Luminescence properties dinuclear

Mohamed, A.A., Kani, I., Ramirez, A.O. and Fackler, J.P. Jr (2004) Synthesis, characterization, and luminescent properties of dinuclear gold(I) xanthate complexes X-ray structure of [Au2(nBu-xanthate)2j. Inorganic Chemistry, 43, 3833-3839. 

Table 14 Luminescence properties of chloride-bridged dinuclear complexes3... 

This dinuclear complex luminesces at both 77 K and room temperature in solid state and emission seems to be related to the fragment AuI-PPh2C=C rather than to aurophilic interactions, which are commonly responsible for the luminescent properties of dinuclear species. 

The luminescence properties of a series of dinuclear platinum alkenylidene complexes [Pt2(/x-C=CHPh)(C=CPh)... 

Pope, S.J.A., Kenwright, A.M., Heath, S.L., and Faulkner, S. (2003) Synthesis and luminescence properties of a kinetically stable dinuclear ytterbium complex with differentiated binding sites. Chemical Communications, 1550. 

The absorption spectra of the free ligand 10 and its mono- and dinuclear complexes Cu.lO, CuCu.lO, CuAg.lO, CuZn-lO " ", CuZn.lO, are reported in Ref. [64] these spectra are well-matched with the sum of the spectra of the two chromophoric (M.5" -type) component units. The luminescence properties of all [3]catenates at 298 and 77 K in CH2CI2 are reported in Table 10. 

Encapsulation of the Eu3 + and Tb3 + ions by cage-like ligands was also achieved using functionalized calixarenes. Metal luminescence properties were studied mostly for complexes of calix[4]arenes, while few results are available for complexes of calix[6]arenes and calix[8]arenes, with the latter being dinuclear complexes. Figure 13 schematically shows the calixarene ligands of the Eu3+ and Tb3+ complexes examined. Some photophysical data and the number of coordinated solvent molecules of these complexes are gathered in Table 4. 

Zinc.—Changes in the fluorescence and phosphorescence yields of / -diketone chelates of Zna+, Be2+, and Al3+ have been attributed to interligand interactions.137 Other authors have studied the luminescence properties of salicylalaniline chelates of Zn2+, Hg2+, Cd2+, and Be2+,138 and of a dinuclear complex of ZnCl2 with zinc salicylidene-toluidinate.139 The photolysis of Zn(N3)2 in the solid state has been reported.140... 

The luminescence properties of a 3-catenand (20) and related 3-catenates containing a copper(I) center [Cu 20]+ were reported in 1991 [96]. The photophysical data are summarized in Table 5. It is interesting to note that while the mononuclear [Cu 20]+ shows ligand-centered tctc, and MLCT emission, the dinuclear complex [Cu2 20] + only reveals a single MLCT phosphorescence band at 700 nm in CH2CI2. The mixed-metal complex [CuCo 20] + is not lumi-... 

Together with platinum(II) complexes, also complexes of group 11 metals have been intensively studied for their luminescence properties, in particular dinuclear complexes of M(I) (M = Cu, Ag, Au), in which one or two dicarbene ligands coordinate in a bridging fashion the two metal centers. The formula of this type of complexes is exemphfied in Fig. 38. 

The luminescence properties of Au(l) alkynyl complexes were first reported by Che and co-woikers, in which the luminescence behavior of the dinuclear Au(I) alkynyl complex, [Au2(/t-dppe)(C=CPh)2], was described (Figure 5.6). Short intermolecular Au - Au contacts of 3.153(2) A were observed in the X-ray crystal structure. As discussed in the previous sections, Au -Au interactions also play an important role in the photophysical properties of Au(I) complexes. The 550-nm emission of the solid sample of [Au2(/t-dppe)(C=CPh)2] at room temperature was described as originating from a [(d5 ) (po) ] triplet excited state arising from the interactions between the two Au atoms. 

In the mechanism of an interfacial catalysis, the structure and reactivity of the interfacial complex is very important, as well as those of the ligand itself. Recently, a powerful technique to measure the dynamic property of the interfacial complex was developed time resolved total reflection fluorometry. This technique was applied for the detection of the interfacial complex of Eu(lII), which was formed at the evanescent region of the interface when bathophenanthroline sulfate (bps) was added to the Eu(lII) with 2-thenoyl-trifuluoroacetone (Htta) extraction system [11]. The experimental observation of the double component luminescence decay profile showed the presence of dinuclear complex at the interface as illustrated in Scheme 5. The lifetime (31 /as) of the dinuclear complex was much shorter than the lifetime (98 /as) for an aqua-Eu(III) ion which has nine co-ordinating water molecules, because of a charge transfer deactivation. 

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