Abstract
In this study, a series of cyclotriphosphazene derivatives containing a Schiff base (3a–3d) were synthesized by the reactions of hexachlorocyclotriphosphazene (1) with bis-aryl Schiff bases ( 2a – 2d ) having different terminal groups (H, F, Cl, and Br). The products ( 3a – 3d ) were characterized by elemental and mass analyses, FT-IR, and 1 H, 13 C, and 31 P NMR spectroscopies. Furthermore, the structure of compound 3a was also determined by X-ray crystallography. The thermal behaviors and the spectral properties of the new cyclotriphosphazene compounds ( 3a – 3d ) were investigated and the results were compared in the series.
Highlights
Heterocyclic systems containing mainly phosphorus, nitrogen, sulfur, and oxygen atoms compose a large class of inorganic compounds and they have applications in various areas [1,2,3,4,5]
Synthesis and characterization of compounds Schiff base ligands (2a–2d) bearing four different side groups at the para position on the terminal phenyl ring were prepared from the condensation reaction of 4-aminophenol with benzaldehyde, p -fluoro, chloro, and bromobenzaldehyde in ethanol [16,39]
The general synthesis route and the structures of compounds 3a–3d are shown in Scheme 1 and Scheme 2
Summary
Heterocyclic systems containing mainly phosphorus, nitrogen, sulfur, and oxygen atoms compose a large class of inorganic compounds and they have applications in various areas [1,2,3,4,5]. Some cyclophosphazene derivatives containing Schiff bases were randomly synthesized in recent years [8,26,27,28,29,30,31,32], their thermal stabilities and absorbance properties have not been investigated systematically. The thermal stabilities of Schiff base-substituted cyclotriphosphazenes (3a–3d) were determined by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Thermal analysis results demonstrated that the thermal stability of the cyclotriphosphazenes containing Schiff bases was significantly higher than that of corresponding Schiff bases Their UV absorption spectra, which were measured in different solvent systems, showed that λmax of compounds from 3a–3d shifts to the red region.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
