Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Near-IR to Near-IR Upconversion Luminescence in Molecular Chromium Ytterbium Salts.

ABSTRACT: Upconversion photoluminescence in hetero-oligonuclear metal complex architectures featuring organic ligands is an interesting but still rarely observed phenomenon, despite its great potential from a basic research and application perspective. In this context, a new photonic material consisting of molecular chromium(III) and ytterbium(III) complex ions was developed that exhibits excitation-power density-dependent cooperative sensitization of the chromium-centered 2 E/2 T1 phosphorescence at approximately 775?nm after excitation of the ytterbium band 2 F7/2 ?2 F5/2 at approximately 980?nm in the solid state at ambient temperature. The upconversion process is insensitive to atmospheric oxygen and can be observed in the presence of water molecules in the crystal lattice.

SUBMITTER: Kalmbach J

PROVIDER: S-EPMC7589230 | biostudies-literature | 2020 Jun

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Near-IR to Near-IR Upconversion Luminescence in Molecular Chromium Ytterbium Salts.

Kalmbach Jens J Wang Cui C You Yi Y Förster Christoph C Schubert Hartmut H Heinze Katja K Resch-Genger Ute U Seitz Michael M

Angewandte Chemie (International ed. in English) 20200818 42

Upconversion photoluminescence in hetero-oligonuclear metal complex architectures featuring organic ligands is an interesting but still rarely observed phenomenon, despite its great potential from a basic research and application perspective. In this context, a new photonic material consisting of molecular chromium(III) and ytterbium(III) complex ions was developed that exhibits excitation-power density-dependent cooperative sensitization of the chromium-centered <sup>2</sup> E/<sup>2</sup> T<su ...[more]

PMID: 32558117

Similar Datasets

Highly near-IR emissive ytterbium(iii) complexes with unprecedented quantum yields.

Project description:The design of highly near-infrared (NIR) emissive lanthanide (Ln) complexes is challenging, owing to the lack of molecular systems with a high sensitization efficiency and the difficulty of achieving a large intrinsic quantum yield. Previous studies have reported success in optimizing individual factors and achieving high overall quantum yields, with the best yield being 12% for Yb(iii). Herein we report a series of highly NIR emissive Yb complexes, in which the Yb is sandwiched between an octafluorinated porphyrinate antenna ligand and a deuterated Kläui ligand, which allowed optimization of two factors in the same system, and one of the complexes had an unprecedented quantum yield of 63% (estimated uncertainty 15%) in CD2Cl2 with a long lifetime (?obs) of 714 ?s. Systematic analysis of the structure-photophysical properties relationship suggested that porphyrinates are effective antenna ligands with a sensitization efficiency up to ca. 100% and that replacement of the high-energy C-H oscillators in porphyrinate and Kläui ligands significantly improves the intrinsic quantum yield up to 75% (?obs/?rad), both of which contribute to enhancing the NIR emission intensity of Yb(iii) up to 25-fold. Besides the high luminescence efficiency, these Yb complexes have other attractive features such as excitation in the visible range and large extinction coefficients which make these Yb(iii) complexes outstanding optical materials in the NIR region.

| S-EPMC5480304 | biostudies-literature

Near-Infrared Upconversion Luminescence and Bioimaging In Vivo Based on Quantum Dots.

Project description:Recently, upconversion luminescence (UCL) has been widely applied in bioimaging due to its low autofluorescence and high contrast. However, a relatively high power density is still needed in conventional UCL bioimaging. In the present study, an ultralow power density light, as low as 0.06 mW cm-2, is applied as an excitation source for UCL bioimaging with PbS/CdS/ZnS quantum dots (UCL-QDs) as probes. The speculated UCL mechanism is a phonon-assisted single-photon process, and the relative quantum yield is up to 4.6%. As determined by continuous irradiation with a 980 nm laser, the UCL-QDs show excellent photostability. Furthermore, UCL-QDs-based probe is applied in tumor, blood vessel, and lymph node bioimaging excited with an eye-safe low-power light-emitting diode light in a nude mouse with few heat effects.

| S-EPMC6402406 | biostudies-literature

Triazole-based osmium(ii) complexes displaying red/near-IR luminescence: antimicrobial activity and super-resolution imaging.

Project description:Cellular uptake, luminescence imaging and antimicrobial activity against clinically relevant methicillin-resistant S. aureus (MRSA) bacteria are reported. The osmium(ii) complexes [Os(N^N)3]2+ (N^N = 1-benzyl-4-(pyrid-2-yl)-1,2,3-triazole (1 2+); 1-benzyl-4-(pyrimidin-2-yl)-1,2,3-triazole (2 2+); 1-benzyl-4-(pyrazin-2-yl)-1,2,3-triazole (3 2+)) were prepared and isolated as the chloride salts of their meridional and facial isomers. The complexes display prominent spin-forbidden ground state to triplet metal-to-ligand charge transfer (3MLCT) state absorption bands enabling excitation as low as 600 nm for fac/mer-3 2+ and observation of emission in aqueous solution in the deep-red/near-IR regions of the spectrum. Cellular uptake studies within MRSA cells show antimicrobial activity for 1 2+ and 2 2+ with greater toxicity for the meridional isomers in each case and mer-1 2+ showing the greatest potency (32 μg mL-1 in defined minimal media). Super-resolution imaging experiments demonstrate binding of mer- and fac-1 2+ to bacterial DNA with high Pearson's colocalisation coefficients (up to 0.95 using DAPI). Phototoxicity studies showed the complexes exhibited a higher antimicrobial activity upon irradiation with light.

| S-EPMC8163367 | biostudies-literature

Phthalocyanine dimerization-based molecular beacons using near-IR fluorescence.

Project description:Herein we demonstrate the use of a novel dimerization-based molecular beacon (MB) probe consisting of two metallo-phthalocyanine (Pc) fluorophores that use near-IR fluorescence, appropriate for highly specific and sensitive in vivo and/or in vitro DNA/RNA detection. Pc's possess a propensity to form nonfluorescent H-dimers that is utilized as the molecular "off" switch in the closed MB conformation. The "on" switch, which is generated when the solution target binds to the loop of the MB forming the open form, also provides two fluorophores for transduction resulting in a doubling of the extinction coefficient and improving the resulting fluorescence yield compared to a classical single-fluorophore/quencher MB system. In addition, the Pc-based MBs possess high thermal, photo, and chemical stabilities that are essential for many highly sensitive applications, such as molecular imaging. The dimer-based MBs were obtained using a simple single-step synthesis procedure and demonstrated excellent quenching efficiencies (98%) as well as a high signal-to-background ratio (approximately 60) exceeding the performance characteristics of many conventionally available MB probes.

| S-EPMC2684671 | biostudies-literature

Huge upconversion luminescence enhancement by a cascade optical field modulation strategy facilitating selective multispectral narrow-band near-infrared photodetection.

Project description:Since selective detection of multiple narrow spectral bands in the near-infrared (NIR) region still poses a fundamental challenge, we have, in this work, developed NIR photodetectors (PDs) using photon upconversion nanocrystals (UCNCs) combined with perovskite films. To conquer the relatively high pumping threshold of UCNCs, we designed a novel cascade optical field modulation strategy to boost upconversion luminescence (UCL) by cascading the superlensing effect of dielectric microlens arrays and the plasmonic effect of gold nanorods, which readily leads to a UCL enhancement by more than four orders of magnitude under weak light irradiation. By accommodating multiple optically active lanthanide ions in a core-shell-shell hierarchical architecture, developed PDs on top of this structure can detect three well-separated narrow bands in the NIR region, i.e., those centered at 808, 980, and 1540 nm. Due to the large UCL enhancement, the obtained PDs demonstrate extremely high responsivities of 30.73, 23.15, and 12.20 A W-1 and detectivities of 5.36, 3.45, and 1.91 × 1011 Jones for 808, 980, and 1540 nm light detection, respectively, together with short response times in the range of 80-120 ms. Moreover, we demonstrate for the first time that the response to the excitation modulation frequency of a PD can be employed to discriminate the incident light wavelength. We believe that our work provides novel insight for developing NIR PDs and that it can spur the development of other applications using upconversion nanotechnology.

| S-EPMC7603315 | biostudies-literature

Bright Blue, Green, and Red Luminescence from Dye-Sensitized Core@Shell Upconversion Nanophosphors under 800 nm Near-Infrared Light.

Project description:In this study, Li-based blue- and green-emitting core@shell (C@S) upconversion nanophosphors (UCNPs) and NaGdF4-based red-emitting C@S UCNPs were synthesized, and IR-808 dyes were conjugated with the C@S UCNPs to enhance upconversion (UC) luminescence. The surface of the as-synthesized C@S UCNPs, which was originally capped with oleic acid, was modified with BF4- to conjugate the IR-808 dye having a carboxyl functional group to the surface of the UCNPs. After the conjugation with IR-808 dyes, absorbance of the UCNPs was significantly increased. As a result, dye-sensitized blue (B)-, green (G)-, and red (R)-emitting UCNPs exhibited 87-fold, 10.8-fold, and 110-fold enhanced UC luminescence compared with B-, G-, and R-emitting Nd3+-doped C@S UCNPs under 800 nm near-infrared (NIR) light excitation, respectively. Consequently, dye-sensitized UCNPs exhibiting strong UC luminescence under 800 nm NIR light excitation have high applicability in a variety of biological applications.

| S-EPMC7728324 | biostudies-literature

Cupredoxin engineered upconversion nanoparticles for ratiometric luminescence sensing of Cu2.

Project description:The NIR excitation and large anti-Stokes shift of upconversion nanoparticles (UCNPs) have made them an ideal choice as biological nanoprobes. A key challenge in the field is to confer biorecognition units to UCNPs so that they can be used to probe specific targets in biological systems. While various agents have been combined with UCNPs to meet such a challenge, most studies are limited to small molecules, while biomolecules such as metalloproteins that possess much higher affinity and selectivity for metal ions have not been explored. Herein we demonstrate that fusion of zwitterion-coated UCNPs with azurin, a member of a family of redox-active copper proteins called cupredoxins that play important roles in diverse biological functions, can serve as an ideal platform for the label-free upconversion luminescence sensing of Cu2+ with a ratiometric response. The selectively binding of apo-azurin with Cu2+ induce a significant absorbance at about 625 nm, and hence decreases the red emission of the UCNPs. In contrast, the green emission of the UCNPs remains constant and acts as an internal standard reference for the ratiometric sensing of Cu2+. This approach opens a new window for the development of assays for biosensing based on a combination of specific metalloproteins with UCNPs.

| S-EPMC7081933 | biostudies-literature

Stable salts of the hexacarbonyl chromium(I) cation and its pentacarbonyl-nitrosyl chromium(I) analogue.

Project description:Homoleptic carbonyl radical cations are a textbook family of complexes hitherto unknown in the condensed phase, leaving their properties and applications fundamentally unexplored. Here we report on two stable 17-electron [Cr(CO)6]•+ salts that were synthesized by oxidation of Cr(CO)6 with [NO]+[Al(ORF)4]- (RF?=?C(CF3)3)) in CH2Cl2 and with removal of NO gas. Longer reaction times led to NO/CO ligand exchange and formation of the thermodynamically more stable 18-electron species [Cr(CO)5(NO)]+, which belongs to the family of heteroleptic chromium carbonyl/nitrosyl cations. All salts were fully characterized (IR, Raman, EPR, NMR, scXRD, pXRD, magnetics) and are stable at room temperature under inert conditions over months. The facile synthesis of these species enables the thorough investigation of their properties and applications to a broad scientific community.

| S-EPMC6367395 | biostudies-literature

Stable Platinum(IV) Corroles: Synthesis, Molecular Structure, and Room-Temperature Near-IR Phosphorescence.

Project description:A series of stable Pt(IV) corrole complexes with the general formula PtIV[TpXPC](m/p-C6H4CN)(py), where TpXPC3- is the trianion of a tris(p-X-phenyl)corrole and X = CF3, H, and CH3, has been synthesized, affording key physicochemical data on a rare and elusive class of metallocorroles. Single-crystal X-ray structures of two of the complexes revealed very short equatorial Pt-N distances of 1.94-1.97 Å, an axial Pt-C distance of ∼2.03 Å, and an axial Pt-N distance of ∼2.22 Å. The complexes exhibit Soret maxima at ∼430 nm, which are essentially independent of the meso-aryl para substituents, and strong Q bands with the most intense peak at 595-599 nm. The substituent-independent Soret maxima are consistent with an innocent PtIV-corrole3- description for the complexes. The low reduction potentials (-1.45 ± 0.08 V vs saturated calomel reference electrode) also support a highly stable Pt(IV) ground state as opposed to a noninnocent corrole•2- description. The reductions, however, are irreversible, which suggests that they involve concomitant cleavage of the Pt-aryl bond. Unlike Pt(IV) porphyrins, two of the complexes, PtIV[TpXPC](m-C6H4CN)(py) (X = CF3 and CH3), were found to exhibit room-temperature near-IR phosphorescence with emission maxima at 813 and 826 nm, respectively. The quantum yield of ∼0.3% is comparable to those observed for six-coordinate Ir(III) corroles.

| S-EPMC6645213 | biostudies-literature

Exploring the dual functionality of an ytterbium complex for luminescence thermometry and slow magnetic relaxation.

Project description:We present a comprehensive investigation of the magnetic and optical properties of an ytterbium complex, which combines two desirable and practical features into a single molecular system. Based upon YbIII ions that promote near-infrared optical activity and a chemical backbone that is ideal for an in-depth understanding of the magnetic behaviour, we have designed a multifunctional opto-magnetic species that operates as a luminescent thermometer and as a single-molecule magnet (SMM). Our magnetic investigations, in conjunction with ab initio calculations, reveal one of the highest energy barriers reported for an YbIII-based complex. Moreover, we correlate this anisotropic barrier with the emission spectrum of the compound, wherein we provide a complete assignment of the energetic profile of the complex. Such studies lay the foundation for the design of exciting multi-faceted materials that are able to retain information at the single-molecule level and possess built-in thermal self-monitoring capabilities.

| S-EPMC6657417 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data