Platinum ethynyl

In the case of the platinum ethynyl compound om.l, for which = 360 nm, a broad 2PA band was observed around 630 nm, with 3max 3.0xl0 GM [162,163]. In dendritic-type compounds containing multiple metal centers but still with phenylene ethynylene ligands, larger 2 PA cross sections were reported. For example, om.3 displays 3max 3.5 x 10 GM for the peak at 740 nm, but no 2PA activity was detected into the lowest one-... 

Oxidative homocoupling Glaser-Hay polymerization of compound 1 [5] - ,poly[trans-bis (Z)-4-ethynyl-6-(triisopropylsilyl)-3-[(triisopropyl-silyl)ethynyl]-hex-3-ene-l,5-diynyl bis(triethylphosphane)platinum(ll)] (2)... 

A hyperbranched polycarbosilane (hb-P22) was prepared by platinum-catalyzed polyhydrosilylation of methyldiethynylsilane 22 (Scheme 11) [43]. The tacky, highly soluble and stable polymer underwent thermo- and photo-induced cross-linking reactions through the peripheral ethynyl groups. 

Finally, a rare example of tellurophene chemistry has to be mentioned, namely the preparation and spectroscopic studies of a platinum complex containing two ethynyl(tellurophen-2-yl)units <07IC7232>. 

A variety of metal acetylide-containing stars and dendrimers have been synthesized.329-332 Dendrimer 280 was prepared via reaction of a chloro-substituted platinum complex 278 with ethynyl functionalized dendron 279 in the presence of Cul (Scheme 2.73).329 This method generated dendrimers with up to 45 platinum units. 

Yamamoto et al. reported a PtBr2-catalyzed cyclization of l-ethynyl-2-(l-alkoxy-but-3-enyl)-benzenes 117, which furnished functionalized indenes 118 in good to allowable yields (Scheme 46) [124]. Notably, the allyl group substituted at benzylic position was indispensable for the success of this cyclization, without which the reaction did not work at all. This observation suggests that the coordination of olefin to platinum at a right position/geometry might be essential for the indene formation. 

A number of metal acetylide-containing dendrimers and stars have also been prepared." Scheme 25 shows the synthesis of a first-generation platinum acetylide dendrimer (87) containing 9 platimun complexes in its structure. Dendrimer 87 was made by the reaction of a chloro-substituted platinum complex (85) with an ethynyl functionalized dendron (86) in the presence of Cul." Dendrimers with up to 45 platinum emits were synthesized using this methodology. 

Cross and Gemmill have not only shown that transfer of methyl-and phenylethynyl groups between the platinum(II) and mercury(II) in Scheme 4 and between two platinum(II) centers in a somewhat similar system involves an Sg(oxidative) process they have also demonstrated that the oxidative-addition and reductive-elimination processes must be cis. During these reactions it is the resident ethynyl group which moves, the mercury, for example, adding perpendicularly to the plane of the starting complex the only plausible intermediate is (8) (Scheme 4, L = PMePH2). 

Reaction of 118a with two equivalents of HC CFc in diisopropyl amine in presence of catalyic amounts of [Cul], or treatment of 118c with LiC CFc in a 1 2 molar ratio produced the nonametallic square-planar structured platinum(ll) complex [(FcC=C)Ph2P]2Pt(C=CFc)2 (119) in excellent yield [84], In 119 a total of four ferrocene ethynyl groups are present. 

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