The thermogram of one of the representative compounds VO

Table 4.
Important IR spectral bands of the synthesized complexes.S. NoComplexesν(CN) (azometh.)ν(C–O) (enolic)ν(CN2) (cyclic)ν(VO)ν(V–O)ν(V–N)ν(OH)ν(NH)/(NH2)(1)[VO(bumphp-sdz)2(H2O)]·H2O1615116415919756394863475 (br)3348(2)[VO(bumphp-sgn)2(H2O)]·H2O1612115015959806344913470 (br)33173245(3)[VO(bumphp-snm)2(H2O)]·H2O1617119515859806344863313 (br)3230(4)[VO(bumphp-smr)2(H2O)]·H2O16071180Merged with ν(CN)9906255023450 (br)3338Full-size tableTable optionsView in workspaceDownload as CSV
The Schiff TH302 ligands used in the present investigation contain six potential donor sites: (i) the enolic oxygen; (ii) the cyclic nitrogen, N1; (iii) the cyclic nitrogen, N2; (iv) the azomethine nitrogen; (v) the sulfonamide (–SO2NH) oxygen or nitrogen and; (vi) the ring nitrogen of sulfa drug. All the Schiff base ligands show a sharp and strong band due to ν(CN) of the azomethine group at 1627–1630 cm−1. The observed low-energy shift of this band in the chelates and appearing at 1607–1617 cm−1, suggests the coordination of the azomethine nitrogen ( Maurya et al., 2002a, Maurya et al., 2002b and Maurya et al., 2002c).