Platinum photophysical properties

The nature of the platform also impacts on the electrochemical and photophysical properties of the interfacial supramolecular assembly (ISA). For example, the density of states within gold, platinum and carbon electrodes are different, so causing subtle changes in the rate of electron transfer across the electrode/ISA interface. In addition, in terms of the photophysical properties, the nature of the platform can radically change the excited-state properties of a molecule upon adsorption. For example, if a adsorbate is located close to (<10 nm) a metal surface and is then pumped into an electronically excited state, efficient energy or electron transfer is expected which will lead to quenching of the excited state. This process can dramatically increase the photostability of compounds that would ordinarily photodecompose in solution. 

Metallo-1,2-enedithiolates did not again come to the attention of those developing new analytical methods until the late 1990s. It was the chemical and photophysical properties of luminescent heterocyclic-substituted platinum-... 

Of particular importance is the study of photophysical properties and the coupling of emission behavior to chemical reactivity. In addition, the further study of the heterocyclic-substituted platinum-1,2-enedithiolates as room temperature dual emitters is warranted. The dual emitters not only allow conventional detection methods but new ratiometric, double-modulation and polarization-based methods to be incorporated into detection strategies (34, 91, 92). At least two of these methods were development solely for the heterocyclic substituted 1,2-enedithiolates. While these detection methods evolved to monitor molecular oxygen, it is likely, given their unique... 

Raithby and co-workers further compared the photophysical properties of several platinum(II) polyynes P25, P27, and P29 with their organic copolyynes.59 Since the nonradiative decay rate for the triplet emission, (Lm)p, is equal or larger than the corresponding radiative decay rate, (Ljjp, the PL quantum efficiencies of the platinum polyynes are reduced from those for the organic polymers. Optical data reveal that the anchoring of octyl side chains on the fluorenyl spacer reduces interchain interaction in the polyynes, while a fluorenonyl spacer affords a donor-acceptor motif along the rodlike backbone. 

The photophysical properties of metal-alkyne materials are rich due to strong metal-ligand orbital overlap and unsaturated n system (16). Photoactive materials can be readily constructed from copper(l) (198-200), rhenium(l) (101, 186, 201-203) platinum(ll) alkynyls (13, 203-219), as well as various gold(l) derivatives (210, 220-226). 

The strong environment dependence of the photophysical properties of platinum complexes allows their application as sensors. A phosphorescent Pt-Pt complex, shown in Fig. 12, can undergo a photoinduced Pt-Pt distance shortening. This leads to the formation of two distinct excited states and dual emission in the steady state. This photoinduced molecular structure change has a strong dependence on the molecule s... 

Another chapter examines recent work in the area of metal-organic complexes derived from palladium(II) and platinum(II) diimine-dithiolate complexes. Pilato (Qiap. S), who is a leader in the development of new luminescent complexes of this family, has pioneered their application to sensing oiganophosphates and oxygen. His chapter describes the synthesis of these complexes, provides a comprehensive overview of their photophysical properties, and gives some examples of their application to the development of solid-state sensors. 

Letuscitesomeothercharacteristicexamples.Thus,basedon5-(6-methylpyridin-2-yl)-3-trifluoromethyl-l,2,4-triazole ligand platinum(II) complexes 202 were synthesized with spatially encumbered chelates, and their photophysical properties were also studied [182]. Compound 202 was found to be weakly emissive in both... 

A series of luminescent platinum(II) complexes have been prepared with a biphenyl dianion (bph) as ligand (Fig. 3.7)S These complexes have the formulae Pt(bph)(Et2S)2, Pt(bph)(MeCN)2, Pt(bph)en, and Pt(bph)(py)2, and although they do not strictly have a nitrogen-based heterocyclic ligand, they are included here because their photophysical properties are in many ways analogous. The biphenyl dianion was chosen as ligand for these complexes because it contains an empty... 

Owing to the advances in the synthesis of organoplatinum(ii) alkynyl compounds as well as the intriguing physical and photophysical properties exhibited by these materials, the evaluation of their structure-property relationship is therefore attractive and feasible. The spectroscopic properties of mononuclear nickel(ii), palladium(ii) and platinum(ii) alkynyl complexes of the type trans-[M(C=CR)2L2] (R = alkyl, aryl L = phosphine, stibine) have been widely investigated [111-114]. The electronic absorption spectra of this class of complexes have been reported by Masai et al. [115], while the emission properties of a series of closely related platinum(ii) complexes were reported by Demas and coworkers [116]. The lowest... 

Besides the platinum and palladium diphosphine systems, platinum polypyridine complexes have also attracted attention in recent years [130-162). Their changes in spectroscopic and luminescence properties brought about by Pt Pt and n-n interactions are of particular interest [138-142). For instance, the square planar platinum(ii) diimine complex [Pt(bpy)Cl2) exhibits polymorphic behavior and rich photophysical properties [142-144). These, together with the recent growing development of platinum alkynyl systems [98, 122, 125, 145-147), mainly due to the... 

SCN, n = 1 X = NH3, n = 2) [152]. McMillin and coworkers recently reported the photophysical properties of a series of platinum] n) terpyridyl complexes with different counter ions [153]. These classes of platinum]n) complexes have also been found to exhibit rich polymorphic properties and have been studied by Gray and coworkers [154]. 

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