Near-IR absorption of porphyrin methylcarbocations
摘要:
Syntheses of stabilized meso-and beta-carbocations of nickel(II) porphyrins are reported and compared. A novel dimeric porphyrin cation absorbing at 1030 nm is also described. (C) 2003 Elsevier Ltd. All rights reserved.
Tris(octaethylporphyrin)s, in which two octaethylporphyrin (OEP) rings are connected with vinylene groups at α,γ- and α,β-meso positions of the central OEP ring, were synthesized. The tris(OEP)s have similar conformational and configurational structures to the corresponding vinylene group-connected bis(OEP). Examination of both 1H NMR and electronic absorption spectra of the tris(OEP)s showed the behavior reflecting the highly symmetrical structure and the mutual interaction between the three OEP rings through the vinylene linkages.
Supramolecular Chirogenesis in Weakly Interacting Hosts: Role of the Temperature, Structural, and Electronic Factors in Enhancement of Chiroptical Sensitivity
A new supramolecular chirogenic system on the basis of tetrakis(nickel porphyrin) and various enantiopure solvents, which was specifically designed for investigation of the chirogenic phenomenon upon extremely weak interaction modes and marginal chiroptical responses, is reported. The temperature was found to be a key factor controlling the chirality transfer process in these assemblies.