Synthesis and Characterization of the First Phosphonic Diamide Containing Thiazolyl Groups: Structural Properties and Tautomeric Equilibrium

GHOLIVAND, KHODAYAR; FARSHADIAN, S.; ERBEN, MAURICIO FEDERICO; DELLA VÉDOVA, CARLOS OMAR

JOURNAL OF MOLECULAR STRUCTURE

ELSEVIER SCIENCE BV

Año: 2010 vol. 978 p. 67 - 73

0022-2860

A new phosphonic diamide containing thiazolyl rings, N,N´ bis(2-thiazolyl) phenylphosphonic diamide, with general formula H5C6P(O)[NHCN(CH)2S]2  (1), was synthesized and characterized by NMR, IR, UV, EI mass-spectrometry and elemental analysis. The X-ray  diffraction structure obtained for 1 shows that the crystalline compound exists in the imine form,  forming centro-symmetric dimers which are produced by intermolecular cooperative hydrogen  bonds leading to a two dimensional polymeric chain. The preferred tautomeric and conformational  equilibria have also been identified in solution. Thus, a tautomeric equilibrium of 97:3 % between  the amine:imine form is observed in DMSO-d6. Structural and conformational properties are analyzed using a combined approach involving crystallographic data, vibrational spectra and theoretical calculations at the B3LYP and MP2 (with 6-311++G** and CBSB7 basis sets) level of approximations.