Octahedral Fe(II) and Ru(II) Complexes Based on a New Bis 1,10-Phenanthroline Ligand That Imposes a Well Defined Axis

• Published in: Journal of the American Chemical Society 2001-12, Vol.123 (49), p.12215-12221
• Main Authors: Pomeranc, Didier, Heitz, Valérie, Chambron, Jean-Claude, Sauvage, Jean-Pierre
• Format: Article
• Language: English
• Subjects: 2,2'-Dipyridyl - analogs & derivatives; Chelating Agents - chemistry; Crystallography, X-Ray; Electrochemistry; Ferrous Compounds - chemical synthesis; Ferrous Compounds - chemistry; Ligands; Luminescent Measurements; Molecular Structure; Organometallic Compounds - chemical synthesis; Organometallic Compounds - chemistry; Phenanthrolines - chemistry; Photochemistry; Ruthenium - chemistry; Spectrum Analysis
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja011250y

A bis-chelating ligand (L1), made of two 7-(p-anisyl)-1,10-phenanthroline (phen) subunits connected with a p-(CH2)2C6H4(CH2)2 spacer through their 4 positions, has been prepared, using Skraup syntheses and reaction of the anion of 4-methyl-7-anisyl-1,10-phenanthroline with α,α‘-dibromo-p-xylene. Its Fe(II) complex, [FeL1(dmbp)](PF6)2, was prepared in one step by reaction of L1 with [Fe(dmbp)3](PF6)2 (dmbp = 4,4‘-dimethyl-2,2‘-bipyridine). On the other hand, its Ru(II) complex, [RuL1(dmbp)](PF6)2, was prepared in two steps from Ru(CH3CN)4Cl2 and L1, followed by reaction with dmbp. X-ray crystal structure analyses show that in the two octahedral complexes, ligand L1 coils around the metal by coordination of the axial and two equatorial positions. It defines a 21 Å long axis (O···O distance) running through the central metal and the terminal anisyl substituents. The complexes were also characterized by 1H NMR, mass spectrometry, cyclic voltammetry, electronic absorption, and, in the case of Ru(II), fluorescence spectroscopy.