Hydrogen cyanide-acetylene complexes

The acetylene-hydrogen cyanide complex is of particular interest in view of the fact that the C-H stretches of both monomers can be probed using the F-center laser. Earlier microwave studies of this system showed the existence of a T-shaped isomer S shown in Figure 3, in which the acetylene acts as the proton acceptor. During our infrared investigation of this species, a linear isomer was also found in which the acetylene now acts as the acid. By studying the two C-H stretch vibrational modes of these two isomers it is possible to learn a great deal about the anisotropy of the vibrational... 

Copper chloride complexes can be used as catalysts in a number of organic reactions. Examples include the Wacker process, which is the oxidization of ethylene to acetaldehyde by oxygen and aqueous Cu and Pd precatalysts (or, alternatively using iron catalysts) plus the synthesis of acrylonitrile from acetylene and hydrogen cyanide using CuCl. Cuprous chloride has also been used as a desulfiuizmg and... 

Earlier we noted that disubstituted acetylenes react with 1 to give TT-bonded complexes. Acetylene and monosubstituted acetylenes react to give trans-hydrido acetylide complexes (23). The DPPE complexes, 3, 4, and 5, also react with acetylenes to give trans-hydrido acetylide complexes (25,37). Iso-electronic hydrido cyanide complexes are obtained upon reaction with hydrogen cyanide. The reaction of HCN with Fe(DMPE)2H(CioH7) is the first reaction reported here (23) that proceeds by a mechanism different from those already discussed. The reaction, which is over essentially upon mixing, seems to involve electrophilic attack prior to loss of naphthalene. 

Moreover, aryl-oxazoles, -imidazoles [17], or-thiazoles [18], anhydrides [19], and imides [20] are accessible via intramolecular Heck-type carbonylations. In addition to typical acid derivatives, aldehydes [21], ketones [22], aroyl cyanides, aroyl acetylenes, and their derivatives [23] could be synthesized via nucleophilic attack of the acyl metal complex with the corresponding hydrogen or carbon nucleophiles. Even anionic metal complexes like [Co(CO)4] can act as nucleophiles and lead to aroylcobalt complexes as products [24]. 

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