Search

In this study, we investigate the energy loss of highly charged ions interacting with various tungsten surfaces. The analysis primarily focuses on elucidating the impact of electron density distributions on energy loss of ions. Furthermore, we explore the correlation between surface azimuthal angles and energy loss under both uniform and inhomogeneous electron density distributions. Utilizing the classical over-the-barrier model (COBM), simulations involving trajectory calculations, energy loss, charge-exchange processes, and surface electron distributions, etc., were performed. Remarkably, the significant influence of axial channeling of surfaces on ion energy loss is observed. For the comparison of ion energy loss under uniform and inhomogeneous electron density distributions, the results reveal a more pronounced effect of electron density inhomogeneity on ion energy loss at higher energy-loss values. Additionally, the calculated energy-loss spectra of Ar16+ ions grazing on graphite surfaces show reasonable agreement with experimental data. These findings are crucial for understanding the surface structure of crystals. [ABSTRACT FROM AUTHOR]

Vanadium complexes have gained considerable attention as biologically active compounds. In this contribution, three previously reported dioxovanadium(V) complexes with pyridoxal semicarbazone, thiosemicarbazone, and S-methyl-iso-thiosemicarbazone ligands are theoretically examined. The intermolecular stabilization interactions within crystallographic structures were investigated by Hirshfeld surface analysis. These experimental structures were optimized at the B3LYP-D3BJ/6-311++G(d,p)(H,C,N,O,S)/def2-TZVP(V) level of theory, and crystallographic and optimized bond lengths and angles were compared. High correlation coefficients and low mean absolute errors between these two data sets proved that the selected level of theory was appropriate for the description of the system. The changes in structures and stability were examined by adding explicit solvent molecules. The Quantum Theory of Atoms in Molecules (QTAIM) was employed to analyze the intramolecular interactions with special emphasis on the effect of substituents. A good correlation between electron density/Laplacian and interatomic distance was found. Through molecular docking simulations towards Bovine Serum Albumin (BSA), the binding affinity of complexes was further investigated. The spontaneity of binding in the active position of BSA was shown. Further experimental studies on this class of compounds are advised. [ABSTRACT FROM AUTHOR]

We report an experimental and theoretical study on the shift of the hyperfine splitting frequency of ground-state Li atoms in noble gases, He, Ne, Ar, and Xe. The frequency shift is due to the change in the electron-spin density at the Li nuclei induced by collisions to the noble-gas atoms. The electron density is calculated along the interatomic distance in a pseudopotential and a dispersion potential. Based on the measured and the calculated frequency shifts, we find the importance of attractive force in collisions to helium as well as heavy noble-gas atoms. Taking advantage of the simple energy structure of the Li atom, we obtain the s wave scattering length for free electrons on noble-gas atoms by using the hyperfine splitting frequency as a precise measure. [ABSTRACT FROM AUTHOR]

The Zintl phase K2BaSi4 has been synthesized from the mixture of precursors KSi and BaSi2. The crystal structure of K2BaSi4 was elucidated from X‐ray powder diffraction data: Pearson symbol oP28, space group Pbcm, a=9.4950(1), b=9.2392(1), c=9.9025(1) Å. The main building block of the crystal structure are tetrahedral anions Si44–. Analysis of chemical bonding for K2BaSi4 and its chemical analogs – molecular H4Si4 and solid state K4Si4 employing the electron localizability approach reveals the basic agreement with the Zintl model in terms of number of basins for Si−Si bonds and lone pairs at Si atoms, as well as the charge transfer direction. The populations of the bond and 'lone‐pair' basins agree with the Zintl count for molecular species and deviate strongly for the solids, in particular, while the 'lone‐pair' basins are over‐populated, the bond basins are essentially under‐populated. The topology of the calculated electron density and electron‐localizability indicator is very sensitive toward the interatomic distances and angles in the Si44− anion. [ABSTRACT FROM AUTHOR]

This paper compares variations on a structure model derived from an X-ray diffraction data set from a solid solution of chalcogenide derivatives of cis-1,2-bis(diphenylphosphanyl)ethylene, namely, 1,2-(ethene-1,2-diyl)bis(diphenylphoshpine sulfide/selenide), C26H22P2S1.13Se0.87. A sequence of processes are presented to ascertain the composition of the crystal, along with strategies for which aspects of the model to inspect to ensure a chemically and crystallographically realistic structure. Criteria include mis-matches between Fobs² and Fcalc², plots of |Fobs| vs |Fcalc|, residual electron density, checkCIF alerts, pitfalls of the OMIT command used to suppress ill-fitting data, comparative size of displacement ellipsoids, and critical inspection of interatomic distances. Since the structure is quite small, solves easily, and presents a number of readily expressible refinement concepts, we feel that it would make a straightforward and concise instructional piece for students learning how to determine if their model provides the best fit for the data and show students how to critically assess their structures. [ABSTRACT FROM AUTHOR]

As a result of external compression applied to crystals, ions relax, in addition to shortening the bond lengths, by changing their shape and volume. Modern mineralogy is founded on spherical atoms, i.e., the close packing of spheres, ionic or atomic radii, and Pauling and Goldschmidt rules. More advanced, quantum crystallography has led to detailed quantitative studies of electron density in minerals. Here we innovatively apply it to high-pressure studies up to 4.2 GPa of the mineral hsianghualite. With external pressure, electron density redistributes inside ions and among them. For most ions, their volume decreases; however, for silicon volume increases. With growing pressure, we observed the higher contraction of cations in bonding directions, but a slighter expansion towards nonbonding directions. It is possible to trace the spatial redistribution of the electron density in ions even at the level of hundredths parts of an electron per cubic angstrom. This opens a new perspective to experimentally characterise mineral processes in the Earth's mantle. The use of diamond anvil cells with quantum crystallography offers more than interatomic distances and elastic properties of minerals. Interactions, energetic features, a branch so far reserved only to the first principle DFT calculations at ultra-high-pressures, become available experimentally. [ABSTRACT FROM AUTHOR]

In this study, we present results of a detailed topological analysis of electron density (ED) of 145 halogen-bonded complexes formed by various fluorine-, chlorine-, bromine-, and iodine-containing compounds with trimethylphosphine oxide, Me3PO. To characterize the halogen bond (XB) strength, we used the complexation enthalpy, the interatomic distance between oxygen and halogen, as well as the typical set of electron density properties at the bond critical points calculated at B3LYP/jorge-ATZP level of theory. We show for the first time that it is possible to predict the XB strength based on the distance between the minima of ED and molecular electrostatic potential (ESP) along the XB path. The gap between ED and ESP minima exponentially depends on local electronic kinetic energy density at the bond critical point and tends to be a common limiting value for the strongest halogen bond. [ABSTRACT FROM AUTHOR]

Analysis of the available experimental data on iron compounds has shown the following: The 57Fe Mössbauer isomer shift (IS) depends on the average interatomic distance between the iron ion and the ions of its first coordination sphere (aID), on the chemical nature of these ions, and also on the iron coordination number. An increase in aID and a decrease in the coordination number lead to an increase in IS. For a given polyhedron, the correlation between IS and aID is close to linear with a slope of about 0.04 mm⋅s-1⋅pm-1. A change in the oxidation state of iron (OSFe) affects IS, since a change in OSFe causes a change in aID due to a change in the number of electrons on the valence shell of iron; the more OSFe, the less IS. If the aID of differently charged ions are close (e.g., for the pair H4[Fe(CN)6] and H3[Fe(CN)6]), then the IS values do not differ significantly. A change in the spin state of an iron ion affects IS insofar as this change causes a change in aID. In particular, the transition from the high-spin to the low-spin state in iron(II) spin-crossover compounds leads to a decrease in aID and, accordingly, to a decrease in IS. A change in the spatial structure of the iron coordination polyhedron may affect IS. This was observed when comparing tetrahedral and square-planar iron(II) oxygen polyhedra. The tetrahedral and square-planar oxygen polyhedra of high-spin iron(II) show increased IS values. In terms of the orbital model of the electron shell of the atom, the above data can be explained by the interactions of the 4s-orbital of iron with its other valence orbitals (undergoing hybridization), as well as with the orbitals of the ions surrounding iron (establishing directional chemical bonds). These interactions affect the electron density at the iron nucleus. The corresponding contributions depend on the distances between the iron ion and the ions surrounding it, but do not depend on the number of orbitals involved into hybridization or on the number of directional chemical bonds. The electron shell of each ion of the iron polyhedron also makes an additional (non-bonding) contribution to the electron density at the iron nucleus. In some specific cases (e.g., for iron in noble gas matrices), the observed unusually low IS can be explained by the filling of the 4s-orbital of iron with its valence non-bonding electron(s). [ABSTRACT FROM AUTHOR]

Using the example of a polymer formed from the T-monomer RFOCH2Si(ORF)3 (RF = CH2CF3), it was shown that rapid hydrolysis of this type of compounds with a linear fluorinated substituent leads to the formation of largely ordered polysiloxanes. A comparison of the interatomic distances obtained from the pair function of the radial distribution of electron density and the oligomer model, as well as data from solid-state NMR spectroscopy, X-ray powder diffraction, and coating properties, shows that polymers are ladder polysiloxanes with a certain ordering of macromolecules in the coating material. [ABSTRACT FROM AUTHOR]

• The 1H NMR spectrum of the alkaloid oxaline shows unexpected and abnormal multiplicity for the nucleus of the prenyl group. • These abnormalities does not modify significantly at higher temperatures, indicating that it is not due conformational mobility restriction. • The use of DFT calculations helped to suggest an spatial effect of quadrupolar nitrogens on these broadening NMR lines observed. • Optimized 3 dimensional structure shows that two of the five nitrogen atoms in oxaline are very close to the prenyl hydrogens, affecting their resonance lines. Oxaline is a bioactive alkaloid that acts as an antibiotic and antiproliferative drug affecting tubulin polymerization. Oxaline and meleagrine alkaloids contain an indoline spiroaminal tricyclic system produced from roquefortine as a biosynthetic precursor. These prenylated indoline spiroaminal alkaloids have been identified mainly by NMR spectroscopy and single crystal X-Ray diffraction. The 1H NMR spectrum of the parent alkaloid roquefortine contains three clear signals for vinyllic hydrogens forming an ABX system and two clear and intense singlets for methyl groups at the prenyl unit. On the other hand, the indoline spiroaminal alkaloids produce 1H NMR containing these same signals but they are formed of broad lines, many times as uninterpretable signals. Although it appears that these unusual signals have not become an important obstacle for correct identification of these alkaloids, nonetheless this broadening line phenomenon has not yet been addressed and correctly figured out. In the present study we applied some computational tools contributing to enhance the understanding of this phenomenon. The Density Functional Theory (DFT) studies of interatomic distances, electron density and electrostatic potential distributions led us to consideration of the possible effect of the quadrupolar field of the nitrogen atoms, especially N-14 and N-11, which are the closest to the prenyl hydrogen atoms. The poor resolution in these signals varies with the solvent and the temperature changes. In addition to conformational mobility, our studies also considered the influence of the quadrupolar field of the nitrogen atoms from the triazaspirocycle system on the resonances of neighbor hydrogens. It is known from the literature that the lines of ½ spin nuclei such as 1H attached to nitrogen (I = 1) have their line-shape, multiplicity and relaxation time affected. In the case of these spiroaminal indoline alkaloids, we found that the 1H nuclei from the prenyl group are affected through space, since they are not directly attached to any of the three quadrupolar-N. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] Two new copper dimers [Cu(L)(µ-Br)] 2 , HL = 2(RS)C 6 H 4 N = NC(COCH 3)-SC 6 H 5 , where R = CH 3 (1), C 6 H 5 (2) were synthesized and characterized using a variety of physicochemical methods, including single crystal X-ray diffraction. The molecular structures of the two binuclear copper(II) complexes show that Cu∙∙∙Cu inter-nuclei distances are 3.662 \AA and 3.392 \AA in 1 and 2, respectively. Structural analysis of the two dimers supported by QTAIM analysis of electron density indicates the presence of competition between Cu∙∙∙Br semi-coordinate bond and C H∙∙∙Br and C H∙∙∙S hydrogen bonding interactions and S∙∙∙S chalcogen bonding interactions. In complex 1 , C H∙∙∙Br and C H∙∙∙S hydrogen bonding interactions exist, in contrast, they are absent in 2. Cu∙∙∙Br semi-coordinate bonds are stronger in 2 as indicated by Cu∙∙∙Br bond distances; Cu∙∙∙Br bond distances are 2.955 and 2.858 Å in 1 and 2.746 Å in 2. There are two weaker S∙∙∙S interactions in 2 and one stronger interaction in 1 as indicated by S∙∙∙S interatomic distances. The two copper dimers and their ligands exhibited good anticancer efficacy against breast (MCF-7), lung (HCT115), and colon human (A549) cancer cell lines. Complex 1 demonstrated strong cancer cell death compared to complex 2. Additionally, the complexes exhibited higher activity than the ligands. Dimer 2 exhibits two quasi-reversible one-electron reduction waves at −0.05 V and −0.37 V. The comproportionating constant for forming the Cu(I/II) mixed-valence complex was 2.57 × 105. The absence of Intervalence transfer (IT) bands in the electronic absorption spectrum for the mixed-valence complex suggested that a single unpaired electron is localized on one copper center. [ABSTRACT FROM AUTHOR]

Electrochemical CO 2 reduction (CO 2 RR) into chemicals and fuels has gained great interest, but is subjected to low current density and poor product selectivity. Here a theory-guided design of sulfur-doped single nickel atom catalyst (Ni-SAC/SNC) with the optimal Ni-S dual active configuration was present for efficient CO 2 RR. Experiments combined with theory verified that the positively charged Ni-S dual sites drastically promoted the electronic localization of Ni center, which improved the stabilization of key COOH* intermediate and thus boosted CO production on Ni. This catalyst exhibited a high CO Faradaic efficiency of ∼98% and a current density of ∼32.5 mA cm−2 at a low overpotential of 620 mV, which exceeded most of single-atom electrocatalysts. This work offers atomic-level insights into the correlation between the electronic density of atomic sites and CO 2 RR performance, promoting the theory-guided rational design of efficient catalysts. [Display omitted] • A theory-guided design of sulfur-doped single Ni atom catalyst was synthesized. • The interatomic distance between Ni and S determined the electron density of Ni. • The Ni-S dual sites drastically promoted the electronic localization of Ni. • Enhanced stabilization of key COOH* was achieved on electron enriched Ni. • High and stable CO Faradaic efficiency and current density were accomplished. [ABSTRACT FROM AUTHOR]

The plasticity of Ag2S and Ag2Se crystals important for applications is associated mainly with AgAg metallophilic bonds, which are related to van der Waals interactions and therefore are not directed. This is demonstrated by the first principles DFT M06 LCAO calculations of Ag2X (X = S, Se) crystals (periodic model) and hypothetical molecules XnAg2n (X = S, Se; n = 1, 2, 4) in gas phase (molecular model). A topological analysis of the calculated electron density, was performed both for periodic and molecular models of Ag2X (X = S, Se). It was found that Ag–Ag interatomic distances are close in periodic and molecular models. The numerical values of electron density, its Laplacian, kinetic, and potential energy densities are also close in both models and confirm the existence of AgAg metallophilic bonds. [ABSTRACT FROM AUTHOR]

We estimate polarizabilities of atoms in molecules without electron density, using a Voronoi tesselation approach instead of conventional density partitioning schemes. The resulting atomic dispersion coefficients are calculated, as well as many-body dispersion effects on intermolecular potential energies. We also estimate contributions from multipole electrostatics and compare them to dispersion. We assess the performance of the resulting intermolecular interaction model from dispersion and electrostatics for more than 1300 neutral and charged, small organic molecular dimers. Applications to water clusters, the benzene crystal, the anti-cancer drug ellipticine--intercalated between two Watson-Crick DNA base pairs, as well as six macro-molecular host-guest complexes highlight the potential of this method and help to identify points of future improvement. The mean absolute error made by the combination of static electrostatics with many-body dispersion reduces at larger distances, while it plateaus for two-body dispersion, in conflict with the common assumption that the simple 1/R6 correction will yield proper dissociative tails. Overall, the method achieves an accuracy well within conventional molecular force fields while exhibiting a simple parametrization protocol. [ABSTRACT FROM AUTHOR]

Two pressure‐induced phase transitions have been theoretically studied in the layered iron phosphorus triselenide (FePSe3). Topological analysis of chemical bonding in FePSe3 has been performed based on the results of first‐principles calculations within the periodic linear combination of atomic orbitals (LCAO) method with hybrid Hartree‐Fock‐DFT B3LYP functional. The first transition at about 6 GPa is accompanied by the symmetry change from R3¯ to C2/m, whereas the semiconductor‐to‐metal transition (SMT) occurs at about 13 GPa leading to the symmetry change from C2/m to P3¯1m. We found that the collapse of the band gap at about 13 GPa occurs due to changes in the electronic structure of FePSe3 induced by relative displacements of phosphorus or selenium atoms along the c‐axis direction under pressure. The results of the topological analysis of the electron density and its Laplacian demonstrate that the pressure changes not only the interatomic distances but also the bond nature between the intralayer and interlayer phosphorus atoms. The interlayer P–P interactions are absent in two non‐metallic FePSe3 phases while after SMT the intralayer P–P interactions weaken and the interlayer P–P interactions appear. [ABSTRACT FROM AUTHOR]

The structure of single-crystal dodecaboride TmB12, which possess metallic properties, has been studied by X-ray diffraction at nine temperatures in the range of 85–293 K. Jahn–Teller distortions of the cubic lattice are revealed. They are found to cause an asymmetric electron density distribution in crystal. Static components of atomic displacements are selected, and characteristic Einstein and Debye temperatures are determined for thulium and boron atoms, respectively. Temperature dependences of interatomic distances are obtained. The problem of localizing conduction electrons by means of X-ray diffraction analysis is stated. [ABSTRACT FROM AUTHOR]

Derivatives of the amino acids sarcosine and proline – triflates TsN(Me)CH2C(O)N(Me)-CH2SiMe2OTf and Ns–Pro–N(Me)CH2SiMe2OTf (Ns is 4-NO2C6H4SO2) – were synthesized by the reaction of trimethylsilyl triflate with halosilanes prepared previously. Bromide NsNHCH(Me)C(O)N(Me)CH2SiMe2Br was synthesized by the cleavage of the Si–O–Si moiety of the appropriate disiloxane with excess acetyl bromide. The X-ray diffraction study of these compounds and of the previously characterized bromide TsN(Ac)CH2C(O)N(Me) CH2SiMe2Br showed that the Si–O coordination bond lengths in the triflates are 1.7692(14)– 1.8623(14) Å. The interatomic distances between the bromine and silicon atoms are 2.7095(8) and 2.9704(7) Å, which indicates that these bonds are weak. To elucidate the nature of Si...X bonding (X = OTf, Br), the topological analysis of electron density was performed and 29Si NMR chemical shifts were calculated. The interatomic Si...X interaction in triflate TsN(Me)CH2C(O)- N(Me)CH2SiMe2OTf and bromide TsN(Ac)CH2C(O)N(Me)CH2SiMe2Br is weak. In triflate Ns–Pro–N(Me)CH2SiMe2OTf and bromide NsNHCH(Me)C(O)N(Me) CH2 SiMe2Br, the Si...X interaction is significantly stronger and corresponds to a weak coordination bond. Hence, the tosylates can be considered as salts, whereas the para-nitrobenzenesulfonyl derivatives are monochelated five-coordinate silicon complexes. [ABSTRACT FROM AUTHOR]

The rotation of the plane of polarization of light transmitted in the directions parallel (ρ||) and perpendicular (ρ⊥) to the optical axis has been calculated for langasite family crystals. It is shown that the ρ|| and ρ⊥ values are, respectively, negative and positive for all the right-handed crystals under study. An analysis of the interatomic potential constructed based on X-ray diffraction data has suggested that this anisotropy of optical activity is structurally based of electron density regions shaped as helices. The atomic helix with an axis parallel to the optical axis is right-handed and three-start, whereas in the direction perpendicular to the optical axis there are three left-handed two-start helices, which intersect in the origin of the unit-cell coordinate system. [ABSTRACT FROM AUTHOR]

A novel approach for calculating deformation densities is presented, which enables to calculate the deformation density resulting from a change between two chemical states, typically conformers, without the need for radical fragments. The Fragment, Atom, Localized, Delocalized, and Interatomic (FALDI) charge density decomposition scheme is introduced, which is applicable to static electron densities (FALDI-ED), conformational deformation densities (FALDI-DD) as well as orthodox fragment-based deformation densities. The formation of an intramolecular NH⋅⋅⋅N interaction in protonated ethylene diamine is used as a case study where the FALDI-based conformational deformation densities (with atomic or fragment resolution) are compared with an orthodox EDA-based approach. Atomic and fragment deformation densities revealed in real-space details that (i) pointed at the origin of density changes associated with the intramolecular H-bond formation and (ii) fully support the IUPAC H-bond representation. The FALDI scheme is equally applicable to intra- and intermolecular interactions. © 2017 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

The Bürgi-Dunitz trajectory traces points along the pathway of bond formation between a nucleophile and electrophile. Previous X-ray crystallographic studies of some molecules containing a nucleophilic nitrogen atom and electrophilic carbonyl group provided some initial evidence for various degrees of bond formation via initial n→π* interactions. Observation of a complete set of points along the trajectory, however, has not yet been attained. In this paper, we present a DFT computational study investigating substituted 2-(dimethylamino)biphenyl-2'-carboxaldehydes as substrates for further examination of n→π* interactions and as a potential framework for more complete tracing of the Bürgi-Dunitz trajectory. These compounds are particulary suitable for study because of the rotational freedom granted by the C-C bond connecting the two aromatic rings allowing the molecule to choose the degree of interaction between the two complementary groups. The extent of interaction is measured by interatomic distance, NBO second-order perturbative analysis energies, volume of transferred electron density as provided by ETS-NOCV analysis, and differences in energies between models that allow for n→π* interactions and those that do not. A series of substituted biphenyls are ultimately identified as future synthetic targets that have maximum potential for providing improved tracing of the Bürgi-Dunitz trajectory. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hydrogen bonds OHN. • "Recipes" of spectral IR diagnostic of hydrogen bond geometry. • Equations linking hydrogen bond length O...N and IR parameters. In this computational work applicability of IR spectral parameters for evaluations of OH···N hydrogen bond length is discussed. For a set of 124 complexes with OH···N hydrogen bond formed by combinations of methanol/acetic acid and pyridine (and their fluorine substituted versions) geometries, energies and IR parameters were calculated at MP2/def2-TZVP level of theory. For a number of IR parameters (the shift of proton donor group stretching vibration Δ ν s , increase of its intensity I , the low-frequency hydrogen bond stretching vibration ν σ , bending in-plane δ and out-of-plane γ vibrations) equations linking them with interatomic distances are proposed, the robustness and accuracy of such equations are discussed. The enthalpy of OH···N hydrogen bond formation Δ H was also linked with electron density parameters in (3; –1) critical point. [ABSTRACT FROM AUTHOR]

A search through Crystal Structure Database was performed and the distances in contacts of X···N,O, X···H(N,O), and X···C type were collected together with the information on spatial arrangement of the interacting fragments. A detailed statistical analysis showed that the shape of the halogen atom cannot be simply concluded on the basis of interatomic distances in crystal state although originally the concept of anisotropic charge distribution around halogen nuclei was postulated on the basis of such an analysis. It was proven that the conclusions in that case strongly depend on the type of center interacting with the halogen atom. Therefore, it was postulated that the shape of the halogen atom can be estimated for the unperturbed (due to intermolecular interactions) halogen atom. For this purpose, a method was provided to make possible a numerical quantification of the anisotropy of the halogen atom on the basis of electron density measurements performed within the framework of Atoms in Molecules Quantum Theory. The anisotropy of Cl and Br atoms in HC-X and FC-X (X=Cl, Br) was estimated for MP2 and DFT-B3LYP methods and several different basis sets. The influence of the method and the basis set on the degree of anisotropic distribution of electron density around halogen nuclei was discussed. [ABSTRACT FROM AUTHOR]

• fac -[Re(CO) 3 (κ2-N im ,S-bptsc)Cl] (2) is a rare example of a Re complex of κ2-N im ,S-coordinated bptsc (1). • Elemental analysis, spectroscopic measurements and X-ray structural analysis confirmed the identity of 2. • The extended structure of 2 disclosed a network of non-covalent [N H ··· X] (X = O or Cl), S ··· S, and C H ··· π interactions. • DFT calculations, spectroscopic and electrochemical measurements on 2 revealed facile delocalization of its electron density. • Electrochemical measurements on 1 and 2 in non-aqueous solvents disclosed sequential electronic transfers leading to their oxidative and reductive decomposition. fac- [Re(CO) 3 (κ2-N im ,S-bptsc)Cl] (2), isolated from the reaction between Re(CO) 5 Cl and benzophenone thiosemicarbazone, bptsc, (1) in refluxing toluene in air, is the first Re compound of 1 and is the second Re(CO) 3 Cl compound of κ2-N im ,S-coordinated ligand (im = imine). The authenticity of 2 was established from the results of its elemental composition, spectroscopic measurements, and X-ray crystallographic analysis. Single crystals of 2 grown from DMF are in the monoclinic space group P 2 1 / c. The asymmetric unit of 2 revealed pseudo-octahedral coordination about Re. Two carbonyl C atoms, an imine N atom and a thione S atom occupy the equatorial sites and the axial sites are occupied by a carbonyl C atom and a Cl atom. The κ2-N,S-coordination of 1 to Re forms a semi-planar five-membered [Re-N-N C-S] metallocyclic ring. The extended structure disclosed stacks of molecules interlocked via a web of N H ··· X (X = Cl or O), S ··· S and C H ··· π interactions. DFT calculations divulged facile delocalization of electron density in the molecule and interatomic distances and angles in good agreement with the solid state structure. Electrochemical measurements on 2 in CH 3 CN and DMF revealed sequential irreversible electron transfers pointing to structural changes due to electrochemically induced thione-thiol tautomerization of the thioamide moiety. Plausible mechanisms for the oxidative and reductive electrochemical decomposition of 1 and 2 are reported. The proposed mechanisms are in good agreement with those reported in the literature for closely related compounds. [Display omitted] [ABSTRACT FROM AUTHOR]