Acetylide complexes, applications

As can be readily ascertained from the tables in this section, researchers have mostly employed the EFISH or HRS techniques to measure second-order nonlinearities of organometallics. Although the initial interest in this field was in metal carbonyl-based complexes, the majority of the measurements are now of ferrocenyl-based complexes or metal acetylides. One reason for this may be pragmatic despite the vast panoply of possible complex types that exists, ferrocenyl or acetylide complexes can be synthesized in high yield by well-established methodologies, both revealed large molecular nonlinearities in initial studies, and both are (comparatively) oxidatively and thermally stable, the latter an important consideration for (putative) longer-term device applications. 

In the polycoupling reactions, the formation of the diyne units proceeded via a Glaser-Hay oxidative coupling route [35-38]. Despite its wide applications in the preparation of small molecules and linear polymers containing diyne moieties, its mechanism remains unclear [38-40]. It has been proposed that a dimeric copper acetylide complex is involved, whose collapse leads to the formation of the diyne product (Scheme 9). 

Much like the emission properties of the Re(l)—Cu(I) or Re(I)—Ag(I) multinuclear bimetallic systems described above, the luminescence of the hexanuclear bimetallic acetylide complexes containing Pt(II) of the form [Pt2Cu4(C6F5)4(C=Ct-Bu)4(acetone)2] (45) have attracted considerable interest for their potential applications in nonlinear optics and... 

Although the aforementioned methods are generally applicable for the incorporation of group 10 metals into metal-acetylide polymers, these approaches could not be extended to metals from groups 8 and 9 due to the instability of the starting complexes in amine solvents. Research efforts into the molecular chemistry of hydrido-acetylide complexes of rhodium have resulted in a facile route to group 9 polymers 169 and This method involves... 

Alkynyl(phenyl)iodonium salts have found synthetic application for the preparation of various substituted alkynes by the reaction with appropriate nucleophiles, such as enolate anions [980,981], selenide and telluride anions [982-984], dialkylphosphonate anions [985], benzotriazolate anion [986], imidazolate anion [987], N-functionalized amide anions [988-990] and transition metal complexes [991-993]. Scheme 3.291 shows several representative reactions the preparation of Ai-alkynyl carbamates 733 by alkynylation of carbamates 732 using alkynyliodonium triflates 731 [989], synthesis of ynamides 735 by the alkyny-lation/desilylation of tosylanilides 734 using trimethylsilylethynyl(phenyl)iodonium triflate [990] and the preparation of Ir(III) a-acetylide complex 737 by the alkynylation of Vaska s complex 736 [991]. 

The use of chiral tricarbonyl (Ti -arene) chromium complexes in the highly stereoselective synthesis is well demonstrated. Baldoli et al. have amply demonstrated the application of this strategy in the synthesis of titled compounds. Known chiral ortfto-substituted benzaldehyde tricarbonyl chromium complexes were exposed to lithium acetylide in THE to furnish diastereoselective adducts in good yields (Scheme 21.9). 

A full report has been published on the preparation and synthetic applications of the acetylenic dianions (35) of note here is their use in the preparation of allene-l,3-dicarboxylic acids (36). Kolbe co-electrolysis of 5-alkynoic adds, RC=C(CH2)3C02H, with half-esters of diadds Me02C(CH2) C02H followed by saponification gives the coupled product (37) in 45—50% yield. Alternative conditions have been reported for the preparation of oi-acetylenic acids from o>-iodoacids (esp. from fatty acids) using the lithium acetylide-ethylenediamine complex in HMPA. ... 

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