New Ni (II) and Cu (II) complexes with pyridoxal-semicarbazone were synthesized and their structures were solved by X-ray crystallography. This analysis showed the bis-ligand octahedral structure of [Ni(PLSC-H)₂]·H₂O and the dimer octahedral structure of [Cu(PLSC)(SO₄)(H₂O)]₂·2H₂O. Hirshfeld surface analysis was employed to determine the most important intermolecular interactions in the crystallographic structures. The structures of both complexes were further examined using density functional theory and natural bond orbital analysis. The photocatalytic decomposition of methylene blue in the presence of both compounds was investigated. Both compounds were active toward E. coli and S. aureus, with a minimum inhibition concentration similar to that of chloramphenicol. The obtained complexes led to the formation of free radical species, as was demonstrated in an experiment with dichlorofluorescein-diacetate. It is postulated that this is the mechanistic pathway of the antibacterial and photocatalytic activities. Cyclic voltammograms of the compounds showed the peaks of the reduction of metal ions. A molecular docking study showed that the Ni(II) complex exhibited promising activity towards Janus kinase (JAK), as a potential therapy for inflammatory diseases, cancers, and immunologic disorders.

Lysergic acid diethylamide (LSD) and its analogs are commonly encountered substances at crime scenes due to their misuse as hallucinogenic compounds. Modern methods have led to synthesizing different LSD analogs with pronounced physiological effects. Theoretical methods can be a valuable tool for predicting the spectra and stability of novel substances, especially when experimental data are partially available. The current work describes the application of theoretical methods in predicting IR, NMR, UV–VIS, and MS spectra of LSD based on the optimized structure at the M05-2X/6-311++G(d,p) level of theory. A suitable functional has been determined by comparison of the theoretically obtained geometrical parameters with the experimental ones based on the crystallographic structure. The MAE values for the structure optimized at M05-2X/6-311++G(d,p) level of theory were 0.0436 Å (bond lengths) and 2.70° (bond angles). The IR spectra of LSD and LSD tartrate have been described in detail, with the prominent bands being well reproduced (the difference between experimental and theoretical C=O stretching vibration wavenumbers was lower than 11 cm⁻¹). Detailed assignment of ¹³C NMR spectra led to a high correlation factor (0.999) and low mean absolute error (2.0 ppm) between experimental and theoretical chemical shifts. Optimizing the ground and excited states allowed for the calculation of the energy difference of 330 nm, which reproduced the observed band position in the UV–VIS spectrum of LSD. The most abundant fragments in the experimental mass spectrum (at 323, 221, 207, 181, and 72 m/z) have been optimized, and their stability has been discussed from the structural point of view. This methodology has been validated by comparison with the experimental GC-MS spectra of sample seized at the crime screen and by structure optimization and computation of NMR spectra of common LSD analogs. The theoretical methods for the structure determination and prediction of spectra show great potential in the fast-developing world of new psychedelics.

Semicarbazones and their transition metal complexes have been investigated as biologically active compounds. This study explores the synthesis, X-ray crystallographic structure, and characterization of a novel Co(III) complex cation with a pyridoxal-isothiosemicarbazone (PLITSC) ligand, [Co(PLITSC-2H)(NH₃)₃]⁺. The structure of the complex was further elucidated by the elemental analysis and spectroscopic techniques (IR and UV–VIS). Hirshfeld surface analysis was applied for the investigation of intermolecular interactions governing crystal structure. Optimization was performed at the B3LYP/6-31 + G(d,p)(H,C,N,O,S)/LanL2DZ(Co) level of theory without any geometrical constraints. The selected level of theory’s applicability was proven after comparing experimental and theoretical bond lengths and angles. The antibacterial activity of the complex towards E. coli and B. subtilis was determined and qualified as moderate compared to Streptomycin. The formation of free radical species in the presence of the complex was further verified in the fluorescence microscopy measurements. The molecular docking towards neural nitric-oxide synthase in the brain has shown that the complex structure and relative distribution of ligands were responsible for the binding to amino acids in the active pocket.

The present research aimed to investigate the demineralizing effects of sulfuric acid on pig bone. Alterations in collagen and phosphate contents and changes in the elemental composition of the bone during the 14-day-long immersion in sulfuric acid solutions of different concentrations were estimated using ATR-FTIR, LIBS, and AAS. FTIR spectra at amide I (1800–1600 cm⁻¹) and phosphate ν₁/ν₃ (PO₄³⁻) (1300–900 cm⁻¹) domains were scrutinized using the deconvolution method for monitoring changes in the protein secondary structure and mineral content. The results implicated sulfuric acid as a powerful demineralization agent and effective in targeting mineral components, such as hydroxyapatite, while leaving the collagen matrix relatively preserved with a complex secondary structure. Collagen maturity marker values gave valuable insights into the structural integrity of the bone. LIBS and AAS indicated changes in bone hardness; phosphorous-to-carbon ratio; and calcium, phosphorous, and magnesium content in the solutions left after the immersion period. The changes in the ratio of ionic-to-atomic calcium lines in the LIBS spectra indicated hardening of the bone, with increasing acid concentration and prolonged action, due to the deposition of calcium sulfate on the surface. The calcium concentration in the solutions decreased with increased acid concentration, while the change in phosphorus and magnesium concentrations was reversed.

Benzodiazepines are frequently encountered in crime scenes, often mixed with adulterants and diluents, complicating their analysis. This study investigates the interactions between two benzodiazepines, lorazepam (LOR) and alprazolam (ALP), with common adulterants/diluents (paracetamol, caffeine, glucose, and lactose) using infrared (IR) spectroscopy and quantum chemical methods. The crystallographic structures of LOR and ALP were optimized using several functionals (B3LYP, B3LYP-D3BJ, B3PW91, CAM-B3LYP, M05-2X, and M06-2X) combined with the 6-311++G(d,p) basis set. M05-2X was the most accurate when comparing experimental and theoretical bond lengths and angles. Vibrational and ¹³C NMR spectra were calculated to validate the functional’s applicability. The differences between LOR’s experimental and theoretical IR spectra were attributed to intramolecular interactions between LOR monomers, examined through density functional theory (DFT) optimization and quantum theory of atoms in molecules (QTAIM) analysis. Molecular dynamics simulations modeled benzodiazepine–adulterant/diluent systems, predicting the most stable structures, which were further analyzed using QTAIM. The strongest interactions and their effects on IR spectra were identified. Comparisons between experimental and theoretical spectra confirmed spectral changes due to interactions. This study demonstrates the potential of quantum chemical methods in analyzing complex mixtures, elucidating spectral changes, and assessing the structural stability of benzodiazepines in forensic samples.

The composition of the plasma obtained by laser ablation of cermet WC–Cu is calculated under the assumption of local thermodynamic equilibrium. Special attention is paid to the effect of lowering the ionization potential, the influence of which in the Saha equations is reflected both through the exponential Boltzmann term and through the partition functions of atomic and ionic species present in the plasma. The effects of these two terms are separated and quantified. It has been shown that the correction to the partition functions due to the reduction of the ionization potential is of greater importance than the correction to the Boltzmann term at higher temperatures for atomic species. It is thus necessary for the precise determination of the plasma composition, especially at higher temperatures. The effect of lowering the ionization potential on different types of atoms as well as on different ionic states is analyzed. The change of the partition function due to the lowering of ionization energy also affects the concentration of single charged ions in an amount comparable to the correction of the Boltzmann term.