Nickel bis-m-terphenylisocyanide dihalide complexes formed from 1, 2-alkyl dihalides: probing for isolable β-haloalkyl complexes of square planar nickel. Issue 11 (2nd July 2016)

• Record Type: Journal Article
• Authors: McNeece, Andrew J.; Mokhtarzadeh, Charles C.; Moore, Curtis E.; Rheingold, Arnold L.; Figueroa, Joshua S.
• Is Part Of: Journal of coordination chemistry. Volume 69:Issue 11/13(2016)
• Page Start: 2059
• Page End: 2068
• Publication Date: 2016-07-02
• Subjects: β-Elimination -- nickel -- polymerization -- vinyl chloride; Coordination compounds -- Periodicals; 541.2242
• DOI: 10.1080/00958972.2016.1172702
• Languages: English
• ISSNs: 0095-8972

Abstract

Abstract: The pentachloroethyl complex NiCl(CCl2 CCl3 )(CNAr Mes2 )2 (Ar Mes2 = 2, 6-(2, 4, 6-Me3 C6 H2 )2 C6 H3 ) was recently shown to be a unique example of an isolable β-chloroalkyl complex of square planar nickel. In an effort to generate additional β-haloalkyl complexes of square planar nickel, the reactivity of the precursor complex Ni(COD)(CNAr Mes2 )2 with alkyl halides has been probed. Treatment of Ni(COD)(CNAr Mes2 )2 with 1, 2-dichloroethane results in the exclusive formation of the dichloride complex NiCl2 (CNAr Mes2 )2 without the buildup of detectable intermediates. Similarly, Ni(COD)(CNAr Mes2 )2 reacts with either 1, 2-dibromoethane or 1, 2-diiodoethane to produce the dibromide, NiBr2 (CNAr Mes2 )2, and diiodide, NiI2 (CNAr Mes2 )2, species, respectively. Observable intermediates were also not detected in these latter reactions, indicating that either β-halo elimination is rapid or 1e − halogen-atom abstraction pathways are accessible to Ni(COD)(CNAr Mes2 )2 . The sterically and electronically modified m -terphenyl isocyanides CNAr Dipp2 and CNAr Clips2 (Ar Dipp2 = 2, 6-(2, 6-( i -Pr)2 C6 H3 )2 C6 H3 ; Ar Clips2 = 2, 6-(2, 6-(Cl)2 C6 H3 )2 -4-( t -Bu)C6 H2 ) were also investigated as ancillary ligands for stabilization of a β-chloroalkyl complex of square planar nickel. Treatment of the zero-valent precursors Ni(COD)(CNAr Dipp2 )2 and Ni(COD)(CNAr Clips2 )2 with either 1, 2-dichloroethane or hexachloroethane resulted in rapid formation of the dichlorides NiCl2 (CNAr Dipp2 )2 and NiCl2 (CNAr Clips2 )2 as exclusive products. These results highlight the unique combination of steric and electronic properties that lead to the stability of the parent β-chloroalkyl complex NiCl(CCl2 CCl3 )(CNAr Mes2 )2 . Abstract :