Reaction in situ found in the synthesis of a series of lanthanide sulfate complexes and investigation on their structure, spectra and catalytic activity

Abstract

A series of lanthanide sulfates coordination complexes, Ln 2 (SO 4 ) 3 (H 2 O) 8 (Ln = Pr (1), Nd (2), Tb (3), Sm (4), Dy (5), Gd (7), Ho (8)), and EuK(SO 4 ) 2 (6), were constructed by the reaction in situ of lanthanide ions (Ln 3+ ) with flexible dodecanedioic acid and rigid aromatic 5-sulfosalicylic acid under hydrothermal conditions. All of them were characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction. The crystal structures and coordination modes of metal centers and sulfate ions, as well as the novel reaction mechanism and different conditions of lanthanide ions and 5-sulfosalicylic acid to form the series of lanthanide sulfate complexes, were discussed in detail. Solid-state properties for these crystalline materials, such as thermal stability and powder X-ray diffraction have been investigated. Additionally, the photoluminescent characterizations of the complexes 3, 4, 5 and 6, and the catalytic properties of all the complexes about cyclohexane being oxidized into cyclohexanone/cyclohexanol were investigated and compared.

Structural and optical properties of synthesized poly(methyl methacrylate) (PMMA) and lanthanide $$\upbeta $$-diketonate complexes incorporated electrospun PMMA nanofibres for optical devices

“…The peak observed at 480 nm in the visible region indicates the band edge emission which is clear from the UV-visible absorption spectra of the present samples. The two peaks at 595 and 645 nm correspond to the characteristic ions present in the complex respectively [26]. The PL spectra of the pure neodymium β-diketonate complex at excitation wavelengths of 300, 400, 500 and 520 nm are shown in figure 12c.…”

Studies on the structural and optical properties of samarium β‐diketonate complex incorporated electrospun poly(methylmethacrylate) nanofibres with different architectures

“…Photoluminescence (PL) spectra of pure PMMA, surface-roughened PMMA, coaxial hollow PMMA nanofibres and the nanofibres with the samarium β-diketonate complex incorporated are shown in Figure 11. The PL spectra of the PMMA nanofibres of different architectures with the complexes incorporated were entirely different from that of the pure samarium complex [34,35] and matched well that of PMMA, which showed the successful incorporation of the complex into the fibre. Here it was observed that pure PMMA nanofibres showed maximum intensity at 330 nm with 501 148 cps.…”

“…Here the samarium complexes produced peaks at 598 nm and 644 nm, which represented the emissions from 4 G 5/2 to 6 H 7/2 and to 6 H 9/2 of interstitial Sm 3+ ions present in the complex; this finding was in agreement with many recent reports. [24,34,[36][37][38][39][40] PL analyses, therefore, clearly confirmed the successful incorporation of the complex into the pure and structurally modified PMMA nanofibres. Other peaks present in the spectra of pure, surface-roughened, and coaxial hollow PMMA nanofibres with the samarium complex incorporated originated from, for example, intermediate energy levels, donor-acceptor pair transitions, oxygen vacancies, and interstitial ions present in the prepared complexes.…”

“…Peaks for the samarium complexes were observed at 598 nm and 644 nm that, respectively, represented emissions from 4 G 5/2 to 6 H 7/2 and to 6 H 9/2 of interstitial Sm 3+ ions present in the complex, as described previously. [24,34,[36][37][38][39][40] The peaks of samarium complexes incorporated in these nanofibres showed the maximum intensity at an excitation wavelength of 320 nm. Therefore, PL analyses clearly showed the successful incorporation of the samarium complex into PMMA nanofibres.…”

A new lanthanum(III) complex, [La(MO)3(DMF)3(H2O)2] (MO = methyl orange), and La2O2SO4 nanoparticles; electrocatalytic activity for adsorption/desorption/evolution of hydrogen

“…In addition, the FT-IR results reveal the formation of La 2 O 2 SO 4 after calcination of the precursor (La(III) complex).The bands at 631 and 591 cm −1 are attributed to the stretching vibrations of the La-O bonds[56,57]. The vibration bands at 1160, 1063, and 672 cm −1 can be due to the characteristic vibrations for the sulfate group[58][59][60].…”