Aminodiphenylphosphanes:: Isotope-induced chemical shifts 1Δ14/15N(31P), coupling constants 1J(31P, 15N), and chemical shifts δ15N and δ31P

A series of aminodiphenylphosphanes 1 [Ph2P-N(H)tBu (a), -NEt2 (b), -NiPr2 (c)], 2 [Ph(2)PPi NHPh (a), -NH-2-pyridine (b), -NH-3-pyridine (c), -NH-4-pyridine (d), NH-pyrimidine (e), NH-2,6-Me-2-C6H3 (f), NH-3-Me-2-pyridine (g)], 3 [Ph2P-N(Me)Ph (a), -NPh2 (b)], and N-pyrrolyldiphenylphosphane 4 (Ph2P-NC4H4) was prepared and studied by NMR (H-1, C-13, P-31 N-15 NMR) spectroscopy. The isotope-induced chemical shifts (1)Delta N-14/15(P-31) were determined at natural abundance of N-15 by using HEED INEPT experiments. A dependence of (1)Delta N-14/15(P-31) on the substituents at nitrogen was found (alkyl < H < aryl; increasingly negative values). The magnitude and sign of the coupling constants (1)J(P-31,N-15) (positive sign) are dominated by the presence of the lone pair of electrons at the phosphorus atom. The X-ray structural analysis of 2b is reported, showing the presence of dieters owing to intermolecular hydrogen bridges in the solid state. (C) 2001 John Wiley & Sons, Inc.