Nickel nitrosyl complexes in a sulfur-rich environment: The first poly(mercaptoimidazolyl)borate derivatives

Abstract

The diamagnetic nickel mononitrosyl complexes (Tm R)Ni(NO) (R = Bu t , p-Tol) and (Bm R)Ni(PPh 3)(NO) (R = Me, Bu t ) have been readily prepared from Ni(PPh 3) 2(NO)Br and the appropriate Na(Tm R) or Na(Bm R) reagents, respectively. These species constitute the first nickel nitrosyl complexes supported by these ligand systems. An X-ray diffraction study of (Tm p-Tol )Ni(NO) confirmed its pseudo-tetrahedral geometry and the presence of a nearly linear nitrosyl ligand. In contrast, (Bm Me)Ni(PPh 3)(NO) can be best described as having a trigonal pyramidal geometry, a spatial arrangement unprecedented in nickel nitrosyl chemistry, which is facilitated by the disposition of the Bm Me ligand and the presence of a weak intramolecular Ni⋯H–B interaction opposite to the apical triphenylphosphine ligand.