Journal article
Luminescent metal-metal-bonded exciplexes involving tetrakis(.mu.-diphosphito)diplatinate(II) and thallium(I)
Journal of the American Chemical Society, Vol.116(25), pp.11379-11386
12/01/1994
DOI: 10.1021/ja00104a018
Abstract
Spectroscopic and kinetic evidence is presented and used to identify and characterize three luminescent, metal—metal-bonded exciplexes. Two long-lived, strongly phosphorescent triplet exciplexes involving the lowest energy triplet excited state of Pt2(P2O5H2)44-(*Pt2,νmax= 1.95 /µm-1, Φlum= 0.5, τ = 10 µs) and Tl1in aqueous solution at room temperature (*Pt2,νmax= 1.79 /Φm-1, Φlum= 0.5, τ = 10 µs; *Pt2Tl2,νmax= 1.70 µm-1, Φlum= 0.5, τ = 10 µs) and one weakly fluorescent singlet exciplex (νmax= 2.32 µm-1, Φlum< 1 x 10-3) are formed as a result of direct Pt—Tl bonding. An inner-sphere mechanism for the formation of the two triplet exciplexes is proposed in which a diffusional approach of the ionic reactants results in relativistically influenced Pt—Tl bonding and is accompanied by substantial desolvation effects. Free energies (-30 and -20 kJ/mol), enthalpies (-19 and -10 kJ/mol), and entropies (36 and 31 J/(mol K)) for the formation of *Pt2T1 and *Pt2T12, respectively, are derived through a novel procedure and, along with the corresponding kinetic values, are consistent with the proposed mechanism. These three exciplexes are the only examples known which form as a result of metal—metal bonding between the reactants.
Details
- Title: Subtitle
- Luminescent metal-metal-bonded exciplexes involving tetrakis(.mu.-diphosphito)diplatinate(II) and thallium(I)
- Creators
- Sarah A ClodfelterTina M DoedeBridget A BrennanJeffrey K NagleDavid P Bender - University of Iowa, Obstetrics and GynecologyWarren A TurnerPaul M LaPunzina
- Resource Type
- Journal article
- Publication Details
- Journal of the American Chemical Society, Vol.116(25), pp.11379-11386
- Publisher
- American Chemical Society
- DOI
- 10.1021/ja00104a018
- ISSN
- 0002-7863
- eISSN
- 1520-5126
- Language
- English
- Date published
- 12/01/1994
- Academic Unit
- Obstetrics and Gynecology
- Record Identifier
- 9983557119702771
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