Herein, a systematic study of [L2Fe2S2](n) model complexes (where L = bis(benzimidazolato) and n 2-, 3-, 4-) has been carried out using iron sulfur K-edge X-ray absorption (XAS) Kβ valence-to-core emission spectroscopies (XES). These data are used as test set to evaluate the relative strengths weaknesses core level in assessing redox changes iron-sulfur clusters. The results correlated density functional theory (DFT) calculations spectra order further support quantitative information that...

High-resolution X-ray spectroscopy provides insights into the electronic structural differences between nitrogenase FeMoco and FeVco clusters.

Abstract The bioinorganic chemistry community has had a long history of utilizing diverse range spectroscopic techniques to obtain detailed geometric and electronic structural insights into metalloprotein active sites. In recent years, the development beamlines optimized for high‐resolution X‐ray spectroscopy provided novel tools elucidation biological site structures. These methods include both non‐resonant resonant emission spectroscopy. Herein, we briefly introduce absorption...

A series of vanadium compounds was studied by K-edge X-ray absorption (XAS) and K $$\beta $$ emission spectroscopies (XES). Qualitative trends within the datasets, as well comparisons between XAS XES data, illustrate information content both methods. The complementary nature chemical insight highlights success this dual-technique approach in characterizing structural electronic properties sites. In particular, contrast to or extended fine structure (EXAFS), we demonstrate that...

In this study, a detailed calibration of the performance modern ab initio wave function methods in domain X-ray absorption spectroscopy (XAS) is presented. It has been known for some time that given level approximation, example, using time-dependent density functional theory (TD-DFT) conjunction with basis set, there are systematic deviations calculated transition energies from their experimental values depend on functional, and chosen treatment scalar relativistic effects. This necessitates...

Herein, a systematic study of series molecular iron model complexes has been carried out using Fe L2,3-edge X-ray absorption (XAS) and magnetic circular dichroism (XMCD) spectroscopies. This spans increasing complexity, starting from ferric ferrous tetrachlorides ([FeCl4]−/2–), to tetrathiolates ([Fe(SR)4]−/2–), diferric mixed-valent iron–sulfur [Fe2S2R4]2–/3–. test set compounds is used evaluate the sensitivity both XAS XMCD spectroscopy oxidation state ligation changes. It demonstrated...

Abstract Nitrogenase enzymes catalyze the reduction of atmospheric dinitrogen to ammonia utilizing a Mo‐7Fe‐9S‐C active site, so‐called FeMoco cluster. and an analogous small‐molecule (Et 4 N)[(Tp)MoFe 3 S Cl ] cubane have both been proposed contain unusual spin‐coupled Mo III sites with (Mo)=1/2 non‐Hund configuration at atom. Herein, we present Fe L ‐edge X‐ray magnetic circular dichroism (XMCD) spectroscopy 2,3 XMCD MoFe protein (containing 8Fe‐7S P‐cluster sites). As P‐clusters =0 total...

In this work, we present a detailed comparison of wavefunction-based multireference (MR) techniques for the prediction transition metal L-edge X-ray absorption spectroscopy (XAS) using [Fe(II)Cl4]2- and [Fe(III)Cl4]1- complexes as prototypical test cases. We focus on MR Configuration Interaction (MRCI) Equation Motion Coupled Cluster (MREOM-CC) methods, which are employed to calculate valence excitation well core Fe XAS spectra complexes. The two investigated approaches thoroughly analyzed...

In recent years, the Fourier transformed infrared spectroscopy is often applied in studies of biological materials on cellular level.Undoubted advantage this method high sensitivity.In presented research FTIR microspectroscopy was used to analyse DNA damage single PC-3 cells (prostate cancer cell line derived from bone metastases) irradiated by counted number protons.Focused proton microbeam 2 MeV Van de Graaff accelerator at Institute Nuclear Physics, Polish Academy Sciences, as an...

In this work, we present a combined experimental and theoretical study on the V L2,3-edge x-ray absorption (XAS) magnetic circular dichroism (XMCD) spectra of VIVO(acac)2 VIII(acac)3 prototype complexes. The recorded XAS XMCD are richly featured in both L3 L2 spectral regions. an effort to predict interpret nature experimentally observed features, first-principles approach for simultaneous prediction framework wavefunction based ab initio methods is presented. theory used here has previously...

Despite growing number of literature demonstrating the piezoelectric effect in bones at macro level there's still a lack papers describing this molecular level.In order to examine more specifically, study has been conducted show possibility using infrared spectroscopy on samples contained electric field.This is first known research applying influence field and compressive stress bones' structure represented by IR spectrum.The used experiment as model were prepared pellet form, made from...

Considerable effort has been devoted to the development of first-row transition-metal catalysts containing redox-active imino-pyridine ligands that are capable storing multiple reducing equivalents. This property allows abundant and inexpensive transition metals, which favor sequential one-electron redox processes, function as competent in concerted two-electron reduction substrates. Herein we report syntheses characterization a series iron complexes contain both π-donating thiolate...

The interaction of O2 with polycrystalline foil Cu, from ultra high vacuum to 1 mbar and up 773 K has been investigated.The study were performed by using the pressure X-ray photoelectron spectroscopy (electron for chemical analysis) ultraviolet system.In this work results mapping copper oxidation states as a function temperature at have presented.

Atherosclerosis is a multietiological inflammatory disease of large and medium-sized arteries increasing incidence in westernized countries.The aim this study was to identify the biochemical changes during progression atherosclerosis by synchrotron radiation Fourier transform infrared microspectroscopy atheromas apoE/LDLR -/-mice fed egg-rich diet supplemented or not with angiotensin converting enzyme inhibitor perindopril.Synchrotron technique used obtain information at high spatial...

The objective of the study was to investigate effects five organic vanadium complexes supplement and a small dose insulin injection on V, Fe, Cu, Zn, Mn, Ca, K level in streptozotocin diabetic rat's kidney during 5-week treatment with tested complexes. In all groups animals, metal lyophilized organs investigated by means proton induced X-ray emission method. Tissue naturally higher vanadium-treated rats. maximum observed ( $$ {x_{\text mean}} =16.6\ \upmu \mathrm{g}/\left. \mathrm{g} \right)...

Diabetes is one of the most frequent diseases in developing countries and thus there a significant interest diabetes related studies.It was found that vanadium compounds have glucose-lowering properties therefore it very important to estimate dose treatment.On other hand, proper estimation concentration due side effects occur supplementation.In this study influence V(IV) V(V) with different ligands on K, Ca, Mn, Fe, Cu, Zn selected rat's tissues investigated by means proton induced X-ray...