Crystal structures of two novel iron isocyanides from the reaction of 2,6-di-methyl-phenyl isocyanide, CNXyl, with bis-(anthracene)ferrate(-1).

The reaction of the [K(18-crown-6)(thf)(2)](1+) (thf is tetra-hydro-furan) salt of bis-(anthracene)ferrate(-1), or [Fe(C(14)H(10))(2)](-), with 2,6-di-methyl-phenyl isocyan-ide (CNX-yl) in thf resulted in the formation of two new iron isocyanide complexes, namely, [(1,2,3,4-η)-anthracene]tris-(2,6-di-methyl-phenyl isocyanide)iron, [Fe(C(14)H(10))(C(9)H(9)N)(3)] or [Fe(1,2,3,4-η-C(14)H(10))(CNX-yl)(3)], and {5,6-bis-(2,6-di-methyl-anilino)-3-(2,6-di-methyl-phen-yl)-1,2,7-tris-[(2,6-di-methyl-phen-yl)imino]-3-azoniahept-3-ene-1,4,7-triido}tris-(2,6-di-methyl-phenyl isocyanide)iron tetra-hydro-furan disolvate, [Fe(C(54)H(56)N(6))(C(9)H(9)N)(3)]·2C(4)H(8)O or [Fe(C(54)H(56)N(6))(CNX-yl)(3)]·2C(4)H(8)O, which were characterized by single-crystal X-ray diffraction. The former is likely an inter-mediate along the path to the known homoleptic [Fe(CNX-yl)(5)], while the latter contains a tridentate ligand that is formed from the 'coupling' of six CNXyl ligands. A third crystal structure from this reaction, (7-methyl-indol-1-ido-κN)(1,4,7,10,13,16-hexa-oxa-cyclo-octa-decane-κ(6) O)potassium, [K(C(9)H(8)N)(C(12)H(24)O(6))] or [K(C(9)H(8)N)(18-crown-6)], contains a 7-methyl-indol-1-ide anion, in which one CNXyl ligand has shed a proton during its reductive cyclization.