Single-crystal X-ray Diffraction Research Articles

Atomically Precise Ternary Cluster: Polyoxometalate Cluster Sandwiched by Gold Clusters Protected by N-Heterocyclic Carbenes.

Coinage metal (Au, Ag, Cu) cluster and polyoxometalate (POM) cluster represent two types of subnanometer "artificial atoms" with significant potential in catalysis, sensing, and nanomedicine. While composite clusters combining Ag/Cu clusters with POM have achieved considerable success, the assembly of gold clusters with POM is still lagging. Herein, we first designedly synthesized two cluster structural units: an Au3O cluster stabilized by diverse N-heterocyclic carbene (NHC) ligands and an amine-terminated POM linker. The subsequent reaction involved amine substitution in the POM linker for the central O atom in the Au3O cluster, resulting in the first ternary composite cluster - a POM cluster sandwiched by two Au clusters protected by NHCs. Single-crystal X-ray diffraction and other characteristic methods characterized their atomically precise structures. Furthermore, altering the NHC ligands decreased the number of gold atoms in the sandwich structures, accompanying the different protonated degrees of amine ligand in the terminal end of the POM linker. These composite clusters showed excellent performances in catalytic H2O2 conversion through the synergistic effect between gold clusters and POM clusters. This work opens a new avenue to functional composite metal clusters and would promote their enhanced catalysis applications through intercluster synergistic interactions within composite systems.

Synthesis and crystal structure of acentric anhydrous beryllium carbonate Be(CO3).

The anhydrous alkaline earth metal carbonate Be(CO3) was synthesized in a laser-heated diamond anvil cell at moderate pressures and temperatures (20(2) GPa and 1500(200) K) by a reaction of BeO with CO2. It crystallizes in the acentric, trigonal space group P3121 with Z = 3. The crystal structure was obtained from synchrotron single crystal X-ray diffraction data and confirmed by density functional theory-based calculations in combination with Raman spectroscopy. Second harmonic generation measurements were employed to verify the acentric space group symmetry. The crystal structure of Be(CO3) is characterized by the presence of isolated [CO3]2--groups and BeO4-tetrahedra. This is a new structure type and such a topology has not been observed in carbonates before. Be(CO3) can be recovered to ambient conditions and is not undergoing a phase transition during decompression.

A new ciprofibrate calcium salt with improved solubility and intrinsic dissolution rate

Ciprofibrate (CIP) is an active pharmaceutical ingredient (API) classified as class II on the basis of biopharmaceutical classification system (BCS), what indicates that it has low solubility in aqueous solvents. The use of API salts has attracted attention due to their improvements in solubility, tolerability, higher rate and extent of absorption, and faster onset of the therapeutic effect. In this work, a new crystalline CIP monohydrated calcium salt (Ca(CIP)2.H2O) was successfully obtained and its crystal structure determined by single crystal X-ray diffraction analysis (SCXRD). Additionally, Ca(CIP)2.H2O was widely characterized by powder X-ray diffraction (PXRD), Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and submitted to solubility, intrinsic dissolution and accelerated stability studies. Ca(CIP)2.H2O exhibited higher solubility and dissolution rate than CIP-free form and was stable up to 6 months at 40°C (75%RH). Therefore, Ca(CIP)2.H2O may be a viable alternative for use in solid dosage forms.

Alkaloids from Anacyclus pyrethrum.

Twelve undescribed alkaloids, including eight pyrrolo[3,2-g]isoquinoline alkaloids (+)/(-)-anacyquinoline A (1a/1b), (±)-anacyquinoline B (2), (+)/(-)-anacyquinoline C (3a/3b), (±)-anacyquinoline D (4), (±)-anacyquinoline E (5), and (±)-anacyquinoline F (6), together with four pyrrolo[2,3-g]quinoline alkaloids (+)/(-)-anacyquinoline G (7a/7b), (±)-anacyquinoline H (8), and (±)-anacyquinoline I (9), were isolated from the roots of Anacyclus pyrethrum (L.) DC. Their structures were determined via spectroscopic analyses (UV, IR, NMR), HRESIMS, quantum chemical calculations of ECD, DP4+ analysis, and single-crystal X-ray diffraction analysis (Cu Kα). Furthermore, in bioassay, (+)/(-)-anacyquinoline G (7a/7b) and (±)-anacyquinoline H (8) showed inhibition on nitric oxide production in lipopolysaccharide -induced RAW 264.7 cells with IC50 values of 41.4, 44.1, and 31.4 μM, respectively, indicating their potential anti-inflammatory bioactivity.

Synthesis, Anti-Oomycete and Anti-Fungal Activities of Anhydride Derivatives of Oleanolic Acid.

Oleanolic acid is a pentacyclic triterpenoid extracted and isolated from the fruit of plants in the Ligustrum lucidum Ait. in the family Oleaceae. To discover biorational natural product-based pesticides, a series of oleanolic acid derivatives containing anhydride active skeletons were prepared by ingeniously introducing an active acyloxy group at its C-28 carboxyl position, and their structures were well characterized by 1H NMR, 13C NMR, HRMS, and m.p.. The stereochemical configuration of compound 8e was confirmed using single-crystal X-ray diffraction. Furthermore, bioactivities of these compounds as anti-oomycete and anti-fungal agents against two serious agricultural pests, Phytophthora capsici and Fusarium graminearum we assessed. Amongst evaluated compounds, 1) Compounds 8h and 8j displayed significant anti-oomycete against P. capsici, with EC50 values of 54.73 and 65.15 mg/L, respectively. 2) The target compounds have obvious selectivity, and their anti-oomycete activity is significantly better than their anti-fungal activity. 3) Interestingly, there are significant differences in the structure-activity relationship of different substituents or the same substituent at different positions anti-oomycete and anti-fungal against P. capsici and F. graminearum, respectively. The study provides an idea for further exploring the bioactivities of 28-acyloxyoleanolic acid derivatives, and develops the application of 28-acyloxyoleanolic acid derivatives containing anhydride in agriculture.

Synthesis and Photocatalytic sp3 C-H Bond Functionalization of Salen-Ligand-Supported Uranyl(VI) Complexes.

Recent years have seen increasing interest in uranyl(VI) photocatalysis. In this study, uranyl complexes were successfully synthesized from ligands L1-L6 and UO2(NO3)2·6H2O under reflux conditions, yielding products 1-6 with yields ranging from 30% to 50%. The complexes were thoroughly characterized using NMR spectroscopy, single-crystal X-ray diffraction, and elemental analysis. The results indicate that complexes 1-5 possess a pentagonal bipyramidal geometry, whereas complex 6 exhibits an octahedral structure. The photocatalytic properties of these novel complexes for sp3 C-H bond functionalization were explored. The results demonstrate that complex 4 functions as an efficient photocatalyst for converting C-H bonds to C-C bonds via hydrogen atom transfer under blue light irradiation.

Synthesis, structural, optical, thermal, Hirshfeld surface analysis and antibacterial investigations of bis(2-aminobenzothiazolium) tetrabromozincate (II) monohydrate

Bis(2-aminobenzothiazolium) tetrabromozincate (II) monohydrate crystal were produced by the slow evaporation of solution technique (SEST) at room temperature and their triclinic structure was determined using single-crystal X-ray diffraction (XRD). FT-IR spectrum analysis revealed the existence of a protonated NH group with symmetric stretching frequency. In UV-DRS, direct band gap energy was determined using the Kubelka–Munk algorithm. The absorption is primarily due to the transitions within the organic part of the hybrid and charge transfer. The compound exhibit solid-state fluorescence at room temperature consistent with photoluminescence investigation. The thermal stability of the compound indicates that the process was exothermic. The CSM calculation of ZnX42- (X=Br) closely aligns with the ideal tetrahedral geometry of the anions. Hirshfeld surface analysis which is obtained from single-crystal XRD data is used to investigate the intermolecular interactions and crystal packing and exposes stronger contacts associated with strong interactions. The antibacterial studies of the investigated compound was comprehensively examined against pathogens including Enterococcus faecalis, Streptococcus pyogenes, Pseudomonas aeruginosa and Proteus mirabilis by using agar well diffusion method. The results indicate significant efficacy in inhibiting bacterial growth for the compound.

Exploring dual-channel ion detection and theoretical insights: Chromone-based colorimetric receptor for Cu2+and its Zn(II)-complex as ultrasensitive fluorescent probe for Ag+ and Fe3+

Present article delineates the design and synthesis of a chromone-appended Schiff base (1) and its complexes with Zn(II) (2) and Cu(II) (3), which have been characterized by various spectro-analytical techniques i.e., elemental analysis, FTIR, 1H & 13C NMR, ESI-MS, UV−vis and fluorescence. Structures of 1 and 3 have also been elucidated using single crystal X-ray diffraction analysis. Compounds 2 showed significant effect in vitro cytotoxicity as compared to 1 Against MDA−MB-231 cell line. Interestingly, 1 serves as a chromogenic sensor for Cu2+ with exceptional selectivity whereas, 2 serves as an ultrasensitive fluorescent probe for Ag+ and Fe3+ in mixed aqueous−ethanol. The presence of Ag+ causes ratiometric change in the fluorescence spectral feature of 2 whereas Fe3+ induces ‘turn-off’ fluorescence in 2. Probe−analyte binding stoichiometry suggested by Job's plot analysis, ESI−MS and DFT studies, has been found to be 1:1 for 1 with Cu2+ and 2 with Ag+ whereas, 1:2 between 2 and Fe3+. Based on diverse analyses and binding constants, it is observed that 2 offers higher selectivity toward Ag+ over Fe3+. Limit of detection (LoD) of 1 for Cu2+ and 2 for Ag+ and Fe3+ have been found to be 2.33 nM, 22.4 µM and 2.05 µM, respectively. Complexes 2+Ag+ and 2+Fe3+ characterized by ESI−MS whereas DFT studies have been carried out to investigate the deeper bonding insights and provide support in our experimental investigations. Further, detection of Ag+ and Fe3+ has been practically accomplished in real water samples using probe 2.

A New Azide-Bridged Polymeric Manganese (III) Schiff Base Complex with an Allylamine-Derived Ligand: Structural Characterization and Activity Spectra

This paper reports the synthesis and structural characterization of a novel azide-bridged polymeric manganese (III) Schiff base complex, using 2-((allylimino)methyl)-6-ethoxyphenol as a ligand. The crystal structure of the synthesized compound, elucidated by single-crystal X-ray diffraction analysis, indicates that it crystallizes in the monoclinic space group P21/c. The complex is found to display an octahedral geometry in which the central manganese Mn(III) coordinates with two bidentate donor Schiff base ligands via oxygen and nitrogen atoms. In addition, the metallic centers are linked together to form a one-dimensional chain bridged by end-to-end azide ligands. To offer a more thorough characterization of the synthesized compound, the study incorporates experimental data from FT-IR, UV-Vis, and cyclic voltammetry, alongside computational results from Hirshfeld surface analysis and DFT calculations conducted for both the ligand and complex. The computational analyses provided valuable insights into the intrachain and interchain interactions within the crystal structure, clarified the conformational characteristics of the isolated ligand molecule, and aided in the interpretation of the experimental IR spectra. Furthermore, an assessment of the compound’s drug-like properties was conducted using activity spectra for substances (PASS) predictions, revealing potential pharmacological activities.

In-silico antibacterial activity of piperazinyl-based copper(II) metallo-organic pharmacophores

The piperazinyl-based Cu(II)-Schiff base complex {[Cu(HL1′)(N3)]2∙(ClO4)2·4H2O} (1) [HL1′ is the Zwitter ionic form of (E)-2-((2-piperazin-1-ylethylimino)methyl)phenol] was synthesized and characterized by spectroscopic and single crystal X-ray diffraction studies. The X-ray single crystal structure analysis shows that the asymmetric unit of 1 contains a four-coordinate discrete complex cation, [Cu(HL1′)(N3)]+ (1a), with a perchlorate anion and a lattice water molecule. Two square planar units of 1a are dimerized by weak Cu···N intermolecular interaction, forming [Cu(HL1′)(N3)]2 2+ (1′a). DFT and TD-DFT calculations of the monomeric cationic unit, [Cu(HL1′)(N3)]+ (1a) were performed. In-silico antibacterial activities of HL1 as well as monomeric and dimeric cationic units 1a and 1'a, respectively, were performed and study shows that 1a (EC50 0.30 μM) and 1′a (EC50 0.06 μM) may be treated as antibacterial drugs after in-vivo analysis and clinical testing.

Substrate-controlled chemoselective assembly of coumarins and Morita–Baylis–Hillman alcohols from salicylaldehydes with acrylates

Substrate-controlled divergent reactions of between salicylaldehydes and acrylates have been developed. By using methyl acrylate as the substrate with salicylaldehydes, a domino reaction was established, delivering coumarins with good yield (up to 81% yields) and high chemoselectivity under mild conditions. Whereas the methyl acrylate was changed to tert-butyl acrylate or iso-propyl acrylate, the classical Morita − Baylis − Hillman adducts were produced in good yields (up to 75% yields) under near exclusivity under the otherwise identical reaction conditions, without any other competitive products. Additionally, the synthetic utility of the present methodology was further demonstrated by synthetic transformation. The structure of the typical product was unambiguously established by single crystal X-ray diffraction analysis.

Arylboronic Acid Pinacol Esters as Stable Boron Sources for Dihydrodibenzoborepin Derivatives and a Dibenzoborole.

The general synthesis of boron-containing cyclic compounds (boracycles) necessitates toxic organotin precursors or highly reactive boron halides. Here, we report the synthesis of seven- and five-membered boracycles utilizing arylboronic acid pinacol esters (ArBpins) as stable boron sources. Grignard reagents generated from 2,2'-dibromodibenzyl or 2,2'-dibromobiphenyl reacted with ArBpins, where Ar = 9-anthryl (Anth), 2,4,6-trimethylphenyl (Mes), or 2,4,6-triisopropylphenyl (Tip), to give 10,11-dihydro-5H-dibenzo[b,f]borepins or dibenzoborole derivatives. This Bpin-based method was successfully applied to a one-shot double boracycle formation, providing a dihydrodibenzoborepin-anthracene-dihydrodibenzoborepin triad molecule in a good yield. The dihydrodibenzoborepin bearing the Anth group was directly converted to the unsaturated borepin by NBS/AIBN. All products were characterized by NMR, HRMS, and in some cases, single-crystal X-ray diffraction analysis. Additionally, the photophysical properties of the products are also reported.

Copper(II) Methacrylate Complexes with Imidazole Derivatives-Structural, Spectral and Antitumor Features.

A series of five novel copper(II) complexes with imidazole derivatives having general core Cu(R-Im)2(Macr)2 (Macr = methacrylate anion; R-Im = 2-methylimidazole/2-MeIm, 4-methylimidazole/4-MeIm, 2-ethylimidazole/2-EtIm, 2-isopropylimidazole/2-iPrIm) has been synthesized and characterized by elemental analysis, Fourier Transform Infrared spectroscopy (FTIR), electronic reflectance spectroscopy, cyclic voltammetry, thermal analysis and single crystal X-ray diffraction. All complexes crystalize in a monoclinic crystal system and form a complex supramolecular network developed through hydrogen bonds. The stereochemistry of the copper ion is distorted octahedral except for the compound with 4-methylimidazole for which the geometry is square-pyramidal. The imidazole derivatives act as unidentate while methacrylate ions are chelated except for compound with 4-methylimidazole where is unidentate. All ligands and complexes inhibited B16 murine melanoma cells in a micromolar range, but the complex with 2-isopropylimidazole was more active. Furthermore, all species do not affect the healthy BJ cells in the concentration range used for assays.

Serial triphenylpropionic acid and N,N'-chelator mixed ligands Cu(II) complexes: Structure and biological properties

Three distinct copper(II) complexes were synthesized using 3,3,3-Triphenylpropionic acid (TPPA) and varying N,N'-chelators, resulting in unique structural and biological properties. The complexes [Cu(TPPA)2(Bipy)(H2O)2·(H2O)] (1), [Cu(TPPA)2(Phen)(H2O)2·0.5(H2O)] (2), and [Cu(TPPA)2(MeBipy)·2(C2H3N)] (3) were thoroughly characterized using single-crystal X-ray diffraction, PXRD, FT-IR, and NMR techniques to confirm their distinct geometries and coordination environments (TPPA=3,3,3-Triphenylpropionic acid, Bipy=2,2′-Bipyridine, Phen=1,10-Phenanthroline, and MeBipy=5,5′-Dimethyl-2,2′-Dipyridyl). Hirshfeld surface analysis provided quantitative insights into the molecular interactions within the complexes, while molecular docking studies revealed a strong binding affinity to PI3K kinase, with calculated binding energies of −10.4, −10.5, and −11.7 kcal/mol for complexes 1, 2, and 3, respectively. DNA fluorescence spectroscopy demonstrated significant ct-DNA binding, with the quencher rate coefficients of 0.1278 for complex 1, 0.2664 for complex 2, and 0.2434 for complex 3. When compared to sodium penicillin, which exhibited an OD600 value of 0.06, complex 2 and complex 3 demonstrated moderate antibacterial activity against Staphylococcus aureus with OD600 values of 0.176 and 0.219, respectively. The IC50 values of complexes 1, 2, and 3 in HepG2 cancer cell inhibition assays were determined to be 0.588, 0.357, and 0.397 μM, respectively. These results demonstrate their superior cytotoxicity compared to Cisplatin and Carboplatin. The findings suggest that these complexes may offer promising avenues for further research and development in antimicrobial and anticancer therapies.

Growth of Single Crystals of (K1-xNax)NbO3 by the Self-Flux Method and Characterization of Their Phase Transitions.

In this study, single crystals of (K1-xNax)NbO3 are grown by the self-flux crystal growth method and their phase transitions are studied using a combination of Raman scattering and impedance spectroscopy. X-ray diffraction shows that single crystals have a perovskite structure with monoclinic symmetry. Single crystal X-ray diffraction shows that single crystals have monoclinic symmetry at room temperature with space group P1211. Electron probe microanalysis shows that single crystals are Na-rich and A-site deficient. Temperature-controlled Raman scattering shows that low temperature monoclinic-monoclinic, monoclinic-tetragonal and tetragonal-cubic phase transitions take place at -20 °C, 220 °C and 440 °C. Dielectric property measurements show that single crystals behave as a normal ferroelectric material. Relative or inverse relative permittivity peaks at ~-10 °C, ~230 °C and ~450 °C with hysteresis correspond to the low temperature monoclinic-monoclinic, monoclinic-tetragonal and tetragonal-cubic phase transitions, respectively, consistent with the Raman scattering results. A conduction mechanism with activation energies of about 0.5-0.7 eV was found in the paraelectric phase. Single crystals show polarization-electric field hysteresis loops of a lossy normal ferroelectric. The combination of Raman scattering and impedance spectroscopy is effective in determining the phase transition temperatures of (K1-xNax)NbO3.

Facile synthesis, SC-XRD, spectroscopic characterization & key electronic properties of nicotinaldehyde based scaffolds

Currently, pyridine based derivatives (TFMPN, BPN, and APN) have been synthesized using the Suzuki Miyaura coupling reaction and their structural confirmation was ensured by various spectroscopic techniques like UV–Visible, NMR (1H and 13C), and single crystal X-ray diffraction (SC-XRD) studies. After structural elucidation the key electronic properties of the synthesized derivatives were investigated through DFT/TD-DFT approaches at the M06/6–31 G (d, p) functional. The FMOs analysis showed effective charge transmission from HOMO towards LUMO, additionally reinforced by TDM and DOS analyses. Global reactivity parameters (GRPs) verified high softness along with substantial reactivity in TFMPN, BPN, and APN. Moreover, the low values of binding energy (Eb = 1.022–1.778 eV) demonstrate a higher exciton dissociation rate along with better hole movement. Among the chromophores listed above, BPN is regarded as the best due to its lowest energy gap (4.628 eV), maximum absorption maxima (344.429 nm), and softness (0.216 eV) characteristics therefore, it exhibits effective key electronic properties among all entitled chromophores.

Copper (II) halide compounds with cationic N-donor ligands: Design, synthesis, structure and magnetism

Copper (II) complexes of the cationic ligands 1-(4′-pyridyl)-pyridinium (L1) and 1-(4′-pyridyl)-pyridin-4-ol (L2) have been prepared and characterized by single crystal X-ray diffraction and variable temperature magnetic susceptibility measurements: [Cu(L1)2X2]X2 [where X = Cl (1), Br (2)], and [Cu(L2)2X2]X2 [where X = Cl (3), Br (4)]. The complexes are fundamentally square planar with L2X2 coordination planes and long, semi-coordinate bonds to the additional halide ions. All compounds crystallize in monoclinic systems with 1 and 2 in the P21/n space group and 3 and 4 in the P21/c space group. The crystal structures are stabilized by both non-classical (in the case of 1 and 2) and classical (3 and 4) hydrogen bonds. EPR data for 1–4 support a rhombohedral structure, in good agreement with the local geometry as seen in the crystal structures. Magnetic susceptibility measurements show the presence of very weak antiferromagnetic interactions. In addition, the syntheses and magnetic properties of two neutral complexes, [Cu(L3)2X2]·2H2O [L3 = 1-(4′-pyridino)-4-pyridone; X = Cl (5), Br (6)] are reported. Magnetic susceptibility data indicate the presence of moderate antiferromagnetic exchange interactions [J ∼ 28 K (5), 60 K (6)] which were well modeled by the S = 1/2 Heisenberg uniform chain model.

One pot synthesis and crystal of N-benzoyl(benzo)thiazol-2-amine borodifluoride complexes (NBO) with aggregation induced luminescence properties

In this paper, N-benzoyl(benzo)thiazol-2-amine borodifluoride complexes (NBOs) were synthesized directly from benzoyl chloride and (benzo)thiazol-2-amine by one-pot method. The molecular structures of the target compounds were characterized by nuclear magnetic resonance (NMR), high resolution mass spectrometry and single crystal X-ray diffraction. The optical properties of the compounds were measured by UV–Vis absorption and fluorescence spectra. In CH2Cl2, this compounds exhibit large Stokes shifts, the maximum absorption peaks of NBO-1, NBO-2 and NBO-3 are 327 nm, 342 nm and 362 nm, and the maximum emission peaks are 400 nm, 442 nm and 498 nm, respectively. It can also be found that the absorption and emission spectra are redshifted with the increase of the conjugated system. Further more, we found that NBO-2 and NBO-3 molecules with additional benzo structure have the properties of aggregation induced emission, while NBO-1 show weak fluorescence in both solution and aggregation state.

Novel Copper (II) Complexes with Fluorine-Containing Reduced Schiff Base Ligands Showing Marked Cytotoxicity in the HepG2 Cancer Cell Line.

Several novel copper (II) complexes of reduced Schiff bases containing fluoride substituents were prepared and structurally characterized by single-crystal X-ray diffraction. The complexes exhibited diverse structures, with the central atom in distorted tetrahedral geometry. The biological effects of the products were evaluated, specifically their cytotoxicity, antimicrobial, and antiurease activities, as well as affinity for albumin (BSA) and DNA (ct-DNA). The complexes showed marked cytotoxic activities in the HepG2 hepatocellular carcinoma cell line, considerably higher than the standard cisplatin. The cytotoxicity depended significantly on the substitution pattern. The best activity was observed in the complex with a trifluoromethyl group in position 4 of the benzene ring-the dichloro[(±)-trans-N,N'-bis-(4-trifluoromethylbenzyl)-cyclohexane-1,2-diamine]copper (II) complex, whose activity (IC50 28.7 μM) was higher than that of the free ligand and markedly better than the activity of the standard cisplatin (IC50 336.8 μM). The same complex also showed the highest antimicrobial effect in vitro. The affinity of the complexes towards bovine serum albumin (BSA) and calf thymus DNA (ct-DNA) was established as well, indicating only marginal differences between the complexes. In addition, all complexes were shown to be excellent inhibitors of the enzyme urease, with the IC50 values in the lower micromolar region.

Multiple-stimuli fluorescent responsive metallo-organic helicated cage arising from monomer and excimer emission

Effectively regulating monomer and excimer emission in a singular supramolecular luminous platform is challenging due to high difficulty of precise control over its aggregation and dispersion behavior when subjected to external stimuli. Here, we show a metallo-cage (MTH) featuring a triple helical motif that displays a unique dual emission. It arises from both intramolecular monomer and intermolecular excimer, respectively. The distorted molecular conformation and the staggered stacking mode of MTH excimer are verified through single crystal X-ray diffraction analysis. These structural features facilitate the switch between monomer and excimer emission, which are induced by changes in concentration and temperature. Significantly, adjusting the equilibrium between these two states in MTH enables the production of vibrant white light emission in both solution and solid state. Moreover, when combined with a PMMA (polymethyl methacrylate) substrate, the resulting thin films can serve as straightforward fluorescence thermometer and thermally activated information encryption materials.