Covalent nano-clip and nano-box compounds based on free base porphyrins

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• 作者：Emilio Scamporrino^a ; Placido Mineo^a ; ^b ; ^{gmineo@unict.it"" rel=""nofollow} ; Daniele Vitalini^c
• 关键词：Cyclic porphyrin-oligomers ; Nano-structure ; MALDI-TOF mass spectrometry ; UV– ; vis spectroscopy ; NMR spectroscopy
• 刊名：Tetrahedron
• 出版年：2011
• 出版时间：20 May 2011
• 年：2011
• 卷：67
• 期：20
• 页码：3705-3713
• 全文大小：760 K

文摘

Novel nano-clip and nano-box compounds were obtained by reaction between dibromomethane and 5,15-di[p-(9-methoxytriethylenenoxy)phenyl]-10,20-di[p-hydroxyphenyl]porphyrin. The molecular architecture varies from a co-facial (nano-clip) to a four wall-box (nano-box) structure. The products were characterized by ¹H NMR and UV–vis spectroscopy and MALDI-TOF mass spectrometric analysis.

The UV–vis spectra of the nano-clip showed a modification of the characteristic porphyrin soret and Q bands, with respect to the monomer and cyclic tetramer, as a probable consequence of a hybrid orbital deformation (HOD) phenomenon involving the two porphyrin π rings forced to a closer co-facial spatial arrangement. The spatial distance between the two co-facial porphyrin units, and therefore the molecular cavity size, can be modified inducing an electrostatic repulsion by means of a reversible protonation of the pyrrolic cores. The ¹H NMR spectra of the nano-box showed a strong high-field shift of some aromatic and ether protons present in the upper and lower rim of the molecular box.