Gold complexes isocyanides

Multinuclear (isocyanide)gold complexes, reactivity, 2, 287 Multi-phase organometallic catalysis, in ionic liquids, 1, 856 Multiple-quantum MAS, half-integer spin quadrupolar nuclei central transition NMR studies, 1, 466 Multistate magnetization transfer, in dynamic NMR magnetization, 1, 410 Multistep catalytic cycles... 

Figure 8.5 Thermal properties of gold complexes with isocyanides having a phenyl or a biphenyl core.

Lateral monofluorination of the p-alkoxyphenyl isocyanide system [XAu (CNC6H40C H2 +i)] (X = C1, Br, I), in ortho-(3-F) (6a) and meta-(2-F) (6b) positions relative to the alkoxy chain was also studied [18]. None of the free fluorinated ligands is a LC, but their gold complexes display mesomorphic properties. This is a typical case of a promesogenic ligand which yields a mesogen upon coordination to a metal. 

In the solid state, the complexes exhibit a yellow-green luminescence under UV irradiation (365 nm). All the emission spectra are similar and consist of three broad emissions above 370 nm (e.g., 384, 490 and 524 nm for m = 10, w = 6), while the free isocyanides (white solids) are luminescent giving one strong emission band with its maximum at about 360 nm. In dicMoromethane solution both the free isocyanides and their gold complexes are luminescent too, but only one intense emission is observed for the complexes in the range of 345-387nm (Figure 8.14). The lifetime... 

As indicated above in chiral mesophases, the introduction of a functional group in mesogenic stmctures offers the opportunity to achieve functional LCs. With this aim, mesomorphic crown-ether-isocyanide-gold(I) complexes (26) have been prepared recently [38]. The derivatives with one alkoxy chain show monotropic SmC mesophases at or close to room temperature. In contrast, the complexes with three alkoxy chains behave as monotropic (n = 4) or enantiotropic (n > 4) LCs. The structure of the mesophases could not be fully eluddated because X-ray diffraction studies in the mesophase were unsuccessful and mesophase characterization was made only on the basis of polarized optical microscopy. These complexes are luminescent not only in the solid state and in solution, but also in the mesophase and in the isotropic liquid state at moderate temperatures. The emission spectra of 26a with n=12 were... 

Coco, S., Cordovdla, C., Donnio, B., Espinet, P., Garda-Casas, M.J. and Gudlon, D. (2008) Self-Organization of Dendritic Supermolecules, Based on Isocyanide-Gold(I), -Copper(l), -Palladium(II), and -Platinum(ll) Complexes, into Micellar Cubic Mesophases. Chemistry - A European Journal, 14, 3544-3552. 

Bayon, R., Coco, S. and Espinet, P. (2002) Twist-Grain Boundary Phase and Blue Phases in Isocyanide Gold(I) Complexes. Chemistry of Materials, 14, 3515-3518. 

Owing to the good ligand properties of isocyanides for complexation of gold(i), complexes of the type [(RNC)2Au]+X are readily available through a variety of synthetic routes. One new approach is the substitution of organic nitriles. The reaction is carried out in acetonitrile and gives quantitative yields (Equation (43)).2... 

Early work focused on compounds with open-chain carbenes generally synthesized in the coordination sphere of the gold atom, for example, by addition of amines or alcohols to isocyanide ligands in the corresponding gold complexes. Subsequent synthetic approaches have relied on the in situ deprotonation of onium salt precursors by a... 

Carbenes are speties with a divalent carbon atom with various substituents and a lone pair of electrons. Classic carbene gold complexes were synthesized in the coordination sphere of the gold atom, addition of amines or alcohols to the coordinated isocyanide ligands. N-Heterocyclic carbenes (Arduengo s carbenes)... 

Espinet also investigated liquid crystalline gold complexes (Scheme 76) of crown ether isocyanides 139 [142],... 

Bis(adamantylimido) compounds, with monomeric chromium(VI) complexes, 5, 348 Bis(alkene) complexes conjugated, Rh complexes, 7, 214 mononuclear Ru and Os compounds, 6, 401 -02 in Ru and Os half-sandwich rj6-arenes, 6, 538 with tungsten carbonyls and isocyanides, 5, 685 Bis(u-alkenylcyclopentadienyl) complexes, with Ti(II), 4, 254 Bis(alkoxide) nitrogen-donor complexes, with Zr(IV), 4, 805 Bis(alkoxide) titanium alkynes, in cross-coupling, 4, 276 Bis(alkoxo) complexes, with bis-Cp Ti(IV), 4, 588 Bis[alkoxy(alkylamino)carbene]gold complexes, preparation, 2, 288... 

Polymeric alkynylmercury derivatives, preparation, 2, 427 Polymeric ferrocene mediators, in biosensing, 12, 594 Polymeric (isocyanide)gold(I) aryl complexes, characteristics, 2, 283... 

Solubility sol dichloromethane, 1,2-dichloroethane, and diethylene glycol dimethyl ether insol diethyl ether and pentane. Preparative Methods the complex is prepared in situ by the reaction of bis(cyclohexyl isocyanide)gold(I) tetrafluoroborate with (R)-N-[2-(N,N-Dimethylamino)ethyl]-N-methyl-l-[(S)-I, 2-bis (diphenylphosphino)ferrocenylJethylamine, typically in dichloromethane. ... 

The gold(I) complex is prepared in situ by the reaction of (1) with bis(cyclohexyl isocyanide)gold(I) tetrafluoroborate (2), typically in anhydrous dichloromethane. The dihydrooxazolines obtained provide a ready access to enantiomerically pure p-hydroxy-a-amino acid derivatives. High diastereo- and enantios-electivity are generally maintained with a wide variety of substituted aldehydes, and a-isocyanoacetate esters. N,N-Dimethyl-a-isocyanoacetamides and a-keto esters have been substituted for the a-isocyanoacetate ester and aldehyde component, respectively, sometimes with improved stereoselectivity. The effect of both the central and planar chirality of (1) on the diastereo- and enantioselectivity of the gold(I)-catalyzed aldol reaction has been studied. The modification of the terminal di-alkylamino group of (1) can lead to improvements in the stereos-... 

The ferrocenylphosphine-silver complex catalyzes the aldol-type reaction of tosylmethyl isocyanide 71 with aldehydes with higher stereoselectivity than the gold complex (Scheme 2-59) [84]. The reaction with several aldehydes produces trans-4-tosyloxazolines 72 in up to 86% ee, which can be converted into optically active l-alkyl-2-aminoethanols by reduction with LiAlH4. 

Gold(I) complexes prepared in situ from bis(cyclohexyl isocyanide)gold(I) tetrafluoroborate (1) [3] and chiral ferrocenylphosphine ligands (i )-(S)-2a-e [4,... 

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