Isocyanides crystallography

Chromium(I) complexes, 702 alkyl isocyanides, 704-709 aryl isocyanides, 704-709 2,2 -bipyridyl, 709 electrochemistry, 713 electronic spectra, 712 ESR spectra, 712 IR spectra, 712 magnetic properties, 710 synthesis, 709 cyanides, 703 fluorophosphine, 716 isocyanides crystallography, 708 electrochemistry, 709 spectroscopy, 708 synthesis, 707 1,10-phenanthroline, 709 electrochemistry, 713 electronic spectra, 712 ESR spectra, 712 IR spectra, 712 magnetic properties, 710 synthesis, 709 tertiary phosphines dinitrogen, 713 tris(bipyridyl)... 

One ought to observe that only this single example using tcrf-butyl isocyanide, [Ni(CNBu )2]jt, is known, as yet. It would obviously be desirable to prepare further examples of complexes of this type, and to attempt to establish a structure, presumably by X-ray crystallography. 

The Si=As bond reacts with organic isocyanides in the same way that the Si=P bond does. Thus, with mesityl isocyanide and 1,6-diisocyano-hexane 44a forms the unusual arsaalkene derivatives 53 and 54, according to Scheme 14. Their molecular structures were determined by X-ray crystallography.39,40... 

The isocyanide and carbene complexes are all colorless or white, air-stable, crystalline solids. The molecular structures of the cis isomers have been established by X-ray crystallography.2 The isocyanide complexes have a strong 1R absorption [(N-C) stretching] in the range 2150-2280 cm"1 for example, cis-PtCl2(PhNC)(PEt3) has at 2190 cm"1 (Nujol mull). The carbene com-... 

The metal(O) isocyanide clusters Ni4(CNBu )7 (45)5 (60), Pt3(CNBu )6 (46) (23) and Pt7(CNXylyl),2 (47) (20) have been characterized crystallographi-cally. In the nickel complex the nickel atoms define the vertices of a highly compressed C3v tetrahedron, with each nickel having a terminal isocyanide and three basal nickel atoms joined by three four-electron donor isocyanide ligands. The unusual feature of the structure of Pt7(CNXylyl),2 is that one... 

These methylene-bridged complexes III are extremely robust, air-stable substances. We have sought without success to effect insertions into the Pd-C bonds. The complexes are unreactive toward carbon monoxide (at 5 atm at 30°C) or sulfur dioxide. Reaction with methyl isocyanide or pyridine results in displacement of the terminal halide ions and produces cations that have been isolated as hexa-fluorophosphate salts [Pd2(dpm)2( -CH2)(CNCH3)2][PF6]2( (CN) = 2217 cm-1) and [Pd2(dpm)2(/Lt-CH2)(py)2][PF6]2. Treatment of III with fluoroboric or trifluoroacetic acid slowly results in the protonation of the methylene group which is converted into a terminal methyl group. The resulting brown complex, which has been isolated as its tetra-fluoroborate salt has been shown by H-l and P-31 NMR spectroscopy and X-ray crystallography to have Structure IV. 

The reaction between 133 and THF or adamantyl cyanide afforded the base adducts 139 and 140, respectively. Complex 140 was characterised by X-ray crystallography and in the solid state one chloride was found to be trans to the methandiide centre, mutually cis to the other chloride which was in turn trans to the coordinated nitrile. The base adduct 141 resulted from the addition of 2,6-dimethylphenyl isocyanide to 132. Neither 139 or 141 were characterised in the solid state so it is not known which geometric isomers were formed. 

Ultra high vacuum studies of nickel and platinum with simple organic molecules like olefins and arenes are described. These surface chemistry studies were done as a function of surface crystallography and surface composition. The discussion is limited to the chemistry of methyl isocyanide, acetonitrile, benzene and toluene, pyridine, trimethylphosphine, ethylene, acetylene and saturated hydrocarbons. Molecular orbital calculations are presented that support the experimental identification of the importance of C-H-M metal bonding for metal surfaces. 

Addition of TiCl4 to a solution of trimethylsiloxyphenylisocyanide in //-hexane yields the air sensitive octahedral diisocyanide complex TiCl4(CNR)2 (Scheme 114). This complex crystallizes with one molecule of //-hexane. Its molecular structure has been determined by X-ray crystallography.227 The formations of isocyanide titanium complexes are studied as species related with the Passerini reaction assisted by TiCl4. Three classes of compounds were identified and exemplified by isolated complexes (Scheme 115).228... 

Isocyanide insertion into an Si—Si bond has been demonstrated by Weidenbruch and coworkers. Thus, the disilacyclobutene (111) reacted with arylisocyanides to form the iminodisilacyclopentanes (112) (Equation (21)). The structure of the 7V-phenyl derivative was confirmed by x-ray crystallography <93J0M(461)35>. A similar insertion into an Ir—N or Ir—O bond also has been reported <88JA3704> (see Section 3.20.9.4). 

Complexes 25 also cycloadd the C=S double bonds in heteroallenes CS2, COS, " and aryl isothiocyanates. The reaction of 25a with CS2 (Scheme 6) gave an 80% yield of the expected bicyclo[2.2.2] complex 30, the structure of which has been established by X-ray crystallography. When the reaction was performed in the presence of water or HBF4, the amido nitrogen bridge in the initial bicyclo[2.2.1] adduct was protonated, which inhibited the insertion of isocyanide, and 31 was isolated in 80% yield. 

With aryl isothiocyanates, 4-XCgH4NCS, (X = H, Me, OMe or NO2), complex 25a reacted in the familiar way by cycloaddition of the C=S bond and isocyanide insertion to form the bicyclo[2.2.2] adducts 32. The structure of 32, X = H, has been determined by X-ray crystallography. In the presence of a second equivalent of isocyanide, the bicyclo[3.2.2] products 33, resulting from a second isocyanide insertion, could be isolated. This reaction is cleanly thermally... 

G. Simonneaux et al. (57) published the synthesis and complexation to ruthenium(II) and iron(in) m 5(9-tetraphenylporphyrins of two new fluorinated alkyl isocyanides, 2-monofluoroethyl isocyanide and 2,2,2-trifluoroethyl isocyanide. A new synthesis of trifluoromethyl isocyanide, pentafluoroethyl isocyanide and heptafluoropropyl isocyanide from R-N=Cp2 (R = CF3, C2F5, C3F7) using triphenyl phosphine has been reported (58). Geometries and HOMO and LUMO energies of fluorinated vinyl isocyanides have been calculated (59). Pentacarbonyl chromium complexes of both isomers of the first fluorinated diisocyanide, l,2-diisocyano-l,2,3,3,4,4-hexafluoro cyclobutane have been isolated from a [2+2] cycloaddition reaction of pentacarbonyl(trifluorovinyl isocyanide) chromium. The structure of the cis isomer has been elucidated by X-ray crystallography (60),... 

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