Use of Ag(II) as a removable template in porphyrin chemistry:: diol cleavage products of [meso-tetraphenyl-2,3-cis-diolchlorinato]silver(II)

The use of Ag-II as a removable template in synthetic porphyrin chemistry is described. Mild procedures for the insertion of Ag-II into chlorins and the demetallation of the [chlorinato]Ag-II complexes are delineated. The UV-vis spectra of the novel [chlorinato]Ag-II complexes are discussed. The diol cleavage products of [meso-tetraphenyl-2,3-diolchlorinato]silver(H) under a number of conditions are characterized and compared to those resulting from the cleavage of the corresponding free base diol chlorin or its N-II, complex, highlighting the unique. templating effect of Ag-II. The scopes and limits of electrospray ionization mass spectrometry (ESI-MS) for the analysis of Ag-II chlorins is described. The use of Ag-II as a templating metal is superior over Ni-II or Zn-II for the preparation of free base pyrrole-modified porphyrins along metal templated pathways. (C) 2003 Elsevier Ltd. All rights reserved.