Title: Mössbauer Study of Tin(II) Sensitizer Deposits on Kapton
Abstract: Mössbauer spectroscopy has been used to study tin(II) sensitizer deposits formed on Kapton films (du Pont polyimide) for use in the recently reported photoselective metal deposition (PSMD) process. Combined with previous results, this work shows that the sensitizer is present as a colloid in the sensitizing bath and is adsorbed on the substrate when it is dipped. This activation mechanism would be expected to apply to other insulating substrates as well. The photosensitive substance contains more tetravalent tin than divalent. The divalent tin is oxidized by exposure either to air or to the Pd activation bath. The photosensitive compound is not any well recognized tin oxychloride or hydroxide.