Sandwich Complexes Research Articles

Dominance of Cyclobutadienyl Over Cyclopentadienyl in the Crystal Field Splitting in Dysprosium Single‐Molecule Magnets

AbstractReplacing a monoanionic cyclopentadienyl (Cp) ligand in dysprosium single‐molecule magnets (SMMs) with a dianionic cyclobutadienyl (Cb) ligand in the sandwich complexes [(η4‐Cb′′′′)Dy(η5‐C5Me4tBu)(BH4)]− (1), [(η4‐Cb′′′′)Dy(η8‐Pn†)K(THF)] (2) and [(η4‐Cb′′′′)Dy(η8‐Pn†)]− (3) leads to larger energy barriers to magnetization reversal (Cb′′′′=C4(SiMe3)4, Pn†=1,4‐di(tri‐isopropylsilyl)pentalenyl). Short distances to the Cb′′′′ ligands and longer distances to the Cp ligands in 1–3 are consistent with the crystal field splitting being dominated by the former. Theoretical analysis shows that the magnetic axes in the ground Kramers doublets of 1–3 are oriented towards the Cb′′′′ ligands. The theoretical axiality parameter and the relative axiality parameter Z and Zrel are introduced to facilitate comparisons of the SMM performance of 1–3 with a benchmark SMM. Increases in Z and Zrel when Cb′′′ replaces Cp signposts a route to SMMs with properties that could surpass leading systems.

Dominance of Cyclobutadienyl Over Cyclopentadienyl in the Crystal Field Splitting in Dysprosium Single-Molecule Magnets.

Replacing a monoanionic cyclopentadienyl (Cp) ligand in dysprosium single‐molecule magnets (SMMs) with a dianionic cyclobutadienyl (Cb) ligand in the sandwich complexes [(η4‐Cb′′′′)Dy(η5‐C5Me4 t Bu)(BH4)]− (1), [(η4‐Cb′′′′)Dy(η8‐Pn†)K(THF)] (2) and [(η4‐Cb′′′′)Dy(η8‐Pn†)]− (3) leads to larger energy barriers to magnetization reversal (Cb′′′′=C4(SiMe3)4, Pn†=1,4‐di(tri‐isopropylsilyl)pentalenyl). Short distances to the Cb′′′′ ligands and longer distances to the Cp ligands in 1–3 are consistent with the crystal field splitting being dominated by the former. Theoretical analysis shows that the magnetic axes in the ground Kramers doublets of 1–3 are oriented towards the Cb′′′′ ligands. The theoretical axiality parameter and the relative axiality parameter Z and Z rel are introduced to facilitate comparisons of the SMM performance of 1–3 with a benchmark SMM. Increases in Z and Z rel when Cb′′′ replaces Cp signposts a route to SMMs with properties that could surpass leading systems.

Synthesis and characterisation of η6-arene(halogenidoaluminato)-lanthanoid(II) and alkaline earth(II) complexes

η6-Arene(iodidoaluminato)lanthanoid(II) complexes, {[Ln(η6-C6H5Me)(AlI4)2]}n [Ln = Sm, 1, Eu, 2, Yb, 3; C6H5Me = toluene] have been prepared by reactions of in situ generated aluminium triiodide with the corresponding lanthanoid metals and 1,2-diiodoethane in toluene (molar ratio: 2:1:1). Compounds 1–3 are polymeric and the lanthanoid(II) atom of 1 and 2 is coordinated by an η6–arene and three chelating κ (I, I′) tetraiodidoaluminate ligands, two of which are also bridging (LnI2AlI2Ln) and one is terminal. 3 is coordinated by an η6–arene, one terminal chelating κ (I, I′) and one chelating and bridging (YbI2AlI2Yb) tetraiodidoaluminate ligand, and one monodentate tetraiodidoaluminate ligand, which is also bridging (YbIAl(I)I2Yb). These are the first X-ray crystal structures of arene(tetrakisiodidoaluminato)lanthanoid(II) complexes. The first reported alkaline earth(II) (η6–arene)iodidoaluminate complexes, namely [Ca(η6-C6H5Me)(AlI4)2]n (4), {[Sr(η6-C6H5Me)(AlI4)2]n·nPhMe} (5), [Ba(η6-C6H5Me)2(AlI4)2] (6), [Ca(η6-C6H3Me3-1,3,5)(AlI4)2]n (7) and {[Sr(η6-C6H3Me3-1,3,5)(AlI4)2]n·0.5n(PhMe3)} (8) have also been obtained in an arene (toluene or mesitylene) solution by a similar method. Complex 4 is isocoordinate with 3, and 5 is isomorphous with 2. Complex 7 has eight coordinate Ca similar to 4, and complex 8 has nine coordinate Sr as in 5. Mononuclear ten coordinate complex 6 is the first example of a monomeric η6–arene sandwich complex of barium. The EuII bromidoaluminate complex {[Eu(η6-C6H5Me)(AlBr4)2]n·0.5nPhMe} (9) has been prepared from Eu metal, AlBr3, and BrCH2CH2Br in toluene and has a unit cell similar to 8 despite the different metal and arene.

Soft Metal Cations Trigger Sandwich‐Cluster Luminescence of a New Au(I)‐Vinylimidazolate Cyclic Trinuclear Complex

AbstractThe formation of heterobimetallic complexes from parent cyclic trinuclear complexes (CTCs) of gold(I) has become straightforward in recent years with this team and others showing that the strategy leads to strengthened Au−M’ bonding and optoelectronic properties. A new gold(I)‐vinylimidazolate CTC, 1, was prepared and the formation of highly emissive sandwich adducts with the soft metal cations Cu+, Ag+, and Tl+, 2–4, respectively, was investigated. Compound 1 does not exhibit peculiar emissive properties at room or cryogenic temperatures as the adducts do. Its unit cell packing displays an unprecedented collection of repeating units for CTCs. While the intermolecular Au…Au distances are versatile (3.470, 3.673, and 4.045 Å), they connect only single Au centres from adjacent CTCs and form extended circular networks. Hirshfeld surface analyses mapped the new CTC contours underlining the possible cooperative effects of not only metallophilic interactions but also C−H…π and hydrogen bonding in the packing of 1 (as opposed to the dominance of the former in most other reported CTCs). DFT calculations validate the formation of sandwich‐like structures for compounds 2–4 with averaged Au−M distances of 2.665 Å, 2.802 Å, and 3.036 Å, respectively, close by to experimental crystal data obtained for similar sandwich compounds.

Development of Cyanine 813@Imidazole-Based Doped Supported Devices for Divalent Metal Ions Detection

A NIR cyanine@imidazole derivative Cy1 was synthesized and evaluated as a metal ion sensor in solution. Cy1 was shown to be very sensitive to all metal ions tested, presenting a blue shift in the absorption from 668 nm to 633 nm, followed by a change in colour from pale green to blue with Zn2+, Cd2+, Co2+, Ni2+ and Hg2+ ions. Despite the blue shift in the absorption, a decrease at 633 nm (with a colour change from pale green to colourless), as well as a quenching in the emission intensity at 785 nm were observed for Cu2+ ions. The results show the formation of sandwich complexes of two ligands per metal ion with the highest association constant observed for Cu2+ (Log Kass.abs = 14.76 ± 0.09; Log Kass.emis. = 14.79 ± 0.06). The minimal detectable amounts were found to be 31 nM and 37 nM, with a naked eye detection of 2.9 ppm and 2.1 ppm for Hg2+ and Cu2+ ions, respectively. These results prompted us to explore the applicability of Cy1 by its combination with nanomaterials. Thus, Cy1@ doped MNs and Cy1@ doped PMMA nanoparticles were synthesized. Both nanosystems were shown to be very sensitive to Cu2+ ions in water, allowing a naked-eye detection of at least 1 ppm for Cy1@ doped MNs and 7 ppm for Cy1@ doped PMMA. This colourimetric response is an easy and inexpensive way to assess the presence of metals in aqueous media with no need for further instrumentation.

Development of an Innovative Quantification Assay Based on Aptamer Sandwich and Isothermal Dumbbell Exponential Amplification.

Detecting blood biomarkers such as proteins with high sensitivity and specificity is of the utmost importance for early and reliable disease diagnosis. As molecular probes, aptamers are raising increasing interest for biosensor applications as an alternative to antibodies, which are used in classical enzyme-linked immuno-sorbent assays (ELISA). We have developed a sensitive and antibody-free molecular quantification assay that combines the specificity of aptamers and the sensitivity of the loop-mediated isothermal amplification (LAMP). For the proof-of-concept, we consider two types of biomarkers: (i) a model of oligonucleotide mimicking nucleic acid targets and (ii) the thrombin involved in the complex coagulation cascade as a model protein for which two relevant aptamers form a stable sandwich. The assay protocol is based on a few successive steps, similar to sandwich ELISA. First, aptamer-coated magnetic beads are added to the sample to specifically capture the targets. Then, the sandwich complex is formed by adding the second aptamer. This secondary aptamer is integrated in a larger oligonucleotide dumbbell sequence designed for LAMP detection using only two primers. After a proper rinsing step, the isothermal dumbbell exponential amplification is performed to detect and quantify a low amount of targets (limit of detection ∼ 1 pM for the oligonucleotide and ∼100 pM for thrombin). This study demonstrates that our innovative aptamero-LAMP assay could be relevant for the detection of different types of biomarkers and their quantification at physiological levels. This may also pave the way for antibody-free molecular assays.

Syntheses and crystal structures of new naphthalene- and anthracene-vanadate salts and an unprecedented dimetallabis(anthracene) sandwich complex: [Na(tetrahydrofuran)3][V2(anthracene)2

Reduction of bis(naphthalene)vanadium(0) by potassium naphthalene (KNp) in tetrahydrofuran (THF) provides a highly reactive, thermolabile, and so far unisolable brown substance, which affords the first reported derivatives of bis(naphthalene)vanadates. From these solutions, thermally stable (298 K) and structurally characterized compounds have been obtained, including dark-red rods of catena-poly[bis(μ3-η4:η6:η4-naphthalene)tetrakis(tetrahydrofuran)dipotassiumvanadium], [K2V(C4H8O)4(C10H8)2]n or [K(THF)2]2[V(C10H8)2] (3), and red plates of (4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane)potassium [1,2-bis(dimethylphosphanyl)ethane]bis(η4-naphthalene)vanadium tetrahydrofuran monosolvate, [K(C18H36N2O6)][V(C10H8)2(C6H16P2)]·C4H8O or [K([2.2.2]cryptand)][V(C10H8)2(dmpe)]·THF [dmpe is 1,2-bis(dimethylphosphanyl)ethane] (4b). Notably, [V(C10H8)2]2- is the only example of a structurally authenticated homoleptic bis(arene)metallate dianion and was obtained by further reduction of the brown material by KNp in THF, in the presence of trimethylphosphane (PMe3). Addition of anthracene (An) to the brown material in THF afforded deep-violet and paramagnetic crystalline (1,4,7,10,13,16-hexaoxacyclooctadecane)bis(tetrahydrofuran)potassium [(η4-anthracene)(tetrahydrofuran)vanadium]-μ-η4:η2-anthracene-[(1,4,7,10,13,16-hexaoxacyclooctadecane)potassium]-μ-η2:η4-anthracene-[(η4-anthracene)(tetrahydrofuran)vanadium] tetrahydrofuran disolvate, [K(C12H24O6)(C4H8O)2][KV2(C12H24O6)(C4H8O)2(C14H10)4]·2C4H8O or [K(18-crown-6)][K(18-crown-6)(THF)2][V(C14H10)2(THF)]2·2(THF) (5), which readily reacted with PMe3 and dmpe to give new vanadate salts. These were structurally characterized as (1,4,7,10,13,16-hexaoxacyclooctadecane)bis(tetrahydrofuran)potassium bis(η4-anthracene)(trimethylphosphane)vanadium tetrahydrofuran monosolvate, [K(C12H24O6)(C4H8O)2][V(C14H10)2(C3H9P)]·C4H8O or [K(18-crown-6)(THF)2][V(C14H10)2(PMe3)]·THF (6), and tetrakis(1,2-dimethoxyethane)potassium bis(η4-anthracene)[1,2-bis(dimethylphosphanyl)ethane]vanadium, [K(C4H10O2)4][V(C14H10)2(C6H16P2)] or [K(DME)4][V(C14H10)2(dmpe)] (DME is 1,2-dimethoxyethane) (7b). The last three structures contain the first known bis(anthracene)vanadates and are thereby derivatives of the unknown bis(anthracene)vanadium(0). Attempts to obtain the sodium salt analog of 5 in THF resulted instead in the formation of a unique substance, (μ3-η6:η6:η6-anthracene)(μ2-η6:η6-anthracene)tris(tetrahydrofuran)sodiumdivanadium, [NaV2(C14H10)2(C4H8O)3] or [Na(THF)3][V2(C14H10)2] (8), containing the first reported dimetallabis(anthracene) sandwich compound.

Theoretical study of photovoltaic performances of Ru, Rh and Ir half sandwich complexes containing N,N chelating ligands in Dye-Sensitized Solar Cells (DSSCs). DFT and TD-DFT investigation

Owing to their low cost and improved energy efficiency, the dye-sensitized solar cells (DSSC) share significant priority in the toolbox of solar cell researchers. Herein, nine mononuclear Ru, Rh and Ir half sandwich complexes used in dye sensitized solar cells containing the phenyl hydrazone functionality and N,N chelating sites have been studied. The structural, electronic and optical properties, namely the FMO energy gap (Eg), chemical hardness (η), softness (S), electronegativity (χ), Natural bond orbital (NBO) charge distribution, open circuit voltage (Voc), molecular electrostatic potential (MEP), light harvesting efficiency (LHE) and driving force of regeneration (ΔGreg), the transition energy and the wavelengths (λ), were calculated at DFT/B3LYP/SDD/6-31+G(d,p) level of theory. A comparative study of the wavelength λ computed at B3LYP/SDD/6-31+G(d,p) level with those at CAM-B3LYP/SDD/6-31+G(d,p) and WB97XD/SDD/6-31+G(d,p) level of theory in gas phase and acetonitrile has also been performed. The predicted results were in conformity with the experiments.

Effect of methyl substituents on the preferred conformations of Bis(pentadienyl) open metallocenes

Density functional theory (DFT) methods indicated that the preferred geometries, spin states, and energetics of unsubstituted bis(pentadienyl)metal open sandwich complexes (C5H7)2M of the first row transition metals (M = Ti to Ni) are similar to those of the corresponding substituted and more stable (2,4-Me2C5H5)2M open sandwich complexes with 2,4-dimethylpentadienyl ligands. Structures with two fully bonded pentahapto η5-C5H7 ligands are energetically preferred for iron and for the transition metals to the left of iron in the Periodic Table. However, for the electron-rich first-row transition metals cobalt and nickel, structures with at least one trihapto η3-C5H7 ligand are preferred in order to prevent the electron configuration of the central metal atom from exceeding the favored 18-electrons. For the manganese systems (C5H7)2Mn and (2,4-Me2C5H5)2Mn the presence of the two methyl substituents is found to have little effect on the complicated potential energy surface with low-energy structures in the doublet, quartet, and sextet spin states.

Synthesis and Structures of Tris(cyclononatetraenyl) Rare-Earth Complexes [Ln(C9H9)3] (Ln = Y, Gd, Tb, Dy, Ho, Er, Tm)

The article reports the synthesis and structural characterization of a series of Ln(C9H9)3 complexes with the cyclononatetraenyl (Cnt, C9H9) ligand (Ln = Y, Gd, Tb, Dy, Ho, Er, Tm). The Yb and Sm complexes were not obtained, and the reaction of the potassium salt of the Cnt ligand with trivalent halide salts of the corresponding metals led to the known bis-Cnt sandwich compounds Ln(C9H9)2. The X-ray diffraction studies on the trivalent complexes show that the Cnt ligand is significantly bent in order to accommodate the large size of the ligand while it maintains its aromaticity. When the size of the lanthanide ion decreases, the ligand does not switch away but swings over the metal ion in order to maximize the electrostatic interactions. 1H NMR and UV–visible spectra, as well as the solid-state magnetism, were recorded. UV–visible spectroscopy highlights a remarkable charge-transfer band in the Tm complex, while ligand-based transitions are principally observed with all other metal ions. The magnetic behavior of the series agrees with trivalent lanthanide ions, and the computations at the CASSCF level confirm the trivalent electronic structure.

The soluble N-terminal autoinhibitory module of the A1 domain in von Willebrand factor partially suppresses its catch bond with glycoprotein Ibα in a sandwich complex.

von Willebrand factor (VWF) senses and responds to the hemodynamic forces to interact with the circulatory system and platelets in hemostasis and thrombosis. The dark side of this mechanobiology is implicated in atherothrombosis, stroke, and, more recently, the COVID-19 thrombotic symptoms. The force-responsive element controlling VWF activation predominantly resides in the N terminal auto-inhibitory module (N-AIM) flanking its A1 domain. Nevertheless, the detailed mechano-chemistry of soluble VWF N-AIM is poorly understood at the sub-molecular level as it is assumed to be unstructured loops. Using the free molecular dynamics (MD) simulations, we first predicted a hairpin-like structure of the soluble A1 N-AIM derived polypeptide (Lp; sequences Q1238-E1260). Then we combined molecular docking and steered molecular dynamics (SMD) simulations to examine how Lp regulates the A1-GPIbα interaction under tensile forces. Our simulation results indicate that Lp suppresses the catch bond in a sandwich complex of A1-Lp-GPIbα yet contributes an additional catch-bond residue D1249. To experimentally benchmark the binding kinetics for A1-GPIbα in the absence or presence of Lp, we conducted the force spectroscopy-biomembrane force probe (BFP) assays. We found similar suppression on the A1-GPIbα catch bond with soluble Lp in presence. Clinically, as more and more therapeutic candidates targeting the A1-GPIbα axis have entered clinical trials to treat patients with TTP and acute coronary syndrome, our work represents an endeavor further towards an effective anti-thrombotic approach without severe bleeding side effects as most existing drugs suffer.

Formation of sandwich and multidecker complexes between O2 and alkali/alkaline earth metals: a DFT study

The feasibility of the formation of sandwich and multidecker complexes between O2 molecules and alkali/alkaline earth metals has been analyzed in the light of density functional theory (DFT).

Actinide arene-metalates: 2. A neutral uranium bis(anthracenide) sandwich complex and elucidation of its electronic structure.

An unprecedented sandwich complex of the actinides is synthesized from the treatment of [UI2(HMPA)4]I (HMPA = OP(NMe2)3) (2) with 3 equiv. of K(C14H10) to give the neutral, bis(arenide) species U(η6-C14H10)(η4-C14H10)(HMPA)2 (1). Solid-state X-ray, SQUID magnetometry, and XANES analyses are consistent with tetravalent uranium supported by [C14H10]2- ligands. In one case, treatment of 1 with an equiv. of AgOTf led to the isolation of U(η6-C14H10)2(HMPA)(THF) (3), formed from ring migration and haptotropic rearrangement. Complete active space (CASSCF) calculations indicate the U-C bonding to solely consist of π-interactions, presenting a unique electronic structure distinct from classic actinide sandwich compounds.

Detection of a miRNA biomarker for cancer diagnosis using SERS tags and magnetic separation.

Detection of miR-29a, a biomarker of cancers, using SERS tags and magnetic separation is described. The assay was designed to detect the miR-29a sequence by taking the complementary sequence and splitting it into a capture and detection probe. The SERS tags comprised the highly Raman active molecule 4-mercaptobenzoic acid (4-MBA) and DNA detection probes assembled onto the surface of gold nanorods (AuNRs) through the self-assembly process. The capture DNA conjugated magnetic nanoparticles (MNPs) were applied as capture probes. The detection was based on the hybridisation and sandwich complex formation. The resultant hybridisation-dependent complexes were recovered and enriched from the samples by magnetic separation. The enriched solution containing target miRNA hybridised with capture probes were dropped on a foil-covered slide to form a droplet for SERS analysis. A characteristic spectrum of 4-MBA was observed to indicate the presence of the miR-29a in the samples. The sensitivity of the assay is examined by measuring the SERS signal of the samples containing different concentrations of the miR-29a. The SERS intensity appears to increase with the concentration of miR-29a. The limit of detection (LOD) was found to be 10 pM without any amplification process. In addition, the selectivity and feasibility of the assay in complex media are evaluated with the non-target miRNAs comprising different sequences from the target miR-29a. The system was capable of detecting the target miR-29a specifically with high selectivity. These results suggest that this solution-based SERS platform has a significant capability for simple, sensitive, and selective miR-29a analysis.

A rapid and quantitative detection method for plasma soluble growth stimulating gene protein 2 based on time resolved fluorescence immunochromatography.

Background: plasma soluble growth stimulating gene protein 2 (sST2) is a new generation biomarker in heart failure (HF), which is an independent predictor of adverse outcomes of heart failure. Thus, the establishment of a rapid and sensitive method for detecting sST2 is urgently needed. Methods: lanthanide element Eu3+ coated fluorescent nanometer microspheres (Eu3+@FMN) can be used as markers to label monoclonal mouse anti-human sST2 antibody ST-01 (ST-01-Eu3+@FMN). When the immune sandwich complex formed between the monoclonal mouse anti-human sST2 antibody ST-02 and ST-01-Eu3+@FMN on the test band with the appearance of target object sST2, we can detect the fluorescence intensity of Eu3+ on the test band and the quality control band using a dry fluorescence analyzer. We calculated the T/C value (T/C = fluorescence intensity of the test band/fluorescence intensity of the quality control band), fitted to the calibration curve, and measured the concentration value of sST2 in the corresponding sample. Results: the best reaction time was 15 min after condition exploration, and the optimal sample volume was 80 μL. The detection sensitivity of the scheme was 2.14 ng mL-1. The calibration curve of the assay was y = 0.0113x + 0.0033, and the linear range was 5-200 ng mL-1. No cross reaction was found when the samples contained BNP, NT-proBNP, and galectin-3, indicating a good specificity. The precision was good with a relative deviation < 15%. The coefficient of variation of detection results of low-concentration samples and high-concentration samples was 4.20% and 3.30% respectively in the same batch of strip tests, so the intra-assay CV was set as <10%; when different batches of strips were used for testing, the coefficient of variation of detection results of low-concentration samples and high-concentration samples was 10.06% and 8.38% respectively, so the inter-assay CV was set as <15%. Stability test results showed that the relative deviation of test results at each time node was <15%, indicating good stability of the assay strips. The correlation coefficient between the ST-01-Eu3+@FMN based time-resolved fluorescence immunochromatography analysis and sST2 ELISA kit was 0.98. To confirm the usage of our proposed TRF-ICA for clinical samples, it was used to determine the concentration of sST2 in samples obtained from 34 patients with heart insufficiency, acute and chronic heart failure. As a result, we successfully detected a minimal concentration of 5.21 ng mL-1 and a maximum concentration of 184.26 ng mL-1 for sST2. Conclusion: this technique provides a rapid, simple and quantitative detection method for sST2 in clinics. It can help clinicians to predict the incidence of adverse events in patients with HF.

A homoleptic tris(diphosphacyclobutadiene) tripledecker sandwich complex.

The synthesis and characterisation of [Co2(η4-P2C2tBu2)2(μ:η4:η4-P2C2tBu2)] (1) is described, featuring two cobalt atoms and three diphosphacyclobutadiene ligands. This compound is the first triple-decker sandwich complex which exclusively contains cyclobutadiene ligands.

Selective carbon-phosphorus bond cleavage: expanding the toolbox for accessing bulky divalent lanthanoid sandwich complexes.

The synthesis of two new tetra- and penta-phenycyclopentadienyldiphenylphosphine pro-ligands which readily undergo selective C-P bond cleavage has allowed for the facile synthesis of bulky divalent octa- and deca-phenylmetallocenes of europium, ytterbium and samarium.

40 Years of Organometallics

ADVERTISEMENT RETURN TO ISSUEEditor's PageNEXT40 Years of OrganometallicsPaul J. Chirik*Paul J. ChirikDepartment of Chemistry, Princeton University, Princeton, New Jersey 08544, United States*Email for P.J.C.: [email protected]More by Paul J. Chirikhttps://orcid.org/0000-0001-8473-2898 and Stephen K. Ritter*Stephen K. RitterAmerican Chemical Society, 1155 16th Street NW, Washington, D.C. 20036, United States*Email for S.K.R.: [email protected]More by Stephen K. Ritterhttps://orcid.org/0000-0002-5223-3741Cite this: Organometallics 2021, 40, 24, 4035–4040Publication Date (Web):December 27, 2021Publication History Published online27 December 2021Published inissue 27 December 2021https://doi.org/10.1021/acs.organomet.1c00667Copyright © Published 2021 by American Chemical SocietyRIGHTS & PERMISSIONSArticle Views894Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (1 MB) Get e-AlertsSUBJECTS:Organometallic chemistry,Metals,Catalysts,Sandwich compounds,Solvents Get e-Alerts

Dual-Stimulus Control for Ultra-Wideband and Multidimensional Modulation in Terahertz Metasurfaces Comprising Graphene and Metal Halide Perovskites.

Perovskites and graphene are receiving a meteoric rise in popularity in the field of active photonics because they exhibit excellent optoelectronic properties for dynamic manipulation of light-matter interactions. However, challenges still exist, such as the instability of perovskites under ambient conditions and the low Fermi level of graphene in experiments. These shortcomings limit the scope of applications when they are used alone in advanced optical devices. However, the combination of graphene and perovskites is still a promising route for efficient control of light-matter interactions. Here, we report a dual-optoelectronic metadevice fabricated by integrating terahertz metasurfaces with a sandwich complex composed of graphene, polyimide, and perovskites for ultra-wideband and multidimensional manipulation of higher-order Fano resonances. Owing to the photogenerated carriers and electrostatic doping effect, the dual optoelectronic metadevice showed different manipulation behavior at thermal imbalance (electrostatic doping state of the system). The modulation depth of the transmission amplitude reached 200%, the total resonant frequency shift was 800 GHz, and the tunable range of the resonant frequency was 68.8%. In addition, modulation of the maximum phase reached 346°. This work will inspire a new generation of metasurface-based optical devices that combine two active materials.

Development and evaluation of a chemiluminescence immunoassay for type Ⅰ procollagen N-terminal peptide

To develop a magnetic nanoparticle chemiluminescence immunoassay (CLIA) for the determination of type Ⅰ procollagen N-terminal peptide (PINP) in human serum, we expressed a recombinant PINP-α1 protein in Corynebacterium glutamicum and used it as an immunogen to immunize BALB/c mice. We obtained three hybridoma cell lines that stably secret antibody against PINP-α1 protein. After further pairing and screening, we chose a monoclonal antibody 8C12 coupled with biotin as the capture antibody, and a monoclonal antibody 1F11 labeled horseradish peroxidase as the detection antibody. The antibodies combined with the serum samples, forming a sandwich complex which was used to detect the concentration of PINP in serum. After optimizing the conditions, we determined that the best working concentration of the capture antibody and the detection antibody were 3 μg/mL, and the incubation time was 30 minutes. The quantitative assay had a detection range of 5-1 100 ng/mL, with recovery rates between 93%-107% and the minimum detection limit of 1.22 ng/mL achieved. The intra-and inter-assay precisions were lower than 10%. The correlation coefficient of PINP results between this CLIA method and the Roche electrochemiluminescence immunoassay system was 0.906 2. Therefore, this CLIA method is specific and can be used to quantitatively detect the content of PINP in serum, which has the potential to become an auxiliary approach for bone disease examination.