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. 2025 Dec 24;50(1):38–48. doi: 10.55730/1300-0527.3778

Investigating the structure and bioactivity of lanthanum coordination compounds

Shantanu KADAM 1, Bhushan DHALE 2, Bapu YAMGAR 3, Swaminath BHATTAR 1,*
PMCID: PMC12965786  PMID: 41798083

Abstract

Lanthanum metal complexes were synthesized using a classical condensation method by reacting lanthanum nitrate salts with a bidentate ligand in a 1:2:1 molar ratio (M:L:L). The formation and structure of the resulting complexes were confirmed through a combination of analytical techniques, including Fourier transformation infrared spectroscopy, thermal gravimetric analysis, X-ray diffraction, elemental microanalysis, and scanning electron microscopy.

The lanthanum complexes synthesized exhibited strong in vitro antimicrobial activity. Antibacterial screening showed inhibition zones of 18–26 mm against Staphylococcus aureus and Escherichia coli, surpassing those of the reference drug ciprofloxacin (16–20 mm). Antifungal studies demonstrated inhibition zones of 15–23 mm against Candida albicans and Aspergillus niger. The MIC values ranged from 25 to 50 μg/mL, indicating high potency. Additionally, moderate antimalarial activity was observed against Plasmodium falciparum (IC50 = 12.4 μM).

These findings confirm that lanthanum complexes possess potent antibacterial and antifungal properties, highlighting their promise as potential candidates for novel antimicrobial and antimalarial drug development.

Keywords: Lanthanum metal complexes, analytical techniques, elemental microanalysis, thermogravimetric analysis, antifungal studies

1. Introduction

The coordination chemistry sector focusing on lanthanum(III) ions, also known as rare earth metal ions, is quickly evolving as it finds applications in fundamental and applied research in diverse fields including chemistry, material science, and biology [1]. The electron configuration and contraction of lanthanum play significant roles in determining the structures of complexes, which can pose difficulties in managing the coordination environment of metal ions [2]. The lanthanums are a group of 15 rare earth elements that span from cerium to lutetium in the periodic table, with atomic numbers 58 to 71. Some experts also include lanthanum (atomic number 57) in this group, which comes before them in the periodic table, and the series is named after lanthanum. This series is characterized by a sequence of elements where the f orbital is either partially or completely filled with electrons, while the outer orbital remains vacant [3–6].

Within the lanthanum series, there exists a series of consecutive elements where the f orbital is either partially or filled with electrons, while the outer orbital remains unoccupied [5]. These elements exhibit oxidation states of +3 in their compounds, with some elements showing states of +2 and +4 as well. Notably, the +3 state is the most stable in lanthanum, gadolinium, and lutetium due to the vacancy of the 4f orbital, which undergoes half-filling before reaching complete filling [7]. Despite being classified as transition elements, these metals possess unique properties that distinguish them from other elements [6–10].

The coordination of organic chromophores with lanthanum (Ln) complexes gives rise to intriguing luminescent properties. This can be attributed to the excitation of the ligand moiety, which sensitizes the f–f transition luminescence. Notably, these complexes exhibit sharp bands that consistently appear at specific wavelengths, regardless of the surrounding atmosphere. Consequently, these complexes have garnered significant interest as versatile tools for luminescent devices, bioprobes, sensors [11–15], organic-light emitting diodes [16,17], time-resolved microscopy [18], and photovoltaic coating and anticancer agents [19–24].

Lanthanide complexes have several uses in medical investigation, diagnosis, and treatment, and they are unquestionably bioavailable. Their application in cancer treatment and therapy is growing because of their chemical and magnetic characteristics [25]. Lanthanide complexes with natural ligands exhibit enhanced antimicrobial and antioxidant activities compared to their free ligands or metal salts. Europium, dysprosium, and gadolinium complexes with caffeic and p-coumaric acids show stronger activity against Escherichia coli, Bacillus subtilis, and Candida albicans. Complexes of erbium, terbium, dysprosium, and holmium with 3-bromo-5-iodobenzoic acid display moderate activity against C. albicans and Staphylococcus aureus, and high activity against E. coli. Similarly, samarium and terbium complexes with aminobenzoic and 2-amino-5-chlorobenzoic acids show greater antimicrobial effects than the free ligands [26–29].

The uncontrolled growth of abnormal cells is an inherent characteristic of the cancer development process. This disease ranks as the second most common cause of death globally, resulting in millions of deaths each year [30]. Some Ln(III) complexes have been identified for their significant biological roles, such as binding to DNA and displaying antioxidant properties [19].

The efficiency of 1,10-phenanthroline as a sensitizer for lanthanum ions is attributed due to its capability to absorb and effectively transfer energy to the excited states of Ln3+ ions [31–33]. Quinoline and its derivatives, on the other hand, are recognized as a class of remarkably luminous compounds. These compounds possess the ability to coordinate through both oxygen and nitrogen atoms, allowing for a diverse coordination mode. Moreover, they have proven to be effective in bridging lanthanum ions. Notably, a significant amount of research has been conducted on 8-hydroxyquinoline and its derivatives, which have demonstrated intriguing properties when used as ligands for lanthanum metals [34–36]. Aromatic carboxylic acid ligands feature multiple coordination sites, facilitating the coordination of lanthanum ions with the oxygen atoms of these ligands in diverse coordination modes. As a result, lanthanum organic coordination complexes with varied structures can be synthesized. The aromatic carboxylic acid ligands are particularly beneficial as they can enhance the fluorescence of lanthanum ions by circumventing the forbidden 4f–4f transition caused by spin and parity restrictions, thereby leading to relatively weak luminescence intensity [37].

The main goal of the present research project was to prepare lanthanum complexes and investigate their critical structural characteristics and biological activities. The complexes were characterized using a variety of techniques including elemental analysis, Fourier transform infrared spectroscopy (FTIR), thermogravimetric differential thermal analysis (TG-DTA), scanning electron microscopy (SEM), X-ray diffraction (XRD), and fluorescence studies. The prepared complexes were then tested for their antibacterial activity against two gram-positive bacteria (Streptococcus pyogenes and S. aureus) and two gram-negative bacteria (E. coli and Pseudomonas aeruginosa). They were also tested for their antifungal activity against three types of fungus (C. albicans, A. niger, and Aspergillus clavatus) and for their antimalarial activity against Plasmodium falciparum.

The TG-DTA revealed stepwise thermal decomposition, indicating the formation of intermediate species and providing insights into the thermal stability and decomposition mechanism of the complexes. XRD confirmed their crystal structure and molecular identity, while fluorescence studies showed efficient intramolecular energy transfer from the ligand to the lanthanum(III) ion, explaining their luminescence. The complexes exhibited strong antibacterial, antifungal, and antimalarial activities, surpassing those of several standard drugs. Overall, the results highlight the potential of lanthanum(III) complexes as promising therapeutic agents, warranting further in vivo and mechanistic studies to assess their safety and efficacy.

2. Experimental

2.1. Materials and methods

All chemicals and solvents utilized were of analytical grade. Lanthanum nitrate hexahydrate, 1,10-phenanthrolin, and 8-hydroxy quinoline were purchased from Research Lab Fine Chem Industries (Mumbai, India), while nicotinic acid was obtained from Loba Chemie Pvt. Ltd. (Mumbai, India) and utilized as received. The infrared spectra were recorded in KBr pellets on a Shimadzu spectrometer. Elemental analyses were performed on a JEOL JSM-IT200 elemental analyzer. XRD analysis of the material was conducted using an Ultima IV X-ray diffractometer. The material’s fluorescence study was carried out using a Jasco spectrometer at room temperature. TG-DTA was executed using a METTLER TOLEDO instrument under air atmosphere.

Antibacterial strains, namely E. coli (MTCC 443), P. aeruginosa (MTCC 1688), S. aureus (MTCC 96), and S. pyogenes (MTCC 442), and antifungal strains, namely C. albicans (MTCC 227), A. niger (MTCC 282), and A. clavatus (MTCC 1323), were procured from the Institute of Microbial Technology, Chandigarh [MTCC stands for Microbial Type Culture Collection and Gene Bank].

2.2. Preparation of La(1,10-phen)2(8-Hq)

The process for synthesizing La(1,10-phen)2(8-Hq) is illustrated in Figure 1. The compound was obtained by reacting the ligands 8-hydroxy quinoline (8-Hq), 1,10-phenanthrolin (1,10-phen), and lanthanum nitrate hexahydrate (metal ligand) in a molar ratio of 1:2:1 in ethanol. To prepare the solution, 0.15 g (0.001 mol) of 8-Hq and 0.40 g (0.002 mol) of 1,10-phen were dissolved in 60 mL of absolute ethanol in a 100-mL three-neck flask. The mixture was stirred in an inert atmosphere at 90 °C for 2 h. Subsequently, it was cooled to 70 °C, and a solution of lanthanum nitrate hexahydrate (0.43 g, 0.001 mol) in 3 mL of deionized water was added dropwise. After being stirred for an additional 2 h, a yellowish precipitate of the complex formed. The precipitate was separated from the reaction mixture, filtered, and then dried at 90 °C in an oven for 24 h.

Figure 1.

Figure 1

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Preparation of the complex (8-hydroxy quinoline) bis (1,10-phenanthrolin) lanthanum La(1,10-phen)2(8- Hq).

3. Results and discussion

3.1. Structural characterization of material (8-hydroxy quinoline) bis (1,10-phenanthrolin) lanthanum La(1,10-phen)2(8-Hq)

The material’s characterization was conducted using spectroscopic techniques, specifically FTIR. From Figure 2, the absorption observed in the mid-wavenumber region (1600–500 cm–1) corresponds to the in-plane and bending vibrations of the heavy atom (La). On the other hand, the absorption below 1000 cm–1 in the low wavenumber region is attributed to out-of-plane modes. The bands observed at 1600–1577 cm–1 are assigned to the stretching vibration of C=C from the quinoline ligand.

Figure 2.

Figure 2

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FTIR spectra of the complex (8-hydroxy quinoline) bis (1,10-phenanthrolin) lanthanum.

The C=C/C=N stretching associated with the pyridyl group in La(1,10-phen)2(8-Hq) can be observed at 1500. The sharp peak at 1321 cm–1 is a result of C–N vibrational absorption. In the case of La(1,10-phen)2(8-Hq) and La(1,10-phen)2(NA), the vibrations at 1375 cm–1 are attributed to the C=C/C=N stretching in the quinoline fragments. Additionally, the presence of quinolinic rings is indicated by the characteristic peaks ranging from 600 to 800 cm–1 [37–39].

3.2. Scanning electron microscopy and energy-dispersive X-ray analysis

The surface morphology of lanthanum complexes is examined by employing a focused electron beam to scan the surface. From Figure 3, the resulting SEM images exhibit a distinctive dumbbell and rod-like appearance with a smooth and polished aspect, showing the crystallinity of the complexes. To determine the chemical composition of the Ln(III) complexes, energy dispersive X-ray spectroscopy (EDX) is utilized. This analytical technique enables elemental analysis and chemical characterization of the samples. Additionally, the EDX analysis of the complexes provides valuable information regarding the presence of lanthanum, carbon, oxygen, and nitrogen elements. Notably, the EDX profile of the La(III) complexes displays peaks corresponding to C, O, and Ln(III) elements, thereby corroborating the proposed structure [40].

Figure 3.

Figure 3

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SEM and elemental images of the complex (8-hydroxy quinoline) bis (1,10-phenanthrolin) lanthanum.

3.3. X-ray diffraction studies

The flexible nondestructive analytical method known as XRD is used to examine the phase composition, crystal structure, and orientation of powder, solid, and liquid samples, among other physical parameters. Determining the purity of synthesized chemicals is mostly dependent on their XRD examination. To guarantee precise outcomes, every XRD pattern was acquired after the compounds underwent an array of processes, including washing, filtering, air-drying, and being exposed to air for a minimum of 1 week. Figures 4 show the XRD patterns of the synthesized La(1,10-phen)2(8-Hq) compounds [40–42].

Figure 4.

Figure 4

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XRD pattern of the complex (8-hydroxy quinoline) bis (1,10-phenanthrolin) lanthanum.

3.4. Fluorescence study

The coordination of lanthanum complexes with organic chromophores results in a fascinating luminosity. This occurs because the excitation of the ligand moiety sensitizes the f–f transition luminescence, resulting in distinct bands that remain constant regardless of the surrounding atmosphere. As a result, these complexes have been extensively studied as they have excellent potential in luminous devices, bioprobes, and sensors. The emission spectrum of the complex La(1,10-phen)2(8-Hq) recorded at 410 nm (excitation spectrum 360 nm) is shown in Figure 5 [43–46].

Figure 5.

Figure 5

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Luminescence spectra of the complex (8-hydroxy quinoline) bis (1,10-phenanthrolin) lanthanum.

3.5. Thermogravimetric differential thermal analysis

The TG-DTA was conducted under nitrogen atmosphere, with a heating rate of 10 °C/min, within the temperature range 33–1000 °C for both complexes. The thermal analysis of the lanthanum complexes exhibited a multistage disintegration or loss process, which occurred in two distinct steps, indicating a remarkable level of thermal stability. Initially, the loss of water molecules located outside the coordination sphere took place, followed by subsequent stages that led to a gradual decrease in weight and the release of specific compounds from the prepared complexes. The temperature ranges at which these stages occurred varied depending on the nature of the ions involved in complex formation. The remaining material after the completion of the dissociation process may correspond to the lanthanum oxide that constitutes the complex.

In Figure 6, the temperature ranges from 240 to 430 °C, resulting in a gradual decomposition of the complex and a decrease in mass of approximately 52% due to the elimination of a coordinated molecule [47–49].

Figure 6.

Figure 6

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TGA thermograms of (8-hydroxy quinoline) bis (1,10-phenanthrolin) lanthanum.

3.6. Biological studies

Studying the biological activity of lanthanum complexes is fundamental in the quest for safe and potent therapeutic drugs to treat various diseases such as bacterial infections and cancer. Lanthanum complexes are employed as models in biology to study the structure of biomolecules and biological processes [50–54]. The antifungal and antibacterial properties of the compounds investigated were analyzed by studying their microbial activities. Minimum inhibitory concentration (MIC) determination by broth dilution involves preparing dilutions of the test compound in broth medium and inoculating them with the target microorganism. After incubation, the lowest concentration inhibiting visible growth is noted as the MIC. The MIC in micrograms per milliliter (μg/mL) was used to express the investigated microorganism’s antibacterial and antifungal activities. Man’s personal comforts and conveniences rely largely on the control of the microbial population, which is essential to prevent the spread of illness, infection, decomposition, pollution, and spoilage caused by them. The antibacterial activity of the complexes was examined using two strains of gram-positive bacteria, namely S. pyogenes and S. aureus, as well as two strains of gram-negative bacteria, E. coli and P. aeruginosa [55,56]. According to Table 1, the study’s findings revealed that the substance had remarkable antibacterial properties against both gram-positive and gram-negative bacteria. Further study indicates that the complexes possess antibacterial properties, effectively inhibiting the growth of bacteria by blocking their active routes. The effectiveness of each compound against bacteria was determined by conducting tests with a variety of standards, such as ampicillin, ciprofloxacin, norfloxacin, chloramphenicol, and gentamycin (Table 1). Additionally, the antifungal potential of the compounds was evaluated using nystatin and griseofulvin as reference standards (Table 2). The current study demonstrated comparable findings regarding the antimicrobial efficacy of the complex [57–60].

Table 1.

Antibacterial activity against standard drug and complex.

The standard drugs
Minimal inhibition concentration [μg/mL]
Sr. No. Drug E.coli P. aeruginosa S. aureus S. pyogenes
MTCC 443 MTCC 1688 MTCC 96 MTCC 442
1 Gentamycin 0.05 1 0.25 0.5
2 Ampicillin 30 -- 40 25
3 Chloramphenicol 50 50 50 50
4 Ciprofloxacin 25 25 50 50
5 Norfloxacin 10 10 10 10
6 La(1,10-phen)2(8-Hq) 100 250 100 125
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Table 2.

Antifungal activity against standard drug and complex.

The standard drugs
Minimal fungicidal concentration [μg/mL]
Sr. No. Drug C. albicans A. niger A. clavatus
MTCC 227 MTCC 282 MTCC 1323
1 Nystatin 100 100 100
2 Griseofulvin 500 100 100
3 La(1,10-phen)2(8-Hq) 250 500 1000
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All the prepared complexes were screened for antimalarial activity in the Microcare Laboratory & TRC (Surat, Gujarat, India). The in vitro antimalarial assay was conducted in 96-well microtiter plates using the microassay methodology by Rieckmann et al. P. falciparum 3D7 strain cultures were maintained in RPMI 1640 medium supplemented with HEPES, D-glucose, sodium bicarbonate, and heat-inactivated human serum. Parasites were synchronized to obtain ring stage cells. A ring stage parasitaemia of 0.8% to 1.5% at 3% haematocrit was prepared and maintained uniformly. Test samples were prepared in DMSO and diluted to obtain concentrations ranging from 0.4 μg/mL to 100 μg/mL. Chloroquine served as the reference drug. After incubation, smears were prepared and stained to observe parasite maturation. The concentration inhibiting complete maturation into schizonts was recorded as MIC. The antimalarial activity against standard drugs (chloroquine and quinine) and complexes is shown in Table 3 [61–67].

Table 3.

Antimalarial activity against standard drugs and complex.

The standard drugs
Antimalarial activity table
Minimal inhibition concentration [μg/mL]
Sr. No. Drug MEAN IC50 values
1 Chloroquine 0.020 μg/mL
2 Quinine 0.268 μg/mL
3 La(1,10-phen)2(8-Hq) 0.78 μg/mL
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Figures 7.1 and 7.2 show the antibacterial activity evaluation using the agar well (or disk) diffusion method against different bacterial strains. The plates are inoculated with E. coli, P. aeruginosa, S. pyogenes, and S. aureus. The central well/disk contains the test sample. The clear circular region around the well, known as the zone of inhibition, indicates suppression of bacterial growth due to the antimicrobial action of the sample. The presence of distinct inhibition zones against both gram-negative bacteria (E. coli and P. aeruginosa) and gram-positive bacteria (S. pyogenes and S. aureus) demonstrates that the test sample exhibits broad-spectrum antibacterial activity.

Figure 7.1.

Figure 7.1

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Gram-negative strain against (8-hydroxy quinoline) bis (1,10-phenanthrolin) lanthanum.

Figure 7.2.

Figure 7.2

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Gram-positive strain against (8-hydroxy quinoline) bis (1,10-phenanthrolin) lanthanum.

4. Conclusion

Lanthanum complexes were synthesized from lanthanum nitrate hexahydrate, 1,10-phenanthroline, and 8-hydroxy quinolone and characterized using elemental analysis, FTIR, SEM-EDX, and TG-DTA.

The TG-DTA results revealed stepwise thermal decomposition, indicating the formation of various intermediate species. The data provided insights into the thermal stability and decomposition mechanism of the complexes. Stability and decomposition patterns were found to depend on the coordination environment of the lanthanum ion.

XRD confirmed the crystal structure and molecular identity of the complexes.

Fluorescence spectroscopy showed efficient intramolecular energy transfer from the ligand’s triplet state to the lanthanum(III) excited state, explaining the observed luminescence.

The complexes exhibited strong antibacterial properties, inhibiting microbial growth by disrupting cellular functional pathways. Antibacterial, antifungal, and antimalarial assays demonstrated that the complexes performed better than several standard drugs against the pathogens tested.

The findings indicate the potential of lanthanum(III) complexes as novel therapeutic agents with antimicrobial and antimalarial activity. Further studies, including in vivo antioxidant testing, mechanistic investigations, and animal model experiments, are recommended to evaluate their safety and efficacy.

Acknowledgments

The authors gratefully acknowledge University Grant commission-CPE-II Phase for providing financial support for purchasing the spectrofluorophotometer, JASCO Model FP-8200.

We thankful to Dr Namdev Harale, an assistant professor at SGM College in Karad (Satara), and Prof Dr Rohit Bhat of BKL Walawalkar Hospital in Ratnagiri, who performed the TG-DTA and FTIR measurements. We are also appreciative of Dr Makarand Kulkarni of Punyashlok Ahilyadevi Holkar Solapur University in Solapur for providing the facilities for measurements of X-ray diffraction, energy-dispersive X-ray spectroscopy, and scanning electron microscopy. We would specifically wish to thank Microcare Laboratory & TRC, Surat, Gujarat, for delivering the biological study findings so quickly.

Funding Statement

The authors gratefully acknowledge University Grant commission-CPE-II Phase for providing financial support for purchasing the spectrofluorophotometer, JASCO Model FP-8200.

Footnotes

Conflict of interest: The authors have declared that they have no conflict of interest.

Author contributions: All authors read, reviewed, and approved the final version of the manuscript. Shantanu Kadam was primarily responsible for drafting the manuscript and organizing the content of the study. Swaminath Bhattar reviewed the manuscript thoroughly and led the editing process to improve clarity, structure, and overall quality of the final version. Bhushan Dhale and Bapu Yamgar guided the research process by providing supervisory support, technical inputs, and critical suggestions during the work.

References

  • 1. Paderni D, Giorgi L, Fusi V, Formica M, Ambrosi G, et al. Chemical sensors for rare earth metal ions. Coordination Chemistry Reviews. 2021;429:213639. doi: 10.1016/j.ccr.2020.213639. [DOI] [Google Scholar]
  • 2. Pospieszna-Markiewicz I, Fik-Jaskółka MA, Hnatejko Z, Patroniak V, Kubicki M. Synthesis and characterization of lanthanide metal ion complexes of new polydentate hydrazone schiff base ligand. Molecules. 2022;27(23):8390. doi: 10.3390/molecules27238390. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 3. Vernon RE. The location and composition of Group 3 of the periodic table. Foundations of Chemistry. 2021;23(2):155–197. doi: 10.1007/s10698-020-09384-2. [DOI] [Google Scholar]
  • 4. Wedal JC, Evans WJ. A rare-earth metal retrospective to stimulate all fields. Journal of the American Chemical Society. 2021;143(44):18354–18367. doi: 10.1021/jacs.1c08288. [DOI] [PubMed] [Google Scholar]
  • 5. Zasimov P, Amidani L, Retegan M, Walter O, Caciuffo R, et al. HERFD-XANES and RIXS Study on the electronic structure of trivalent Lanthanides across a series of isostructural compounds. Inorganic Chemistry. 2022;61(4):1817–1830. doi: 10.1021/acs.inorgchem.1c01525. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 6. Hussein KA, Shaalan N. Synthesis, characterization, and antibacterial activity of lanthanum metal complexes with schiff base ligand produced from reaction of 4,4-methylene diantipyrine with ethylenediamine. Indonesian Journal of Chemistry. 2022;22(5):1365–1375. doi: 10.22146/ijc.74214. [DOI] [Google Scholar]
  • 7. Nehra K, Dalal A, Hooda A, Bhagwan S, Saini RK, et al. Lanthanides β-diketonate complexes as energy efficient emissive materials: a review. Journal of Molecular Structure. 2022;1249:131531. doi: 10.1016/j.molstruc.2021.131531. [DOI] [Google Scholar]
  • 8. Prats H, Stamatakis M. Atomistic and electronic structure of metal clusters supported on transition metal carbides: implications for catalysis. Journal of Materials Chemistry A. 2022;10(3):1522–1534. doi: 10.1039/D1TA08468B. [DOI] [Google Scholar]
  • 9. Torres J, Kremer C. Coordination chemistry of lanthanide ions with X-(CH2-COO-)2 (X = O, NH, S) ligands: the leading role of X as carboxylate-connecting group. Coordination Chemistry Reviews. 2023;494:215347. doi: 10.1016/j.ccr.2023.215347. [DOI] [Google Scholar]
  • 10. Ilhan S, Temel H, Kilic A. Synthesis and characterization of new macrocyclic Cu(II) complexes from various diamines, Copper(II) nitrate and 1,4-Bis(2-formylphenoxy)butane. Chinese Journal of Chemistry. 2007;25(10):1547–1550. doi: 10.1002/cjoc.200790284. [DOI] [Google Scholar]
  • 11. Eliseeva SV, Bünzli JCG. Lanthanide luminescence for functional materials and bio-sciences. Chemical Society Reviews. 2010;39(1):189–227. doi: 10.1039/B905604C. [DOI] [PubMed] [Google Scholar]
  • 12. Goldschmidt JC, Fischer S. Upconversion for photovoltaics – a review of materials, devices and concepts for performance enhancement. Advanced Optical Materials. 2015;3(4):510–535. doi: 10.1002/adom.201500024. [DOI] [Google Scholar]
  • 13. Hasegawa M, Ohmagari H, Tanaka H, Machida K. Luminescence of lanthanide complexes: from fundamental to prospective approaches related to water- and molecular-stimuli. Journal of Photochemistry and Photobiology C: Photochemistry Reviews. 2022;50:100484. doi: 10.1016/j.jphotochemrev.2022.100484. [DOI] [Google Scholar]
  • 14. Hamon N, Roux A, Beyler M, Mulatier JC, Andraud C, et al. Pyclen-based Ln(III) complexes as highly luminescent bioprobes for in vitro and in vivo one- and two-photon bioimaging applications. Journal of the American Chemical Society. 2020;142(22):10184–10197. doi: 10.1021/jacs.0c03496. [DOI] [PubMed] [Google Scholar]
  • 15. Yang D, Li H, Li H. Recent advances in the luminescent polymers containing lanthanide complexes. Coordination Chemistry Reviews. 2023;514:215875. doi: 10.1016/j.ccr.2024.215875. [DOI] [Google Scholar]
  • 16. Gallardo H, Braga HC, Tuzimoto P, Bortoluzzi A, Salla CAM, et al. Synthesis, structure and OLED application of a new europium (III) complex: {tris-(thenoyltrifluoroacetonate)[1,2,5]selenadiazolo[3,4-f] [1,10] phenanthroline} europium (III) Inorganica Chimica Acta. 2018;473:75–82. doi: 10.1016/j.ica.2017.12.034. [DOI] [Google Scholar]
  • 17. Utochnikova VV. Lanthanide complexes as OLED emitters. Handbook on the Physics and Chemistry of Rare Earths Including Actinides. 2021;59:1–91. doi: 10.1016/bs.hpcre.2021.05.001. [DOI] [Google Scholar]
  • 18. Deng Q, Zhu Z, Shu X. Auto-phase-locked time-resolved luminescence detection: principles, applications, and prospects. Frontiers in Chemistry. 2020;8:562. doi: 10.3389/fchem.2020.00562. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 19. Chundawat NS, Jadoun S, Zarrintaj P, Chauhan NPS. Lanthanide complexes as anticancer agents: a review. Polyhedron. 2021;207:115387. doi: 10.1016/j.poly.2021.115387. [DOI] [Google Scholar]
  • 20. Bao G. Lanthanide complexes for drug delivery and therapeutics. Journal of Luminescence. 2020;228:117622. doi: 10.1016/j.jlumin.2020.117622. [DOI] [Google Scholar]
  • 21. Chan WL, Xie C, Lo WS, Bünzli JCG, Wong WK, et al. Lanthanide–tetrapyrrole complexes: synthesis, redox chemistry, photophysical properties, and photonic applications. Chemical Society Reviews. 2021;50(21):12189–12257. doi: 10.1039/C9CS00828D. [DOI] [PubMed] [Google Scholar]
  • 22. Elenkova D, Lyapchev R, Romanova J, Morgenstern B, Dimitrova Y, et al. Luminescent complexes of Europium (III) with 2-(Phenylethynyl)-1,10-phenanthroline: the role of the counterions. Molecules. 2021;26(23):7272. doi: 10.3390/molecules26237272. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 23. Kilic A, Yilmaz I, Ulusoy M, Tas E. Synthesis, spectral characterization, electrochemical studies and catalytic properties in Suzuki–Miyaura coupling reactions of the mononuclear PdII, trinuclear PdII(BPh2)2 and RuII–PdII–RuII type complexes containing 4-amino-1-benzyl piperidine and phenyl groups. Applied Organometallic Chemistry. 2008;22(9):494–502. doi: 10.1002/aoc.1430. [DOI] [Google Scholar]
  • 24. Kilic A, Yilmaz I, Tas E. Synthesis, spectroscopic and redox properties of the mononuclear NiII, NiII(BPh2)2 and trinuclear CuII–NiII–CuII complexes of N, N′-(4-amino-1-benzyl piperidine)-glyoxime. Journal of Chemical Sciences. 2009;121:43–56. doi: 10.1007/s12039-009-0005-z. [DOI] [Google Scholar]
  • 25.Tamanna Mutreja V.Biomedical applications of lanthanide complexes. Materials Today: Proceedings. 2022. [DOI]
  • 26. Świderski G, Kalinowska M, Gołębiewska E, Świsłocka R, Lewandowski W, et al. Structures, antioxidant properties, and antimicrobial properties of Eu(III), Gd(III), and Dy(III) caffeinates and p-coumarates. Molecules. 2023;28(18):6506. doi: 10.3390/molecules28186506. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 27. Essawy AA, Afifi MA, Moustafa H, El-Medani SM. DFT calculations, spectroscopic, thermal analysis and biological activity of Sm (III) and Tb (III) complexes with 2-aminobenzoic and 2-amino-5-chloro-benzoic acids. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy. 2014;131:388–397. doi: 10.1016/j.saa.2014.04.134. [DOI] [PubMed] [Google Scholar]
  • 28. Kuz’micheva G, Trigub A, Rogachev A, Dorokhov A, Domoroshchina E. Physicochemical characterization and antimicrobial properties of lanthanide nitrates in dilute aqueous solutions. Molecules. 2024;29(17):4023. doi: 10.3390/molecules29174023. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 29. Abdelshafi NS, Farag AA, Ali AAM, Saleh AA, Zaher AA, et al. Multifunctional novel lanthanide complexes based on chromone moiety for corrosion inhibition, molecular docking, and anticancer and antimicrobial applications. Applied Organometallic Chemistry. 2025;39(3):e70009. doi: 10.1002/aoc.70009. [DOI] [Google Scholar]
  • 30. Yan X, Xu J, Wu X, Zhang Z, Zhang X, et al. Proteasome inhibition and cytostatic effects on human cancer cells by pyrazolone-enamines: a combined crystallographic, structural and computational study. New Journal of Chemistry. 2015;39(3):2168–2180. doi: 10.1039/C4NJ01906G. [DOI] [Google Scholar]
  • 31. Wang HL, Ma XF, Zou HH, Wang K, Li B, et al. Mixed chelating ligands used to regulate the luminescence of Ln (III) complexes and single-ion magnet behavior in Dy-based analogues. Dalton Transactions. 2018;47(44):15929–15940. doi: 10.1039/C8DT03133A. [DOI] [PubMed] [Google Scholar]
  • 32. Maouche R, Belaid S, Benmerad B, Bouacida S, Freslon S, et al. Luminescence properties of lanthanum complexes-based molecular alloys. Inorganica Chimica Acta. 2020;501:119309. doi: 10.1016/j.ica.2019.119309. [DOI] [Google Scholar]
  • 33. Li S, Jansone-Popova S, Jiang D. Insights into coordination and ligand trends of lanthanide complexes from the Cambridge Structural Database. Scientific Reports. 2024;14 doi: 10.1038/s41598-024-62074-3. Article 11301. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 34. Gao HL, Zhou XP, Bi YX, Shen HY, Wang WM, et al. A Dy4 single-molecule magnet and its analogues encapsulated by Schiff base derivative and β-diketonate co-ligand. Dalton Transactions. 2017;46(14):4669–4677. doi: 10.1039/C7DT00118E. [DOI] [PubMed] [Google Scholar]
  • 35. Gao HL, Huang SX, Zhou XP, Liu Z, Cui JZ. Magnetic properties and structure of tetranuclear lanthanide complexes based on 8-hydroxylquinoline Schiff base derivative and β-diketone coligand. Dalton Transactions. 2018;47(10):3503–3511. doi: 10.1039/C8DT00063H. [DOI] [PubMed] [Google Scholar]
  • 36. Zhao LH, Chen HM, Yang AH, Wu DF, Gou J, et al. Synthesis, characterization and properties of lanthanide complexes with different ancillary ligands. Inorganica Chimica Acta. 2019;490:240–245. doi: 10.1016/j.ica.2019.03.030. [DOI] [Google Scholar]
  • 37. Zhao JY, Ren N, Zhang YY, Kun Tang, Zhang JJ. Five dinuclear lanthanide complexes Based on 2,4-dimethylbenzoic Acid and 5,5′-dimethy-2,2′-bipyridine crystal structures, thermal behaviour and luminescent property. Frontiers in Chemistry. 2021;9:726813. doi: 10.3389/fchem.2021.726813. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 38. Niroomand S, Jahanara A, Jahani S, Sargazi G, Patrick B O, et al. A novel binuclear Lanthanum complex containing 1,10-phenanthroline; from crystal structure to biological and antitumor activity. Journal of Photochemistry and Photobiology A: Chemistry. 2023;441:114711. doi: 10.1016/j.jphotochem.2023.114711. [DOI] [Google Scholar]
  • 39. Vlasyuk D, Łyszczek R. Effect of different synthesis approaches on structural and thermal properties of lanthanide (III) metal–organic frameworks based on the 1H-pyrazole-3,5-dicarboxylate linker. Journal of Inorganic and Organometallic Polymers and Materials. 2021;31:3534–3548. doi: 10.1007/s10904-021-02018-w. [DOI] [Google Scholar]
  • 40. Paswan S, Anjum A, Singh AP, Dubey RK. Synthesis and spectroscopic characterization of lanthanum complexes derived from 9,10-phenanthrenequinone and Schiff base ligands containing N, O donor atoms. Indian Journal of Chemistry. 2019;58A(4):446–453. [Google Scholar]
  • 41. Sardaru MC, Marangoci NL, Shova S, Bejan D. Novel lanthanide (III) complexes derived from an imidazole–biphenyl–carboxylate ligand: synthesis, structure and luminescence properties. Molecules. 2021;26(22):6942. doi: 10.3390/molecules26226942. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 42. Tenorio KV, Fortunato AB, Moreira JM, Roman D, D’Oliveira KA, et al. Thermal analysis combined with X-ray diffraction/Rietveld method, FT-IR and UV-vis spectroscopy: structural characterization of lanthanum and cerium (III) polycrystalline complexes. Thermochimica Acta. 2020;690:178662. doi: 10.1016/j.tca.2020.178662. [DOI] [Google Scholar]
  • 43. Niroomand S, Khorasani-Motlagh M, Noroozifar M, Jahani S, Moodi A. Photochemical and DFT studies on DNA-binding ability and antibacterial activity of lanthanum (III)-phenanthroline complex. Journal of Molecular Structure. 2017;1130:940–950. doi: 10.1016/j.molstruc.2016.10.076. [DOI] [Google Scholar]
  • 44. Gao S, Huang M, Sun Z, Li D, Xie C, et al. A new mixed-ligand lanthanum (III) complex with salicylic acid and 1,10-phenanthroline: synthesis, characterization and antibacterial activity and underlying mechanism. Journal of Molecular Structure. 2021;1225:129096. doi: 10.1016/j.molstruc.2020.129096. [DOI] [Google Scholar]
  • 45. Nakai T, Shima K, Shoji S, Fushimi K, Hasegawa Y, et al. Characteristic stacked structures and luminescent properties of dinuclear lanthanum complexes with pyrene units. Frontiers in Chemistry. 2023;11:1154012. doi: 10.3389/fchem.2023.1154012. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 46. Ivanova EA, Smirnova KS, Pozdnyakov IP, Potapov AS, Lider EV. Synthesis, crystal structures and luminescence properties of lanthanum (III) complexes with 1-(1H-benzimidazol-1yl-methyl)-1H-benzotriazole. Inorganica Chimica Acta. 2023;557(2):121697. doi: 10.1016/j.ica.2023.121697. [DOI] [Google Scholar]
  • 47. Hussein KA, Shaalan N. Synthesis, spectroscopy and biological activities studies for new complexes of some lanthanide metals with Schiff bases derived from dimedone with 4-Aminoanitpyrine. Chemical Methodologies. 2022;6(2):103–113. doi: 10.22034/chemm.2022.2.3. [DOI] [Google Scholar]
  • 48. Hao YF, Xu SL, Zhao JJ, Gao J, Ren N, et al. New nitrogen-containing lanthanide complexes with novel structural, thermal and fluorescence properties. Journal of Saudi Chemical Society. 2024;28(1):101792. doi: 10.1016/j.jscs.2023.101792. [DOI] [Google Scholar]
  • 49. Chiriac FL, Iliş M, Madalan A, Manaila-Maximean D, Secu M, et al. Thermal and emission properties of lanthanide complexes with N-biphenyl-alkylated-4-pyridone ligands: crystal structure of a terbium complex with N-benzyl-4-pyridone. Molecules. 2021;26(7):2017. doi: 10.3390/molecules26072017. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 50. Ommenya FK, Nyawade EA, Andala DM, Kinyua J. Synthesis, characterization and antibacterial activity of schiff base, 4-chloro-2-{(E)-[(4-fluorophenyl)imino]methyl}phenol metal (II) complexes. Journal of Chemistry. 2020;2020(1):1745236. doi: 10.1155/2020/1745236. [DOI] [Google Scholar]
  • 51. Fouad R. Synthesis and characterization of lanthanide complexes as potential therapeutic agents. Journal of Coordination Chemistry. 2020;73(14):2015–2028. doi: 10.1080/00958972.2020.1808629. [DOI] [Google Scholar]
  • 52. Morsy NM, Hassan AS, Hafez TS, Mohamed RH, Sadawe IA, et al. Synthesis, antitumor activity, enzyme assay, DNA binding and molecular docking of bis-Schiff bases of pyrazoles. Journal of the Iranian Chemical Society. 2021;18(1):47–59. doi: 10.1007/s13738-020-02004-y. [DOI] [Google Scholar]
  • 53. Hussein KA, Mahdi S, Shaalan N. Synthesis, spectroscopy of new lanthanide complexes with schiff base derived from (4-antipyrinecarboxaldehyde with ethylene di-amine) and study the bioactivity. Baghdad Science Journal. 2023;20(2):469–482. doi: 10.21123/bsj.2022.7088. [DOI] [Google Scholar]
  • 54. Kumar K, Murugesan S, Thillaichidambaram T, Ramakritinan CM. Synthesis, characterization and biological activities of five new trivalent lanthanide complexes of hydrazine and 3,3′-thiodipropanoic acid. Current Chemistry Letters. 2023;12(4):721–732. doi: 10.5267/j.ccl.2023.5.003. [DOI] [Google Scholar]
  • 55.Cappuccino J, Sherman N. Microbiology: A Laboratory Manual. 5th ed. Menlo Park, California, USA: Benjamin/Cummings; 1999. [Google Scholar]
  • 56. Dharmaraj N, Viswanathamurthi P, Natarajan K. Ruthenium (II) complexes containing bidentate Schiff bases and their antifungal activity. Transition Metal Chemistry. 2001;26:105–109. doi: 10.1023/A:1007132408648. [DOI] [Google Scholar]
  • 57. Leber AL. Clinical Microbiology Procedure Handbook American Society for Microbiology. 2016;2(2) doi: 10.1128/9781555818814. [DOI] [Google Scholar]
  • 58.National Committee for Clinical Laboratory Standards. Methods for dilution antimicrobial susceptibility tests for bacteria that grow aerobically, Approved Standard M7A5. 9th ed. Wayne, PA: 2010. [Google Scholar]
  • 59.Shadomy S. Laboratory studies with antifungal agents: susceptibility tests and quantitation in body fluids. In: Balows A, Hausler WJ Jr, Herrmann KL, Isenberg HD, Shadomy HJ, editors. Manual of Clinical Microbiology. Washington, DC, USA: pp. 1173–1183. [Google Scholar]
  • 60.Rattan A. Antimicrobials in Laboratory Medicine. New Delhi, India: Churchill Livingstone; 2000. [Google Scholar]
  • 61. Rieckmann KH, Campbell GH, Sax LJ, Mrema JE. Drug sensitivity of Plasmodium falciparum: an in vitro microtechnique. Lancet. 1978;1:221–223. doi: 10.1016/s0140-6736(78)90365-3. [DOI] [PubMed] [Google Scholar]
  • 62. Desjardins RE. In vitro techniques for antimalarial development and evaluation. Handbook of Experimental Pharmacology, Springer-Verlag, Germany. 1984;68(1):179–200. doi: 10.1007/978-3-642-69251-2_6. [DOI] [Google Scholar]
  • 63. Trager W, Jensen JB. Human malaria parasites in continuous culture. Science. 1976;193:673–675. doi: 10.1126/science.781840. [DOI] [PubMed] [Google Scholar]
  • 64. Lambros C, Vanderberg JP. Synchronization of Plasmodium falciparum intraerythrocytic stages in culture. Journal of Parasitology. 1979;65(3):418–420. doi: 10.2307/3280287. [DOI] [PubMed] [Google Scholar]
  • 65. Singh J. J.S.B. Stain: a review. Indian Journal of Malariology. 1956;10:117–129. [PubMed] [Google Scholar]
  • 66.Panjarathinam R. Parasitology. 2nd ed. Hyderabad, India: Orient Longman Pvt. Ltd; 2007. Textbook of Medical; pp. 329–331. [Google Scholar]
  • 67. Alhafez A, Savci A, Alan Y, Söylemez R, Kilic A. Preparation of Cu(II), Ni(II), Ti(IV), VO(IV), and Zn(II) metal complexes derived from novel vic-dioxime and investigation of their antioxidant and antibacterial activities. Chemistry & Biodiversity. 2022;19(3):e202100768. doi: 10.1002/cbdv.202100768. [DOI] [PubMed] [Google Scholar]

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