Wydział Chemii

Miłosz Pawlicki

Lechosław Latos-Grażyński

2003

Chemistry-A European Journal

9

4650-4660

10.1002/chem.200304899

Naukowa

Angielski

Artykuł

Condensation of 2,4-bis(phe-nylhydroxymethyl)furan with pyrroleandp-toluylaldehyde formed, insteadof the expected 5,20-diphenyl-10,15-di(p-tolyl)-2-oxa-21-carbaporphyrin, apyrrole addition product [(H,pyr)-OCPH]H2; this product can formallybe considered as an effect of hydro-genation of 3-(2'-pyrrolyl)-5,20-diphen-yl-10,15-di(p-tolyl)-2-oxa-21-carbapor-phyrin ([(pyr)OCPH]H). The new oxa-carbaporphyrinoidpresentsthe1HNMRspectroscopy features of an aromaticmolecule, including the upfield shift ofthe inner H21 atom. Insertion of NiCl2or PdCl2into [(H,pyr)OCPH]H2gavetwo structurally related organometalliccomplexes, [(pyr)OCP]NiII] and [(pyr)-OCP]PdII], in which the metal ions arebound by three pyrrolic nitrogens andthe trigonally hybridized C21 atom ofthe inverted furan. The reaction of[(H,pyr)OCPH]H2with silver(i) acetate yields a stable AgIIIcomplex [(C2H5O,-pyr)OCP]AgIII] substituted at the C3position by the ethoxy and pyrrolemoieties. The macrocyclic frame of[(H,pyr)OCPH]H2is conserved. Addi-tion of trifluoroacetic acid to [(C2H5O,-pyr)OCP]AgIII] yielded a new aromaticcomplex [(pyr)OCP]AgIII]‡. The struc-tures of [(pyr)OCP]NiII] and [(C2H5O,-pyr)OCP]AgIII] have been determinedby X-ray crystallography. In both mole-cules the macrocycles are only slightlydistorted from planarity and the nickel-(ii) and silver(iii) are located in theNNNC plane. The dihedral angle be-tween the macrocyclic and appended-pyrrole planes of [(pyr)OCP]NiII] re-flects the biphenyl-like arrangement with the N Hgroup pointing out towardthe adjacent phenyl ring on the C5position. Tetrahedral geometry aroundthe C3 atom was detected for [(C2H5O,-pyr)OCP]AgIII]. The NiC and AgCbond lengths are similar to other nick-el(ii) or silver(iii) carbaporphyrinoidswhere the trigonal carbon atom coordi-nates the metal ion. The trend detectedin the13C chemical shifts for the ap-pended-pyrrole resonances has beenrationalized by the extent of effectiveconjugation between the macrocycleand the appended pyrrole moiety con-trolled by the hybridization of the C3atom and the metal ion oxidation state.The dianionic or trianionic macrocycliccore of the pyrrole-appended deriva-tives is favored to match the oxidationstate of nickel(ii), palladium(ii), or sil-ver(iii), respectively

macrocyclic ligands, nickel, palladium, porphyrinoids, silver

https://doi.org/10.1002/chem.200304899

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