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)] (thf is tetra-hydro-furan) salt of bis-(anthracene)ferrate(-1), or [Fe(CH)], 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(CH)(CHN)] or [Fe(1,2,3,4-η-CH)(CNX-yl)], 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(CHN)(CHN)]·2CHO or [Fe(CHN)(CNX-yl)]·2CHO, 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)], 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-κ)(1,4,7,10,13,16-hexa-oxa-cyclo-octa-decane-κ )potassium, [K(CHN)(CHO)] or [K(CHN)(18-crown-6)], contains a 7-methyl-indol-1-ide anion, in which one CNXyl ligand has shed a proton during its reductive cyclization.