Coordination of trivalent lanthanum with polyethylene glycol in the presence of picrate anion: Spectroscopic and X-ray structural studies

Crystal Structure and Photoluminescence Properties of Gadolinium Picrate Triethylene Glycol Complex

“…A small amount of water in the mixture helped the complexes form more readily. This recommended adding a small amount of water is due to the small chain length of the EO3 ligand [1][2][3][4]. The found and calculated percentages of elemental analysis are in a well agreement with each other and prove the suggested molecular formula of the resulted Gd complex.…”

“…Upon complexation, the typically absorption stretching bands of m(O-H), m(C-C) and m(C-O-C) were shifted towards the frequencies of free EO3 ligand [1][2][3][4]. The m(C-O) stretching frequency shifted to lower value of 34 cm -1 , indicating the chelation of the donor oxygen atoms from the EO3 ligand by the Gd(III) ion.…”

“…The lanthanum analog was also observed and give evidence as a diamagnetic ordering. Its molecular structure has been reported by Saleh et al [2]. The coordination behavior of lanthanide ion with the acyclic EO3 ligand has attracted interest due to the strong coordination capability with the metal ion, flexible structure and its donor oxygen atoms can be coordinated to the metal ion in a tetradentate or bidentate modes effects for their ability to adopt different structural diversity [1][2][3][4].…”

“…The coordination behavior of lanthanide ion with the acyclic EO3 ligand has attracted interest due to the strong coordination capability with the metal ion, flexible structure and its donor oxygen atoms can be coordinated to the metal ion in a tetradentate or bidentate modes effects for their ability to adopt different structural diversity [1][2][3][4]. We have previously reported the series of EO3-Ln-Pic complexes with Ln = La, Ce, Pr, Eu, which display a high stability and the inner-coordination sphere containing water molecules, except for the La complex [2]. It is noted that the relaxivity of the lanthanide complexes can be significantly increased by increasing the number of inner-sphere water molecules [5].…”

“…In the present study, we report the synthesis, characterization, photoluminescent and crystal structure of the gadolinium complex, [Gd(Pic) 2 [1][2][3][4]. A mixture of EO3 (0.454 g, 3.0 mmol), HPic (0.917 g, 4 mmol), and Gd(NO 3 ) 3 Á6H 2 O (0.434 g, 1 mmol) was dissolved in 30 mL acetonitrile:methanol:water (3:3:1 v/v) and stirred for 10 min at room temperature.…”