Abstract: Partial reduction of transition metal oxides via defect engineering is a promising strategy to enhance their electronic and photocatalytic properties. In this study, we systematically explore the mechanochemical reduction of Nb2O5 using LiBH4 and NaBH4 as reducing agents. Electron paramagnetic resonance (EPR) spectroscopy confirms a successful partial reduction of the oxide, as seen by the presence of unpaired electrons. Interestingly, larger hydride concentrations do not necessarily enable a higher degree of reduction as large amounts of the boron hydrides act as a buffer material and thus hinder the effective transfer of mechanical energy. Powder X-ray diffraction (PXRD) and 7Li solid-state NMR spectroscopy indicate the intercalation of Li+ into the Nb2O5 lattice. Raman spectroscopy further reveals the increased structural disorder, while optical measurements show a decreased band gap compared to pristine Nb2O5. The partially reduced samples show significantly enhanced photocatalytic performance for methylene blue degradation relative to the unmodified oxides.

Abstract: A mononuclear complex [Dy(phenN6)(HL')2]PF6.CH2Cl2 (H2L' = R/S-1,1'-binaphthyl-2,2'-diphenol) with local D6h symmetry was synthesized. Structural determination shows that Dy3+ was wrapped in the coordination cavity of the neutral hexaaza macrocyclic ligand phenN6, and the whole coordination plane was not planar. The axial positions are coordinated by two phenoxy groups of binaphthol in the trans form. The local configuration of Dy3+ is close to the regular hexagonal bipyramid D6h configuration. The axial Dy-Ophenoxy distances are 2.189(5) and 2.144 (5) Å, respectively, and the bond lengths of Dy-N on the equatorial plane are in the range of 2.525 (7)–2.719 (5) Å. The axial Ophthalmoxy-Dy-Ophthalmoxy bond angle is 162.89(18), which deviates from the ideal linearity. Under the excitation of 320 nm, the characteristic emission peak of naphthalene ring appeared at 360 nm in the complex. The results of AC magnetic susceptibility test show obvious temperature dependence and frequency dependence in the AC magnetic susceptibility signals, typical of single-molecule magnetic behavior. The Cole-Cole curve in the temperature range of 6.0-28.0 K is fitted by the formula including Orbach and Raman relaxation mechanisms, giving the effective energy barrier Ueff = 300.2 K and the relaxation time τ0 = 6.7×10-7 s.

Abstract: This work investigates the effects of gamma irradiation (0.1–10 kGy) on four Italian wheat matrices, such as durum, conventional soft, integrated soft and biological soft wheat by coupling Raman, FTIR-ATR and EPR spectroscopies to provide complementary insights into the structural, conformational, and radical-based transformations occurring in starch, the primary polysaccharide in wheat. As a general trend, gamma irradiation up to 10 kGy does not induce drastic degradation or depolymerization of wheat components. However, deeper investigations reveal that wheat composition is crucial in modulating the effects of gamma irradiation on structural and conformational rearrangements of starch units. Raman and FTIR-ATR spectroscopy analyses showed an increase in random coil fractions with the most significant changes observed in durum wheat, plausibly attributed to its higher protein content. EPR analyses confirmed a dose-dependent increase in free radicals, with different recombination kinetics between wheat types, influenced by their intrinsic composition and molecular organization. The proposed spectroscopic approaches allow for rapid and nondestructive analyses of molecular structure, chemical composition and free radical content in irradiated wheat matrices with minimal sample preparation. These approaches can be extended in the development of screening methods for a wide range of polysaccharides in a variety of crops.

Abstract:

The crystallization of nickel (II) bis-phosphine and nickel and zinc cluster complexes have been carried out in localized magnetic fields set up using neodymium magnets, including custom made Magnetic Crystallization Towers (MCTs). In all cases, whether the product complex is diamagnetic or paramagnetic, a complex spatial patterning of the crystals occurs based on the orientation of the magnetic field lines. The effects of nucleation, and solution concentration gradients on the crystallization process are also explored. These observations therefore show how the crystallization process is affected by magnetic fields and thus these results have far-reaching effects which most certainly will include crystallization and ion migrations in biology.

Abstract:

The reaction of the bulky ligand 1,2-bis-(di-tert-butylphosphinomethyl)benzene with [Ni(DME)Cl₂] affords the blue Zwitterionic complex containing a phosphonium group and an anionic nickel trichloride. The neutral and stable complex is of interest as it shows an apparently Zwitterionic structure, one counter-anion to the Ni(II) being delocalised into the backbone of the ligand. This complex decomposes in alcohols such as methanol and turns yellow. A discussion of the mechanism leading to the observed product is presented. In dimethylformamide, however, the complex exhibits thermochromic properties: an ambient temperature pale blue solution changes colour reversibly to yellow on cooling. The structures of the previously prepared molybdenum complex, [1,2-(C₆H₄-CH₂P^tBu₂)₂Mo(CO)₄] and the diphosphine sulfide 1,2-(C₆H₄-CH₂P(S)^tBu₂)₂ are described for comparative purposes.

Abstract: Boron Neutron Capture Therapy is a re-emerging therapy for the treatment of cancer, and the development of new neutron-reactive nuclei carriers with enhanced efficiency is of great importance. In this work we propose three new boron-based solid compounds, of formula [Ca(H2O)6](C14H8O6B)2 (CaSB), [Cu(C14H8O6B)] (CuSB), and [Li(C14H8O6B)(H2O)] (LiSB), usable as nanoparticles for the carriage of the 10B isotope. The copper atom in CuSB was introduced because it is known that its presence magnifies the effect of the radiation into cells. Furthermore, the lithium atom in LiSB allows to include also the 6Li isotope, that can take part in the nuclear reactions enhancing the efficiency of the anti-cancer treatment. The compounds were characterized with single crystal X-ray diffraction, to compare the densities of the reactive isotopes in the materials, a key parameter related to the efficiency of the materials. In this work, we used a computational method to calculate the dose absorbed by a tumor mass treated with nanoparticles of the compounds, in order to select the most efficient one for the therapy. The encouraging results are reported in this work.

Abstract: In a review intended as an introduction to bioinorganic chemistry for the senior undergraduate and novice postgraduate student, the role played in biological systems by the metals of the first row of the d block is examined using selective and illustrative examples and highlighting current thinking in the field.

Abstract: Palladium-doped silver nanoclusters (NCs) have been highlighted for their unique physico-chemical properties and potential applications in catalysis, optics, and electronics. Anion-directed synthesis offers a powerful route to control the morphology and properties of these NCs. Herein, we report a novel Pd-doped Ag NC, [Pd(H)Ag13(S){S2P(OiPr)2}10] (PdHAg13S), synthesized through the inclusion of sulfide and hydride anions. This NC features a unique linear S-Pd-H axis enclosed in a 4-5-4 stacked arrangement of silver atoms. The distinctive hydride environment was characterized by NMR spectroscopy, and the total structure was determined by single-crystal X-ray diffraction (SCXRD) and supported by computational studies. Mass spectrometry and X-ray photoelectron spectroscopy (XPS) further confirmed the assigned composition. This unique con-struct exhibits promising hydrogen evolution reaction (HER) activity. Our findings highlight the potential of anion-directed synthesis for creating novel bimetallic NCs with tailored structures and catalytic properties.

Abstract: Two new Co(II) coordination compounds viz. [Co(H2O)(bz)2(μ-3-Ampy)2]n (1) and [Co(4-Mebz)2(2-Ampy)2] (2) (where; bz = benzoate, 4-Mebz = 4-Methylbenzoate and Ampy = Aminopyridine) were synthesized and characterized by elemental (CHN), electronic spectroscopy, FT-IR spectroscopy, and thermogravimetric analysis (TGA). The crystal structures were determined by single crystal X-ray diffraction analysis, inferring that compound 1 crystallizes as a 3-Ampy bridged Co(II) coordination polymer; whereas, compound 2 crystallizes as mononuclear Co(II) compound. Compound 1 unfolds the presence of N‒H∙∙∙O, C‒H∙∙∙O, O‒H∙∙∙O, C‒H∙∙∙N and aromatic π∙∙∙π interactions; while for compound 2, N‒H∙∙∙O, C‒H∙∙∙O, C‒H∙∙∙C and C‒H∙∙∙π interactions are observed. Both the compounds showcase scarcely reported chelate ring interactions involving the benzoate moiety (chelate ring∙∙∙π in 1 and N‒H∙∙∙chelate ring in 2). We have also carried out theoretical studies comprising of combined QTAIM/NCI plot analysis, DFT energy calculation and MEP surface analysis to analyze the non-covalent interactions present in the crystal structures. As per QTAIM parameters, the predominance of π-stacking interactions over hydrogen bonds in stabilizing the assembly in compound 1 is affirmed. Likewise, in compound 2, both hydrogen bonding (HBs) and C–H···π interactions are deemed pivotal in stabilizing the dimeric assemblies. The in vitro antiproliferative activity of compounds 1 and 2 were evaluated against Dalton’s lymphoma (DL) malignant cancer cell lines using cytotoxicity and apoptosis assays which showcases higher cytoxicity of compound 1 (IC50 = 28 μM) over compound 2 (IC50 = 34 μM). Additionally, molecular docking study investigates the structure activity relationship of these compounds and to understand the molecular behavior after treatment.

Abstract: We report on a series of SrMo1-xMnxO3-δ perovskite oxides designed as potential anode materials for solid oxide fuel cells (SOFCs). These materials were synthesized using a citrate method, yielding scheelite-type precursors with nominal SrMo1-xMnxO4 compositions, which were further reduced to obtain the active perovskite oxides. Their structural evolution was examined through X-ray diffraction (XRD) and neutron powder diffraction (NPD). These techniques provided insights into the crystallographic changes upon Mn doping, revealing key factors influencing ionic conductivity. Whereas the oxidized scheelite precursors are tetragonal, space group I41/a, the reduced perovskite specimens are cubic, space group Pm-3m, and show the conspicuous absence of oxygen vacancies, even at the highest temperature of 800ºC. The transport properties were analyzed through electrical conductivity measurements, exhibiting a metallic-like behavior. Thermogravimetric analysis (TGA) and dilatometry give insights into the thermal stability and expansion behavior, essential for SOFC operation. Test single SOFC were built in an electrolyte-supported configuration, on LSGM pellets of 300m thickness, assessing the performance of the title materials as anodes. This work emphasizes the critical relationship between the crystal structure and its electrochemical behavior, providing a deeper understanding of how doping strategies can optimize fuel cell performance.

Abstract: The oxime group is important in organic and inorganic chemistry. In most cases this group is part of an organic molecule possessing one or more donor sites capable of forming bonds to metal ions. One family of such compounds is the group of 2-pyridyl (aldo)ketoximes. Metal complexes of 2-pyridyl oximes continue to attract the intense interest of many inorganic chemistry groups around the world for a variety of reasons, including their aesthetically beautiful structures, physical and biological properties, and applications. A unique member of 2-pyridyl ketoximes is di-2-pyridyl ketoxime (dpkoxH), which contains two 2-pyridyl groups and an oxime functionality that can be easily deprotonated giving the deprotonated ligand (dpkox-). The extra 2-pyridyl site confers a remarkable flexibility resulting in metal complexes with exciting structural and reactivity features. Our and other research groups have prepared and characterized many metal complexes of dpkoxH and dpkox- over the past 30 years or so. This work is an attempt to build a “periodic table” of dpkoxH which is near completion. The filled spaces of this “periodic table” contain metal ions whose dpkoxH/dpkox- complexes have been structurally characterized. This work reviews comprehensively the to-date published coordination chemistry of dpkoxH with emphasis on the syntheses, reactivity, relationship to metallacrown chemistry, structures and properties of the metal complexes; selected unpublished results from our group are also reported. The sixteen coordination modes adopted by dpkoxH and dpkox- have provided access to monomeric and dimeric complexes, trinuclear, tetranuclear, pentanuclear, hexanuclear, heptanuclear, enneanuclear and decanuclear clusters, as well as to a small number of 1D coordination polymers. With few exceptions ({MIILnIII2} and {NiII2MnIII2}; M = Ni, Cu, Pd and Ln = lanthanoid), most complexes are homometallic. The metals whose ions have yielded complexes with dpkoxH and dpkox- are Cr, Mn, Fe, Co, Ni, Cu, Zn, Ru, Rh, Pd, Ag, Cd, Re, Os, Ir, Au, Hg, lanthanoids and U. Most metal complexes are homovalent, but some mixed-valence Mn, Fe and Co compounds have been studied. Metal ion-assisted/promoted transformations of dpkoxH, i.e. reactivity patterns of the coordinated ligand, are also critically discussed. Some perspectives concerning the coordination chemistry of dpkoxH and research work for the future are outlined. Our efforts to complete the “periodic table” of di-2-pyridyl ketoxime are continued.

Abstract:

The clean high yielding, synthesis and structure of the tetraphosphine ligand, 1,1´,2,2´-tetrakis-(di-isopropyl-phosphino)ferrocene, (tdipf), is described. In addition, an improved synthesis of the 1,1´,2,2´-tetrakis(diphenylphosphino)ferrocene, (tppf) and 2,2´-bis-(diphenylphosphino)-1,1´-dibromoferrocene are also reported and the synthetic method is generalised to include the synthesis of 3,3’-bis-(diphenylphosphino)-1,1´,2,2´-tetrabromoferrocene. The related ligands 2,2´-bis-(iso-propylphosphino)-1,1´-bis-diphenylphosphinoferrocene (diprdppf) and 2,2´-bis-(di-isopropylphosphino)-dibromoferrocene have also been prepared and characterised. The crystal structure of the square planar bimetallic nickel (II) dichloride of tdipf is also described, together with a brief NMR study investigating the synthesis of this and related metal complexes. The crystal structures of the palladium and platinum dichloride complexes of 2,2’-bis-(di-isopropylphosphino)-1,1’-dibromoferrocene, bpdbf, are also discussed in the context of comparison with previously known crystal structures in the same general family. A general discussion on the synthetic methodology is given and pointers to future research other researchers might explore.

Abstract: Coordination compounds, characterized by the coordination of metal ions with ligands, represent a pivotal area of research in chemistry due to their diverse structures and versatile applications. This review delves into the synthesis, characterization, biological evaluation, and practical ap-plications of these compounds. A variety of synthetic methodologies (traditional solution-based techniques) are discussed to highlight advancements in the field. Investigations into the structural, electronic, and spectral properties of coordination compounds are emphasized to provide insights into their functional attributes. The biological evaluation section focuses on their roles in anti-microbial, anticancer, and enzyme-inhibitory activities, underscoring their potential in therapeutic development. Аttention is paid to nanoparticles, which are increasingly used for the treatment of oncological diseases. The metal complexes have been shown to have antibacterial, antifungal, antiviral, antioxidant and antiproliferative properties. Additionally, the review ex-plores their applications across domains such as catalysis illustrating their multifaceted utility. By synthesizing recent findings and trends, this article aims to bridge the gap between fundamental chemistry and applied sciences, paving the way for innovative uses of coordination compounds in both biological and industrial contexts.

Abstract:

In this work, a series of boronated amidines based on the closo-dodecaborate anion and amino acids containing an amino group in the side chain of the general formula [B₁₂H₁₁NHC(NH(CH₂)_nCH(NH₃)COOH)CH₃], where n = 2, 3, 4, were synthesized. These derivatives contain conserved α-amino and α-carboxyl groups recognized by the binding centers of the large neutral amino acid transporter (LAT) system, which serves as a target for the clinically applied BNCT agent para-boronophenylalanine (BPA). The paper describes several approaches to synthesizing the target compounds, their acute toxicity studies, and tumor uptake studies in vivo in two tumor models.

Abstract: A UO22+ complex bearing N,N,N’,N’-tetraisopropyldiglycolamide (TiPDGA) and two DMF molecules was designed and prepared to explore a catalytic activities of the Lewis-acidic U centre. The cationic complex, [UO2(TiPDGA)(DMF)2]2+, was successfully obtained as a ClO4− salt under optimized reaction condition with appropriate mixing ratio between UO22+ and TiPDGA to maintain 1:1 stoichiometry, non-coordinating ClO4− counteranion to reserve coordination sites for substrate activation, and presence of extra HClO4 to suppress undesired hydrolysis of UO22+ competing with the expected complex formation. This UO22+ complex was thoroughly characterized by IR, elemental analysis, X-ray crystallography, and 1H NMR to confirm the desired [3+1+1] equatorial coordination is actually formed in the solid state, and still maintained even after dissolution in CD2Cl2. [UO2(TiPDGA)(DMF)2]2+ was further subjected to nucleophilic acyl substitution reactions of acid anhydrides to assess its activity and capability as a Lewis-acid catalyst there. Although the observed reaction rates are not very rapid, some characteristic aspects to gain reaction- and substrate-selectivity have appeared thanks to the equatorial coordination sphere sterically regulated by the tridentate auxiliary TiPDGA ligand and labile monodentate DMF molecules to activate an acid anhydride after ligand substitution.

Abstract:

A Schiff base ligand is synthesized from the condensation of dapsone and 4-dimethylaminobenzaldehyde using cashew nut shell liquid (CNSL) anacardic acid as a green and natural effective catalyst via solvent-free simple physical grinding technique. Furthermore, metal(II) complexes Co(II), Cu(II) and Zn(II) coordinated by a new Schiff base ligand (L) were prepared. The composition of Schiff base ligand and its metal(II) complexes were analyzed by various analytical techniques. The Schiff base ligand and its complexes have been tested in vitro to evaluate their antimicrobial activity against Escherichia coli, Staphylococcus aureus and Candida albicans using well-diffusion method. It has been found that the Schiff base ligand and its complexes show significant antimicrobial activity against all tested bacterial species. Molecular docking study of Cu(II) complex with target protein HER2 has revealed good binding energy.

Abstract: This paper presents a methodology for the preparation of a new active component for ion-selective membranes, based on a di-substituted sulfonium derivative of the closo-decaborate anion at the apical vertices with octadecylalkyl substituents 1,10-B10H8(S(C18H37)2)2. This approach is characterised by physicochemical methods of analysis (11B, 1H, 13C NMR spectroscopy, IR spectroscopy and elemental analysis). The compound obtained was used as an active component of a PVC-membrane selective to terbinafine hydrochloride. The sensor developed is highly selective to the drug to be detected, and has a linearity range of 4.0 × 10-8 – 1.0 × 10-2 and a detection limit of 1.0 × 10-8, and can detect terbinafine hydrochloride in the pH range of 3 to 6.

Abstract: A trinuclear Co(II)-containing complex was assembled using the non-innocent hexahydroxytriphenylene bridging ligand. Cyclovoltammetry and spectro-electrochemistry studies revealed that the central ligand can sustain five reversible redox events leading to different spices with diverse optical behavior. Complementary analysis of the molecular structure confirmed by ab initio theoretical calculations are consistent with the bridge in the tris-semiquinone (sq) state for the trinuclear complex. The exchange coupling among the electrons of the bridge results in a spin doublet (s = ½) localized close to one of the three Co(II) ions, as suggested by the experimental magnetic data. The central doublet undergoes one large antiferromagnetic exchange coupling with one Co(II) and almost no coupling with the two other metal ions.

Abstract:

Solid-state Nuclear Magnetic Resonance (NMR) spectroscopy has become an invaluable tool for elucidating the structural, dynamic, and compositional properties of chemical compounds across various fields, from organic and inorganic chemistry to materials science. This review summarizes recent advancements in solid-state NMR techniques, including high-field NMR, magic-angle spinning (MAS), and multidimensional approaches, which have significantly enhanced spectral resolution and sensitivity. The review explores applications in studying crystalline and amorphous compounds, probing atomic-level structure, and investigating molecular dynamics critical to catalysts, polymers, pharmaceuticals, and complex hybrid materials. Additionally, it highlights the synergy between solid-state NMR and other characterization methods, such as X-ray diffraction and electron microscopy, which together provide a comprehensive understanding of material properties. Concluding with an outlook on future developments, this review underscores solid-state NMR’s growing impact on molecular and materials characterization.

Abstract: Inspired by the reported crystal structure of compound 1, we aimed to synthesize and determine the structure of compound 2, where two imidazolium (H₂im⁺) ions serve as diamagnetic counter cations. Here, we report the thermal stabilities, FT-IR, visible, and RSE spectra, as well as the magnetic properties of both compounds. In these structures, µ-EDTA acts as a pentadentate chelator for both terminal Cu centers within the centrosymmetric linear trinuclear anion. The Cu(µ-EDTA) chelates bind to the central Cu(Him)₄ unit in subtly different ways: in compound 1, µ-EDTA has a free acetate arm and binds the central Cu(II) center through a syn,anti-carboxylate group. In contrast, in compound 2, the non-chelating acetate arm serves as a monodentate O-donor to the central Cu(II) atom, increasing the Cu(terminal)···Cu(central) distance from 6.08 Å in 1 to 6.80 Å in 2. Additionally, pairs of H₂im⁺ ions in compound 2 display antiparallel π-stacking interactions. We conclude that the H₂im⁺ counterions in compound 2 enable the magnetic isolation of the nearly identical trinuclear anion present in both compounds. DFT calculations further support the role of different interactions in stabilizing each crystal structure. In compound 2, dominant contributions from N–H···O hydrogen bonds and π-stacking interactions are accompanied by other, less conventional interactions, such as multiple C–H···O contacts and an O···CO(π-hole) interaction within the trinuclear anion.