Three and four bond phosphorus-proton couplings in isomeric tolylphosphonates and tolylphosphine oxides

New phosphorus‐containing quinone derivatives

“…The aromatic protons of DDPO‐2‐HQ ( 2b ) in the 1 H NMR spectrum represent a triplet at 7.06 ppm with 4 J H‐P = 3.75 Hz (DMSO‐ d 6 ). In the case of the para ‐substitution, a significantly larger coupling constant 3 J H‐P (above 10 Hz) for the protons next to the phosphorus units would be expected 26,27. Furthermore, the ortho ‐structure is confirmed by X‐ray analysis (Fig.…”

Dependence of the long‐range phosphorus–hydrogen coupling constant nJP–H (n = 3,6,7) on the bond order between phosphorus and its substituents: preparation and spectroscopic characterization of several phosphoramidates

“…2 Griffin, 3 Stothers and Robinson 4 and Berry et al 5 have reported the correlation between the hybridization state of the phosphorus atom with proton shift and spin-spin coupling constant J P -H , which was interpreted by Hendrickson et al 6 The influence of benzene on the 1 H NMR spectra of mononuclear phosphorus(V) amides and dimethylamino cyclotriphosphazatrienes is described by Keat and Shaw. 7 Several other publications have described the short-and long-range J P -H in phosphorus compounds 3 -22 and four-and five-bond coupling constants ( 4 J P -H , 5 J P -H ) in allylic and homoallylic phosphorus compounds. 11,13,14,19,22 The observations of five, six, and seven bond couplings in isomeric methylbenzylphosphonium salts have been reported by Khaleeludin and Scott 15 and Gordon and Griffin 14,16 and some other studies have reported 3 J P -H spin-spin coupling too. 6,16 In the above-mentioned studies, several models have been put forward to explain the mechanism of long-range Ł Correspondence to: K. Gholivand, Department of Chemistry, Tarbiat Modarres University, PO Box 14155-4838, Tehran, Iran.…”

Nuclear magnetic resonance, crystal, and molecular structure analysis of 5,10-dihydro-10-methyl-5-phenylacridophosphin-10-ol and related "butterfly" C-P heterocycles. Evidence of a P...H-O hydrogen bond in the crystal of the title compound

“…In view of the isolation of 4a and x-ray analysis thereof (discussed later in this paper), the interrelationship of salts 5 and 6 and oxides 7 and 8 can be discerned. Direct oxidation 4a H20.…”

“…6 (mp 276-277.5 and 282-283 °C, respectively) formed from reaction with 4a and could be separated but only by a difficult fractional recrystallization. Although the mixture of salts 5 and 6 perhaps suggested two butterfly conformer precursors, the possibility of invertomers (on phosphorus) could not be eliminated. Moreover, quaternization could have proceeded initially with CH3I on 3b followed by Grignard attack on the carbonyl group from two different directions.…”