Polynuclear platinum complexes

Qu, Y. Scarsdale, N. J. Tran, M. C. Farrell, N. Cooperative effects in long-range 1,4 DNA-DNA interstrand crosslinks formed by polynuclear platinum complexes an unexpected syn-orientation of adenine bases outside the binding sites. J Biol Inorg Chem 2003, 8, 19-28. 

Mononuclear platinum complexes often have been used as models for catalytic intermediates since systematic studies of synthesis, reactivity, and mechanism are often convenient and because metallic platinum is a very important catalyst. However, using binuclear or polynuclear platinum complexes as models for proposed intermediates in heterogeneous catalysis has not been studied, probably because planned routes to such complexes have not been available. This chapter describes our first studies in this area. 

Figure 9 Selection of polynuclear platinum complexes. Numbers are explained in the text...

Biological Activity of Polynuclear Platinum Complexes. Summary and p53 Status of Human Tumors Treatable by BBR3464... 

Structure-Activity Relationships in Polynuclear Platinum Complexes... 

A logical place, therefore, to begin to examine for the structural origin of differential effects between mononuclear and polynuclear platinum complexes is in the structures of interstrand cross-links. Interstrand cross-linking of poly(dG-dC).poly(dG-dC) by cw-DDP does not cause a B -> Z transition. The inter-... 

Most of the complexes reported in this section contain 1,5-cod, probably because this diene is easily displaced in subsequent reactions with other ligands and metalloligands, thus providing an easy entry to novel mono- and polynuclear platinum complexes. 

Farrell, N. In Polynuclear Charged Platinum Complexes as a New Class of Anticancer Agents Kelland, L. R., Farrell, N., Eds. Humana Press Totowa, NJ,... 

Chiral bis-(binaphthophosphole) (bis(BNP)) ligands have been used in the asymmetric hydroformylation of styrene. In solution, the free diphospholes display fluxional behavior. Consistent with their structure, the reaction of the bis(BNP) compounds with platinum(II) derivatives gives either cis chelate mononuclear complexes or trans phosphorus-bridged polynuclear derivatives. Coordination to platinum enhances the conformational stability of bis(BNP)s and diastereomeric complexes can be detected in solution. In the presence of SnCl2, the platinum complexes give rise to catalysts that exhibit remarkable activity in the hydroformylation of styrene. Under optimum conditions, reaction takes place with high branched selectivity (80-85%) and moderate enantio-selectivity (up to 45% ee). 

The polynuclear platinum compounds stand in vivid contrast to mononuclear platinum complexes because the predominant DNA lesions are long-range inter- and intrastrand cross-links where the sites of platination may be separated by up to four base pairs. The consequent structural and conformational changes in DNA are also distinct. 

Heterometallic metallomesogens, liquid crystals, 12, 223—224 Heterometallic polynuclear platinum carbonyl complexes heterodinuclear clusters, 8, 415 triangular clusters, 8, 417... 

Platinum complexes (continued) with aryls, thallium adducts, 3, 399 with bis(alkynyl), NLO properties, 12, 125 with bisalkynyl copper complexes, 2, 182-186 with bis(3,5-dichloro-2,4,6-trifluorophenyl), 8, 483 and C-F bond activation, 1, 743 in C-H bond alkenylations, 10, 225 in C-H bond electrophilic activation studies, 1, 707 with chromium, 5, 312 with copper, 2, 168 cyclometallated, for OLEDs, 12, 145 in diyne carbometallations, 10, 351-352 in ene-yne metathesis, 11, 273 in enyne skeletal reorganization, 11, 289 heteronuclear Pt isocyanides, 8, 431 inside metallodendrimers, 12, 400 kinetic studies, 1, 531 on metallodendrimer surfaces, 12, 391 mononuclear Pt(II) isocyanides, 8, 428 mononuclear Pt(0) isocyanides, 8, 424 overview, 8, 405-444 d -cP oxidative addition, PHIP, 1, 436 polynuclear Pt isocyanides, 8, 431 polynuclear Pt(0) isocyanides, 8, 425 Pt(I) isocyanides, 8, 425 Pt(IV) isocyanides, 8, 430... 

In contrast with the common structure presented by polynuclear Pt111 complexes in which the Pt-Pt axis is perpendicular to a four-ligand equatorial plane, there are also a few reports of formal Pt111 species for which all bonds involving the platinum center are in a plane [48] [54], These compounds, having a structure essentially different from that of any other polymeric Pt111 species, will not be described in detail in this chapter. 

There has been considerable interest in binuclear and polynuclear metal complexes as models for intermediates proposed to be formed during reactions which are heterogeneously catalysed by transition metals (1). Since platinum is one of the most versatile catalysts, we have begun an investigation into the synthesis, and chemical and catalytic properties of some binuclear organo-platinum complexes. In this article some hydrido and methyl complexes will be described, and a preliminary account of catalysis with binuclear complexes given. In addition, structural studies indicate that Pt-Pt bonding interactions may take several different forms in these complexes and so the nature of the Pt-Pt bond will also be discussed. 

Polynuclear assemblies can also be readily formed due to the ability of the alkyne ligands to form strong o-bonds with metals, as well as then-propensity for 71 coordination (t -fashion) (102) with electrophilic metal centers like Cu(I), Ag(I), and Au(I). Fornies and co-workers (44, 45, 103, 104) prepared interesting examples of di- and polynuclear alkynyl platinum complexes (Scheme 12). The [PtCu4(C=CPh)g] (105-107)... 

In polynuclear platinum(II) complexes of spermidine, which showed to have significant cytotoxic and antiproliferative properties on the HeLa cell... 

Lang, H., and Stein, T. (2001). Bis(alkynyl)-Titaniiun and -Platinum Complexes in the Synthesis of Oligo- and Polynuclear Early-Late and/or Late-Late Transition Metal Species An Overview. Abhath Al-Yarmouk Basic Sci. Eng., 10, 155 Chem. Abstr. (2001), 142,38297. 

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