Dynamic1H,13C,31P NMR spectroscopy of the crown containing N-(thio)phosphoryl(thio)urea

The variable temperature and concentration¹H,¹³C,³¹P NMR spectroscopy of the N,N′-bisdiisopropoxy(thio)phosphorylamido-(thio)carbonyl]-1,10-diaza-18-crown-6 containing the reaction pentade C(X)NHP(Y) and stereononrigid macrocycle in solutions (CD₂CL₂, CD₃CN, (CD₃)₂CO as solvent) was studied. The complex chemical exchange is described in terms of tautomeric processes, hindered rotation around C-N bond and macrocycle ring inversion. NMR spectral parameters (chemical shifts and spin-spin coupling constants) of the observed exchange partners as well as thermodynamic parameters of the equilibrium and transition between tautomeric and conformational forms are given.