Competitive Formation of Helical Cycloocta- and Cyclododecapyrroles
作者:Jennifer A. Wytko、Martin Michels、Lars Zander、Johann Lex、Hans Schmickler、Emanuel Vogel
DOI:10.1021/jo0011890
日期:2000.12.1
largest cyclopolypyrroles known to date. These two newmacrocycles have been structurally characterized by variable temperature 1D and 2D NMRexperiments, as well as by single-crystal X-ray diffraction analysis. In solution both the cyclooctapyrrole 6 and cyclododecapyrrole 7 exhibit dynamic behavior. At 337 K 6 adopts a D(2)-symmetric conformation, whereas at 196 K two equivalent C(2) conformers that
of a 5,5-disubstituted-dipyrromethanes (6a, 6b) with a 1,9-diformyl-pyrromethane (7) under MacDonald conditions in the presence of zinc(II) acetate affords zinc(II) salts (8a, 8b) possessing the isoporphyrin chromophore, which is stable with respect to transformation into porphyrin; some spectroscopic properties of (8a) and (8b) are described.
recently synthesized metal complex hexadecaethylspirodicorrolato-dinickel(II) (5) (the corrole units in 5 are isoforms) is investigated. To have a suitable reference compound at our disposal, tetraethylhexamethylisocorrolato nickel(II) (7) has been prepared. On comparing the electronic spectra of this reference compound and the spiro-complex, bathochromic shifts of all absorption bands in the NIR/Vis-region