4964
Organometallics 2007, 26, 4964-4971
Syntheses and Reactions of Iron(II) Complexes Containing Diphosphine Ligands with Pendant Nitrogen Bases George M. Jacobsen,† R. K. Shoemaker,† M. Rakowski DuBois,‡ and Daniel L. DuBois*,‡ Department of Chemistry and Biochemistry, UniVersity of Colorado, Boulder, Colorado 80309, and Chemical and Materials Sciences DiVision, Pacific Northwest National Laboratory, 902 Battelle BouleVard, P.O. Box 999, Richland, Washington 99352 ReceiVed May 22, 2007
A series of new iron(II)-hydride complexes that contain diphosphine ligands with pendant amine bases of the formula cis-[HFeL(PNP)2]+, where PNP ) Et2PCH2NMeCH2PEt2 and L ) CH3CN (3), CO (4), P(OEt)3 (5), have been synthesized and characterized. Protonations of the pendant bases in the PNP complexes have been characterized, and for selected complexes, pKa values have been determined. The acidity of the PNHP ligand depends significantly on the electronic properties of the Fe center to which it is bound, ranging from
