Synthetic And Spectroscopic Investigations Of The 1,3 – Dipyridylazaallyl “Smif” Anion With 2Nd And 3Rd Row Transition Metals And A Series Of Diarylimine Iron Bisphosphine Complexes That Selectively Extract Dinitrogen From Air

Aryl-based chelates containing oxazoline or imine donors were synthesized, and their reactivity with 1st -row transition metals were investigated in an attempt to generate metal complexes containing strong field ligands. Successful arylation of nickel was accomplished with a bis-methylated benzyl-oxazoline aryl anion. The reactivity of the dipyridyl imine ligand, 1,3-di-(2-pyridyl)-2-azapropene (smifH), was investigated with Ru, Rh, Ir, Mo and Pd. The d6 bis-smif metal complexes were successfully generated with Ru, Rh and Ir, while carbon-carbon bond formation was observed with Mo and Pd. Treatment of cis-(Me3P)4FeMe2 with ortho-substituted diarylimines afforded two equivalents of CH4, PMe3, and generated tris-PMe3 Fe(II) complexes. Exposure to O2 caused rapid degradation, but substitution of the unique PMe3 with N2 occurred upon exposure to air or N2, yielding iron-dinitrogen compounds; CO, CNMe and N2CPh2 derivatives were also prepared. Dihydrogen or ammonia binding was found comparable to N2, while PMe3 and pyridine adducts were unfavorable. Protolytic conditions were modeled using primary acetylenes as weak acids, and trans-{[kappa]-C,N-(3,4,5-(F)3-C6H2)CH2N=CH(3,4,6-(F)3-C6H-2-yl)}Fe(PMe3)3(CCR) (R = Me, Ph) were generated from tris-PMe3 complexes. Reactions of tris-PMe3 Fe(II) with N2O or tosyl azide generated iron-dinitrogen complexes and Me3PO or Me3P=N(SO2)tol, respectively. Calculations revealed Fe-N2 to be thermodynamically and kinetically favored over the calculated Fe(III) superoxide complex