THE NUCLEAR MAGNETIC RESONANCE SPECTRA OF THE LEWIS BASES, $(CH_{3})_{2}NPF_{2}$ AND $|(CH_{3}]_{2}N]_{2}PF$, AND THEIR ADDUCTS WITH BORON CONTAINING LEWIS $ACIDS^{*}$

Abstract

Both $(CH_{3})_{2}NPF_{2}$ and $[(CH_{3})_{2}N]_{2}PF$ are excellent Lewis bases whose coordination chemistry is of particular interest because of the possibility of bonding through either the phosphorus or nitrogen atom. Infrared spectroscopic results support the conclusion that $(CH_{3})_{2}NPF_{2} BH_{3}$ and $[(CH_{3})_{2}N]_{2}PF_{2}BH_{3}$ contain phosphorus-boron bonds while $(CH_{3})_{2}NPF_{2}BF_{2}$ contains a nitrogen boron $bond.^{1}$ Nuclear magnetic resonance studies for all magnetic nuclei (with the excepting of ${^{14}}N$) have been carried out both for the free ligands and for the addition compounds. The complementary use of such resonance data in determining bonding site will be discussed. The nuclear magnetic resonance data conclusively establish phosphorus-boron bonding in the borane adducts and strengthen evidence of nitrogen-bonding in the $BF_{3}$ adduct.