDO/S Hamiltonian.9)EPR data for several metallocomplexes are also reported.
机译：已经合成了四唑（Taps），酞菁（PCS），萘酞菁（PCS），萘酞菁（NCS）和炭氰胺（ACS），其具有四个叔丁基附着在类似位置，其电子吸收，磁性圆形二色（MCD），IR，在量子 - 机械计算的帮助下研究和解释了伏安性和解释。用相同数量的相同取代基的一系列化合物的制备，清楚地衍生出环系统尺寸的增加的影响。主要结果可以概括如下。统一，第二和第三苯单元的效果大约为0.8和0.5，分别为0.5），无金属化合物中的Q带的分裂随着分子大小的增加而降低，使得Q带H_2NC和H_2AC出现单带。 H NMR光谱似乎随着分子大小的增加而降低.5）第一减少电位变得更少，但仅略微略微，而第一个氧化电位显示出在较小的分子大小的较低阳性值的显着变化，表明HOMO显着稳定随着分子变大.6）在5）中，用分子大小的同性全调的程度根据中央金属而不同，因此产生较小的稳定化效果的金属可以允许较大的宏杂种。所研究的金属，最有效的是钴，并且实际尺寸限制由ACS.7表示）IR光谱变得更简单，分子越大，并且通过DFT计算分配主带.8）TH通过使用Zindo / s Hamiltonian的Mo计算，通过实验确定的氧化还原电位和电子吸收和MCD光谱进行了趋势。

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