DEPOSITION OF WATERSOLUBLE PORPHYRINS ON SOLID SUBSTRATES

The deposition of a fourfold positively charged tetrakis(4-methyl pyri dinium) porphyrin (H(2)TMPyP) and its metal derivatives on glass surfa ces from basic aqueous solutions has been studied by optical and ion b eam techniques. Upon exposure to a buffered porphyrin solution, the gl ass surface is initially almost completely coated with a monomolecular porphyrin layer (5 X 10(13) molecules cm(-2)). Subsequently the area of the glass surface available for deposition of porphyrins increases due to leaching by the buffer solution, resulting in an almost linear increase of the amount of adsorbed organic material. Adsorption is lim ited to a monolayer in the presence of trace amounts of zinc ions.