Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita 565-0871 (Japan).
Catalysis Research Center, Hokkaido University, Sapporo 001-0021 (Japan).
Angew Chem Int Ed Engl. 2015 May 18;54(21):6227-30. doi: 10.1002/anie.201501496. Epub 2015 Mar 30.
meso-Monobenzoporphycene (mMBPc) and meso-dibenzoporphycene (mDBPc), in which one or two benzene moieties are fused at ethylene-bridged positions (meso-positions) of porphycene, were prepared in an effort to further delocalize the π-electrons within the porphycene molecule. mMBPc and mDBPc were fully characterized by mass spectrometry, (1)H and (13)C NMR spectroscopy, and X-ray crystallography. The longest-wavelength Q-bands of mMBPc and mDBPc are red-shifted by 92 nm and 418 nm, respectively, compared to that of the unsubstituted porphycene (Pc). Electrochemical measurements indicate that the HOMO is destabilized and the LUMO is stabilized by the fused benzene moieties at the meso positions. Furthermore, both XPS and theoretical studies support the presence of a cis tautomeric form in the ground state of mDBPc, despite the fact that essentially all known porphycene derivatives adopt the trans tautomeric form.
中-单苯并卟吩（mMBPc）和中-二苯并卟吩（mDBPc），其中一个或两个苯环在卟吩的亚乙烯桥接位置（中位）融合，旨在进一步使卟吩分子内的π电子离域。通过质谱、（1）H 和（13）C NMR 光谱和 X 射线晶体学对 mMBPc 和 mDBPc 进行了充分的表征。与未取代的卟吩（Pc）相比，mMBPc 和 mDBPc 的最长波长 Q 带分别红移 92nm 和 418nm。电化学测量表明，中位融合的苯环使 HOMO 不稳定，LUMO 稳定。此外，XPS 和理论研究都支持 mDBPc 基态中存在顺式互变异构体，尽管实际上所有已知的卟吩衍生物都采用反式互变异构体。
