Phen Complexes Research Articles

Preparation, characterization, and DNA interaction studies of cationic europium luminescent copolymer

This paper proposed a simple synthetic strategy towards a novel cationic europium luminescent copolymer, poly(METAC-co-NIPAm-co-Eu(AA)3Phen) (PMNEu), and investigation about their complexation ability with DNA. In this approach, first, Eu(AA)3Phen complex monomer containing Eu3+, acrylic acid (AA), and 1,10-phenanthroline (Phen) was synthesized, and subsequently, free radical copolymerization of Eu(AA)3Phen complex monomer with other two functional monomers, [2-(methacryloyloxy) ethyl] trimethylammonium chloride (METAC) and N-isopropylarylamide (NIPAm), was carried out in methanol using azodiisobutyronitrile (AIBN) as the initiator. 1HNMR, GPC, fluorescence spectroscopy, UV–vis spectroscopy, and TEM were used to investigate the chemical structures, molecular weight and molecular weight distribution, fluorescence properties, UV spectra, and morphologies of PMNEu copolymer, respectively. Furthermore, the interaction of PMNEu with DNA was also studied with fluorescence spectroscopy, UV–vis spectroscopy, and agarose gel electrophoresis. These results indicated that PMNEu could interact with DNA via an electrostatic bonding mode and the bonding constant was 2.2 × 105 L/mol. Additionally, TEM observation showed that pure PMNEu formed micelles in water solution, while the size-controllable aggregations of PMNEu with DNA were obtained when PMNEu was mixed with DNA at various concentration ratios. A good biocompability of PMNEu was demonstrated through in vitro cytotoxicity assays.

Synthesis Of Tb0.7Eu0.3(acac)3 Phen Organic Polymer Complex For Display Devices

Synthesis of volatile Eu(acac)3phen and Tb(acac)3phen complexes by solution technique were reported in this paper. The combination of Eu and Tb complexes, namely TbxEu(1-x)(acac)3phen (x=0.1,0.3,0.5,0.7,0.9) were also synthesized by maintaining stoichiometric ratio. Optical properties of these synthesized complexes were studied using photoluminescence technique. Eu(acac)3phen exhibits red intense emission at 612 nm with a sharp spectral bandwidth 5 nm when excited at a wavelength of 323nm, while Tb(acac)3 phen shows green emission at 547 nm when excited at 347nm. The emission spectra of TbxEu(1-x)(acac)3phen reveals that Tb0.7Eu0.3(acac)3 phen complex exhibits maximum intensity among all the stichiometrically doped complexes. When Tb0.7Eu0.3(acac)3 phen was molecularly doped in poly methyl Metacrylate (PMMA) to check its compatibility in polymers, enhancement in intensity was observed in these blended films, proving that these complexes can be used as emissive materials for fabricating OLEDs and displays by vacuum deposition as well as solution techniques.

Sol–gel derived silica thin films immobilized with 1,10-phenanthroline and their binding activity toward iron(II)

Transparent sol–gel thin films immobilized with 1,10-phenanthroline were prepared via the acid-catalyzed sol–gel reaction of tetraethylorthosilicate (TEOS) in the presence of phen. Three surfactants that include cationic cetyl trimethyl ammonium bromide (CTAB), anionic sodium dodecyl sulfate (SDS) and non-ionic Triton X-100 (TX-100) were tested for the improvement of the host material mesostructure, increasing its porosity and good accommodation of the phen within the silica matrix. The immobilized phen thin films showed similar behavior as their free counterpart in aqueous solution. The immobilized phen complex retained its activity toward Fe2+ metal ions by immobilization and produced a stable complex without any shift in the wavelength of Vis absorption spectra comparing with its free counterpart. Different parameters including concentrations of phen, Fe2+ and surfactant, type of surfactant, lifetime and number of measurements were investigated. The phen thin film sensor showed high sensitivity, chemical stability, good reproducibility and long lifetime behavior. The immobilized phen thin films were used for quantification of iron(II) in versatile aqueous samples. The polarized light microscopy indicated that the phen molecules were distributed uniformly within the host silica network.

Electrochemical Reaction of Tris(1,10-phenanthroline)Iron Complexes in Some Amide-Type Ionic Liquids

Electrode reactions of tris(1,10-phenanthroline)iron complexes, [Fe(phen)3]3+/2+, were investigated in some amide-type ionic liquids. The diffusion coefficients of [Fe(phen)3]2+ and [Fe(phen)3]3+ were smaller than those of tris(2,2'-bipyridine)iron complexes, [Fe(bpy)3]2+ and [Fe(bpy)3]3+, in each ionic liquid, reflecting the phen complexes are larger than the bpy complexes. The ratio of diffusion coefficient of the trivalent species to the divalent one for [Fe(phen)3]3+/2+ was smaller than that for [Fe(bpy)3]3+/2+, indicating the coulombic interaction between the charged species and the ions composing the ionic liquid is dependent on the charge densities of complexes. The rate constants for [Fe(phen)3]3+/2+ were close to those for [Fe(bpy)3]3+/2+, suggesting the outer components of reorganization energies for both complexes are similar to each other. On the other hand, the reaction entropies for [Fe(phen)3]3+/2+ were smaller than those for [Fe(bpy)3]3+/2+, reflecting the difference in the charge densities of complexes.

Photoacoustic Spectral Study of Lanthanide Complexes Doped in Silica Matrix

Lanthanide phenanthroline (phen) complexes \(\mathrm{Eu(phen)}_{2}\mathrm{Cl}_{3}{\cdot } \mathrm{2H}_{2}\mathrm{O}\) and \(\mathrm{Nd(phen)}_{2}\mathrm{Cl}_{3}{\cdot } \mathrm{2H}_{2}\mathrm{O}\) were incorporated into a silica matrix by an ultrasonic assisted sol–gel method. In the region of ligand absorption, the photoacoustic (PA) intensity for a lanthanide complex is the same as in wet gels. Upon heat treatment at 120\(\,^{\circ }\)C, however, the PA intensity of a \(\mathrm{Nd(phen)}_{2}\mathrm{Cl}_{3}{\cdot }\mathrm{2H}_{2}\)O-doped sample is much larger than that of a \(\mathrm{Eu(phen)}_{2}\mathrm{Cl}_{3} {\cdot } \mathrm{2H}_{2}\)O-doped sample. The characteristic emissions of \(\mathrm{Eu}^{3+}\) complex-doped samples were used to interpret the stability of the complex in silica matrices. The luminescence spectra are consistent with the PA results. The study indicates that phen can only coordinate with lanthanide ions in a silica matrix after a suitable heat treatment. Moreover, the covalency parameters and PA bands of f–f transionts of \(\mathrm{Nd}^{3+}\) have been used to study the formation of the complex in a silica matrix.

Anomalous chemosensitivity of SOD mimetic sulfurated amino acid–phen complexes: synthesis, characterization, and DNA cleavage efficacy

The DNA interaction efficacies of mixed-ligand complexes [ML(phen)2]Cl [L = a Schiff base derived from p-substituted benzaldehyde (L1 = NO2/L2 = –OCH3) and methionine; phen = 1,10-phenanthroline, the co-ligand] have been explored by absorption, electrochemistry, viscosity measurements, and agarose gel electrophoresis. The results indicate that these complexes can bind to calf thymus DNA via an intercalative mode and show efficient cleavage activity in the presence of H2O2. They are dose dependent. The antioxidative properties reveal that one complex has a stronger radical-scavenging potency than ligands. The complexes exhibit superoxide dismutase (SOD)-like activity with their IC 50 values ranging from 0.46 to 2.93 µM. Moreover, all the complexes have shown relatively high antibacterial and antifungal potencies. The in vitro chemosensitivity of the studied complexes exhibits significant cytotoxic effects, comparable to those reported for cisplatin. These findings represent a prompting to search for the probable interaction of these complexes with other cellular elements of fundamental consequence in cell proliferation.

Probing the cell death signaling pathway of HepG2 cell line induced by copper-1,10-phenanthroline complex

Copper-1,10-phenanthroline (phen) complex [Cu(phen)2] has been typically known as DNA-cleaving agent. And now it becomes more important for developing multifunctional drugs with its improved cytotoxic properties. In our study, we probed the cytophysiological mechanism of Cu(phen)2. HepG2 cells were more sensitive to Cu(phen)2 with an IC50 of 4.03 μM than other three kinds of cell lines. After treated by Cu(phen)2, HepG2 cells had some typical morphological changes which happened to its nucleus. DNA ladder's occurence and Annexin V-positive increased cells indicated that Cu(phen)2 induced HepG2 cells into apoptosis. Further studies showed that Cu(phen)2 treatment resulted in significant G2/M phase arrest and collapse of mitochondrial membrane potential. Several cell cycle-related factors were down-regulated, including Cyclin A, Cyclin B1 and Cdc2. But p21 and p53 were up-regulated. DNA damage, microtubule disorganization and mitotic arrest through spindle assembly checkpoint activation were observed in Cu(phen)2-treated cells. The activation of caspase-3, 8 & 9 were checked out. The increased-expression ratio of Bax/Bcl-2 was detected. The expression levels of Bcl-xL and Bid were found to decrease. These meant that a mitochondrial-related apoptosis pathway was activated in treated HepG2 cells. Furthermore, some ER stress-associated signaling factors were found to be up-regulated, such as Grp78, XBP-1and CHOP. Ca(2+) was also found to be released from the ER lumen. Collectively, our findings demonstrate that Cu(phen)2 induces apoptosis in HepG2 cells via mitotic arrest and mitochondrial- and ER-stress-related signaling pathways.

Effect of UV Treatment on Optical Properties of Low-Density Polyethylene Films Doped with Eu(TTA)<sub>3</sub>phen Complex

Low-Density Polyethylene (LDPE) films doped with Eu (TTA)3phen complex (TTA=2-thenoyltrifluoroacetone, phen=1,10-phenanthroline) were fabricated by hot-blowing technique for thickness of 100 μm. The films were doped with 0.1 % of Eu (TTA)3phen to the total weight of LDPE and exposed to UV irradiation from deuterium lamp for 5, 10, 20, 40 and 60 hours to investigate the effect of its optical properties. The films were characterized by Spectrofluorometer, UV/VIS Spectrophotometer and FT-IR Spectrometer to measure their emission spectra, lifetimes, transmission transparency and chemical bonding. Photoluminescence of the room-temperature Eu (TTA)3phen doped films consist of typical Eu3+emission transition lines with hypersensitive5D07F2emission band at 610 nm. After 20 hours UV treatment, the peak intensity dropped by 90 % and shortened the luminescent lifetimes from 0.654 ms to 0.305 ms. Longer UV treatment also has accelerated degradation in doped LDPE films shown by significant reducing in absorption peak of FTIR at 3395, 3186 and 1645 cm-1. The results would provide a mechanism to improve the lifetime of the LDPE by utilizing the light-manipulation property of Eu (TTA)3phen complex to absorb UV spectrum and covert into red emission.Keywords: LDPE, rare-earth complex, photoluminescence

Luminescent properties of tri-cellulose acetate composites doped with rare earth terbium (III) complex

Rare earth terbium (III) ternary complexes were synthesized using acrylic acid (AA) or 5-sulfosalicylic acid (SSA) as the first ligand and 1,10-phenanthroline (Phen) as the second ligand. Tri-cellulose acetate (TCA)/Tb(AA)3Phen or TCA/Tb(SSA)3Phen composites were prepared by means of solution blend, and their luminescent properties were investigated by fluorescence spectrophotometer. The luminescence spectra of TCA/Tb(AA)3Phen and TCA/Tb(SSA)3Phen composites display the characteristic excitation and emission bands of terbium ions and suggest some influence of the TCA matrix on luminescent properties of the terbium complexes. The maximum excitation peak at around 343 nm for the Tb(SSA)3Phen system is redshifted for 14 nm, compared with 329 nm for the Tb(AA)3Phen system, which is correlated to the electron-donating/attractive groups of ligands. In the range of doping concentration of the Tb(AA)3Phen complex (1, 2 and 5 wt.%) or the Tb(SSA)3Phen complex (1, 2, 3 and 5 wt.%), emission intensities increase with the increment of corresponding doping concentration and concentration quenching effect has not taken place.

DFT studies on the mechanism of veratryl alcohol oxidation catalyzed by Cu–phen complexes

Density functional theory (DFT) calculations have been performed to investigate the catalytic mechanism for the oxidation of veratryl alcohol to veratraldehyde by Cu–phen catalyst. In this work, the most favorable mechanism has been predicted and we hope the obtained results could provide useful insights for the reaction process.

Selection of Suitable Micellar Catalyst for 1,10-Phenanthroline Promoted Chromic Acid Oxidation of Formic Acid in Aqueous Media at Room Temperature

In the present investigation, kinetic studies of oxidation of formic acid with and without catalyst and promoter in aqueous acid media were studied under the pseudo-first order conditions (formic acid)T >>(Cr(VI))T at room temperature. In the 1,10-phenanthroline (phen) promoted path, the cationic Cr(VI) phen complex is the main active oxidant species under- goes a nucleophilic attack by the substrate to form a ternary complex which subsequently experiences a redox decomposition through several steps leading to the products CO2 and H2 along with the Cr(III) phen complex. The anionic surfactant (i.e., sodium dodecyl sulfate, SDS) and neutral surfactant (i.e., Triton X-100, TX-100) act as catalyst and the reaction undergo simultaneously in both aqueous and micellar phase with an enhanced rate of oxidation in the micellar phase. Whereas the cat- ionic surfactant (i.e., N-cetyl pyridinium chloride, CPC) acts as an inhibitor restricts the reaction to aqueous phase. The observed net enhancement of rate effects has been explained by considering the hydrophobic and electrostatic interaction between the sur- factants and reactants. The neutral surfactant TX-100 has been observed as the suitable micellar catalyst for the phen pro- moted chromic acid oxidation of formic acid.

Co-luminescence properties of terbium ions–benzoic acid–phen complexes doped with europium ions

Series of complexes Eu x Tb1−x (BA)3phen (0.01 ≤ x ≤ 0.50) were synthesized by co-precipitation method, BA was used as the carboxylic acid ligand and 1, 10-phenanthroline was used as the electrically neutral ligand. The samples were characterized by means of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermal gravimetric analyses and differential scanning calorimetry (TG–DSC), ultraviolet and visible spectrophotometer absorption spectra, and photoluminescence spectra to study the structure, the energy absorption, the thermal, and luminescent properties of the rare earth complexes. The results show that the series rare earth organic complexes are well crystallized and show high thermal stability. The luminescent intensity of europium ion in the complexes increases as terbium ion transfers the absorbed energy to europium ion in the complexes. The emission of terbium ion at 545 nm is not quenched by europium ion but increases with the content of europium ion decreasing. When the x value is 0.01, the fluorescence intensity reaches the maximum as well as the emission intensity of terbium ions at 545 nm and europium ions at 614 nm are almost equal. It realizes the co-luminescence phenomenon of terbium ion and europium ion. The series rare earth organic complexes with different colors can be obtained by adjusting the ratio of terbium ion and europium ion.

μ-Oxamido binuclear copper (II) complexes: Synthesis, crystal structure, DNA interaction and antibacterial studies

Four binuclear copper (II) complexes [Cu(oxpn)Cu(B)]2+ (2–5) bridged by N, N′-bis[3-(methylamino) propyl] oxamide (oxpn), where, B is N, N-donor heterocyclic bases (viz. 2,2′-bipyridine (bpy, 2), 1,10-phenathroline (phen, 3), dipyrido[3,2-d:2′,3′-f]quinoxaline (dpq, 4) and dipyrido[3,2-a:2′,3′-c]phenazine (dppz, 5) are synthesized, characterized by different spectroscopic and single crystal X-ray data technique. The phen (3) and dpq (4) complexes were structurally characterized by X-ray data analysis. Their DNA binding, oxidative cleavage and antibactirial activities were studied. The dpq (4) and dppz (5) complexes are avid binders to the Calf thymus DNA (CT-DNA). The phen (3), dpq (4) and dppz (5) complexes show efficient oxidative cleavage of supercoiled DNA (SC DNA) through hydroxyl radical (OH) pathway in the presence of Mercaptopropionic acid (MPA).

Copper(II) complexes of N-(2-{[(2E)-2-(2-Hydroxy-(5-substituted)-benzylidene)-hydrazino]carbonyl}phenyl)benzamide ligands and heterocyclic coligands

Some copper(II) complexes of the type [Cu(L1–3)(phen]⋅CH2Cl2 (1a–3a) and [Cu(L1–3) (bipy)]⋅CH2Cl2 (1b–3b) (where L1=N-(2-{[(2E)-2-(2-Hydroxy-benzylidene)-hydrazino]carbonyl}phenyl)benzamide, L2=N-(2-{[(2E)-2-(2-Hydroxy-(5-bromo)-benzylidene)-hydrazino]carbonyl}phenyl)benzamide, L3=N-(2-{[(2E)-2-(2-Hydroxy-(5-methoxy)-benzylidene)-hydrazino]carbonyl}phenyl)benzamide; phen=1,10-phenanthroline, bipy=2,2′-bipyridine) have been prepared and characterized on the basis of elemental analyses, IR, UV–Vis and EPR spectral studies. IR spectra indicate that the ligand L1–3 exists in the keto form in the solid state, while at the time of complexation, it tautomerises into enol form. The single crystal X-ray diffraction study of the representative complex [Cu(L1) (phen)]⋅CH2Cl2 (1a) reveals the distorted square pyramidal geometry around copper(II). Crystal data of (1a): space group=P21/n, a=11.5691(16)Å, b=11.0885(15)Å, c=24.890(4)Å, V=3166.2(8)Å3, Z=4. The electrochemical behavior of all the complexes indicate that the phen complexes appears at more positive potential as compared to those for bipy complexes, as a consequence of its stronger π acidic character. All the complexes exhibit blue–green emission as a result of the fluorescence from the intra-ligand (π→π∗) emission excited state.

A novel photoluminescent nanohybrid of poly(ε-caprolactone) grafted Mg/Al layered double hydroxides and Tb3+ ions: Synthesis and characterization

This paper demonstrates a systematic study of the synthesis and characterization of the hybrid of Mg–Al layer double hydroxides (LDHs), poly(ε-caprolactone) (PCL), and terbium ions (Tb3+). The hybrid LDH-g-PCL-Tb3+-1,10-phenanthroline (Phen) was prepared by the combination of ring opening polymerization (ROP), click chemistry, and coordination chemistry. First, LDHs with a molar ratio of Mg/Al = 2 were prepared by the co-precipitation method, which was subsequently functionalized with (3-chloropropyl) trimethoxysilane in order to introduce azide groups through the reaction of chlorine with sodium azide. Meanwhile, the acetylene functionalized PCL was prepared by ROP of ε-CL, followed by esterification of the hydroxyl groups using succinic anhydride. The click reaction of alkyne-PCL and N3-LDHs successfully afforded LDH-g-PCL, which was coordinated with Tb3+ ions in the presence of Phen. The structure and properties of the nanohybrids were investigated by FT-IR, XPS, EDS, SEM, and TGA analyses. The data indicate the coordination of Tb3+ ions with LDH-g-PCL nanohybrids. The content of Tb3+ ions in the LDH-g-PCL-Tb3+-Phen complex was calculated to be 8.7% (w/w). The LDH-g-PCL-Tb3+-Phen complexes showed four emission bands with high fluorescence intensity centered at 489 nm (5D4 → 7F6), 546 nm (5D4 → 7F5), 586 nm (5D4 → 7F4) and 623 nm (5D4 → 7F3) with excitation at 328 nm (3F6 → 5G6). The stability of LDH-g-PCL-Tb3+-Phen complexes under UV irradiation was high, and no leaching effect was observed.

The Preparation of Tri-Cellulose Acetate Hybrid Material Containing Rare Earth Europium (III) Complex

Europium (III), acrylic acid and 1,10-phenanthroline three ternary complexes was synthesized with acrylic acid (AA) as the first ligand and 1,10-phenanthroline as the second ligand. Tri-cellulose acetate (TCA)/Eu (AA)3Phen hybrid material was prepared by the method of solution blend, dimethyl sulfoxide (DMSO) as the mutual solvent. The Fourier transform infrared spectroscopy (FT-IR) results confirmed the molecular structure of the Eu (AA)3Phen complex and the formation of the doping TCA/Eu (AA)3Phen hybrid material.

Synthesis and luminescence properties of ternary complexes of Sm x Tb1−x (TTA)3Phen nanoparticles and their surface modification

A series of SmxTb1−x(TTA)3Phen (x = 1.0, 0.9, 0.7, 0.5, 0.3, 0.1, 0) complexes was synthesized by wet chemical method and characterized using Fourier transform infrared spectroscopy and fluorescence spectroscopy. The IR absorption spectra indicate that α-thenoyltrifluoroacetone was coordinated to the rare earth ions and that chemical bonds were formed between rare earth ions and the nitrogen atoms in 1,10-Phenanthroline (Phen). The fluorescence spectra of the complexes indicate that the emission intensity of Sm3+ was enhanced by the addition of substitutive Tb3+. These data show that not only the ligands (TTA and Phen) but also Tb3+ could absorb and transmit energy to Sm3+ in the complexes. Formation of dual-core complexes appears to be responsible for co-fluorescence, which can greatly promote the illuminant ability of Sm (TTA)3Phen complex. After further encapsulation by SiO2, the SmxTb1−x(TTA)3Phen@SiO2 core–shell structure was very stable to UV light.

Synthesis, characterization, crystal structure and antitumor activities of a novel demethylcantharidato bridged copper(II) phenanthroline complex

A new polymeric demethylcantharidato (DCA) bridged copper(II) phenanthroline (phen) complex ([Cu(DCA)(phen)]n·nH2O) has been synthesized and characterized by elemental analysis, IR and electronic spectra studies, molar conductivity measurement, and single crystal X-ray diffraction. The complex crystallizes in the orthorhombic space group Pbca with crystallographic data: a = 12.4537(4) A, b = 9.3897(5) A, c = 30.1264(10) A, and Z = 8. In the crystal structure, the octahedral coordinated copper(II) ions are bridged by demethylcantharidate ligands into a one-dimensional zigzag-like structure with the Cu…Cu separation of 6.1719 A, along with phen ligands attached to both sides of the chain alternatively. Interdigitation of the chelating phen ligands of two neighboring chains via hydrophobic interaction and van der Waals forces along ac plane forms two-dimensional polymeric bilayers with discrete water sandwich layer between the adjacent polymeric bilayers. The evaluation of the cytotoxic activity of the copper(II) complex against HCT-8 (colorectal carcinoma), A549 (pulmonary carcinoma), HeLa (cervical cancer), HepG2 (hepatocarcinoma), BGC-823 (gastric carcinoma), and MCF-7 (breast adenocarcinoma) cell lines revealed that it is a potent cytotoxic agent, superior to Na2DCA and phen against HeLa, HepG2 and BGC-823 cells.

Selection of Suitable Combination of Nonfunctional Micellar Catalyst and Heteroaromatic Nitrogen Base as Promoter for Chromic Acid Oxidation of Ethanol to Acetaldehyde in Aqueous Medium at Room Temperature

AbstractThe effect of the promoter and micellar catalyst on chromic acid on the oxidation of ethanol in aqueous acid media has been studied. Picolinic acid (PA), 1,10‐phenanthroline (phen), and 2,2′‐bipyridine (bipy) are used as promoters. Sodium dodecyl sulfate (SDS), cetyl pyridinium chloride (CPC), and Triton‐X‐100 (TX‐100) are tested as micellar catalysts. Hexavelent chromium is an active species in the absence of the promoter. In the presence of the heteroaromatic nitrogen bases used as the promoter, Cr(VI)–PA, Cr(VI)–bipy, and Cr(VI)–phen complexes have been proposed as the active oxidants. The time taken for completion of the reaction using different combinations of promoter and micellar catalysts are different. Although the rate is highest (12.5 times) in TX‐100 in the absence of the promoter, it is observed that the rate is almost 737 times faster for the combination of SDS and bipy compared to the unpromoted and uncatalyzed path. CPC inhibits the oxidation process. The observed acceleration and retardation of the rate of oxidation process has been explained on the basis of partitioning of the reactants in the micellar and aqueous phase. © 2013 Wiley Periodicals, Inc. Int J Chem Kinet 45: 175–186, 2013

Preparation of NaGdS2 via thermolysis of Gd[S2CN(C4H8)]3-phen complexes and sodium diethyldithiocarbamate mixtures

A novel, simple thermolysis method is adopted to prepare alkali metal rare earth ternary sulphide NaGdS2 using Gd(S2CNEt2)3-phen complexes and NaS2CNEt2·3H2O mixtures as precursors in a nitrogen atmosphere at 600–1000°C. The obtained NaGdS2 presents a microrod morphology with an average diameter of 112nm, average length of 236nm, and length diameter ratio of 2.1. Furthermore, the as-prepared NaGdS2 has excellent transmission over a very wide range of wavelengths (>430nm) and may be an ideal IR window material.