|
Transition Metal Chemistry
Journal Prestige (SJR): 0.306  Citation Impact (citeScore): 1 Number of Followers: 6  Hybrid journal (It can contain Open Access articles)ISSN (Print) 1572-901X - ISSN (Online) 0340-4285 Published by Springer-Verlag  [2468 journals]
|
- Preparation, characterization and electrochemical properties of ruthenium
carbonyl octaethylporphyrins with axial quinoline and quinine ligands-
Free pre-print version: Loading...
Abstract: The six-coordinate ruthenium(II) porphyrin complexes (OEP)Ru(CO)(Q), (OEP = 2,3,7,8,12,13,17,18-octaethylporphyrinato dianion; Q = quinoline, Qnl (2); quinine, QN (3)) have been prepared from (OEP)Ru(CO) (1) and characterized by MS, IR, UV–visible and 1H NMR spectroscopy. The X-ray crystal structure of 2 has been determined, which reveals quinoline coordination to Ru through the nitrogen atom. In the crystal packing of 2, the two Qnl groups of adjacent porphyrins are positioned relatively parallel to each other at a close distance of 3.30 Å, implying a relatively strong π-π interaction. The X-ray crystal structure of 1 was obtained, which revealed coordination of the water to the ruthenium center. By comparing the spectroscopic data for 1, 2 and 3, it was determined that the site of binding of QN to Ru is likely through the nitrogen atom of the quinoline moiety. The redox behavior of the complexes at a Pt working electrode studied in a CH2Cl2 solution with NBu4PF6 as support electrolyte by cyclic voltammetry revealed oxidations that are porphyrin-centered. Graphical abstract
PubDate: 2023-11-21
-
- Book review
-
Free pre-print version: Loading...
PubDate: 2023-11-08
-
- A novel Cd(II) compound of flucytosine: synthesis, structure, and optical
properties-
Free pre-print version: Loading...
Abstract: Background The study and development of fluorouracil metal complexes are important in the development of new synthetic methods and materials with applications in pharmaceuticals, agrochemicals, and materials science. Mothodology A new Cd(II) compound, (H-5FC) [(H-5FC) Cd Cl ] (1), (where H-5FC is HFlucytosine), was successfully synthesized and crystallized by slow evaporation at room temperature. The compound was characterized by single-crystal X-ray diffraction technique and UV–Visible spectroscopy. Results The structure shows that the compound constitutes of an independent protonated (H-5FC)+ cation and two protonated flucytosine molecules that coordinate to the Cd(II) ion via an oxygen atom to form a trinuclear [(H-5FC)2Cd3Cl10]2− anionic moieties. The independent protonated (H-5FC)+ bridges the [(H-5FC)2Cd3Cl10]2− anions via N/C–H···Cl/O hydrogen bonds. Supramolecular structure analysis of (1) with the aid of Hirshfeld calculations showed the importance of the H···Cl, O···H, C···Cl, and F···Cl interactions. Their percentages were calculated to be 42.2, 10.3, 6.6, and 8.7%, respectively. The band gap energy of the compound, deduced from the Tauc plot of the absorption spectrum, indicated a wide energy gap of 3.65 eV.
PubDate: 2023-11-03
-
- New binuclear Cu (II) complex: synthesis, structural elucidation,
cytotoxic and DNA-binding evaluation-
Free pre-print version: Loading...
Abstract: Abstract A novel copper complex [Cu(μ2–OH)(1,10-phenanthroline)(4-aminobenzenesulfonic acid)·3H2O]2 (1) was synthesized and characterized by X-ray single-crystal diffraction, elemental analysis and IR spectroscopy. X-ray crystallography of complex 1 showed strictly planar bridged μ2–Cu2(OH)2 core where copper (II) center exhibited a distorted square pyramidal coordination geometry. The interaction of the complex with calf thymus DNA (CT DNA) was investigated by absorption titration and viscosity measurement. The results revealed an intercalation binding between DNA and complex 1 with a binding strength of 6.0731 × 106 ± 0.0032 M−1. The antitumor capacity of the complex was tested in vitro against human colorectal (HCT 116) cancer cell lines by metabolic tests, using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide reagent. Complex 1 showed remarkably low IC50 values of 4.844 ± 0.025 μM compared to 5-fluorouracil (7.3 μM), a widely used clinical antitumor drug.
PubDate: 2023-10-27
-
- Effect of precursors on structural, optical and surface properties of ZnO
thin film prepared by spray pyrolysis method: efficient removal of Cu (II)
from wastewater-
Free pre-print version: Loading...
Abstract: Abstract In this study, ZnO thin films were prepared with different precursors using the spray pyrolysis technique, zinc acetate (ZAC-0.2), zinc chloride (ZCL-0.2), and dehydrated zinc nitrate (ZNH-0.2) precursors. The formation of ZnO thin films was confirmed using a variety of characterization techniques, including UV–vis spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction (XRD). The primary aim of this study is to explore how different precursor materials affect the properties of ZnO thin films and to demonstrate the efficacy of these films in removing copper ions from wastewater. The structure, microstructure, and optical properties of these materials were investigated, along with their adsorption activity. The results revealed that all ZnO films exhibited a hexagonal wurtzite crystal structure. The ZAC-0.2 sample demonstrated the highest transparency within the 400–800 nm wavelength range. The sample with the least band gap was ZNH-0.2, with a value of 1.96 eV, and exhibited the highest Urbach energy (Eurb) at 1.150 eV. Moreover, the ZnO thin films displayed high efficiency in removing 80% of copper ions from an aqueous solution.
PubDate: 2023-10-26
-
- Theoretical study of Cr–Cr bonding in [Cp*2Cr2(CO)2(µ-PMe2)2],
[Cp*2Cr2(CO)4(µ-H) (µ-PMe2)], and [Cp*3Cr3(CO)3(μ-S) (μ-PMe2)]
complexes by QTAIM theory-
Free pre-print version: Loading...
Abstract: Abstract Chromium–chromium and chromium–ligand bonding interactions existing in the [Cp*2Cr2(CO)2(μ-PMe2)2], [Cp*2Cr2(CO)4(μ-H) (μ-PMe2)], and [Cp*3Cr3(CO)3(μ-S) (μ-PMe2)] complexes are studied at DFT level of theory. Several local and integral topological parameters of the electron density such as electron density ρ(b), Laplacian ∇2ρ(b), local energy density H(b), local kinetic energy density G(b), potential energy density V(b), ε(b), and bond localization index (A, B) were evaluated according to QTAIM (quantum theory of atoms in a molecule). The calculated topological parameters are consistent with the relevant transition metal complexes in the literature. The computed data allow comparisons between the topological properties of related but different atom–atom interactions, such as other ligand-bridged Cr–Cr interactions and H-bridged ligand interactions versus S and P ligands. The QTAIM results confirm that the metal atoms bridged by two phosphorus atoms in binuclear complex1 are connected through a localized Cr–Cr bond that implicates little electron density (0.040). In contrast, such bonding was not found in binuclear complexes 2 (bridged by H and P) and trinuclear complex 3 (bridged by S and P). A multicenter 4c–5e, 4c–3e, and 4c–4e interactions are proposed to exist in the bridged parts, Cr(1)–P(1)–Cr(2)–P(2) in complex 1, Cr(1)–H–Cr(2)–P in complex 2, and Cr3–S in complex 3, respectively. Finally, the delocalization indices δ(Cr····O) calculated for the Cr–CO bonds in the three compounds confirm the presence of significant CO to Cr π-back-donation except for Cr(2)–O(2) and Cr(3)–O(1) bonds in complex 3, indicating that there is no π-back-donation.
PubDate: 2023-10-19
-
- Synthesis, crystal structure and antimicrobial activities of two silver(I)
complexes based on bis(pyrazole) and carboxylic acid co-ligands-
Free pre-print version: Loading...
Abstract: Abstract Two dinuclear and centrosymmetric silver-containing complexes, namely [Ag2(3,5-dmpz)2(3,5-dmpz methanol)2(tbtc)] (1) and [Ag2(3,5-dmpz)2(3,5-dmpz methanol)2(dbtc)] (2) (3,5-dmpz: dimethylpyrazole; 3,5-dmpz methanol: 3,5-dimethylpyrazole methanol; H2tbtc: tetrabromoterephthalic acid; H2dbtc: 2,5-dibromoterephthalic acid), were prepared and characterized. X-ray crystallographic data of 1 and 2 revealed that trigonal environment of the Ag ions has a “compressed Y’s” geometry. The antimicrobial activity of 1 and 2 was tested against the Gram-positive, Gram-negative bacteria and fungus, displaying the better inhibiting activity than the individual AgNO3 and 3,5-dimethylpyrazole, especially for Candida albicans (IC50 2.5 ± 0.1 mg mL −1 and 2.8 ± 0.2 mg mL−1). The quantified IC50 values displayed that complexes 1 and 2 were more effective against fungus than the Gram-negative bacteria and Gram-positive bacteria.
PubDate: 2023-10-16
-
- Mechanochemical synthesis of 3-EtO-salen and 3-EtO-salophen Co(II) and
Fe(III) metal complexes from precursors in a single step without isolating
the ligand-
Free pre-print version: Loading...
Abstract: Abstract The work in this paper presents a one-pot mechanochemical synthesis of Co(II) and Fe(III) complexes of 3-EtO-salen and 3-EtO-salophen ligands without solvent and catalyst. The reaction was carried out by using ball mill technique starting with 3-ethoxysalicylaldehyde(a), 1,2-phenylenediamine(b), or ethylenediamine(c) and metal salts directly without isolating the ligand. Mechanochemical activation enables domino processes that do not require the isolation of the ligand and use of a solvent, in contrast to solution chemistry.
PubDate: 2023-10-14
-
- Photocatalytic CO2 reduction to CO by Cobalt(II)
Pyridinyl-1,3,5-Triazine-Diamine complexes-
Free pre-print version: Loading...
Abstract: Abstract The development of molecular photocatalytic systems for CO2 reduction is a continuous challenge for chemists. Herein, the photocatalytic reductions of CO2 by [CoII(L1)(η1-ONO2)2] (1) (L1 = 6,6'-(pyridine-2,6-diyl)bis(1,3,5-triazine-2,4-diamine)) and [CoII(L2)(H2O)2]2+ (2) (L2 = 6,6'-([2,2'-bipyridine]-6,6'-diyl)bis(1,3,5-triazine-2,4-diamine)) have been investigated. With Ir(ppy)3 as the photosensitizer and 1,3-dimethyl-2-phenyl-2,3-dihydro-1H-benzo[d]imidazole as the sacrificial reductant in DMF/triethylamine solution under irradiation by white light-emitting diode (λ > 420 nm), CO was selectively produced with a turnover number (TON) of 36 and 89 for 1 and 2, respectively. Based on the electrochemical studies, the triply reduced [Co0(L2•)]ˉ species from 2 is found to be responsible for the activation of CO2 with a large rate constant of k = 506 M−1 s−1. However, the strong CO binding constant of CoI(L2)-CO adduct (K = 5.01 × 106) and the slow CO release from Co0(L2)-CO adduct limit the catalytic efficiency.
PubDate: 2023-10-08
-
- Allen J. Bard, Larry. R. Faulkner, Henry S. White: Electrochemical
Methods: Fundamentals and Applications, 3rd edition, Wiley-
Free pre-print version: Loading...
PubDate: 2023-09-13
-
- Selectivity through an asymmetric pathway in the degradation of
non-steroidal anti-inflammatory drugs (NSAIDs) using mixed-ligand
cobalt(II) complexes: experimental and theoretical insights-
Free pre-print version: Loading...
Abstract: Understanding the asymmetric catalytic mechanism involving organometallic species provides exceptional insight into the strategies for the degradation of emerging organic contaminants. The present work demonstrates such insights on the oxidation of commonly used non-steroidal anti-inflammatory drugs (NSAIDs) such as diclofenac, paracetamol, ibuprofen, and aspirin using optically active novel Schiff base Co(II) complexes derived from salicylaldehyde containing five different amino acids (L-methionine, L-leucine, L-asparagine, L-tryptophan, and L-glutamic acid). Among the studied chiral catalysts, asymmetric degradation in the presence of a Co(II) complex containing glutamic acid mixed ligand showed an elevated rate of oxidation of non-amine NSAIDs such as ibuprofen (3.86 × 10–2 s−1) and aspirin (3.70 × 10–3 s−1) using H2O2 oxidant under visible light conditions at neutral pH. The formation of chiral intermediate species in both drugs has been detected and characterized by FTIR and Raman analysis. On the other hand, NSAIDs containing secondary amine groups (–NH–), such as diclofenac and paracetamol, generate effective coordination between the complex catalyst and the nitrogen atom. This explains the high activity of the Co(II) complex with glutamic acid mixed salicylaldehyde with 100% selectivity in the degradation of ibuprofen and aspirin. The thermodynamical feasibility of the proposed degradation route for ibuprofen and aspirin was analyzed with theoretically calculated total energy values of all the intermediates formed in each step of the proposed mechanism. Graphical abstract
PubDate: 2023-09-13
DOI: 10.1007/s11243-023-00553-8
-
- Fabrication of hollow metallic copper particles using a standard electrode
potential difference-
Free pre-print version: Loading...
Abstract: Abstract Hollow metallic particles have a lower density than their bulk counterparts with an equivalent apparent volume; therefore, they are expected to be applied in fields requiring low density and large surface area materials. This study proposes a method for synthesizing hollow metallic Cu particles in an aqueous solution. An aqueous suspension of hollow metallic Cu particles was prepared by placing metallic Zn particles in an aqueous Cu acetate solution. Based on the displacement plating related to the standard electrode potential difference between Cu and Zn, Cu2+ ions were reduced to metallic Cu by receiving electrons from metallic Zn, while metallic Zn dissolved into the aqueous solution. Consequently, metallic Cu with a shell-like shape formed near the surface of the original metallic Zn particles before Zn dissolution, yielding hollow metallic Cu particles. Thus, this study revealed that the Cu acetate concentration should be appropriately controlled to fabricate hollow particles. Moreover, the developed method can easily fabricate hollow metallic particles in one step without adding external reducing agents.
PubDate: 2023-09-08
DOI: 10.1007/s11243-023-00554-7
-
- Synthesis and structural elucidation of 1,2-naphthoquinone derivatives,
Schiff base complexes and ternary complexes with 8-hydroxyquinoline:
comparative studies of their antimicrobial, anti-inflammatory and
anti-diabetic activities-
Free pre-print version: Loading...
Abstract: Abstract Herein, a new derivative of 1,2-naphthoquinone with semicarbazide and its Schiff base complexes and ternary complexes have been synthesized with some transition metals such as Ni(II), Co(II) and Zn(II) by using the conventional reflux method and 8-hydroxyquinoline (8-HQ) as a secondary ligand for ternary complexes. All the compounds were characterized using elemental analysis, molar conductance, melting point, Powder XRD, magnetic moment measurement and various spectral techniques such as FTIR, 13C NMR, 1H NMR, and Mass Spectra. The specific peak of the enolic proton in 1H NMR spectra of the tridentate ligand (L) explained the amido-iminol tautomerism in semicarbazone. In addition, powder XRD analysis and TGA confirmed the crystalline nature and the thermal study of metal chelates, respectively. In vitro, all the compounds were screened for antimicrobial (against bacterial strains: S. aureus and E. coli; Fungal strain: A. niger), anti-diabetic and anti-inflammatory activity with their obtained IC50 values and compared with Acarbose and Aspirin standard drugs. Bioactivities of azomethine containing free ligand (L), their Schiff base complexes and ternary metal chelates were compared to each other. Free Schiff base (L) was found most potent for all selective bioactivities compared to their all-metal complexes, except Ni (II) Schiff base complex showed excellent activity against C. albicans.
PubDate: 2023-09-02
DOI: 10.1007/s11243-023-00551-w
-
- Synthesis, spectroscopic characterization, and photophysical properties of
new p-anisolylthiol-functionalized platinum(II) bis(alkenylarylalkynyl)
complexes-
Free pre-print version: Loading...
Abstract: A series of organic sulfur-functionalized trans-platinum(II) bis(alkenylarylalkynyl) complexes, having one anisolylthio group with general formula trans-[(PEt3)2Pt{C≡C–Ar–CH=CH(SC6H4–OCH3)}2], (2a-2d), (Ar = phenylene/biphenylene/2,5-dimethylphenylene/2,5-dimethoxyphenylene) was synthesized in excellent yields. All the new platinum(II) complexes have been fully characterized by physico-chemical and spectroscopic methods. Photophysical properties of the complexes were studied by absorption and emission spectroscopy. The lowest energy absorption band for the complexes, in the UV/Vis spectra, in THF solution, at room temperature, 2a-2d was observed in the range 355–391 nm, which depend on the spacers in the acetylide ligand e.g., the absorption of 2d is red shifted to 391 nm for the donor (OCH3) substituents in phenyl spacer. These absorptions originated predominantly from π–π*orbitals of acetylide ligand with significant contribution from the platinum dπ orbital as evident from the HOMO and LUMO, obtained from TD-DFT calculations. Fluorescence was observed in all complexes at room temperature in the range 400–428 nm with PLQY of 2–5%. At 77 k, the complexes 2a-2b only exhibited phosphorescence in the range 579–585 nm, but there is no phosphorescence at ambient temperature. Graphical abstract
PubDate: 2023-08-16
DOI: 10.1007/s11243-023-00550-x
-
- Facile synthesis of paramagnetic Co(II)-hexaborate(2-)-based semi-organic
complexes: a combined investigation on X-ray crystal structure, Hirshfeld
surfaces analysis, optical and magnetic properties-
Free pre-print version: Loading...
Abstract: Abstract Two new paramagnetic hybrid cobalt(II)-hexaborate(2-)-based semi-organic complexes: (2A3MP)2[Co{κ3O–B6O7(OH)6}2].2H2O (1) and (2A4MP)2[Co{κ3O–B6O7(OH)6}2].2H2O (2) (2A3MP = 2-amino-3-methylpyridinium, 2A4MP = 2-amino-4-methylpyridinium) have been obtained and characterized by X-ray diffraction, FT-IR, TG–DTA, optical and magnetic measurements. X-ray diffraction revealed two isostructural compounds based on Co(II) complexes of bis(κ3O-donor hexaborate(2-)) ligands, [Co{κ3O–B6O7(OH)6}2]2−, differing only in the organic counter cation. The hydrated oxidopolyborate anions are extensively H-bounded to form 3D-porous supramolecular anionic frameworks. In both 1 and 2 isostructures, 2A3MP and 2A4MP cations are present in the created voids of the inorganic frameworks through a set of H-bonds with 58.5 and 60.5% H…O/O…H intercontact contributions, respectively, for 1 and 2 as confirmed by Hirshfeld surfaces analysis. The optical band gap of Co(II) complexes ranges between 2.72 and 2.82 eV. Both compounds exhibited well-resolved paramagnetic properties with magnetic susceptibility values ranging between 0.9552 cm3 mol−1 (at 2 K) and 0.0088 cm3 mol−1 (at 300 K), typical of octahedral Co(II) complexes.
PubDate: 2023-08-16
DOI: 10.1007/s11243-023-00549-4
-
- Design and fabrication of novel coordination polymers containing Co(II),
Ni(II), and Cu(II) for electrochemical detection of both ascorbic acid and
Cr(VI)-
Free pre-print version: Loading...
Abstract: Abstract For the rapid detection of ascorbic acid (AA) and Cr(VI), three novel 2D coordination polymers (CP) with different metal centers [Co(L)(5-NIPA)(H2O)]·H2O (1), [Ni(L)(5-NIPA)(H2O)]·H2O (2) and [Cu(L)(5-NIPA)]·H2O (3) were synthesized by the traditionally hydrothermal method (L = N,N′-bis(pyridine-3-ylmethyl)-4-(4-carboxybenzyl)oxybenzamide, 5-NIPA = 5-nitroisophthalic acid). CPs 1 and 2 are isomorphic 2D regular (4,4)-connected networks, and CP 3 has a twisted 2D lamellar structure. All of the above complexes present highly sensitive and selective electrocatalytic sensing performances for AA and Cr(VI). The detection limits of the three complexes were 0.320, 3.360 and 3.600 μM for AA, and 0.2349, 0.9928 and 3.6054 μM for Cr(VI), respectively.
PubDate: 2023-08-09
DOI: 10.1007/s11243-023-00544-9
-
- Zn (II) octahedral complex with new ketimine ligand: design, synthesis and
single-crystal studies-
Free pre-print version: Loading...
Abstract: Abstract The present investigation deals with the synthesis and single-crystal X-ray analysis of Zu (II) coordination complex of ketimine ligand which was obtained by reaction of dehydroacetic acid with carbohydrazide (3) and characterized the title compound with elemental analysis, multinuclear (1H and 13C) NMR, UV visible, and FTIR spectral data. It crystallized in orthorhombic crystal system with space group Pbcn and unit cell dimensions: a = 18.7959 (4), b = 11.2890 (2) and c = 13.4480 (3) Å, and α = β = γ = 90°. The suggested geometry obtained after experimental analysis was distorted octahedral due to some angle strain between axial homonuclear N donor atoms around central Zn, and it was very close to the expected geometry. The DNA co-relation analysis was carried out by using fixed concentration of Calf Thymus DNA against the solution of analyte using UV spectroscopy. The ligand and metal complexes were examined for antibacterial and fungal activities against E. coli, M. luteus, E. aerogenes, S. aureus, and C. albicans, and the titled complex was found to be active against all the tested strains.
PubDate: 2023-08-01
DOI: 10.1007/s11243-023-00547-6
-
- Stereospecific formation of vanadium mandelato complexes with
[Fe(2,2′-bipyridine)3]2+ as a counter ion-
Free pre-print version: Loading...
Abstract: Two vanadium complexes of mandelic acid having [Fe(bpy)3]2+ as counterion, [Fe(bpy)3][V2O4(rac-mand)2]·4.9H2O·0.1CH3CN (1, FeV2L2) and (H3O)[Fe(bpy)3]4[V3O7(S-mand)2]3·28H2O (2, FeV3L2) (bpy = 2,2’-bipyridine, mand2– = mandelato ligand, C8H6O32–) have been synthesized and characterized by single crystal X-ray diffraction and spectral methods. The FeSO4—bpy—KVO3—H2mand—H2O—CH3CN system exhibits a stereospecific behaviour: while from the system including racemic mandelic acid only the complex of the V2L2 type (1) could be obtained in crystalline form, the system with S-mandelic acid afforded the V3L2 (2) complex as the single crystalline product. All vanadium atoms exhibit tetragonal pyramidal coordination geometry with oxygen donor atoms of the oxido ligands and carboxylate anion. The stereospecific behaviour was investigated using the 51 V NMR spectroscopy, which revealed different composition of systems with racemic mandelic acid and S-mandelic acid after some preliminary period (≈ 15 days). The compound 2 is chiral non-racemic compound (space group P21212), the structure of which contains Δ-[Fe(bpy)3]2+ cations and [V3O7(S-mand)2]3– anions. Graphical abstract
PubDate: 2023-08-01
DOI: 10.1007/s11243-023-00543-w
-
- Hydrogen-bonded supramolecular structures in copper(II) nitrobenzoates
with N-methylnicotinamide: synthesis, supramolecular structure, Hirshfeld
surface analysis, spectral and DFT study-
Free pre-print version: Loading...
Abstract: Abstract The synthesis of six new copper(II) nitrobenzoate complexes with N-methylnicotinamide, used as an auxiliary ligand for a supramolecular interaction study, is reported. Crystal structures of six novel compounds [Cu(2-NO2bz)2(mna)2(H2O)2] (1), [Cu(2-NO2bz)2(mna)2(H2O)2]∙2H2O (2), [Cu(3-NO2bz)2(mna)2(H2O)2] (3), [Cu(3,5-(NO2)2bz)2(mna)2(H2O)2]∙2H2O (4), [Cu(4-NO2bz)2(mna)2(H2O)2]∙2(4-NO2bzH) (5) and [Cu(3,5-(NO2)2bz)2(mna)(H2O)3] (6) (mna = N-methylnicotinamide, 2-NO2bz = 2-nitrobenzoate, 3-NO2bz = 3-nitrobenzoate, 4-NO2bz = 4-nitrobenzoate, 3,5-(NO2)2bz = 3,5-dinitrobenzoate) were determined by X-ray analysis. Compounds 1–6 are mononuclear with a tetragonal-bipyramidal geometry around the Cu2+ ion. The molecules of the studied complexes are mostly linked by a combination of N–H…O and O–H…O hydrogen bonds between N-methylnicotinamide and water molecules into supramolecular hydrogen-bonded coordination chains and networks. Intermolecular interactions in the supramolecular structures were also studied using Hirshfeld surface analysis. In addition, the complexes 1–6 have been characterised by elemental analysis, IR, UV–Vis and EPR spectroscopy. Density functional theory calculations were performed in order to reproduce the EPR magnetic parameters. DFT calculations of the EPR parameters show a good agreement with the experimental results.
PubDate: 2023-07-27
DOI: 10.1007/s11243-023-00542-x
-
- The effect of alkyl substituents in the β-side on the conformation,
molecular structure, and copper-oxygen bond strength of
bis(β-diketonato)copper(II) complexes by DFT results and experimental
vibrational and UV spectra-
Free pre-print version: Loading...
Abstract: Abstract The conformation, geometry, and relative energies of bis (2,6-dimethylheptane-3,5-dionato)copper(II), (Cu(DIMHD)2), and bis (5,5-dimethylhexane-2,4-dionato)copper(II), Cu(DMHD)2 have been assayed through using calculated results from atoms-in-molecules (AIM) analysis, time-dependent density functional theory (TD-DFT), natural bond orbital (NBO), and density functional theory (DFT). The electronic and vibrational spectra of these compounds have also been studied using experimental infrared, Raman, and ultraviolet (UV) spectra. All theoretical and empirical vibrational frequencies of the mentioned compounds have been assigned. The DFT was used to characterize the conformers of the complexes mentioned above, as well as the observed vibrational and UV spectra. Similar complexes, including copper (II) acetylacetonate Cu(AA)2, bis(3,5-heptanedionato)copper(II) (Cu(HPD)2), and copper (II) 2,2,6,6-tetramethylheptane-3,5-dionate (Cu(TMHD)2), have been chosen to evaluate the influence of isopropyl (iPr) and tert-Butyl (t-Bu) groups substituents instead of methyl and ethyl groups. All experimental, spectroscopic, and DFT results confirmed that the O-Cu bond strength in Cu(DIMHD)2 and Cu(DMHD)2 is between Cu(TMHD)2 and Cu(AA)2 and close to Cu(HPD)2.
PubDate: 2023-07-22
DOI: 10.1007/s11243-023-00545-8
-
