Synthesis and characterization of N, N′-bis (isatin) diamino zirconium (IV) complexes

Abstract

N, N′-bis (isatin) diamine schiff base ligands were synthesized by the condensation reaction of Isatin with various diamine (ethane-1,2-diamine, propane-1,3-diamine and hexane-1,6-diamine) in 2:1 molar ratios. These ligands were used to prepare Zr (IV) complexes. Prepared ligands and complexes were characterized by using conductance measurement, FT-IR, UV-Visible and 1 HNMR spectroscopy. The presence of FT-IR band for azomethine group supports the formation of ligand. Vibrational bands for Zr←N and Zr←O in complexes signify the coordination through O and N sites of ligands. 1 HNMR peak for NH moiety in ligand gets almost disappeared in complex reveals tautomerism of NH with nearby carbonyl oxygen due to the effect of complexation. The absence of peak above 500 nm in the electronic spectra indicates d 0 system of zirconium in complexes. The elemental analytical data was analogous to theoretical composition of ligands and complexes. The molar conductance values obtained for the complexes represent their non-electrolytic character.

Graphitic Carbon Nitride Modified with Zr-Thiamine Complex for Efficient Photocatalytic CO2 Insertion to Epoxide: Comparison with Traditional Thermal Catalysis

“…In Figure S7, peaks centered at 465 and 480 cm –1 are visible in the enlarged domain. Though the pristine g-CN also has peaks at the same positions, a continuous increase in the intensity of these peaks with increasing the Zr-thiamine contents confirms the formation of Zr–N species, which is also confirmed from XPS analysis . The FT-IR spectra of thiamine (before and after pyrolysis) are compared with the g-CN, and the Zr-thiamine FT-IR spectrum is compared with Zr-Thia/g-CN (Figure S8a,b).…”

“…This suggests that the structural integrity of g-CN remains intact and no structural deformation is observed after modification with Zr-Thia. However, a closer inspection of the FT-IR spectra of all the materials investigated here indicates the existence of Zr–N species present in Zr-Thia­( x )/g-CN catalysts . In Figure S7, peaks centered at 465 and 480 cm –1 are visible in the enlarged domain.…”

“…However, a closer inspection of the FT-IR spectra of all the materials investigated here indicates the existence of Zr−N species present in Zr-Thia(x)/g-CN catalysts. 39 In Figure S7, peaks centered at 465 and 480 cm −1 are visible in the enlarged domain. Though the pristine g-CN also has peaks at the same positions, a continuous increase in the intensity of these peaks with increasing the Zr-thiamine contents confirms the formation of Zr−N species, which is also confirmed from XPS analysis.…”

“…Though the pristine g-CN also has peaks at the same positions, a continuous increase in the intensity of these peaks with increasing the Zr-thiamine contents confirms the formation of Zr−N species, which is also confirmed from XPS analysis. 39 The FT-IR spectra of thiamine (before and after pyrolysis) are compared with the g-CN, and the Zrthiamine FT-IR spectrum is compared with Zr-Thia/g-CN (Figure S8a,b). The overlapping of absorption peaks of pyrolyzed thiamine and g-CN in the range of 1200−1650 cm −1 suggests that during the pyrolysis process C, N, and S fragments were integrated with the g-CN framework.…”

Molybdenum(VI) complexes of N, N′-bis isatin diamine Schiff base: Synthesis and characterization

“…The band for the O-H stretching frequency is reported in the region 3200-3500 cm -1 (Sarker et al 2019) The bands in the region 3150-3300 cm -1 are assigned due to the N-H stretching mode in the free ligands (Pickard and Polly, 1954). Absorption band are observed at 3267.41, 3234.62 and 3244.27 cm -1 relating to N-H absorption frequencies in the ligand L 1 , L 2 and L 3 , and 3190.26, 3199.91 and 3192.91 cm -1 relating to N-H absorption frequencies for complex MoO 2 L 1 , MoO 2 L 2 and MoO 2 L 3 , respectively.…”