Synthesis, characterization and ab initio computations on some phosphoric triamides

SHARIATINIA, ZAHRA; DELLA VÉDOVA, CARLOS OMAR; ERBEN, MAURICIO FEDERICO; TAVASOLINASAB, V.; GHOLIVAND, KHODAYAR

JOURNAL OF MOLECULAR STRUCTURE

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2012 vol. 1023 p. 18 - 24

0022-2860

New phosphoric triamides with general formula P(O)X3 where X= N-4-methylpiperazinyl (1),N-4-phenylpiperazinyl (2), N-4-ethoxycarbonyl piperazinyl (3), N-2-tetrahydrofurfuryl (4)were synthesized and characterized by 1H, 13C, 31P NMR, IR, Mass spectroscopy and elemental analysis. The molecular structure for compounds 1-4 were obtained by using quantumchemical calculations (HF and B3LYP methods with the 6-31+G** basis set). Moreover,optimized structures for previously reported 4-FC6H4C(O)NHP(O)X2 phosphoric triamides, X= pyrrolidin-1-yl (5), piperidin-1-yl (6) and hexamethyleneimin-1-yl (7) were obtained using the solid state structure (CIF files) as a starting point for the gas phase computation in which all independent molecules in structures 6 (seven structures) and 7 (two structures) were included. The computed results were in good agreement with the data obtained from the X-ray crystalstructures reported earlier. The nuclear quadrupole coupling constants (NQCCs or s) were calculated about 5.0 and 10.0 MHz for the 17O atoms of P=O and C=O bonds. For nitrogen atoms bonded to the phosphorus the NQCCs were found in the range between 4.0 and 5.5 MHz, whereas for compounds 4-7, the expected values for amidic hydrogen atoms are near 300 kHz.