Platinum complexes luminescence properties

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

Alkynyl complexes contain metal-carbon bonds in which the metal is bound to the sp-hybridized carbon at the terminus of a metal-carbon triple bond. The materials properties of these complexes have been investigated extensively. The properties of these complexes include luminescence, optical nonlinearity, electrical conductivity, and liquid crystallinity. These properties derive largely from the extensive overlap of the metal orbitals with the ir-orbitals on the alkynyl ligand. The M-C bonds in alkynyl complexes appear to be considerably stronger than those in methyl, phenyl, or vinyl complexes. Alkynyl complexes are sometimes prepared from acetylide anions generated from terminal alkynes and lithium bases (e.g., method A in Equation 3.42), but the acidity of alkynyl C-H bonds, particularly after coordination of the alkyne to the transition metal, makes it possible to form alkynyl complexes from alkynes and relatively weak bases (e.g., method B in Equation 3.42). Alkynyl copper complexes are easily prepared and often used to make alkynylnickel, -palladium, or -platinum complexes by transmetallation (Equation 3.43). This reaction is a step in the preparation of Ni, Pd, or Pt alkynyl complexes from an alkyne, base, and a catalytic amoimt of Cul (Equation 3.44). This protocol for... 

In general, the reaction of perfluoroarylplatinum(II) complexes with d metals yields preferentially discrete compounds in which the platinum(II) center binds a metal on only one side of its coordination plane. However, recent work has demonstrated that thallium(I) tends to display a different behavior in that it forms extended structures [27, 46, 58, 59]. The growing interest in these compounds comes from the fact that many of them exhibit interesting luminescent properties. 

The idea of metal-metal bond establishment in the excited state of this complex has also stimulated the interest on the photophysical and photochemical investigations of related d -d complexes. In 1970, Dori and co-workers first reported the luminescence properties of phosphine complexes of d metal centers such as copper(I), silver(I), gold(I), nickel(0), palladium(0), and platinum(0) [12]. Later in 1985, Caspar reported the luminescence properties of polynuclear nickel(O), palladium(O), and platinum(O) complexes of phosphine, phosphite, and arsine [13]. Similar to the related d -d systems, the emissive states of [Pd2(dppm)3] and [Pd Cdpam),] have been suggested to be metal-centered (d-p) in nature modified by metal-metal interaction. 

Hissler M, Connick WB, Geiger DK et al (2000) Platinum diiminebis (acetylide) complexes synthesis, characterization, and luminescence properties. Inorg Chem 39 447 57... 

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... 

Apart from the platinum(ii) diimine system, analogous platinum(ii) systems with planar tridentate ligands are also hot topics in current chemical research. Their useful physical and biological properties, such as interaction with DNA and proteins, were first reported by Lippard and coworkers [150, 151]. Subsequent reports by Che and coworkers described the luminescence properties of a series of platinum(ii) complexes with terpyridine ligands, [Pt(trpy)X] (X = Cl, Br, I, N3,... 

Figure 36 Platinum(ll) complexes with luminescence properties described and discussed in ref. 201.

Figure 37 New examples of platinum(ll) complexes characterized by luminescence properties.

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. 

Sun W-YR, Chow AL-F, Li X-H, Yan JJ, Chui SS-Y, Che C-M. Luminescent cyclometalated platinum(II) complexes containing N-heterocyclic carbene ligands with potent in vitro and in vivo anti-cancer properties accumulate in cytoplasmic structures of cancer cells. Chem Set. 2011 2 728-736. 

Emission due to excited state energy transfer has been reported in layered low dimensional rare earth complexes such as uranyl phosphates [50],cryptates [51] and platinum tetracyanides [52, 53]. The luminescence properties of the low dimensional rare earth compounds of the type RE[M(CN)2]3 where RE = Eu, Dy, Gd " and M = Au, Ag are also interesting in this regard. We recently reported [16] that efficient excited state energy transfer from the Au(CN)2 and Ag(CN)j ions to Eu " enhances the luminescence observed from the rare earth ion. A similar result is obtained from other rare earth salts [17]. In some cases vibronic structure appears in the luminescence spectrum. 

Santoro, A., Whitwood, A.C., Williams, J.A.G., Kozhevnikov, V.N., Bruce, D.W. Synthesis, mesomorphism, and luminescent properties of calamitic 2-phenylpyridines and their complexes with platinum(ll). Chem. Mater. 21(16), 3871-3882 (2009)... 

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