Pyrano[2,3-c]pyrazole fused spirooxindole-linked 1,2,3-triazoles as antioxidant agents: Exploring their utility in the development of antidiabetic drugs via inhibition of α-amylase and DPP4 activity.

Environment-benign, multicomponent synthetic methodologies are vital in modern pharmaceutical research and facilitates multi-targeted drug development via synergistic approach. Herein, we reported green and efficient synthesis of pyrano[2,3-c]pyrazole fused spirooxindole linked 1,2,3-triazoles using a tea waste supported copper catalyst (TWCu). The synthetic approach involves a one-pot, five-component reaction using N-propargylated isatin, hydrazine hydrate, ethyl acetoacetate, malononitrile/ethyl cyanoacetate and aryl azides as model substrates. Mechanistically, the reaction was found to proceed via in situ pyrazolone formation followed by Knoevenagel condensation, azide alkyne cycloaddition and Michael's addition reactions. The molecules were developed using structure-based drug design. The primary goal is to identifying anti-oxidant molecules with potential ability to modulate α-amylase and DPP4 (dipeptidyl-peptidase 4) activity. The anti-oxidant analysis, as determined via DPPH, suggested that the synthesized compounds, A6 and A10 possessed excellent anti-oxidant potential compared to butylated hydroxytoluene (BHT). In contrast, compounds A3, A5, A8, A9, A13, A15, and A18 were found to possess comparable anti-oxidant potential. Among these, A3 and A13 possessed potential α-amylase inhibitory activity compared to the acarbose, and A3 further emerged as dual inhibitors of both DPP4 and α-amylase with anti-oxidant potential. The relationship of functionalities on their anti-oxidant and enzymatic inhibition was explored in context to their SAR that was further corroborated using in silico techniques and enzyme kinetics.

Comparison of inflammatory markers in low-pressure pneumoperitoneum with deep neuromuscular block versus standard pressure pneumoperitoneum among patients undergoing laparoscopic cholecystectomy for gallstone disease: a randomized control trial.

BACKGROUND: Low-pressure pneumoperitoneum (LPP) is an attempt to improve laparoscopic surgery. Lower pressure causes lesser inflammation and better hemodynamics. There is a lack of literature comparing inflammatory markers in LPP with deep NMB to standard pressure pneumoperitoneum (SPP) with moderate NMB in laparoscopic cholecystectomy. METHODOLOGY: This was a single institutional prospective randomized control trial. Participants included all patients undergoing laparoscopic cholecystectomy for symptomatic gall stone disease. Participants were divided into 2 groups group A and B. Group A-Low-pressure group in which pneumoperitoneum pressure was kept low (8-10 mmHg) with deep Neuromuscular blockade (NMB) and Group B-Normal pressure group (12-14 mmHg) with moderate NMB. A convenience sample size of 80 with 40 in each group was selected. Lab investigations like CBC, LFT, RFT and serum IL-1, IL-6, IL-17, TNF alpha levels were measured at base line and 24 h after surgery and compared using appropriate statistical tests. Other parameters like length of hospital stay, post-operative pain score, conversion rate (low-pressure to standard pressure), and complications were also compared. RESULTS: Eighty participants were analysed with 40 in each group. Baseline characteristics and investigations were statistically similar. Difference (post-operative-pre-operative) of inflammatory markers were compared between both groups. Numerically there was a slightly higher rise in most of the inflammatory markers (TLC, ESR, CRP, IL-6, TNFα) in Group B compared to Group A but not statistically significant. Albumin showed significant fall (p < 0.001) in Group B compared to Group A. Post-operative pain was also significantly less (p < 0.001) in Group A compared to Group B at 6 h and 24 h. There were no differences in length of hospital stay and incidence of complications. There was no conversion from low-pressure to standard pressure. CONCLUSION: Laparoscopic cholecystectomy performed under low-pressure pneumoperitoneum with deep NMB may have lesser inflammation and lesser post-operative pain compared to standard pressure pneumoperitoneum with moderate NMB. Future studies with larger sample size need to be designed to support these findings.

Exploring the role of neutral ligands in modulating the photoluminescence of samarium complexes with 1,1,1,5,5,5-hexafluoro-2,4-pentanedione.

Four eight-coordinated luminescent samarium complexes of type [Sm(hfpd)3L2] and [Sm(hfpd)3L'] [where hfpd = 1,1,1,5,5,5-Hexafluoro-2,4-pentanedione L = tri-octyl-phosphine oxide (TOPO) and L' = 1,10-phenanthroline (phen), neocuproine (neoc) and bathocuproine (bathoc) were synthesized via a stoichiometrically controlled approach. This allows for precise control over the stoichiometry of the complexes, leading to reproducible properties. This investigation focuses on understanding the impact of secondary ligands on the luminescent properties of these complexes. Infrared (IR) spectra provided information about the molecular structures, whereas 1H and 13C nuclear magnetic resonance (NMR) spectra confirmed these structural details along with the coordination of ligands to trivalent Sm ion. The UV-vis spectra revealed the molar absorption coefficient and absorption bands associated with the hfpd ligand and photoluminescence (PL) spectroscopy demonstrated intense orange-red emission (648 nm relative to 4G5/2 → 6H9/2) from the complexes. The Commission Internationale de l'Éclairage (CIE) triangles indicated that the complexes emitted warm orange red light with color coordinates (x, y) ranging from (0.62, 0.36) to (0.40, 0.27). The investigation of the band gap as well as color parameters confirms the utility of these complexes in displays and LEDs.

Structural, morphological, and optical characteristics of Gd2 Si2 O7 :Dy3+ nanophosphors for WLEDs.

Yellowish-white light-emitting Gd2-x Si2 O7 :xDy3+ (x = 1-5 mol%) nanophosphors were prepared using a solution combustion synthesis method. Fluorescence spectrophotometry and X-ray diffraction measurements were performed to scrutinize the optical performances and phase recognition of the designated nanophosphors. The outcomes specified that the prepared phosphors were crystallized into a triclinic phase with a P-1 space group. As the concentration of Dy3+ ions was increased, the unit-cell volume decrease proportionally due to the replacement of large-sized Gd3+ by small-sized Dy3+ ions. Under ultraviolet excitation at 349 nm, emission spectra consisted of two pronounced emission lines at ~482 nm (blue line), ~578 nm (yellow line), and a relatively weaker emission at ~670 nm (red line) due to 4 F9/2 →6 H15/2 , 4 F9/2 →6 H13/2 , and 4 F9/2 →6 H11/2 intraconfigurational transitions of Dy3+ ions, respectively. The evidence about the site symmetry around Dy3+ ions was examined by considering the ratio of yellow-to-blue emission intensity. The observed critical distance (Rc ) value was ~20.56 Å (≫5 Å), which signified that energy transfer primarily occurred due to multipolar interaction. The obtained coordinates were close to the white region of the Commission Internationale de l'Éclairage chromaticity diagram, which marked a significant milestone in the development of white light-emitting diodes.

Crystallographic, morphological and photoluminescent investigations of Tb3+ -doped YAlO3 perovskites for lighting applications.

Terbium(III)-doped yttrium aluminate perovskite (YAP:xTb3+ ) (x = 0.01-0.08 mol) was synthesized using a simple gel-combustion method. Structural elucidations were performed using X-ray diffraction (XRD) and Rietveld analysis. Fourier-transform infrared spectral studies validated the efficient synthesis of designed doped samples. Transmission electron microscopic images showed the agglomerated irregular dimensions of the synthesized nanocrystalline materials. When excited at 251 nm, a strong emissive line attributed to 5 D4 → 7 F5 electronic transition was observed at 545 nm (green emission). The maximum luminescence was found at the optimized concentration (0.05 mol) of Tb3+ ions; this emission was quenched by dipolar-dipolar (d-d) interactions. Chromaticity (x and y) and correlated colour temperature parameters were obtained by analysing the emission profiles. Finally, the colour coordinates of nanophosphors were closer to the National Television Standards Committee green coordinates, which replicates their potency in the design and architecture of R-G-B-based white LEDs.

Synthesis of green emissive terbium(III) complexes for displays: Optical, electrochemical and photoluminescent analysis.

A series of heteroleptic terbium(III) complexes with fluorinated 2-thenoyltrifluoroacetone (TTFA) and other heteroaromatic units have been synthesized. The developed heteroleptic complexes were inspected via elemental study, cyclic voltammetry, thermal analysis and spectroscopic investigations. Optical band-gap data proposed the conducting property of prepared complexes. The photoluminescence emission profiles illustrated peaks based on terbium(III) cation (Tb3+ ) positioned at ~617, 586, 546 and 491 nm, imputed to 5 D4 to 7 FJ (J = 3,4,5,6) transitions separately. Most intense peak at 546 nm corresponding to 5 D4 → 7 F5 transition is accountable for the green emissive character of developed complexes. The luminous character of complexes reveals the sensitization of Tb3+ by ligands. Color parameters further corroborates the green emanation of Tb3+ complexes. The photometric characteristics of complexes recommended their usages in designing display devices.

Partial Deoxygenative CO Homocoupling by a Diiron Complex.

One route to address climate change is converting carbon dioxide to synthetic carbon-neutral fuels. Whereas carbon dioxide to CO conversion has precedent in homo- and heterogeneous catalysis, deoxygenative coupling of CO to products with C-C bonds-as in liquid fuels-remains challenging. Here, we report coupling of two CO molecules by a diiron complex. Reduction of Fe2 (CO)2 L (2), where L2- is a bis(ß-diketiminate) cyclophane, gives [K(THF)5 ][Fe2 (CO)2 L] (3), which undergoes silylation to Fe2 (CO)(COSiMe3 )L (4). Subsequent C-OSiMe3 bond cleavage and C=C bond formation occurs upon reduction of 4, yielding Fe2 (µ-CCO)L. CO derived ligands in this series mediate weak exchange interactions with the ketenylidene affording the smallest J value, with changes to local metal ion spin states and coupling schemes (ferro- vs. antiferromagnetism) based on DFT calculations, Mössbauer and EPR spectroscopy. Finally, reaction of 5 with KEt3 BH or methanol releases the C2 O2- ligand with retention of the diiron core.

Activation of Dinitrogen by Polynuclear Metal Complexes.

Activation of dinitrogen plays an important role in daily anthropogenic life, and the processes by which this fixation occurs have been a longstanding and significant research focus within the community. One of the major fields of dinitrogen activation research is the use of multimetallic compounds to reduce and/or activate N2 into a more useful nitrogen-atom source, such as ammonia. Here we report a comprehensive review of multimetallic-dinitrogen complexes and their utility toward N2 activation, beginning with the d-block metals from Group 4 to Group 11, then extending to Group 13 (which is exclusively populated by B complexes), and finally the rare-earth and actinide species. The review considers all polynuclear metal aggregates containing two or more metal centers in which dinitrogen is coordinated or activated (i.e., partial or complete cleavage of the N2 triple bond in the observed product). Our survey includes complexes in which mononuclear N2 complexes are used as building blocks to generate homo- or heteromultimetallic dinitrogen species, which allow one to evaluate the potential of heterometallic species for dinitrogen activation. We highlight some of the common trends throughout the periodic table, such as the differences between coordination modes as it relates to N2 activation and potential functionalization and the effect of polarizing the bridging N2 ligand by employing different metal ions of differing Lewis acidities. By providing this comprehensive treatment of polynuclear metal dinitrogen species, this Review aims to outline the past and provide potential future directions for continued research in this area.

Synthesis, Optoelectronic and Photoluminescent Characterizations of Green Luminous Heteroleptic Ternary Terbium Complexes.

This article presents four ternary terbium complexes based on fluorinated 2-thenoyltrifluoroacetone (TTFA) and N donor bidentate neutral ligands. The prepared complexes were examined by elemental study, electrochemical analysis, spectroscopically and thermo-gravimetrically. Spectral analysis shows the bonding of Tb3+ ion with oxygen and nitrogen atom of diketone and neutral ligand respectively. Upon excitation in UV region, synthesized terbium complexes show luminescence in green region of electromagnetic spectrum. Photoluminescence emission spectra of complexes do not show any ligand based peak suggesting the effective transferal of energy from ligand to metal ion. Green emanation by terbium complexes is owing to intense peak ~547 nm (5D4 → 7F5). The outcome of emission data and CIE coordinates correlate with each other and affirms the utility of green luminous complexes as potential emissive material for optoelectronic gadgets applied in lighting system.

Red-emitting ß-diketonate Eu(III) Complexes With Substituted 1,10-phenanthroline Derivatives: Optoelectronic and Spectroscopic Analysis.

A series of europium diketonate complexes with 1-phenyl-1,3-butanedione (PBD) and 1,10-phenanthroline derivatives were synthesized and explored spectroscopically. Photophysical characteristics of synthesized complexes have been investigated experimentally as well as theoretically. Photoluminescence emission spectra of complexes do not contain any peak of ligand revealing efficient transferal of energy from ligand to Eu3+ ion. Presence of peak at 611 nm corresponding to 5D0 → 7F2 transition is responsible for red emanation of ternary europium complexes. Photophysical parameters viz., Judd-Ofelt, quantum efficiency, radiative and non radiative decay rates were also estimated theoretically from LUMPAC software. Geometry optimization of complexes was done via Avogadro software. All synthesized trivalent complexes exhibit red emission which was further sustained by the position of chromaticity coordinates in CIE triangle. These red emanating materials could be utilized in designing electroluminescent display devices.

Luminescent Features of Ternary Europium Complexes: Photophysical and Optoelectronic Evaluation.

Trivalent europium complexes exhibit good luminescent characteristics. A series of octacoordinated ternary europium complexes with fluorinated diketone and heteroaromatic auxiliary unit were synthesized. The synthesized europium complexes were characterized by elemental, thermal, electrochemical and spectroscopic analyses. Band gap values lie in range of semiconductors which confirm the conducting behavior of prepared complexes. Photoluminescence spectra were recorded in solid state and DMSO solvent. Emission spectral profiles have displayed most intense peak at ~ 612 nm corresponding to hypersensitive 5D0 → 7F2 transition. Colorimetric parameters suggest red luminous nature of europium complexes. The luminescent heteroleptic europium complexes might be utilized as emissive materials for fabricating display.

Red emissive ternary europium complexes: synthesis, optical, and luminescence characteristics.

Solid ternary europium complexes consisting of fluorinated ß-diketone (thenoyltrifluoroacetone, TTFA) and heteroaromatic bidentate auxiliary ligands were synthesized. The luminescence features of the complexes were estimated using various spectral measurements and clearly proved that the Eu3+ ion is efficiently sensitized by ligands by an antenna effect. Photoluminescence excitation spectra have shown that Eu(III) complexes are excited effectively in the ultraviolet (UV) region and the corresponding emission spectra consist of characteristic peaks attributed to the 5 D0 →7 FJ transitions of the europium ion with the strongest emission peak at 611 nm (5 D0 →7 F2 ). From photoluminescence (PL) data, decay time, Judd-Ofelt parameters, transition rates, and quantum efficiency of the complexes were also determined. The Commission Internationale de l'éclairage (CIE) colour coordinates indicated the bright red emission of ternary europium complexes. Correlated colour temperature values indicated the utilization of these complexes in display devices. Judd-Ofelt and photophysical parameters were also estimated theoretically using LUMPAC software. Various frontier molecular orbitals and their respective energy were determined. These red emissive europium complexes could be utilized for fabricating solid-state lighting systems.

Fluorinated ß-diketone-based Sm(III) complexes: spectroscopic and optoelectronic characteristics.

The synthesis and characterization of a series of octa-coordinated Sm(III) complexes with 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedione (TFNB) and 2,2'-bipyridine (Bpy) derivatives as ancillary ligand are described here. The complexes were analyzed by elemental, spectroscopic such as infrared spectroscopy, 1 H NMR, and thermogravimetric analyses. The fluorinated TFNB ligand absorbs in the range from 200 to 400 nm. The complexes show the sharp and structured Sm-based emissions in visible region upon irradiation in UV range. Excitation spectra of complexes show similarity to the absorption spectra of ligands suggesting that excitation energy is transferred from ligands to Sm(III) centre by the antenna effect. Photoluminescence emission spectra and colour parameters affirmed that the complexes show luminescence in orange-red region. These luminous Sm(III) complexes might be applied as emissive layer in organic electroluminescent devices.

Luminous LaAlO3 :Dy3+ perovskite nanomaterials: Synthesis, structural, and luminescence characteristics for white light-emitting diodes.

A single-phase perovskite LaAlO3 :Dy3+ phosphor was synthesized using a gel-combustion method at 600°C utilization with hexamethylenetetramine as a fuel. Further calcination of the samples was carried out (800 and 1000°C) to investigate the resultant effect on the crystalline and luminescence behaviour. The crystal structure had a cubic unit cell (space group Pm3̅m) and was examined using the Rietveld refinement and X-ray diffraction data. Additionally, Debye-Scherrer and Williamson-Hall equations were applied to determine other structural features. The particle size and morphology of phosphors were evaluated using transmission electron microscopy. Diffraction measurements were supported by the various metal-oxygen vibration modes studied with the help of Fourier transform infrared spectroscopy. Energy-dispersive X-ray analysis verified the chemical composition of synthesized sample. Luminescence spectra of the LaAlO3 :Dy3+ phosphors exhibited intense bands for 4 F9/2 →6 H15/2 (482 nm, bluish region) and 4 F9/2 →6 H13/2 (574 nm, yellowish region) transitions. Commission Internationale de L'Eclairage and correlated colour temperature data confirmed the cool-white emission of the samples under ultraviolet light excitation. The interesting and advantageous luminescence characteristics of LaAlO3 :Dy3+ phosphors make them potential materials for white light-emitting diodes.

Emerging green light emission of Er3+ -activated single phased GdAlO3 phosphors for lighting applications.

An erbium ion (Er3+ )-activated gadolinium aluminate (GdAlO3 ) nanophosphor was synthesized by utilizing urea assisted gel-combustion method. The crystal structure along with all other crystal parameters was determined by X-ray diffraction (XRD) patterns. The selected samples are of orthorhombic phase with Pnma space group. The agglomerated particles within nanorange have been confirmed by transmission electron microscopy (TEM) micrographs. Elemental investigation was performed by energy dispersive X-ray spectroscopy (EDX). Photoluminescence excitation (PLE) spectrum reveals a strong excitation band corresponding to the gadolinium ion (Gd3+ ) (276 nm) and a band near ultraviolet (UV) absorption for Er3+ (377 nm). Strong excitation band of Gd3+ was evident for the energy transfer between Gd3+ and Er3+ ions. All the doped sampled are excited at 377 nm wavelength. The photoluminescence (PL) spectrum exhibits an intense band at 546 nm (4 S3/2 → 4 I15/2 ) which is responsible for the green emission in the processed samples. The color coordinate values define their color in the green region and correlated color temperature (CCT) values affirm their utility as a cold light source.

Mononuclear luminous ß-diketonate Ln(III) complexes with heteroaromatic auxiliary ligands: synthesis and luminescence characteristics.

A series of lanthanide (samarium and terbium) ß-diketonates with heteroaromatic auxiliary ligands was synthesized. The prepared complexes were characterized through electrochemical, thermal, and spectroscopic analyses. Infrared analysis revealed the binding of the respective metal ion to oxygen and nitrogen atoms of diketone and ancillary ligands. Thermogravimetry/differential thermogravimetry profiles provided thermal information and specified the high thermal stability of the prepared complexes. The complexes exhibited the sharp and structured Ln-based emission in the visible region upon irradiation in the ultraviolet range. Photophysical analysis demonstrated the green and orange-red emission due to the respective characteristic transitions of Tb3+ and Sm3+ ions. Photophysical properties affirmed the luminous behaviour of the synthesized complexes. These luminous lanthanide complexes could be used as emitting materials in the design of organic light-emitting diodes.

Proficient exclusion of pesticide using humic acid-modified magnetite nanoparticles from aqueous solution.

Extensive dispersal of the pesticides to shield the different types of vegetation from pests has increased the production but at the same it has resulted in an increase in environmental pollution. Consequently, it is necessary to eliminate these undesired pollutants from the environment. The current investigation offers the synthesis of humic acid-coated magnetite nanoparticles towards effective removal of the most common insecticide, imidacloprid, from aqueous solution using a batch adsorption method. These synthesized nanoparticles were characterized with the help of several analytical and spectroscopic techniques. To acquire the maximum conceivable adsorption, effects of different influencing parameters like pH of the solution, time of contact, concentration of pesticide solution, amount of adsorbent and temperature were also examined. Moreover, the kinetic studies were found to be in good agreement with a pseudo-second-order kinetic model supporting the occurrence of chemisorption phenomenon. Additionally, isotherm modeling proved that the adsorption process was in accordance with the Langmuir model of isotherm. Thermodynamic parameters depicted the endothermic and spontaneous behavior of the adsorption process. Desorption studies were also carried out to examine the reusability of these nano-adsorbents. These verdicts confirmed that the surface modified magnetite nanoparticles may be treated as proficient material for exclusion of imidacloprid from the aqueous solution.

Incidence, risk factors, treatment, and consequences of antibody-mediated kidney transplant rejection: A systematic review.

BACKGROUND: Antibody-mediated rejection (AMR) is a leading cause of kidney allograft failure, but its incidence, risk factors, and outcomes are not well understood. METHODS: We searched Ovid MEDLINE, Cochrane, EMBASE, and Scopus from January 2000 to January 2020 to identify published cohorts of ≥500 incident adult or 75 pediatric kidney transplant recipients followed for ≥1 year post-transplant. RESULTS: At least two reviewers screened 5061 articles and abstracts; 28 met inclusion criteria. Incidence of acute AMR was 1.1%-21.5%; most studies reported 3%-12% incidence, usually within the first year post-transplant. Few studies reported chronic AMR incidence, from 7.5%-20.1% up to 10 years. Almost all patients with acute or chronic AMR received corticosteroids and intravenous immunoglobulin; most received plasmapheresis, and approximately half with rituximab. Most studies examining death-censored graft failure identified AMR as an independent risk factor. Few reported refractory AMR rates or outcomes, and none examined costs. Most studies were single-center and varied greatly in design. CONCLUSIONS: Cohort studies of kidney transplant recipients demonstrate that AMR is common and associated with increased risk of death-censored graft failure, but studies vary widely regarding populations, definitions, and reported incidence. Gaps remain in our understanding of refractory AMR, its costs, and resulting quality of life.

Selective Detection of Picric Acid and Pyrosulfate Ion by Nickel Complexes Offering a Hydrogen-Bonding-Based Cavity.

This work describes the synthesis and characterization of three mononuclear nickel complexes supported with amide-based pincer ligands. All three complexes presented an H-bonding-based cavity due to the migration of amidic protons to the appended heterocyclic rings that formed H-bonds with the metal-ligated solvent molecule(s). These complexes functioned as the nanomolar chemosensors for the detection of picric acid and pyrosulfate ion as inferred by the detailed absorption and emission spectral studies while further supported with FTIR, NMR, and mass spectra of the isolated products. We also illustrate a few practical detection methods for the sensing of picric acid in the solution state as the naked-eye colorimetric methods and in the solid state by employing polystyrene films.

Bis(µ-thiolato)-dicopper Containing Fully Spin Delocalized Mixed Valence Copper-Sulfur Clusters and Their Electronic Structural Properties with Relevance to the CuA Site.

With aromatic and aliphatic thiol-S donor Schiff base ligands, the copper-sulfur clusters, [(L1)8CuI6CuII2](ClO4)2·DMF·0.5CH3OH (1) and [(L2)12CuI5CuII11(µ4-S)(µ4-O)6](ClO4)·4H2O, respectively, have been reported ( Chem. Commun. 2017, 53, 3334); HL1/HL2 are 2-(((3-methylthiophen-2-yl)methylene)amino)benzene/ethanethiol). Complex 1 comprises a wheel shaped Cu8S8 framework, made up of interlinked Cu2{µ-S(R)}2 units. To understand the properties with relevance to the CuA site and to check whether self-assembly generates similar type clusters to 1, three complexes, [(L3)8CuI6CuII2](ClO4)2·(C2H5)2O·2.5H2O (2), [(L3Cl)8CuI6CuII2](ClO4)2·1.25(C2H5)2O·1.25CH3OH·2H2O (3), and [(L3CF3)8CuI6CuII2](ClO4)2·2(C2H5)2O·H2O (4) have been synthesized with supporting ligands HL3X (HL3 = 2-((furan-2-ylmethylene)amino)benzenethiol when X = -H; X = -Cl or -CF3 para to thiol-S are HL3Cl and HL3CF3 ligands, respectively). The X-ray structures of 3 and 4 feature a similar Cu8S8 architecture to 1. The spectroscopic properties and the X-ray structures revealed that 2-4 are fully spin delocalized mixed valence (MV) of class-III type clusters. The structural parameters of the N2Cu2{µ-S(R)}2 units of 3 and 4 closely resemble those of the MV binuclear CuA site. With the aid of UV-vis-NIR, EPR, and spectroelectrochemical studies, the electronic properties of these complexes have been described in comparison with the MV model complexes and CuA site.