Structural and spectroscopic studies of the 1 : 1 complex of 4-nitrophenyl[bis(ethylsulfonyl)]methane-1,5,7-triazabicyclo[4.4.0]dec-5-ene

In the crystal of the 1:1 complex of 4-nitrophenyl[bis(diethylsulfonyl)]met hane with 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) the proton is transferr ed from the C-H acid to TBD to yield an ion pair. In the ionic structure th e N-H protons of protonated TBD molecule are hydrogen-bonded with sulfonyl oxygens. The lengths of these N-(HO)-O-... hydrogen bonds are of 2.851(2) a nd 2.911(2) Angstrom. The structure of the complex in solid is very well re flected in its FT-IR spectrum. On the basis of the FT-IR and 'H NMR studies of the complex, in chloroform, its structure similar to that in the solid state is postulated. In acetonitrile a dissociation of the complex and a fo rmation of a new structure is proposed. (C) 2001 Published by Elsevier Scie nce B.V.