1349903-53-2Relevant academic research and scientific papers
Synthesis and Characterization of (smif)2Mn (n = 0, M = V, Cr, Mn, Fe,Co, Ni, Ru; N = +1, M = Cr, Mn, Co, Rh, Ir; Smif =1,3-di-(2-pyridyl)-2-azaallyl)
Frazier, Brenda A.,Bartholomew, Erika R.,Wolczanski, Peter T.,DeBeer, Serena,Santiago-Berrios, Mitk'el,Abruna, Hector D.,Lobkovsky, Emil B.,Bart, Suzanne C.,Mossin, Susanne,Meyer, Karsten,Cundari, Thomas R.
, p. 12414 - 12436 (2011)
A series of Werner complexes featuring the tridentate ligand smif, that is, 1,3-di-(2-pyridyl)-2-azaallyl, have been prepared. Syntheses of (smif) 2M (1-M; M = Cr, Fe) were accomplished via treatment of M(NSiMe 3)2(THF)n (M = Cr, n = 2; Fe, n = 1) with 2 equiv of (smif)H (1,3-di-(2-pyridyl)-2- azapropene); ortho -methylated ( oMesmif)2Fe (2-Fe) and (oMe2smif)2Fe (3-Fe) were similarly prepared. Metatheses of MX2 variants with 2 equiv of Li(smif) or Na(smif) generated 1-M (M = Cr, Mn, Fe, Co, Ni, Zn, Ru). Metathesis of VCl3(THF)3 with 2 Li(smif) with a reducing equiv of Na/Hg present afforded 1-V, while 2 Na(smif) and IrCl3(THF) 3 in the presence of NaBPh4 gave [(smif) 2Ir]BPh4 (1+-Ir). Electrochemical experiments led to the oxidation of 1-M (M = Cr, Mn, Co) by AgOTf to produce [(smif)2M]OTf (1+-M), and treatment of Rh2(O2CCF3)4 with 4 equiv Na(smif) and 2 AgOTf gave 1+-Rh. Characterizations by NMR, EPR, and UV-vis spectroscopies, SQUID magnetometry, X-ray crystallography, and DFT calculations are presented. Intraligand (IL) transitions derived from promotion of electrons from the unique CNCnb (nonbonding) orbitals of the smif backbone to ligand π*-type orbitals are intense (σ ≈ 10 000-60 000 M -1cm-1), dominate the UV-visible spectra, and give crystals a metallic-looking appearance. High energy k-edge spectroscopy was used to show that the smif in 1-Cr is redox noninnocent, and its electron configuration is best described as (smif(-))(smif(2-))Cr(III); an unusual S = 1 EPR spectrum (X-band) was obtained for 1-Cr.
