Structure and FT-IR spectroscopic analyses of complexes phosphorylated betaines with rare earth metal ions

• FT-IR spectroscopy analysis the complexes. • Structure of complexes with RRE metals. The analyses of complexes phosphorylated betaines L1-L4 with rare earth metal ions were studied by Fourier Transform InfraRed spectroscopy. The changes in the nitrato ligand stretching bands, phosphoryl stretching bands were monitored and characterized. The main centers of coordination of the ligands L1-L4 have been established. The obtained results are confirmed by single crystal X-ray diffraction analysis. Single crystal X-ray diffraction analysis showed that the Sm and Nd ions form metal complexes with butyl {[benzyl(dibutyl)ammonio]methyl} phosphonate L1 and pentyl {[benzyl (dibutyl)ammonio]methyl} phosphonate L2, respectively. The both metal complexes form 1D polymer chains. Two nitrato ligand and the oxygen atom of the phosphonate group of L2 are bridging in the Nd compound and Nd 3 (NO 3 ) 9 L2 3 is formed, while the independent part of the Sm compound consists of two metal complexes connected by the bridging nitrato ligand, which exhibits bidentate properties. Sm1 ion is coordinated by three nitrato ligand, oxygen atom of phosphonate group of L1 and water molecule, while Sm2 ion is coordinated by four nitrato ligand, oxygen atom of phosphonate group L1 thus Sm 2 (NO 3 ) 6 (L1) 2 H 2 O·CH 3 OH system is formed. The polymer chain is organized due to the oxygen atom of the phosphonate group.