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[Display omitted] • Synthesis of new benzothiazol- pyrimidin-2-ylidene metal chelates and their characterization. • Geometry optimization for structural confirmation. • Intensive biomedical applications against microbes, free radicals and carcinoma cell lines. • Docking studies for the inspected compounds against Covid-19. The reaction of BSP benzothiazol-2-yl-(4,6 -dimethyl-1H-pyrimidin-2-ylidene)-amine with Fe3+, Ni2+ and Pd2+ resulted into three novel complexes. The ligand and metal complexes' structural details were revealed by M.P, IR, 1H NMR, 13C NMR, electronic spectra, CHN analysis, Mass spectra, TGA, magnetic susceptibility, as well as theoretical calculations have been performed at DFT level of theory using B3LYP functional and 6-31G (d, p) as a basis set. The DFT calculations' recommended structures and the observations from experiments match well. Using the information gathered, the complexes accommodated the molecular formulae; ([Fe(BSP) 2 (NO 3) 2 ](NO 3).(H 2 O)), ([Ni(BSP) 2 (NO 3) 2 ].(H 2 O)) and ([Pd(BSP)(OCOCH 3) 2 ].(H 2 O) 2) respectively. The produced compounds' in vitro antibacterial activities were assessed in comparison to various bacterial and fungi's stains by disc diffusion method in agar solution. The finding reflects that the metal complexes especially BSPPd complex much helpful antimicrobial initiatives towards S. marcescence and G. candidum contrasted to the other microbes. The compounds' antioxidant characteristics were assessed in order to assess their capacity to scavenge free radicals. Additionally, the compound's in vitro cytotoxicity towards MCF-7, HCT-116 and HepG-2 cell lines was adjudicated and it was discovered that there was an enhanced expression, which effectively destroyed cancer cells even at low levels. The geometry of BSP before and after docking was also compared displaying, suggesting fascinating further investigation. [ABSTRACT FROM AUTHOR]

[Display omitted] • New Fe(III) (C1), Ni(II) (C2), and Cu(II) (C3) with the ligands moxifloxacin (MOX) and tri-substituted imidazole (TSI) complexes were synthesized and characterized. • The complexes were investigated in vitro for antibacterial efficacy against two gram-positive and two gram-negative bacteria. • The C1, C2, and C3 complexes have been proven to be more biologically effective than a ligand without the antibiotic MOX. • Compared to ascorbic acid, all newly synthesized compounds exhibit similar IC 50 values for free radical scavenging. Herein, three new mixed-ligand complexes were synthesized through the reaction of Fe(III), Ni(II) and Cu(II) with moxifloxacin (MOX) in the presence of tri-substituted imidazole (TSI) to investigate their antibacterial, antifungal, and antioxidant potential. Elemental analysis, molar conductivity, electronic spectra, infrared spectroscopy, mass spectrometry, magnetic studies, thermal gravimetric investigations have been utilized for insuring the chelation process and structural elucidation. Results revealed that MOX and TSI interact with the metal ions via the (carbonyl oxygen and the carboxylic oxygen) and (hydroxyl oxygen and imidazole-ring nitrogen) atoms for MOX, and TSI, respectively. Octahedral geometries have been proposed for the Fe(III), Ni(II) complexes, while a distorted tetrahedral geometry was proposed for the Cu(II) complex. The proposed structures had been optimized via Density functional theory (DFT) calculations. Moreover, the frontier molecular orbitals (FMOs), in terms of HOMO and LUMO, and the molecular electrostatic potential (MEP) were obtained. Furthermore, the energy gap, chemical hardness, softness, chemical potential, electrophilicity index were evaluated. The antimicrobial potential was in vitro investigated against some common pathogenic bacterial and fungal strains; moreover, the antioxidant activity was evaluated using DPPH method. Results revealed that the three synthesized complexes had high antimicrobial activity against all tested phytopathogens and a significant antioxidant potential, compared to the free ligands. Furthermore, the in vitro potential was validated utilizing molecular docking investigation against four target receptors: 5JQ9, 6CLV, 3CKU, and 5IJT. The molecular docking results showed that Fe(III), Ni(II), and Cu(II) complexes had the highest activity towards the 5JQ9, (6CLV and the 3cku), and 5IJT receptors, respectively. [ABSTRACT FROM AUTHOR]

The synthesis, antibacterial screening and mode of action copper pyridyl complexes towards drug resistant bacteria. [Display omitted] • Novel series of copper complexes with pyridyl-based ligands were successfully synthesized using mechanochemical methods, resulting in favorable yields of 80–90%. • Characterization data confirmed the successful synthesis of the complexes and the electronic spectra and magnetic susceptibility data indicated that the copper complexes were d9 tetrahedral complexes with parallel spin electrons. • The copper complexes exhibited promising antibacterial activity, with higher efficacy against Gram-positive bacteria, particularly CuL4 , which showed exceptional activity against MRSA and S. aureus. • Time-kill kinetics analysis indicated that the copper complexes displayed bacteriostatic activity at their minimum inhibitory concentrations (MIC) but exhibited bactericidal tendencies after 24 h. • Cell membrane disruption studies revealed that CuL4 , the nitro group complex, was the most effective in disrupting the cell membrane of S. aureus , followed by Cu4PY-H and the control AgSD , indicating potential modes of action. A series of four new copper complexes containing pyridyl-based ligands of the type [Cu(Cl) 2 (L) 2 ] were prepared by solid-state methods and evaluated for antibacterial activity. Their elemental analysis showed that the grinding method produced pure complexes. FTIR spectroscopy confirmed the coordination of ligands to copper ions by identifying shifts in vibrational frequencies. Furthermore, their successful synthesis was confirmed by the coordinating bonds being shifted to lower frequencies. Electronic spectra and magnetic susceptibility data proved the complexes to be d9 tetrahedral complexes. Thermal studies of the copper complexes indicated that they had good thermal stability. In the thermal analysis, a recurring pattern emerges as each copper complex experiences multiple mass losses and exhibits characteristic transitions in DSC profiles, shedding light on their distinct thermal behaviors. The mass spectra of the copper complexes showed that the data agreed with the elemental analysis and other elucidation techniques. The complexes displayed characteristic molecular ion peaks and adducts consistent with their calculated masses, substantiating the successful synthesis of these complexes and enhancing understanding of their composition and stability. The copper complexes also displayed solubility in highly polar and heavy solvents thus reduced the chances of forming good-quality crystals. The copper complexes were more effective against Gram-positive bacteria, with CuL4 performing best, notably against MRSA and S. aureus. All of the active complexes were bacteriostatic against MRSA and S. aureus based on the time kill kinetics. Additionally, it was shown that the CuL4 and Cu4PY-H disrupted the S. aureus cell membrane more effectively than the AgSD control. Finally, the CuL4 membrane disruption studies were not significantly different to the AgSD control on MRSA. The results of cell membrane disruption were supported by molecular docking scores, where CuL4 outperformed the other active compounds, and the trends corroborated the experimental results. [ABSTRACT FROM AUTHOR]

[Display omitted] • Advanced oxidation processes, photocatalysis principles and the basic working mechanism were discussed. • Majorly all bismuth -based catalysts with their crystal structures were discussed. • Modification approaches implemented for enhancing the light absorption spectra and modifying the band energy potentials were discussed. • Fabrication methods were discussed and how these methods control the morphology of the catalysts were discussed. In the recent past years, layered bismuth-based nano and micro photocatalysts have established substantial consideration in comparison with other photocatalytic materials due to its evolving potential towards the various photocatalytic applications in environmental reintegration. The electronic band structure of Bismuth(III) characterises suitable band-gap for visible-light photocatalytic activity. The photocatalytic activity of these Bismuth-based Materials (BBMs) can be methodically increased by implementing various approaches including interface modification, formation of heterojunction, implementing the sensitizers, doping the metal or non-metal, developing the composites, and forming the oxygen vacancies. Even so, its visible light operations limits up due to greater recombination of photoinduced charge carriers. This article thoroughly encapsulates electronic spectra, strategies implemented for higher separation of charge carriers, and establishing its potential in the field of degrading manageable & recalcitrant pollutants as well as anti-microbial activity. Finally, the future challenges and attributes of using BBM photocatalysts are summarised. [ABSTRACT FROM AUTHOR]

[Display omitted] • The electronic properties of pristine and Pt-doped AlNNTs were studied. • Electronic spectra of Pt-doped AlNNTs complex with SO 2 , SOF 2 , SO 2 F 2 gases exhibit a shift toward higher value. • Pt-AlNNTs could be used as potential gas for detection of SO 2 , SOF 2 , SO 2 F 2 gases. Developing a sensor for detecting SF 6 decomposed gasses is considered important for the insulation of electrical equipment. First-principles density functional theory computations are undertaken to examine the possible use of metal-doped one-dimensional (1D) nanomaterials in gas sensors, and to investigate their sensitivity, adsorption and electronic properties. Within this work, a platinum (Pt)-doped aluminum nitride nanotube (Pt-AlNNT) was used to investigate the adhesion of SF 6 decomposed gasses, namely SO 2 , SOF 2 , SO 2 F 2. Two possible sites were considered to investigate the stable structure of Pt-AlNNT. The binding energy of the structure with most stability was − 1.314 eV. Also, the sensitivity and adhesion energy of the above-mentioned gasses demonstrated that Pt-AlNNT had more suitable sensing and adhesion properties compared to other materials. The results can provide useful insights into investigating Pt-AlNNT as a suitable sensor for detecting SF 6 decomposed gasses for the insulation of electrical equipment. [ABSTRACT FROM AUTHOR]

A new creation of symmetric bis-Schiff base (H2L) prepared by combining bis-1,4-diaminobenzene with 2,4-dihydroxybenzaldehyde (2:1 M ratio) (H2L). Copper (II), Cobalt (II), Nickel (II), Manganese (II), and Cadmium (II) acetates were used to make complexes with the produced Schiff base ligand (H2L). Minimal inhibition concentration of compounds against the pathogenic bacteria. [Display omitted] • A new creation of symmetric bis-Schiff base (H2L) prepared by combining bis-1,4-diaminobenzene with 2,4-dihydroxybenzaldehyde (2:1 M ratio) (H2L). • Copper (II), Cobalt (II), Nickel (II), Manganese (II), and Cadmium (II) acetates were used to make complexes with the produced Schiff base ligand (H2L). • ESR and electronic spectrum data were used to calculate the bonding properties of this complex. • The ligand and its complexes' minimum inhibitory concentration (MIC) for certain bacterial strains had been identified, and the antibacterial behavior was dose dependent. A novel symmetric bis-Schiff base (H 2 L) derived from bis-1,4-diaminobenzene with 2,4-dihydroxybenzaldehyde (2:1 M ratio) (H 2 L) has been prepared. The synthesized Schiff base ligand (H 2 L) were allowed for complexation with Cu(II), Co(II), Ni(II), Mn(II), Cd(II) acetates. The structure of the synthesized compounds (1 – 5) was elucidated with the help of various spectral and physicochemical techniques. Conductivity data showed the non-electrolytic nature of complexes. Based on the ESR and electronic spectral data, the bonding parameters of this complex have been calculated. From the magnetic moment and electronic spectra data, it is found that the geometrical structures of these complexes are octahedral except complex (5) is tetrahedral structure. Furthermore, the antimicrobial activity of the ligand and its metal complexes (1 – 5) were investigated against some pathogenic bacteria, fungal and yeast strains. The complex (5) revealed the highest antibacterial activity compared with the ligand, complexes, and standard antibiotic (penicillin). Minimal inhibitory concentration (MIC) for the ligand and its complexes against bacterial strains were determined. The molecular docking between the receptors (Bacillus cereus (1fez), Staphylococcus aureus (3q8u), Escherichia coli (3 t88), breast cancer (1jnx), prostate cancer (2q7k), colon cancer (2hq6) and lung cancer (1x2j)) with the ligand was studied. It is observed that the effective of the receptors increases in the order E. coli (3 t88) > B. cereus (1fez) > S. aureus (3q8u). [ABSTRACT FROM AUTHOR]

[Display omitted] • Electronic properties of TiO 2 with the low doping concentration of Cu has been calculated. • The microstructures of the Cu-TiO 2 nanoparticles deposited on film. In this paper, we demonstrate that the low Cu doping concentration modifies electronic properties of TiO 2 through experimental and computational studies (Density Functional theory-DFT). Cu-to-TiO 2 thin films with different Cu wt% were prepared by electrostatic spray pyrolysis method. The effect of Cu doping on TiO 2 were analyzed using various characterizations such as X-ray diffraction (XRD), ultraviolet–visible (UV–vis) spectroscopy, Raman spectroscopy, and scanning electron microscopy. The XRD reveals that the Cu-doped TiO 2 crystallizes in a tetragonal structure with an anatase phase. Raman spectroscopy confirmed the presence of strong chemical bonds and functional groups at the TiO 2 interface. UV–vis spectroscopy was used to record the optical characteristics of doped and undoped samples. UV–vis spectroscopy revealed a reduction in band gap after doping. Surface morphology of the Cu-doped TiO 2 thin films were analysis using SEM. SEM images revealed no significant changes in particle size or microstructures of the synthesized materials. Additionally, DFT modelling was carried out to confirm the effects of dopants on electronic properties of the thin film. The results were analyzed, and the experimental results were corroborated, by the analysis. [ABSTRACT FROM AUTHOR]

[Display omitted] • The structural, magnetic and electronic properties of Ba 1-x SrxFe 12 O 19 hexaferrite have been studied by experimental and DFT calculation. • The increases of Sr rate induce in improvement in magnetic properties Ba 1-x SrxFe 12 O 19 samples. • The exchange interaction integral anisotropy parameters of Ba 1-x SrxFe 12 O 19 (x = 0 and 1) are examined. • The studied materials can be classed as promising candidates candidate that can be used in the manufacture of permanent magnets. Nanopowder hexaferrites, (Ba 1-x Sr x Fe 12 O 19) (x = 0, 0.5 and 1) were synthesized by the auto-combustion method and were characterized by XRD, VSM, and DFT calculation. Hysteresis loops prove an enhancement of magnetic properties when the Sr rate increases. The corrective field went from 1498.14 Oe (119.2182 kA/m) to 1891.55 Oe (150.3782 kA/m) indicating the suitability of the studied materials in the manufacture of permanent magnets. The band structure of Ba 1-x Sr x Fe 12 O 19 Compounds was calculated by spin-polarized DFT + U method and indicated a semiconductor behavior for the materials. Using DFT calculations we extracted the saturation magnetization (Ms) and the magnetic moment on Fe ions together with their density of spin resolved states (DOS). The integral exchange coupling (Js) was calculated using a correlation between the Heisenberg model and DFT calculation. By including the SOC (spin–orbit coupling) in the DFT + U calculation, we determined the energy anisotropy and the anisotropy constant which increase with the increases of Sr rate. [ABSTRACT FROM AUTHOR]

The Lewis base–Lewis acid adducts with the Lewis bases pyrazine, triphenyphosphine, neocuproine (2,9-dimethyl-1,10-phenanthroline), cuproine (2,2′-diquinolyl) and triphenylborane as Lewis acid were prepared. Their electronic spectra are characterized by low-energy electronic transitions which are attributed to phenyl (BPh 3 ) to Lewis base, ligand to ligand charge transfer (LLCT) transitions. These Lewis base-BPh 3 complexes display a distinct blue to green fluorescence in solution which originates from the lowest-energy LLCT singlets. [ABSTRACT FROM AUTHOR]

Organometallic rhenium(I) carbonyls were synthesized and compounds were studied for diverse biological activities i.e., anticancer, antibacterial, in vivo and in vitro cytotoxicity and DNA interaction. Some compounds have better biological activities than standard drugs. [Display omitted] • Substituted imidazole-pyrazole based organometallic Re(I) carbonyls were synthesized and characterized by various spectrometric and analytical techniques. • The heterocyclic compounds and their organometallic compounds were screened for biomolecular interactions and various medicinal activities. • The compounds are more cytotoxic compared to standard anticancer drugs. • The compounds can be used as prototype for development of novel chemotherapeutic agents. Organometallic rhenium(I) complexes (I-VI) using substituted 5-(2-butyl-5-chloro-1H-imidazol-4-yl)-1,3-diaryl-4,5-dihydro-1H-pyrazole were synthesized and characterized by the spectroscopic method. For evaluation of HOMO-LUMO energy gap, estimation of bond angle, bond length data and Mulliken charge analysis DFT studies were performed. The interactions between synthesized compounds and HS-DNA were carried out by viscosity measurements and absorption titration gives information about modes of binding and the nucleolytic efficiency of compounds. Molecular docking study was performed to support the results of the viscosity measurements and absorption titration, Groove binding was suggested as the most possible mode and the DNA-binding (K b) constants of the complexes were between 1.7 × 106 to 8.8 × 106 M−1. Thermodynamic parameter ΔG0 value ranging from −7227.0 to −9463.0 J/mole . K. According to the thermodynamic parameter, the main binding force could be judged. In vivo and in vitro cytotoxicity against the eukaryotic and prokaryotic cells gives the toxic nature of the synthesized compounds. An antimicrobial study was carried out by estimating MIC against two Gram-positive and three Gram-negative bacteria. the Electronic spectra and conductivity measurement confirm the different transition and non-electrolytic nature of the metal complexes. [ABSTRACT FROM AUTHOR]

Abstract: The palladium(II) complexes of the formulations [Pd(clpbpy)Cl2], [Pd(clcpbpy)Cl2], [Pd(brcpbpy)Cl2], [Pd(clmpbpy)Cl2] {clpbpy═4-(4-chlorophenyl)-6-phenyl-2,2′-bipyridine (L1), clcpbpy═4,6-bis(4-chlorophenyl)-2,2′-bipyridine (L2), brcpbpy═4-(4-bromophenyl)-6-(4-chlorophenyl)-2,2′-bipyridine (L3) and clmpbpy═6-(4-chlorophenyl)-4-p-tolyl-2,2′-bipyridine (L4)} have been synthesized and characterized using elemental analysis, electronic spectra, IR and mass spectra. The study on the interaction of the palladium complexes with calf thymus DNA (CT DNA) has been performed using absorption titration, viscosity measurements and thermal denaturation techniques. The study suggests the intercalative mode of DNA binding. Gel electrophoresis assay demonstrates the ability of the complexes to cleave the pUC19 DNA. The antibacterial activity of complexes has been screened against two Gram(+ve) and three Gram(−ve) microorganisms. [Copyright &y& Elsevier]

The complexes [Re I (L–L)(CO) 3 Cl] with L–L = lumazine and folic acid were prepared and their electronic spectra were measured. The free ligands L–L, as well as both complexes, show an emission which is attributed to the fluorescence of L–L. This luminescence is apparently facilitated by excited state proton transfer. [ABSTRACT FROM AUTHOR]

[Display omitted] • A cyclometalated Rh(III) complex was synthesized. • It was characterized by CHN analysis, UV–Vis, FT-IR and NMR spectra. • Its molecular structure was confirmed by X-ray crystallography. • The comparison of the experimental and calculated data (DFT) was carried out. • Compound exhibited significant antibacterial activity. • Phosphorescent emissions were observed at 508 and 538 nm in solvent and solid state, respectively. In this work, structural and spectroscopic properties of the cyclometalated Rh(III) complex, [Rh(ppy) 2 (Mdtc)]·H 2 O with ppy = 2-phenylpyridine and Mdtc = morpholine-4-dithiocarbamate were studied by X-ray crystallography and IR, 1H and 13C NMR, electronic absorption and Fluorescence spectroscopy. The title complex crystallized in triclinic, space group P-1 , Z = 2, a = 9.7173(19) Å, b = 11.399(2) Å, c = 12.398(3) Å and α = 107.63(3)˚, β = 100.76 (3)°, γ = 90.84(3)˚. Electronic spectrum of the complex show that ligand-centered (LCT) transitions and ligand-to-metal charge transfer (LMCT). Geometric structure, frontier orbital and electronic absorption spectrum property of the compound were investigated by using density functional theory (DFT) and compared with the experimental data. Calculated geometric parameters agree with the experimental data. Then the agar disc diffusion method was used to determine the antibacterial activity of the ligands and complex on the growth profile of Four Gram-negative bacteria, i.e., Pseudomunas aeroginosa , Salmonella typhai , Proteus mirabilis and Yersinia enterocolitica and two Gram-positive bacteria, i.e., Staphylococcus aureus and Enterococcus faecalis. The activity of the Rh (III) complex against bacteria was considerably stronger than the ligands. [ABSTRACT FROM AUTHOR]

Abstract: Two 1,8-naphthyridine (nap) metal complexes (nap)ReI(CO)3Cl (1) and [(nap)CuI(DPEPhos)]PF6 (2) were synthesized and characterized by NMR-, emission, and absorption spectroscopy, elemental analysis, mass spectrometry, and X-ray structural analysis. In both complexes, the nap ligand coordinates with both N atoms to the metal centre in a bidentate manner. 1 and 2 exhibit a broad phosphorescence in solid state at T =300K, which is completely quenched in solution at r.t. In addition, the gas-phase structures of both complexes were optimized at the B3LYP/6-31G(d,p) level of theory. [Copyright &y& Elsevier]

Abstract: The structures of [Pt2(P2O5H2)4X2]4− (X=Cl (1), Br (2) and I (3)) were optimized using the ab initio and density functional theory methods. It is shown that the geometry parameters estimated by MP2 and XαVWN are closer to experimental values. We performed the time-dependent density functional theory (TD-DFT) calculations to explore the influence of different density functionals and structures on electronic absorption spectra in solution. The experimental absorptions with the featured and transitions are well reproduced by the theoretical calculations. [Copyright &y& Elsevier]

Abstract: The electronic spectrum of the diperoxo complex MeReVII(O2)2O shows a peroxide IL (intraligand) absorption at λ max ∼260nm in addition to the well-known peroxide to Re(VII) LMCT band at λ max =358nm. Upon IL excitation, the diperoxo group undergoes a dismutation. Accordingly, MeRe(O2)2O photolyzes to MeReVIIO3 and O2. LMCT excitation at λ irr =405nm is assumed to generate the radical pair in the primary photochemical step. Back electron transfer and reaction with water leads finally to the monoperoxo complex MeReVII(O2)O2 and H2O2. [Copyright &y& Elsevier]

The complex [(η-C5Me5)RhIII(η-C7H7)]3+ is characterized by a C5Me5- → C7H7+ ligand-to-ligand charge transfer transition which appears at λmax=340 nm in absorption and 596 nm in emission. [Copyright &y& Elsevier]

A mechanochemical synthesis of Mn(II), Co(II) and Ni(II) tris(pyrazolylborates) (Tp−) was developed, which enabled preparation of metal complexes of the type TpMCl and TpMCl · Hpz type (Hpz is the substituted pyrazole generated by hydrolysis of the corresponding Tp− ligand). The X-ray structure of a new Co(II) tris(pyrazolylborate) and the electronic spectra of these coordination compounds are discussed. [Copyright &y& Elsevier]

The complex (phanephos)ReI(CO)3Cl with phanephos=4,12-bis(diphenylphosphino)-[2.2]-paracyclophane is characterized by a lowest-energy intraligand (IL) excited state of the 2,2-paracyclophane moiety. This IL transition appears at λmax=340 nm in absorption and at 383 (fluorescence) and 480 nm (phosphorescence, at r.t.) in emission. [Copyright &y& Elsevier]

A series of mixed-ligand heterobimetallic complexes of the form MM′(C7H4NS2)4(py)2 and MM′(C7H4NS2)4(N–N) and complex heterobimetallic salts [M(N–N)3][M′(C7H4NS2)4] [M=Co(II) or Ni(II); M′=Zn(II) or Hg(II); N–N=ethylenediamine(en) or 1,10-phenanthroline(phen)] has been prepared and characterized by IR and UV–visible spectroscopy, microanalysis and conductivity techniques. Except with NiZn(C7H4NS2)4(py)2 which is insulator all of the compounds exhibit σrt in the 10−12–10−5 S cm−1 range and semiconduct over 303–393 K. [Copyright &y& Elsevier]

[Display omitted] • [Co(H 2 P 2 O 7) 2 (H 2 O) 2 [(CH 3) 3 C-NH 3 2 ·2H 2 O a new hybrid phosphate is reported. • IR spectroscopy confirmed the existence of the phosphate group P 2 O 7. • Five 4 f –4 f ascribed absorption bands are observed in the UV-NIR fields. [Co(H 2 P 2 O 7) 2 (H 2 O) 2 [(CH 3) 3 C-NH 3 2 ·2H 2 O, a new organically templated dihydrogen-pyrophosphate compound, was synthesized and characterized. The crystal structure was determined using single crystal X-ray diffraction data; [Co(H 2 P 2 O 7) 2 (H 2 O) 2 [(CH 3) 3 C-NH 3 2 ·2H 2 O crystallizes in orthorhombic space group Cmce (n 64), Z = 4, a = 11.9 642(10), b = 9.1565(8), c = 24.488(2), V = 2682.7(4) Å3. Final agreement factors for the refined structure model are R/Rw (%) were 3.96/9.12. The open framework of [Co(H 2 P 2 O 7) 2 (H 2 O) 2 [(CH 3) 3 C-NH 3 2 ·2H 2 O might be described as phosphor-metallic slabs, made of isolated octahedrons [Co(H 2 P 2 O 7) 2 (H 2 O) 2 , which interact through intra-slab H-bonds, while inter-slabs H-bonds ensure the interactions of neighbouring slabs. The inter-slabs host the counter ion [(CH 3) 3 C-NH 3)]+ ions and H 2 O molecules. Raman and FTIR spectra of the newly synthesized compound confirm the structural data obtained by X-Ray diffraction. The complementary information about vibrational modes prove the presence and the coordination of the phosphates as well as the organic moieties. UV–Vis spectrophotometry provide evidence of d-d transitions that are typically found in octahedral Co(II) compounds. In the visible region, the electronic spectrum is dominated by a well resolved strong band at 505 nm assigned to the spin allowed transition 4T 1g (F) →4T 1g (P), and a shoulder at about 460 nm which is assigned to 4T 1g (F) →4A 2g (F) transition that is manifold splitted due to multiplet coupling. [ABSTRACT FROM AUTHOR]

Abstract: Telluroxanthone shows a r.t. phosphorescence at λ max =510nm. The emitting state is of the CT type involving Te as donor and the carbonyl substituent as acceptor. An analogy between the emitting CT triplet of telluroxanthone and emitting MLCT triplets of transition metals complexes is emphasized. [Copyright &y& Elsevier]

Abstract: The yellow colour of silver hyponitrite is attributed to an LMCT band at λ max =419nm. Solid Ag2N2O2 and its suspensions in water or acetonitrile are light sensitive. LMCT excitation leads to a photolysis according to the equation Ag2N2O2 →2Ag+2NO. In the presence of air and water, NO is finally converted to HNO2. [Copyright &y& Elsevier]

Abstract: The electronic spectra of the cations [(BQDI)SeII]2+ and [(BQDI)SII]2+ are compared to that of [(BQDI)ReI(CO)3Cl] with BQDI= o-benzoquinone diimine. While these species show a BQDI-localized ππ∗ absorption between 300 and 360nm, a longer-wavelength band extends to the visible region. This absorption is attributed to a CT transition from ReI (λ max =538), SeII (λ max =432) and SII (λ max =360nm) to the π∗ orbitals of BQDI. The analogy of MLCT and related CT transitions involving non-metals as CT donors is emphasized. [Copyright &y& Elsevier]

Abstract: The complex Ag(NH3)NO2, which can be viewed as a ligand-based mixed-valence compound, undergoes a photoconproportionation of nitrogen from −III and +III to 0. It is suggested that this photolysis originates from a NH3 to LLCT state which is populated from a IL state. In this context, the excited state properties of AgNO2 and Ag(H2O)NO2 are also discussed. [Copyright &y& Elsevier]

Abstract: Alizarin complexone (AC) in ethanol shows two fluorescence bands which originate from the lowest excited singlet before and after proton transfer. Upon addition of various metal ions (Ni2+, Zn2+, Gd3+, Th4+) to AC in ethanol the formation of well known AC complexes takes place. They are characterized by intense colours which are caused by IL (or ILCT) transitions. If low-energy LF states (Ni2+) are absent (Zn2+, Gd3+, Th4+) these complexes show a weak fluorescence. Even in the case of Gd and Th a heavy-atom effect is not apparent and fluorescence quenching is not observed. Moreover, AC complexes are not phosphorescent under any conditions. [Copyright &y& Elsevier]

Abstract: Dry silver sulfadiazine (AgSD) is not light sensitive but shows a greenish-blue r.t. photoluminescence at λ max =482nm which is suggested to originate from an IL triplet. In the presence of water AgSD undergoes a partial hydrolysis with the formation of free sulfadiazine (HSD) which has been previously shown to be photoreactive. Moreover, irradiation of an aqueous suspension of AgSD leads also to the photoreduction of Ag+ to elemental silver. This photolysis might explain the origin of argyria which can occur when AgSD in contact with human skin is exposed to sun light [Copyright &y& Elsevier]

Abstract: The oxonium ions and are phosphorescent at r.t. and 77K, respectively. It is suggested that these ions which are characterized by a rather flat trigonal pyramid in the ground state undergo a distortion to a steeper pyramid in their phosphorescent states. This structural change is caused by metal–metal bonding in the excited state. [Copyright &y& Elsevier]

Abstract: The metallofulvene or carbene complex RuII(PI)(PCy3)2Cl2 with PI=3-phenylindenylidene and Cy=cyclohexyl shows a long-wavelength absorption at λ max =490nm which is attributed to a RuII → π ∗ carbene MLCT transition. MLCT excitation leads to a reversible release of the carbene ligand which can be intercepted by oxygen. The oxygen adduct (or O-oxide) undergoes a fragmentation which yields CO2 and anthracene. [Copyright &y& Elsevier]

• Single crystal X-ray structural analysis revealed that the valence of Co ion to be +III and DBCat is formally a catecholate dianion, also the electronic state is ls -CoIII(Cat). • However, its acetonitrile solution exhibits MLCT band at 575 nm, this band disappears with decreasing temperature. • This behavior suggests that [Co(DBCat)(pbqa)](PF 6) undergose a temperature-dependent change from hs -CoII(SQ) to ls -CoII(Cat). • [Co(DBCat)(pbqa)](PF 6) demostrates valence tautomerism due to a strong π-π interaction between the quinolyl rings of the ancillary ligand like pbqa. Co-dioxolene complex [Co(DBCat)(pbqa)](PF 6) (DBCat = 3,5-di- tert -butylcatechol, pbqa = (2-pyridylmethyl) bis (2-quinolylmethyl)amine), was prepared from methanol solution. Single crystal X-ray structural analysis revealed that the valence of the cobalt ion to be +III, as DBCat is formally a catecholate dianion, whereas the acetonitrile solution exhibits an MLCT absorption near 575 nm, suggesting it is present as hs -CoII(SQ). Of note, this MLCT band disappears with decreasing temperature. This behavior suggests that [Co(DBCat)(pbqa)](PF 6) undergoes a temperature-dependent change from hs -CoII(SQ) to ls -CoIII(Cat). Magnetic susceptibility vs. temperature data for the compound displayed a gradual variation over 250 K, due to intramolecular electron transfer in the solid-state as well. [Co(DBCat)(pbqa)](PF 6) demonstrates valence tautomerism due to a strong π-π interaction between the quinoline rings of the ancillary ligand. Comparison of this pbqa compound to similar Co compounds provides further evidence for these conclusions. [ABSTRACT FROM AUTHOR]

Abstract: The solid compound Ag(binap)NO3 with binap=2,2′-bis(diphenylphosphino)-1,1′-binaphthyl shows an IL phosphorescence at λ max =510nm under ambient conditions. The silver–phosphine bonding is sufficiently covalent to transmit the heavy-atom effect of silver to the binaphthyl chromophore. [Copyright &y& Elsevier]

Abstract: The complex [Ir(azulene)(1,5-cyclocta-diene)]+ shows long-wavelength absorptions which are assigned to spin-allowed (λ max =536nm) and spin-forbidden (675nm) transitions. They are of mixed MLCT (Ir→azulene) and ILCT (azulene) character. At 77K the solid complex displays an emission (λ max =816nm) which originates from the MLCT/ILCT triplet. At r.t. in solution the complex undergoes a photosubstitution of the azulene ligand. It is suggested that in the CT state the azulene ligand looses its coordinating ability. [Copyright &y& Elsevier]

Abstract: The complex PtII(cyclooctatetraene)(CN)2 shows a longest-wavelength absorption (λ max =430nm) which is assigned to a (PtII →π∗ C8H8) MLCT transition. At r.t. the solid complex displays an intense orange emission at 572nm which originates from the MLCT triplet. The emission spectrum exhibits a vibrational structure which may indicate an IL contribution. [Copyright &y& Elsevier]

Abstract: The complex tetraphenylcyclobutadiene palladium(IV) chloride shows a longest-wavelength absorption at λ max =530nm which is assigned to a LMCT transition from the C4Ph4 dianion to Pd(IV). LMCT excitation leads to the release of Pd(CH3CN)2Cl2 and neutral C4Ph4 which dimerizes to octaphenylcyclooctatetraene. [Copyright &y& Elsevier]

Abstract: The anhydrous CeX3 solids with X=Cl, Br, I show two emission bands which are separated by ca. 2000cm−1 due to spin–orbit coupling. The longer-wavelength maximum appears at λ max =362nm for CeCl3, 390nm for CeBr3 and 514nm for CeI3. It is suggested that this red shift is caused by an increasing interaction of the cerium 5d orbitals with the halide nd orbitals. Accordingly, the emission originates from a metal-centered 4f5d excited state which is mixed with a cerium 4f→halide nd MLCT state. [Copyright &y& Elsevier]

• Bioinspired copper(II) complexes are reported as the model for type 2 copper site in phenoxazinone synthases. • They catalyze the conversion of the substrate 2-aminophenol into 2-aminophenoxazine-3-one using molecular oxygen in water. • Spectral, redox, and kinetic studies were performed in water to mimic accurate enzymatic reaction conditions. A new series of copper(II) complexes [Cu(L)Cl 2 ] 1 – 5 , where L is dimethyl-(2-{[(pyridin-2-ylmethyl)-amino]-methyl}-phenyl)-amine (L1); dimethyl-{2-[(2-pyridin-2-yl-ethylamino)-methyl]-phenyl}-amine (L2); 2-((3-(dimethylamino) propylamino)-methyl)- N,N -dimethylbenzenamine (L3); 2-((2-(dimethylamino) ethylamino) methyl)- N,N -dimethylbenzenamine (L4) and (2-{[(1 H -benzimidazole-2-ylmethyl)-amino]-methyl}-phenyl)-dimethylamine (L5) have been synthesized and characterized as the model for type 2 copper site in phenoxazinone synthases. The molecular structure of 1 exhibits nearly a perfect square pyramidal geometry (τ , 0.01). The complexes showed Cu(II)/Cu(I) redox potentials around −0.128 to −0.215 V in water. The electronic spectra of 1 – 5 exhibited d-d transitions around 620–643 nm in water. All the complexes exhibit almost similar electron paramagnetic resonance (EPR) parameter (g || , 2.21–2.27; A ||, 161–175 × 10−4 cm−1) corresponds to square-based geometry. The complexes have catalyzed the conversion of substrate 2-aminophenol into 2-aminophenoxazine-3-one using molecular oxygen. The formation was accomplished by appearance of a new absorption band at 433 nm with the reaction rate of 6.14–9.89 × 10−3 s−1 in water. [ABSTRACT FROM AUTHOR]

The complex Mo0(diphos)(CO)(NO)(dtc) with diphos=1,2-bis(diphenylphosphino)ethane and dtc-=dimethyldithiocarbamate shows a longest-wavelength absorption at λmax=520 nm which is assigned to a (dtc- → NO+) ligand-to-ligand charge transfer (LLCT) transition. LLCT excitation leads to the release of NO and dtc which form a blue species (λmax=690 nm). The photolysis proceeds with φ=0.018 at λirr=546 nm. [Copyright &y& Elsevier]

In solution HgIIPh2 undergoes a photoredox decomposition (φ=0.006 at λirr=254 nm in CH3CN) which is induced by ligand-to-metal charge transfer excitation. In the solid state this decomposition is largely prevented but a phosphorescence appears which originates from the lowest-energy ππ* (phenyl) intraligand triplet. [Copyright &y& Elsevier]

The complex ethylenebis(indenyl)zirconium(IV) binolate with binol=1,1′-binaphthyl-2,2′-diol is characterized by a lowest-energy ππ* binolate IL (intraligand) excited state (absorption λmax=348 nm). The IL triplet undergoes an emission at λmax=490 nm under ambient conditions. [Copyright &y& Elsevier]

Iron(III) complexes with phenolate ligands (m-cresolate and tyrosinate) undergo a redox photolysis in aqueous solution upon phenolate → Fe(III) ligand-to-metal charge transfer excitation. At λirr=577 nm the quantum yields of Fe(II) formation are approximately φ=10−4. [Copyright &y& Elsevier]

The complex [(C6H7)Fe(CO)3]+ in aqueous solution undergoes a photodecomposition which leads to the formation of cyclohexadiene and Fe2+ with a quantum yield of φ=0.32 at λirr=280 nm. It is suggested that the reactive excited state is of the (Fe→C6H7) metal-to-ligand charge transfer (MLCT) type. MLCT excitation facilitates an electrophilic addition of a proton at the C6H7 ligand while in the ground state a nucleophilic attack is favoured. [Copyright &y& Elsevier]

The complex CuI(BTA)(hfac) with BTA=bis(trimethylsilyl)acetylene and hfac=1,1,1,5,5,5-hexa-fluoroacetylacetonate shows a longest-wavelength absorption at at λmax=324 nm (ϵ=5400 M−1 cm−1) which is assigned to a spin-allowed CuI→π* (BTA) metal-to-ligand charge transfer (MLCT) transition. The solid complex displays an emission at λmax=601 nm which is assumed to originate from the lowest-energy MLCT triplet. In solution MLCT excitation leads to the release of the acetylene with 6×10−4 at λirr=333 nm. [Copyright &y& Elsevier]

Light pink crystal of composition [Co(4-CH2OH-5-CH3im)4](NO3)2 (where 4-CH2OH-5-CH3im denotes 4-hydroxymethyl-5-methylimidazole) were obtained from 2-propanol. The complex has been characterized by single-crystal X-ray as well as by electronic and vibrational spectroscopy. The immediate surrounding of the central ion is made up of four nitrogen atoms of the heterocyclic rings and two oxygen atoms of the hydroxymethyl group (CoN4O2 chromophore) The shape of the coordination polyhedron of the cobalt(II) ion is that of a slightly distorted octahedral. [Copyright &y& Elsevier]

The photolysis of FeIII(et2dtc)3 with et2dtc− = diethyldithiocarbamate in inert solvents (e.g., CH3CN) and in the presence of 1,2-bis(diphenylphosphino)ethane (dppe) leads to the formation of FeII(et2dtc)2(dppe) and (et2dtc)2 = tetraethylthiuramdisulfide. At equimolar concentrations (2.76×10−5 M) of FeIII(et2dtc)3 and dppe the quantum yields are φ=0.007 at λirr=333 nm and 0.003 at 436 nm. This photoreaction, which is initiated by ligand-to-metal charge transfer excitation, generates FeII(et2dtc)2 and a et2dtc radical in the primary photochemical step. Product formation occurs by the interception of FeII(et2dtc)2 with dppe. [Copyright &y& Elsevier]

With regard to its electronic structure, the cation Icoll2+ (coll = collidine or 2,4,6-trimethylpyridine) is viewed as a coordination compound of iodine(I) with a p4 electron configuration. The lowest-energy excited state of Icoll2+ is suggested to be a ππ* collidine intraligand (IL) triplet which appears in absorption (λmax=332 nm, ϵ=250) and emission (λmax=405 nm, φ=0.001, τ∼90 ns). Owing to the heavy-atom effect of iodine this phosphorescence occurs at r.t. The longest-wavelength pp absorption is apparently obscured by the intense spin-allowed IL band at λmax=268 nm. [Copyright &y& Elsevier]

The reaction of tetracycline with K2PtCl4 in glacial acetic acid leads to the dehydration of tetracycline to anhydrotetracycline (ahtc) which coordinates as a bidentate ligand to the PtCl2 moiety. The composition of Pt(ahtc)Cl2 is confirmed by elemental analysis and mass spectrometry. On the basis of the electronic spectra it is suggested that the coordination takes place at the A ring of ahtc while the BCD ring system is preserved as separate chromophore. It is characterized by a long-wavelength absorption and fluorescence which appear at λmax=428 and 550 nm, respectively, for the free ahtc ligand and λmax=425 and 550 nm for Pt(ahtc)Cl2. [Copyright &y& Elsevier]

The complex (dmp)CuI(BH4) with dmp=2,9-dimethyl-1,10-phenanthroline displays a long-wavelength absorption at λmax=465 nm which is assigned to a BH4−→dmp ligand-to-ligand charge transfer (LLCT) transition. In the solid state the LLCT state is emissive (λmax=626 nm). In non-coordinating solvents such as CH2Cl2,CHCl3 or toluene the complex undergoes a photoredox decomposition leading to the generation of metallic copper. At λirr=436 nm (dmp)CuI(BH4) disappears with φ=1.2×10−3. [Copyright &y& Elsevier]

The complex CpCuI(PEt3) with Cp=cyclopentadienyl shows a longest-wavelength absorption at λmax=350 nm (in n-hexane) which is assigned to a Cp−→PEt3 ligand-to-ligand charge transfer (LLCT) transition. An analogy to the ylide Cp−–P+Propyl3 is drawn which displays the Cp− to phosphonium charge transfer (CT) absorption at λmax=267 nm (in n-hexane). Solid CpCu(PEt3) exhibits an emission at λmax=525 nm which is assumed to originate from the LLCT triplet. [Copyright &y& Elsevier]

Abstract: The complex trichloro(phenylazo)bis(triphenylphosphine)ruthenium(II) shows a longest-wavelength absorption at λ max =520nm which is assigned to a Ru(II)→phenyldiazonium+ MLCT transition. MLCT excitation leads to the oxidation of the metal and reduction of the diazonium cation which decays to nitrogen and phenyl radical. [Copyright &y& Elsevier]