Cottonsauer9258

A critical evaluation considers both the benefits and obstacles of utilizing the method for universal diagnostics. It is clear based on the evidence provided herein Raman spectroscopy in combination with machine learning provides the first glimmer of hope for the development of an accurate, inexpensive, fast, and non-invasive method for universal medical diagnostics.Rational design of AuNST morphology requires adequate computational models. The bulk dielectric function is not applicable to sharp nanostar spikes. We suggest a two-component dielectric function in which the nanostar core is treated as a bulk material, whereas the size-corrected dielectric function of the spikes is treated by a modified Coronado-Schatz model. In addition to the strong broadening of plasmonic peaks, the simulated absorption and scattering spectra show unusual properties, which are not observed with bulk dielectric functions. The effect of NIR water absorption on nanostar spectra is small, and the absorption peak demonstrates the expected small decrease in the absorbing media. Surprisingly, however, water absorption increases the scattering peak by 30%. For the common surfactant-free Vo-Dinh AuNSTs, we report, for the first time, very intense SWIR plasmonic peaks around 1900 nm, in addition to the common strong peak in the UV-vis-NIR band (here, at 1100 nm). For bilayers of AuNSTs in air, we recorded two similarly intense peaks near 800 and 1500 nm. To simulate the experimental extinction spectra of colloids and bilayers on glass in air, we develop a statistical model that includes the major fraction of typical Vo-Dinh AuNSTs and two minor fractions of sea urchins and particles with protrusions. In contrast to the general belief, we show that the common UV-vis-NIR plasmonic peak of surfactant-free AuNSTs is related to short spikes on a spherical core, whereas long spikes produce an intense SWIR plasmonic mode. Such a structural assignment of vis-NIR and SWIR peaks does not seem to have been reported previously for surfactant-free nanostars. With our model, we demonstrate good agreement between simulated and measured spectra of colloids and bilayers on glass in air.Antimonene is an exfoliated 2D nanomaterial obtained from bulk antimony. It is a novel class of 2D material for energy storage applications. In the present work, antimonene was synthesized using a high-energy ball milling-sonochemical method. The structural, morphological, thermal, and electrochemical properties of antimonene were comparatively analyzed against bulk antimony. X-ray diffractometry (XRD) analysis confirms the crystal structure and 2D structure of antimonene, as a peak shift was observed. The Raman spectra show the peak shift for the Eg and A1g modes of vibration of antimony, which confirms the formation of antimonene. Scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) images depict the exfoliation of antimonene from bulk antimony. Thermal analysis unveiled the thermal stability of antimonene up to 400 °C with only 3% weight loss. X-ray photoelectron spectroscopy (XPS) analysis reveals the formation of antimonene, which is free from contamination. The electrochemical properties of antimony and antimonene were investigated using cyclic voltammetry (CV) and chronopotentiometric (CP) analysis, using 2 M KOH as an electrolyte. Antimonene exhibited a relatively high specific capacitance of 597 F g-1 compared to ball-milled antimony (101 F g-1) at a scan rate of 10 mV s-1. Moreover, electrochemical impedance spectroscopy (EIS) analysis revealed that antimonene has a relatively low equivalence series resistance (RESR) and low charge transfer resistance (RCT) compared to bulk antimony, which favors high electrochemical performance. The cyclic stability of antimonene was studied for 3000 cycles, and the results show high cyclic stability. The electrochemical results demonstrated that antimonene is a promising material for energy storage applications.Small alcohol confinement within narrow carbon nanotubes has been extensively and systematically studied via rigorous free-energy calculations. Employing molecular dynamics simulations, thermodynamic integration and thermodynamic cycling, the loading process of methanol and ethanol from aqueous solution into (6,6), (7,7) and (8,8) single-walled carbon nanotubes was computed and decomposed into its entropic and energetic terms. For all tubes and alcohols, loading is favoured from infinite dilution in water; for the same alcohol, wider tubes allow for the formation of a collective dipole which is cooperative in terms of electrostatics and reduce the rotational freedom of the loaded particles; narrow tubes only permit the formation of dipole-dipole dimers instead, with a (rotational) entropic gain that compensates for the loss of long-range dipole-dipole interactions. The latter renders deeper loading chemical potentials for narrower tubes when partitioning small alcohols from aqueous solution and it is a clear example of an entropy-energy compensation phenomenon.Coumarin-based lanthanide complexes of general formula [Ln(coum)3(phen)(H2O)x]·yH2O (Ln-phen, x = 0,1, 0 ≤ y ≤ 1.5; phen = 1,10-phenanthroline; coum = 3-acetyl-4-hydroxylato-coumarin; Ln = Eu, Tb, Dy, Tm) and [Ln(coum)3(batho)]·0.7EtOH (Ln-batho, batho = 4,7-diphenyl-1,10-phenanthroline; Ln = Eu, Tb, Dy, Tm) were synthesized. The magnetic relaxation and photoluminescence behavior of these complexes was compared with that of the related compounds [Ln(coum)3(EtOH)(H2O)]·EtOH (Ln-coum), so as to investigate the effects of incorporating a second chromophore, either the phen or batho ligand, to the original coordination scaffold, provided with three coumarin (coum) ligands. Slow relaxation of the magnetization under H = 0 with moderate activation energies was observed for the Dy-phen (U/kB = 99.1 K) and Dy-batho (U/kB = 67.1 K) compounds, whereas Tb analogues presented field-induced single molecule magnet (SMM) behavior, with U/kB = 11.7 K (16.6 K@3 kOe) for Tb-phen (Tb-batho), respectively. Luminescent emission in the visible range was observed for all the Ln-coumarin based compounds upon ligand sensitization, with high quantum yields of 45 (40%) for Eu-phen (Eu-batho) compounds and 65-76-58% for Tb-coum, phen, batho analogues. Sensitization is mainly provided by the coumarin ligand having the energy difference ΔE between its triplet state T1 and the lanthanide emitting level closest to the optimum, while the second ligand can play either a synergistic or competing sensitizing role. The Tb-phen/batho compounds presented simultaneously SMM and luminescent behavior, with excellent values of the bifunctional figure of merit (ηSMM-QY ∼ 1000% K). The reported compounds represent a new class of bifunctional materials with potential interesting application in various fields.In this contribution we have carried out a systematic magnetostructural investigation to establish a robust one-to-one correlation between the quasi-orthogonal bridging mode of a pyrazolate ring and ferromagnetic coupling. Generating a complex with an elusive quasi-orthogonal pyrazolate bridging is a challenging task but would ineluctably result in a ferromagnetic exchange pathway. Notwithstanding the rarity, we report herein a series of bis-pyrazolato copper complexes. We have successfully exploited a so-called hypothetical-deductive model on a particular set of ligand systems that forced the pyrazolate moiety to adopt an unusual bridging mode with the M-Npz-Npz-M torsion angles in the range from 49.7° to 72.8°. The corroborating variable temperature direct current (DC) magnetic susceptibility data unequivocally confirm the ferromagnetic coupling for the complexes with the torsion angles greater than 71.37°. CP 43 concentration Furthermore, the experimental results are in excellent agreement with theoretical calculations. Based on density functional theory (DFT) calculations, again a one-to-one correspondence is made between the ligand structure and magnetic behaviour. The diradical character (y0) of the complexes is correlated with the extent of bonding interactions between the Cu centers and hence, their ferromagnetic or antiferromagnetic nature. The broken symmetry (BS) calculations on the magnetically active molecular orbitals indicate the essential magnetic behaviour of the complexes, while the EPR g-tensor calculations confirm that dx2-y2 is the magnetic orbital.A family of pyrazine-bridged, linear chain complexes of Cu(ii) of the formula [CuL2(H2O)2(pz)](ClO4)2 [pz = pyrazine; L = n-methyl-2(1H)-pyridone, n = 3 (1), 5 (2), and 6 (3)] has been prepared. Single-crystal X-ray diffraction shows six-coordinate, pyrazine-bridged chains with trans-pairs of ancillary ligands. The substituted pyridine molecules exist in their pyridone tautomers and are coordinated through the carbonyl oxygen atom. The structure is stabilized by intramolecular hydrogen bonds between the pyridone and water molecule, and via hydrogen bonds between the water molecules and perchlorate ions. 2 undergoes a crystallographic phase transition between C2/c (high temperature phase) and P1[combining macron] (low temperature phase). Powder EPR spectra reveal that all complexes are rhombic, although differences between gx and gy can only be seen clearly at Q-band. Variable temperature magnetic susceptibility data show antiferromagnetic interactions and the data were fit to the uniform chain model yielding J/kB = -9.8, -9.2 and -11 K for 1-3 respectively. Attempts to model an interchain interaction strength indicate that the chains are very well isolated.We have studied the local structure of layered Eu(La,Ce)FBiS2 compounds by Bi L3-edge extended X-ray absorption fine structure (EXAFS) measurements as a function of temperature. We find that the BiS2 sub-lattice is largely distorted in EuFBiS2, characterized by two different in-plane Bi-S1 distances. The distortion is marginally affected by partial substitutions of Ce (Eu0.5Ce0.5FBiS2) and La (Eu0.5La0.5FBiS2). The temperature dependence of the local structure distortion reveals an indication of possible charge density wave like instability in the pristine self-doped EuFBiS2 and Ce substituted Eu0.5Ce0.5FBiS2 while it is suppressed in La substituted Eu0.5La0.5FBiS2. In compounds with higher superconducting transition temperature, the axial Bi-S2 bond distance is elongated and the related bond stiffness decreased, suggesting some important role of this in the charge transfer mechanism for self-doping in the active BiS2-layer. In-plane Bi-S1 distances are generally softer than the axial Bi-S2 distance and they suffer further softening by the substitutions. The results are discussed in relation to an important role of the Bi defect chemistry driven asymmetric local environment in the physical properties of these materials.Neutral and cationic calcium water complexes are studied by means of high-level quantum calculations. Both the geometric and electronic structure of these species is investigated. We study complexes with up to eight water molecules in the first solvation sphere of calcium Ca(H2O)n=1-80,+, and examine their stability with respect to Ca(H2O)n-k@kH2O0,+, where a number k of water molecules resides at the second solvation shell. For the cationic species, we find that five water molecules readily attach to calcium and the sixth water molecule goes to the second shell. The hexa-coordinated calcium core is restored after the addition of a seventh water molecule. For neutral species, zero-point energy corrections are critical in stabilizing structures with water ligands directly bound to calcium for up to six water ligands. The (one or two) valence electrons of Ca+ and Ca are displaced gradually from the valence space of calcium to the periphery of the complex forming solvated electron precursors (SEPs). For example, in the ground state of Ca(H2O)6+ one electron occupies an s-type diffuse peripheral orbital, which can be promoted to higher energy p-, d-, f-, g-atomic-type orbitals (1s, 1p, 1d, 2s, 1f, 2p, 2d, 1g, 3s) in the excited states of the system.