Reactions of cyclobutenedione and cyclopentenetrione with zero-valent nickel triad complexes of isocyanide. X-Ray crystal structures of (3–4-η-3,4-diphenylcyclobut-3-ene-1,2-dione)- and (4–5-η-4,5-diphenylcyclopent-4-ene-1,2,3-trione)-tris(t-butyl isocyanide)nickel

Abstract

Hg[{Pt₃(2,6-Me₂C₆H₃NC)₆}₂] reacts with 3,4-diphenylcyclobut-3-ene-1,2-dione, (1), to give the 4,5-diphenylplatinacyclopent-4-ene-2,3-dione complex, (3a). Reactions of (1) and 4,5-diphenyl-cyclopent-4-ene-1,2,3-trione, (2), with [Pd₃(RNC)₆] or [Ni(RNC)₄] give the olefinic complexes [Pd(2,6-Me₂C₆H₃NC)₂{(Ph[graphic omitted]O}](4a), [Pd(RNC)₂Ph[graphic omitted]O}][R = 2,6-Me₂C₆H₃(6a) or Bu^t(6c)], [Ni(RNC)₃{Ph[graphic omitted]O}][R = 2,6-Me₂C₆H₃(5a) or Bu^t(5c)], and [Ni(RNC)₃{Ph[graphic omitted]O}][R = 2,6-Me₂C₆H₃(7a) or Bu^t(7c)]. The structures of (5c) and (7c) have been established by single-crystal X-ray analysis: both crystals are monoclinic, space group P2₁/c, with Z= 4 in a unit cell of dimensions a= 13.027(7), b= 18.255(9), c= 17.727(9)Å and β= 128.67(8)° for (5c) and a= 19.679(13), b= 16.499(11), c= 11.694(8)Å, and β= 106.14(7)° for (7c).