Metal-assisted assembly of pyridine-containing arylene ethynylene strands to enantiopure double helicates.
Metal-assisted assembly of pyridine-containing arylene ethynylene strands to enantiopure double helicates.
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DOI：
10.1021/ja048327d
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发表时间：
2004-07
影响因子：
15
通讯作者：
A. Orita;Takehiro Nakano;Delie An;Kazumi Tanikawa;K. Wakamatsu;J. Otera*
中科院分区：
文献类型：
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作者：
A. Orita;Takehiro Nakano;Delie An;Kazumi Tanikawa;K. Wakamatsu;J. Otera*
含吡啶的亚芳基乙炔链连接至(R)-和(S)-1,1'-联萘模板的2-和2'-位置。亚芳基乙炔基部分与 Ag(I) 或 Cu(I) 离子进行分子内配位，形成对映体纯双螺旋。基于圆二色（CD）光谱阐明了双螺旋结构。通过与带有单链的配体进行比较，证实了双链分子内络合对于螺旋形成的重要性。通过醚键连接的链能够分选由双螺旋亚芳基亚乙炔基部分引起的棉花效应。 CD激子手性方法明确证明了链的末端在络合时彼此接近，并且诱导的螺旋性的意义与分子模型预测的相同。
Pyridine-containing arylene ethynylene strands were connected to the 2- and 2'-positions of (R)- and (S)-1,1'-binaphthyl templates. The arylene ethynylene moieties underwent intramolecular coordination with Ag(I) or Cu(I) ion to afford enantiopure double helicates. The double-helical structure was elucidated on the basis of circular dichroic (CD) spectra. The importance of intramolecular complexation of the double strands for the helicate formation was confirmed by comparison with a ligand bearing a single strand. Connection of the strands through an ether linkage enabled a sorting out of the Cotton effect induced by double-helical arylene ethynylene moieties. The CD exciton chirality method unambiguously proved that the termini of the strands approach each other upon complexation and that the sense of the induced helicity is the same as predicted by molecular modeling.