87189-92-2Relevant articles and documents
Organometallic nitrosyl chemistry. 20. (η5-C5H5)W(NO)2BF4, a versatile organometallic electrophile
Legzdins, Peter,Martin, David T.
, p. 1785 - 1791 (2008/10/08)
Treatment of a CH2Cl2 solution of (η5-C5H5)W(NO)2Cl with an equimolar amount of AgBF4 results in the rapid formation of a precipitate of AgCl and a bright green solution of (η5-C5H5)W(NO)2BF4. This organometallic complex is a thermally unstable, air- and moisture-sensitive species whose characteristic chemistry in CH2Cl2 is dominated by its electrophilic nature. Hence, it readily forms adducts of the type [(η5-C5H5)W(NO)2L]BF4 with Lewis bases, L, capable of good σ donation such as PPh3 or P(OPh)3. In an analogous manner, the novel complex [(η5-C5H5)W(NO)2(η 2-C8H14)]BF4 results when (η5-C5H5)W(NO)2BF4 is exposed to an excess of cis-cyclooctene. Other olefins, however, either do not react (e.g., allylbenzene) or undergo dimerization (e.g., 1,1-diphenylethene) or isomerization (e.g., 2,3-dimethyl-1-butene), the latter transformations probably occurring via electrophile-induced formation of incipient carbocations. (η5-C5H5)W(NO)2BF4 also reacts with CH2Cl2-soluble anionic nucleophiles, X-, to form (η5-C5H5)W(NO)2X (X = H or Br) products. Of greater interest is the fact that the organometallic nitrosyl reactant is sufficiently electrophilic to cleave the M-C linkages in organic derivatives of the main-group elements (i.e., M = B, Al, or Sn) and so produce some new (η5-C5H5)W(NO)2R (R = Et, CH2Ph, or Ph) complexes. This chemistry has also been extended to encompass some of the pentamethylcyclopentadienyl analogues derivable from (η5-C5Me5)W(NO)2BF4. The physical properties of all new compounds prepared are presented and discussed in relation to possible molecular structures.
