Ruthenium piano-stool complexes bearing imidazole-based PN ligands

A variety of piano-stool complexes of cyclopentadienyl ruthenium(II) with imidazole-based PN ligands have been synthesized starting from the precursor complexes [CpRu(C10H8)]PF6, [CpRu(NCMe)3]PF6 and [CpRu(PPh3)2Cl]. PN ligands used are imidazol-2-yl, -4-yl and -5-yl phosphines.Depending on the ligand and precursor different types of coordination modes were observed; in the case of polyimidazolyl PN ligands these were κ1P-monodentate, κ2P,N-, κ2N,N- and κ3N,N,N- chelating and μ-κP:κ2N,N-brigding. The solid-state structures of [CpRu(1a)2Cl ]·H2O (5.H2O) and [{CpRu(μ-κ2-N,N-κ’1-P-2b)}2](C6H5PO3H)2(C6H5PO3H2)2, a hydrolysis product of the as well determined [{CpRu(2b)}2](PF6)2.2CH3CN (7b.2CH3CN) were determined (1a = imidazol-2-yldiphenyl phosphine, 2b = bis(1-methylimidazol-2-yl)phenyl phosphine, 3a = tris(imidazol-2-yl)phosphine). Furthermore, the complexes [CpRu(L)2]PF6 (L = imidazol-2-yl or imidazol-4-yl phosphine) have been screened for their catalytic activity in the hydration of 1-octyne.

Graphical abstractPiano-stool complexes of cyclopentadienyl ruthenium(II) with imidazole-based PN ligands have been screened for their catalytic activity in the hydration of 1-octyne. PN ligands used were imidazol-2-yl, -4-yl and -5-yl phosphines. Different types of coordination modes for the polyimidazolyl PN ligands were observed: k1P-monodentate, k2P,N-, k2N,N- and k3N,N,N- chelating and μ-kP:k2N,N-brigding.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Piano-stool complexes of cyclopentadienyl ruthenium (II) with imidazole-based PN ligands have been synthesized and characterized. ► Different types of coordination modes are observed. ► Polyimidazolyl PN ligands show κ1P-monodentate, κ2P,N-, κ2N,N-and κ3N,N,N-chelating and κ-μP:κ2N,N-brigding coordination modes. ► Complexes [CpRu (L)2] PF6 (L = imidazol-2-yl or imidazol-4-yl phosphane) have been screened for their catalytic activity in the hydration of 1-octyne.