Abstract
2,4-Dichlorophenoxyacetic acid derived Schiff base (HL) and its lanthanide [La(III), Pr(III), Nd(III), Sm(III), Eu(III), Gd(III), Dy(III), Y(III)] complexes were synthesized and characterized by various spectroscopic (1H,13C, DEPT and 2D HMQC NMR, FT-IR, UV-Vis, and mass) techniques and other analytical methods. HL exhibits “E” and “Z” isomerism and was confirmed by variable temperature1H NMR studies. The spectral and analytical data reveals the bidentate coordination of HL to lanthanide(III) ion, through carboxylic acid group via deprotonation. Fluorescence spectrum of europium complex shows bands at 578, 592, and 612 nm assignable toD05→F07,D05→F17, andD05→F27, respectively. Auxin activity of HL and lanthanum(III) complex on wheat seeds (Triticum durum) was measured at different concentrations. The percentage germination, root length, and shoot length were recorded. An enhancement in the plant growth activity of the ligand was observed on complexation and the best activity was observed at 10−6 M concentration.
Highlights
Rare earth elements are being used in agriculture as micronutrients and fertilizers [1,2,3,4]. ese are found to have nitrogen xing capacity, to enhance activity of hydrolytic enzymes, to promote seed germination, to strengthen photosynthetic rate, and to reduce water loss in plants [5, 6]
DWR-2006 (Triticum durum), a local variety of wheat seeds developed at University of Agricultural Sciences, Dharwad, India, was selected to investigate the growth activities of the synthesized compounds. e solutions of HL, lanthanum(III) complex, La(NO3)3, and 2,4-dichlorophenoxyacetic acid were prepared by dissolving them in minimum quantity of DMSO (∼1 mL) and further diluted with distilled water to obtain the solutions of 1 × 10−5 M, 1 × 10−6 M and, 1 × 10−7 M concentrations
E absence of band due to carboxylic OH group in the spectra of all lanthanide (III) complexes suggests the coordination to the metal ion via deprotonation. e band due to υυ(C=O) of carboxylic acid of HL was absent in all the lanthanide(III) complexes, indicating the participation of carbonyl oxygen in coordination to the metal ion [22,23,24]
Summary
Rare earth elements are being used in agriculture as micronutrients and fertilizers [1,2,3,4]. ese are found to have nitrogen xing capacity, to enhance activity of hydrolytic enzymes, to promote seed germination, to strengthen photosynthetic rate, and to reduce water loss in plants [5, 6]. E effect of lanthanide(III) complexes on the growth of plants has been an important topic in agricultural eld. Literature survey reveals that chelation of lanthanide metal ions with plant growth promoting auxins synergistically increases the plant growth [12]. Keeping this in view, we have synthesized 2,4-dichlorophenoxy acetic acid derived Schiff base and its lanthanide(III) complexes and screened for their auxin activity on wheat seeds. E work is focused on the synthesis, characterization, spectroscopic investigation, thermal, uorescent behavior, and plant growth promoting activity of a series of rare earth complexes of 2,4dichlorophenoxy acetic acid derived Schiff base (HL) We have synthesized 2,4-dichlorophenoxy acetic acid derived Schiff base and its lanthanide(III) complexes and screened for their auxin activity on wheat seeds. e work is focused on the synthesis, characterization, spectroscopic investigation, thermal, uorescent behavior, and plant growth promoting activity of a series of rare earth complexes of 2,4dichlorophenoxy acetic acid derived Schiff base (HL)
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
