Ruthenium(II) and iron(II) complexes of N-pyridyl substituted imidazolin-2-ylidenes

Remarkable Stability of Copper(II)–N-Heterocyclic Carbene Complexes Void of an Anionic Tether

“…18,19 We have recently been working with imidazolium salts and NHC ligands with an appended pyridyl group, to examine the effect of further donors on copper−ligand stability. 20 Pyridyland picolyl-substituted NHC ligands have been described in the literature previously and coordinated to palladium (II), 21−23 nickel (II), 24,25 ruthenium (II), 26 iron(II), 27 and copper(I). 28−30 In addition, pyridyl-and picolyl-tethered NHC ligands have been coordinated to copper (II), though these ligands also contain an anionic pyrazolate substituent on the second nitrogen of the NHC (i.e., a stabilizing anionic ancillary donor).…”

[Ru(bpy)3]2+ Analogues Containing an N-Heterocyclic Carbene Ligand

“…1). 5 More recently, Hahn and coworkers succeeded in the preparation of bis(cyclometalated) systems of type V. 6 The scarce appearance of NHC analogues of ruthenium polypyridine complexes is remarkable when considering that the strong donor properties of NHCs 7 favorably affect the redox potential of coordinated metal centers, 8 thus inducing useful properties for the fabrication of functional materials. 9 Specifically, the stronger donor ability is expected to facilitate charge separation as required in solar cell active sites.…”

“…9 Specifically, the stronger donor ability is expected to facilitate charge separation as required in solar cell active sites. [Ru(bpy) 3 ] 2+ and [Ru(terpy) 2 ] 2+ comprising N-heterocyclic carbene ligands (X = PF 6 , R = Mes).…”

Nickel(II) and Iron(II) Complexes with Tetradentate NHC/Amide Hybrid Ligands

“…The remaining amide group of each ligand stays dangling. Fe-C NHC distances are found between 1.929 and 1.917Å and are thus slightly shorter than in IV (1.916 -1.986Å [27]), but in the range observed for six-coordinate ferrous NHC complexes (1.91/1.96Å [36,37]). The Fe-N amide distances in 5 are 2.040 and 2.032Å.…”