title: Peripheral stepwise degradation of a porphyrin J-aggregate.
abstract: For metalation of the acidic form of tetrakis(4-sulfonatophenyl)porphyrin (dianionic H(4)TPPS(4)) by Cu(II), the order of reagent mixing determines the rate and mechanism of CuTPPS(4) formation. When copper salts are added last, the kinetic profile is fit as a (pseudo)-first-order process. However, J-aggregates of the H(4)TPPS(4) porphyrin are rapidly formed at pH ~ 3 when Cu(II) salts are incorporated in solution prior to porphyrin addition. The subsequent porphyrin units metalation leads to the disassembling of these arrays via a pseudo-zero-order kinetic profile, suggesting an attack of the metal ion at the rims of the nanostructure.
authors.affiliation: Dipartimento di Chimica Inorganica, Chimica Analitica e Chimica Fisica, Università di Messina, and CIRCMSB, viale Stagno d'Alcontres 31, 98166 Messina, Italy.
authors.forename: Ilaria
authors.initials: I
authors.lastname: Occhiuto
authors.forename: Giovanna
authors.initials: G
authors.lastname: De Luca
authors.forename: Mariachiara
authors.initials: M
authors.lastname: Trapani
authors.forename: Luigi Monsù
authors.initials: LM
authors.lastname: Scolaro
authors.forename: Robert F
authors.initials: RF
authors.lastname: Pasternack
mesh_terms: D002413:Cations, Divalent / Q000737:chemistry; D003300:Copper / Q000737:chemistry*; D008665:Metalloporphyrins / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry; D012492:Salts / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet
chemical_list: D002413:Cations, Divalent; D008665:Metalloporphyrins; D012492:Salts; C441604:meso-tetra(4-sulphonatophenyl)porphyrinato copper(II); D003300:Copper