Journal article
Metal-Metal Interactions of Aqueous Lead(ii) and Tin(ii) Ions with the Ground-States and Excited-States of Tetrakis(mu-Diphosphito)diplatinate(ii)
Inorganica Chimica Acta, Vol.225(1-2), pp.201-205
10/01/1994
DOI: 10.1016/0020-1693(94)04048-6
Abstract
The interactions of the metal-metal bonded compound tetrakis(μ-diphosphito)diplatinate(II), Pt2(P205H2)44−, in its ground state (Pt2; λabs=368 nm) and lowest energy triplet excited state (*Pt2; λlum=514 nm) with the metal ions Pb2+ and Sn2+ in aqueous solution are investigated by electronic absorption and photoluminescence spectroscopies. New bands in the visible region of the absorption spectrum are assigned to charge transfer transitions from Pt2 to Pb2+ and Sn2+. These transitions are proposed to result from ground state metal-metal interactions of Pb2+ and Sn2+ with Pt at the axial sites of Pt2, interactions which also appear to be responsible for the observed static quenching of *Pt2 by these ions. In the case of Pb2+ in aqueous acid solutions ionic strength-dependent diffusional quenching of *Pt2 occurs (k≈ 109−1010 l mol−1 s−1), and no evidence for ground state interactions was found. The quenching process is proposed to be due to an excited state electron transfer reaction from *Pt2 to Pb2+ yielding Pt2+ and Pb+. These results are consistent with recent estimates of the reduction potentials of the Pt2+/*Pt2 and Pb2+/Pb+ redox couples and enable an estimate of Eo>−1.6 V versus NHE for the aqueous Sn2+/Sn+ couple to be made. The sharply contrasting behavior between the isoelectronic Pb2+ and Tl+ ions towards Pt2 and *Pt2 is discussed in the context of these results.
Details
- Title: Subtitle
- Metal-Metal Interactions of Aqueous Lead(ii) and Tin(ii) Ions with the Ground-States and Excited-States of Tetrakis(mu-Diphosphito)diplatinate(ii)
- Creators
- David P. Bender - University of IowaJeffrey K. Nagle
- Resource Type
- Journal article
- Publication Details
- Inorganica Chimica Acta, Vol.225(1-2), pp.201-205
- DOI
- 10.1016/0020-1693(94)04048-6
- ISSN
- 0020-1693
- Language
- English
- Date published
- 10/01/1994
- Academic Unit
- Obstetrics and Gynecology
- Record Identifier
- 9983557494702771
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