Sm Complexes Research Articles

Synthesis of Bis(2,6-Diadamantyl Aryloxide) Ln(II) Complexes of Samarium, Europium, and Ytterbium and Their Ln(III) Precursors.

The syntheses of Ln(II) bis(aryloxide) complexes of Sm, Eu, and Yb have been examined with the bulky aryloxide ligand (OC6H2-2,6-Ad2-4-tBu)1- [(OAr*)1-; Ad = 1-adamantyl]. These LnII(OAr*)2(THF)2 complexes were pursued for comparison with the tris(aryloxide) Ln(II) complexes [LnII(OAr*)3]1- (Ln = La, Ce, Nd, Gd, Dy, and Lu), which have 4fn5d1 electron configurations, and with 4f14 [YbII(OAr*)3]1-. Although the Ln(II) chemistry of Sm, Eu, and Yb is often similar since they all adopt 4fn+1 electron configurations, their chemistry is surprisingly diverse with (OAr*)1-. Reactions of LnIII2(THF)2 with KOAr* in THF form the bis(aryloxide) Ln(II) complexes LnII(OAr*)2(THF)2, 1-Ln, that were characterized by X-ray diffraction for 1-Sm and 1-Yb, but crystals of 1-Eu have been elusive. Reduction of the tris(aryloxide) Sm(III) complex, SmIII(OAr*)3, 2-Sm, prepared from SmIII(NR2)3 (R = SiMe3) and HOAr* in refluxing toluene, generated the bis(aryloxide) complex, 1-Sm, and KOAr* rather than a Sm analogue of [YbII(OAr*)3]1-. Reduction of EuIII(OAr*)3, 2-Eu, prepared from EuCl3 with KOAr* in THF, caused an immediate dark blue-purple to bright red-orange color change, but crystals of the product were elusive. Neither reduction of TmIII(OAr*)3, 2-Tm, nor the reaction of TmIII2(DME)3 with KOAr* provided crystalline Tm(II) complexes.

Syntheses, Structures and Magnetism of Trinuclear Bimetallic MnIILnIIIMnII Complexes (Ln = La, Nd, Sm, Gd, Dy and Er) with 2,6‐Dipicolinoylbis(N,N‐Diethylthiourea)

AbstractSelf‐assembled reactions of 2,6‐dipicolinoylbis(N,N‐diethylthiourea) (H2L) with Mn(CH3COO)2 ⋅ 4H2O and LnCl3, where Ln = La, Nd, Sm, Gd, Dy, Er in MeOH lead to formation of stable trinuclear complexes of the composition [LnMn2(L)2(μ1,3‐CH3COO)2X] (MnIILnIIIMnII), where X− can be κ2‐CH3COO− or κ1‐CH3COO−. Single crystal X‐ray studies reveal their symmetric structures comprising one central Ln(III) ion, two terminal Mn(II) ions sandwiched by two doubly deprotonated ligands {L2−}. The magnetic properties of MnIILaIIIMnII and MnIIGdIIIMnII complexes are successfully simulated using symmetrical magnetic interaction models, giving the best fitted parameters: JMn‐Mn=−0.120(1) cm−1, gMn=1.99(1), TIP=4.45(7) ⋅ 10−4 cm3 mol−1 K for MnIILaIIIMnII and JGd‐Mn=0.042(1) cm−1, JMn‐Mn=−0.076(1) cm−1, gMn=1.96(1), gGd=2.01(1) and TIP=3.59(14) ⋅ 10−4 cm3 mol−1 K for MnIIGdIIIMnII complex. The magnetic interactions between the Mn(II) and Ln(III) ions in the other MnIILnIIIMnII complexes are studied by comparing their χM values to the sum of χM values of the MnIILaIIIMnII and the analogous ZnIILnIIIZnII complexes. The MnIIErIIIMnII complex reveals a strong ferromagnetic interaction, while the Sm, Nd, Gd and Dy complexes show weak ferromagnetic interactions.

Bipyridyldicarboxamides and f-metals: the influence of electron effects on the structure, stability, separation, and photophysical properties of their complexes.

In this work, three isomeric fluorinated bipyridyldicarboxamides were studied to evaluate the impact of the fluorine atom position on the structure, stability, Am(III)/Ln(III) separation, and photophysical properties of their complexes. The complexes of the fluorinated amides have a metal-to-ligand composition of 1 : 1, which is independent of the fluorine atom position or lanthanide metal. The bipyridyl fragments in the fluorinated complexes are flattened compared with those in unsubstituted ones. Ln-to-heteroatom distances are more affected by steric hindrance in the ligand and further by lanthanide ion radius contraction. This leads to significant effectivity of heavy lanthanide extraction compared with the light ones, particularly for 4F diamide. Fluorination leads to a slight variation in the excited triplet state of the complexes, and hence, the effectiveness of luminescence increases for Eu, Sm, and Tb complexes. Moreover, fluorination significantly affects the CIE chromaticity coordinates for the complexes.

Sm(Ⅲ), Gd(Ⅲ), and Eu(Ⅲ) complexes with 8-hydroxyquinoline derivatives as potential anticancer agents via inhibiting cell proliferation, blocking cell cycle, and inducing apoptosis in NCI-H460 cells.

Four lanthanide complexes with 8-hydroxyquinoline-2-aldehyde-2-hydrazinopyridine (H-L1), 8-hydroxyquinoline-2-aldehyde-2-hydrazimidazole (H-L2): [Sm(L1)2][Sm(L1)(NO3)3]·CHCl3·2CH3OH (1), [Gd(L1)2][Gd(L1)(NO3)3]·CHCl3·2CH3OH (2), [Sm(L2)(NO3)2]2·CH3OH (3), and [Eu(L2)(NO3)2]2·CH3OH (4) were synthesized and characterized. In vitro cytotoxicity evaluation showed that the ligands and four lanthanide complexes exhibited cytotoxicity to the five tested tumor cell lines. Among them, complex 1 showed the best antiproliferative activity against NCI-H460 tumor cells. Mechanistic studies demonstrated that complex 1 arrested the cell cycle of NCI-H460 cells in G1 phase and induced mitochondria-mediated apoptosis, which resulted in the loss of mitochondrial membrane potential, enhanced intracellular Ca2+ levels and reactive oxygen species generation. In addition, complex 1 affected the expression levels of intracellular apoptosis-related proteins and activated the caspase-3/9 in NCI-H460 cells. Therefore, complex 1 is a potential anticancer agent.

Lanthanide-Dependent Photochemical and Photophysical Properties of Lanthanide-Anthracene Complexes: Experimental and Theoretical Approaches.

The structural, photophysical, and photochemical properties of Ln(depma)(hmpa)2(NO3)3 (Ln = La, Ce, Nd, Sm, Eu, Tb, Ho, Er, and Yb) complexes 1-Ln were investigated with a multidisciplinary approach involving synthesis, photocycloaddition-based crystal engineering, spectroscopic analytical techniques and quantum chemical ab initio calculations. Depending on the Ln3+ ion the isostructural 1-Ln complexes exhibit quite different behavior upon excitation at 350-400 nm. Some 1-Ln complexes (Ln = La, Ce, Sm, Tb, Yb) emit a broad and strong band near 533 nm arising from paired anthracene moieties, whereas others (Ln = Nd, Eu, Ho, Er) do not. 1-Eu is not emissive at all, whereas 1-Nd, 1-Ho, and 1-Er exhibit a Ln3+ based luminescence. Upon irradiation with 365 nm ultraviolet (UV) light 1-Ln (Ln = La, Ce, Sm, Tb, Yb) dimerize by means of a photochemically induced [4 + 4] cycloaddition of the anthracene moieties, whereas 1-Ln (Ln = Nd, Eu, Ho, Er) remain monomers. We propose three models, based on the matching of the energy levels between the Ln3+ ion and the paired or dimerized anthracene units in the energy-resonance crossing region, as well as on internal conversion-driven and intersystem crossing-driven energy transfer, which explain the Ln3+ ion regulated photophysics and photochemistry of the 1-Ln complexes.

Synthesis and photoluminescent studies of orange–red emissive samarium(III) complexes with 1,1,1-trifluoro-5,5-dimethyl-2,4-hexanedione and 2,2′-bipyridine and its distinctive analogous

Highly luminescent octa-coordinated samarium(III) complexes including [Sm(TFDH)3(Bpy)] (Sm1), [Sm(TFDH)3(S1)] (Sm2), [Sm(TFDH)3(S2)] (Sm3) and [Sm(TFDH)3(S3)] (Sm4) were synthesized utilizing fluorinated β-diketone i.e. 1,1,1-trifluoro-5,5-dimethyl-2,4-hexanedione (TFDH) and bidentate auxiliary ligands. Here, S1 is 5,5ʹ-dibromo-2,2′-bipyridine; S2 is 5-bromo-5ʹ-(3,4-(ethylenedioxy)thien-2-yl)2,2′-bipyridine and S3 is 5,5′-bis(3,4-(ethylenedioxy)thien-2-yl)2,2′-bipyridine. Different properties of prepared complexes were examined using numerous characterization techniques such as elemental, FT-IR, 1H NMR, absorption and thermogravimetric analyses. Nuclear magnetic resonance (NMR) data affirms the coordination of three TFDH units and one bidentate ligand with metal ion in each complex. Sm(III) complexes exhibit thermal stability up to 250 °C when subjected to an inert atmosphere composed of nitrogen (N2) gas. The luminescent characteristics of the powdered Sm1-Sm4 complexes were also investigated. Each complex displays distinct peaks at around 564, 605, 648 and 707 nm in their emission profiles. The orange-red emission of these complexes was observed via colorimetry which strongly aligns with the highly intense peak observed at 648 nm (4G5/2→6H9/2). The strong luminosity and color coordinates suggest that the complexes could serve as potential candidates for use in OLEDs and display panel.

Design and photophysical characterization of dinuclear lanthanide complexes incorporating spacer ligands along with their mononuclear analogues: A comparative study

Two heteroleptic homo-dinuclear complexes of Dy(III) and Sm(III) with pyrazine (pyz) as spacer ligand [Ln(TFPB)3(μ-pyz)Ln(TFPB)3], along with their mononuclear analogue [Ln(TFPB)3(pyz)2] were synthesized and characterized. Diketone TFPB (4,4,4-trifluoro-1-phenyl-1,3-butanedione) was incorporated as main ligand. NMR analysis depicted single peak for pyz protons for dinuclear complexes and two for mononuclear ones, which confirmed the bridging nature of pyz in former complexes. UV spectra revealed two absorption bands despite of the different metal ion and nuclearity of complex, suggesting the absorption of UV-radiation by coordinated moieties inspite of the metal ion involved. The emission spectra exhibited significant intensity of yellow and orange-red peaks for Dy(III) and Sm(III) complexes, respectively, indicating effective sensitization of metal center. The enhanced emission intensity observed in dinuclear Sm-complexes, compared to their mononuclear counterparts, indicates a synergistic effect of the two metal ions on the overall emission properties, rather than a mere additive effect that would be expected from two independent mononuclear units. The photoluminescent properties of synthesized complexes were examined and discussed, suggesting potential applications in display devices. The Correlated Color Temperature (CCT) of these complexes falls within a range suitable for warm light sources and the highest branching ratio observed for 4G5/2 → 6H9/2 (for Sm3+ ion) and 4F9/2 → 6H13/2 (for Dy3+ ion) transitions suggests potential application in laser amplification. The alignment between band gap measurements obtained from UV and CV analyses highlight the possibility of employing these complexes in semiconductor technologies.

Similarities and Differences in Benzene Reduction with Ca, Sr, Yb and Sm: Strong Evidence for Tetra‐Anionic Benzene

AbstractInverse sandwich complexes of Yb and Sm stabilized by a bulky β‐diketiminate (BDI) ligand have been prepared: (BDI)Ln(η6,η6‐C6H6)Ln(BDI); Ln=lanthanide. Coordinated benzene ligands can be neutral, di‐anionic or, often controversially discussed, even tetra‐anionic. The formal charge on benzene is correlated to assignment of the metal oxidation state which generally poses a problem. Herein, we take advantage of the structural similarities found when comparing CaII with YbII, and SrII with SmII complexes. In this work, we found an excellent overlap of the Ca/Yb inverse sandwich structures but a striking difference for the Sr/Sm pair. The much shorter Sm−N and Sm‐C6H6 distances are strong evidence for a SmIII‐benzene−4‐SmIII assignment. This was further supported by NMR spectroscopy, magnetic susceptibility, reactivity and comprehensive computational investigation.

Similarities and Differences in Benzene Reduction with Ca, Sr, Yb and Sm: Strong Evidence for Tetra-Anionic Benzene.

Inverse sandwich complexes of Yb and Sm stabilized by a bulky β-diketiminate (BDI) ligand have been prepared: (BDI)Ln(η6,η6-C6H6)Ln(BDI); Ln=lanthanide. Coordinated benzene ligands can be neutral, di-anionic or, often controversially discussed, even tetra-anionic. The formal charge on benzene is correlated to assignment of the metal oxidation state which generally poses a problem. Herein, we take advantage of the structural similarities found when comparing CaII with YbII, and SrII with SmII complexes. In this work, we found an excellent overlap of the Ca/Yb inverse sandwich structures but a striking difference for the Sr/Sm pair. The much shorter Sm-N and Sm-C6H6 distances are strong evidence for a SmIII-benzene-4-SmIII assignment. This was further supported by NMR spectroscopy, magnetic susceptibility, reactivity and comprehensive computational investigation.

Ciprofloxacin Metal Complexes–Silica Nanoparticles: Characterization, Spectroscopic Study, DNA Interaction and Biological Activity

Ciprofloxacin (CIPH) was classified as one of the most effective quinolone antibiotics, which is commonly used to cure a wide range of infections resulting from Gram-negative and Gram-positive microorganisms. The complexes which formed due to the interaction of Ni(II), Zn(II), Cu(II), Gd(III) and Sm(III) with ciprofloxacin were characterized by CHN% analysis, conductivity, FTIR, electronic spectra, fluorescence measurements, and magnetic susceptibility, besides studying the complex–DNA interaction. Meanwhile, the molar conductance values (0.001 mol·L−1 in DMSO) revealed the electrolytic behavior of the complexes and could be designated with the A−B+ formula. In addition, the geometry of the compounds was confirmed from the electronic transitions as well as the μeff values as octahedral for all complexes. The postulated formula could be generally assigned as [M(CIP)a(CIPH)b(H2O)c](NO3)(H2O)n(C2H5OH)m. Moreover, the interaction between metal complexes and DNA revealed that the Cu complex had the highest binding constant. Nanotechnology was applied to synthesized compounds using silica nanoparticles (SiNPs), which were prepared using a sol–gel process. The silica nanoparticles were chemically functionalized for binding the ligand and its metal complexes; this enables the as-prepared compounds to enhance their features as a drug delivery platform. Meanwhile, the antimicrobial activity was tested for the free complexes and SiNPs composites. Collectively, Sm complex gave the largest zone of inhibition, while the Cu(II)–SiNPs composite showed the strongest potential to reduce the bacterial activity. Furthermore, the fluorescence data of CIPH, ligand–metal mixture and the effect of silica nanoparticles on them were studied.

Synthesis, characterization and luminescent properties of N-donor based samarium-tris-β-diketonate: Tuning optoelectronic characteristics for displays applications

Ternary Sm(III) complexes of general representation [Sm(TFDH)3L] were synthesized to understand influence of different auxiliary moieties on their optoelectronic properties. The synthesized complexes were thoroughly investigated using elemental, IR, NMR, UV and PL studies. In these complexes, the emitting metal ion is bonded with six O atoms from di-ketone 1,1,1-trifluoro-5,5-dimethyl-2,4-hexanedione and two nitrogen atoms from neutral ligand i.e. 1,10-phenanthroline and its derivatives. Proton NMR spectral data showed that samarium ion induced chemical shift is dipolar in nature. The photoluminescence analysis showed that the complexes show intense orange-red emission due to 4G5/2 → 6H9/2 transition. Moreover, CIE color coordinates supported the results obtained from photoluminescence study, providing additional confirmation of the luminescent properties of prepared complexes within the orange-red region. Their utility in displays and OLED's was confirmed by studying their optical and electronic band gaps.

Comprehensive Photophysical and Nonlinear Spectroscopic Study of Thioanisolyl‐Picolinate Triazacyclononane Lanthanide Complexes

AbstractDetailed photophysical studies of luminescent lanthanide complexes are presented and elaborated using a newly developed thioanisolyl‐picolinate antenna and the related tacn macrocyclic ligand. The new ligand proved to sensitise Nd(III), Sm(III), Eu(III) and Yb(III) emission. Eu(III) complex showed complete energy transfer, yielding high quantum yield (44 %) and brightness, while the Tb(III) analogue underwent a thermally activated back‐energy transfer, resulting in a strong oxygen quenching of the triplet excited state. Transient absorption spectroscopy measurements of Gd(III), Tb(III) and Eu(III) compounds confirmed the sensitization processes upon the charge‐transfer antenna excitation. The triplet excited state lifetime of the Tb(III) complex was 5‐times longer than that of the Gd(III) analogue. In contrast, the triplet state was totally quenched by the energy transfer to the 4f‐metal ion in the Eu(III) species. Nonlinear two‐photon absorption highlighted efficient biphotonic sensitization in Eu(III) and Sm(III) complexes. In case of the Nd(III) compound, one‐photon absorption in 4f–4f transitions was predominant, despite the excitation at the antenna two‐photon band. This phenomenon was due to the Nd(III) 4f–4f transitions overlapping with the wavelength‐doubled absorption of the complex.

Synthesis, Spectroscopy and Biological Activities of Some Trivalent Lanthanide Complexes of Octadecyl N-salicylaldimine (ONsal)

A series of Ln(III) complexes of octadecyl N-salicylaldimine (ONsal) were synthesized and characterized by CHN analysis, magnetic moment, conductivity, thermoanalytical and spectroscopic methods. Elemental and thermal analysis data confirmed the formation of heptacoordinated [Ln(ONsal)2Cl2(H2O)]Cl complexes where Ln = Ce3+, Nd3+, Sm3+, Eu3+, Gd3+, Tb3+, Dy3+, Ho3+, which is further supported by the respective mass spectra. The ligand acts as a neutral bidentate species coordinating through azomethine nitrogen and phenolic O-atom. The linkage of one H2O molecule in all the complexes has been inferred from the thermal analysis. All the Ln(III) complexes are paramagnetic in nature and act as 2:1 electrolyte in 0.002 M DMF at 25 ºC. The complexes of Sm(III), Eu(III) and Tb(III) display luminescent properties. The powder XRD patterns of Nd(III) and Dy(III) complexes could be successfully indexed for monoclinic crystal systems, while the diffraction lines of Eu(III) complex are indexed for a triclinic crystal system. Methanolic solutions of the ligand and complexes were checked for α-glucosidase and α-amylase inhibitory properties where some of the Ln(III) complexes show significant α-glucosidase inhibitory potency while only Tb(III) complex shows inhibition against α-amylase.

Stability trend analysis of light lanthanide complexes with a fluorophenyl-dipicolinamide: A quantum chemical study

Extracting lanthanides (Ln) from actinides (An) is a crucial step in reprocessing spent nuclear fuel, and the interaction between ligands and Ln inevitably deserves careful study. In this study, we employ density functional theory (DFT) calculations to analyze the stability trend of trivalent light lanthanides (Ln (III), from La(III) to Eu(III)) complexes with N,N'‑diethyl-N,N'-di(para)fluorophenyl-2,6-dipicolinamide (FDPA), which has emerged as a promising ligand in Ln-An separation. The bond length, nature of bonding and electronic energy density properties of Ln-N and Ln-O bonds have been investigated. The quantum theory of atoms in molecules calculation shows that Ln(III)-FDPA complexes are stable, via closed-shell interactions. The Gibbs free energy changes (∆G) of La(III), Pr(III), Pm(III), Sm(III), and Eu(III) complexes with FDPA are approximately -0.07 Kcal/mol. In contrast, the ∆G values of Ce(III) and Nd(III) complexes with FDPA are 1.534 and 0.781 Kcal/mol, respectively. These findings indicate that La(III), Pr(III), Pm(III), Sm(III), and Eu(III) can be excellently extracted by FDPA from acidic solvents, whereas Ce(III) and Nd(III) do not. Our study contributes to a better understanding of the mechanism of lanthanide complexes and provides guidance for the design of ligands that can effectively discriminate lanthanides in nuclear waste reprocessing.

Sm complex assembly and 5' cap trimethylation promote selective processing of snRNAs by the 3' exonuclease TOE1.

Competing exonucleases that promote 3' end maturation or degradation direct quality control of small non-coding RNAs, but how these enzymes distinguish normal from aberrant RNAs is poorly understood. The Pontocerebellar Hypoplasia 7 (PCH7)-associated 3' exonuclease TOE1 promotes maturation of canonical small nuclear RNAs (snRNAs). Here, we demonstrate that TOE1 achieves specificity toward canonical snRNAs through their Sm complex assembly and cap trimethylation, two features that distinguish snRNAs undergoing correct biogenesis from other small non-coding RNAs. Indeed, disruption of Sm complex assembly via snRNA mutations or protein depletions obstructs snRNA processing by TOE1, and in vitro snRNA processing by TOE1 is stimulated by a trimethylated cap. An unstable snRNA variant that normally fails to undergo maturation becomes fully processed by TOE1 when its degenerate Sm binding motif is converted into a canonical one. Our findings uncover the molecular basis for how TOE1 distinguishes snRNAs from other small non-coding RNAs and explain how TOE1 promotes maturation specifically of canonical snRNAs undergoing proper processing.

Density functional theory investigations on the mechanisms of homogeneous Sm complex catalyzed CO[formula omitted] cycloaddition with epoxides

Converting excess CO2 into chemically valuable products is a promising routine for sustainable development. Catalyzing epoxides and CO2 cycloaddition reactions homogeneously with rare-earth compounds is an emerging approach. The reaction efficiency can be understood by mechanism study. In this work, we report a detailed density functional theory investigation on a well-designed experimental Sm catalyst. We calibrate the ωB97XD exchange–correlation functional as the best candidate functional for this specific catalytic system. The energetic span of catalytic cycle is approximately 25 kcal mol−1. The rate-determining transition state is the one for ring-closure to generate the product. Two competing paths are revealed. Through both ionic and covalent metal–ligand interactions, the lowering of the epoxide substrate ring-opening step barrier is significant compared with the Sm compound free case. This work demonstrate the values for utilizing modern density functional theory to complement the understandings on the homogeneous rare-earth catalytic processes.

Effect of Sm(DBM)3Phen incorporation methodology on spectroscopic properties of PVA nanofibres

Electrospun nanofibres are an advancing area of research because of their flexible characteristics and numerous applications in sensors, optoelectronic devices, etc. Herein, we first prepared lanthanide complex Sm(DBM)3Phen. The synthesized complex was then incorporated into and onto the surface. The detailed study of spectroscopic properties of electrospun nanofibres into and onto the surface is presented. The fabricated nanofibres of Sm(DBM)3Phen into the nanofibres surface had a diameter of around 295 nm and length > 200 µm and the surface morphology of the complex incorporated nanofibres presented that the nanofibres were smooth and straight and were highly interlaced. The nanofibres with Sm complex on the surface presented a rough surface morphology. The spectroscopic analysis shows energy transfer from the ligand Dibenzoylmethane (DBM) to Sm3+ ion, enhancing its photoluminescence intensity. Under UV excitation, the Sm(DBM)3Phen incorporated nanofibres exhibited emission peaks between 550 nm and 710 nm and with sharp peaks at 564, 598 nm, and 646 nm, which are assigned to the transition from 4G5/2 to 6HJ (J = 5/2, 7/2, and 9/2) attributed to DBM. The photoluminescence intensity of the two nanofibres varied with the incorporation method. A detailed spectroscopic analysis of the synthesized samples with the incorporation methodology is carried out.

Heteroleptic samarium complexes with high quantum yields for temperature sensing applications.

Two new crystallographically characterized samarium complexes, [Sm(fod)3(L1)] (1) and [Sm(fod)3(L2)] (2) {L1 = 4,7-diphenyl-1,10-phenanthroline (bath), L2 = 2,2':6',2''-terpyridine and fod = anion of 6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedione (Hfod)}, were synthesized and thoroughly characterized. Single-crystal (SC) analysis shows that complex 1 is an eight-coordinate structure with a distorted square antiprism geometry (D4d), whereas complex 2 possesses a nine-coordinate structure with distorted muffin geometry (Cs). The NMR results are in line with SC-XRD analysis, which further validate that the complexes remain intact in solutions. The photophysical characteristics of the complexes were studied in both visible and near infra-red (NIR) regions. The PLQY values of the present complexes were found to be higher than those reported in the literature except for a tetrakis Sm complex. This result indicates that both the ligands act as effective antennas for the present systems. A comparison of PLQY and emission lifetime values within the present complexes (in solid state) reveals that energy transfer from terpy to Sm3+ is more effective than that from the bath ligand. Various color parameters of the complexes were calculated, and the determined CCT values suggest that the complexes may be used as warm light sources. The determined band gap values for the complexes are in the range of those for semiconductors, which suggest the application of present systems in the field of optoelectronics. The curve between the emission intensity and temperature for complex 1 shows a perfect linearity (χ2 = 0.99), which suggests that this complex can have potential application as a temperature sensor in the range 60-350 K.

Lanthanide complexes with a new luminescent iminophosphonamide ligand bearing phenylbenzothiazole substituents.

A new iminophosphonamine Ph2P(HNPbt)(NPbt) (1, HL) bearing chromophore 2-(phen-2'-yl)-1,3-benzothiazole (Pbt) substituents was synthesized and introduced into lanthanide complexes. It was found that salt metathesis reactions between KL (2) generated in situ and LnCl3 lead to the formation of tris-iminophosphonamide complexes [LnL2]L (Ln = Y (3), Sm (4), Gd (5), Dy (6)), regardless of the 2/LnCl3 ratio. Compounds 3-6 consist of a cationic fragment [LnL2]+, where the lanthanide atom is surrounded by two rigidly κ4-coordinated ligands, and an L- anion residing in the outer coordination sphere. Iminophosphonamine 1 shows a rare excitation wavelength-dependent two-band luminescence in the solid state. For compounds containing the deprotonated form, namely potassium salt KL and complexes of Gd and Dy, a single-band luminescence with the color changing from turquoise to orange was observed. The Sm complex reveals a set of a few narrow well-resolved bands corresponding to the f-f transitions against the background of the outer-sphere ligand's emission.

Determination of apoptotic effects of newly synthesized avobenzone Sm(III) complex in non-small cell lung cancer

In this study, we aimed to investigate the apoptotic effects of the lanthanide complex TBK-23, which was used in biological imaging due to its magnetic and spectroscopic properties. The study utilized HTB-54 and BEAS-2B cell lines. The cells were subjected to TBK-23 and cisplatin at active doses for a duration of 24 hours. Subsequently, flow cytometry was employed to assess the quantity of apoptotic cells, while quantitative RT-PCR was used to measure the expression levels of BAX, BCL-2, and BCL-xL. While cisplatin at 31 µM increased the proapoptotic BAX expression level in HTB-54 and BEAS-2B cells, TBK-23 increased BAX in cancer cells at the same concentration, but there was no observable effect in healthy cells. TBK-23 was found to have higher inhibitory effect on the expression of the antiapoptotic BCL-2 gene in cancer cells compared to that of cisplatin-treated cells. Consequently, it was determined that TBK-23, a novel metal-based compound, exhibited apoptotic effects similar to that of cisplatin and could be a potential chemotherapeutic agent.