Mesoporous Mo-doped PtBi intermetallic metallene superstructures to enable the complete electrooxidation of ethylene glycol.

Metallenes, intermetallic compounds, and porous nanocrystals are the three types of most promising advanced nanomaterials for practical fuel cell devices, but how to integrate the three structural features into a single nanocrystal remains a huge challenge. Herein, we report an efficient one-step method to construct freestanding mesoporous Mo-doped PtBi intermetallic metallene superstructures (denoted M-PtBiMo IMSs) as highly active and stable ethylene glycol oxidation reaction (EGOR) catalysts. The materials retained their catalytic performance, even in complex direct ethylene glycol fuel cells (DEGFCs). The M-PtBiMo IMSs showed EGOR mass and specific activities of 24.0 A mgPt-1 and 61.1 mA cm-2, respectively, which were both dramatically higher than those of benchmark Pt black and Pt/C. In situ infrared spectra showed that ethylene glycol underwent complete oxidation via a 10-electron CO-free pathway over the M-PtBiMo IMSs. Impressively, M-PtBiMo IMSs demonstrated a much higher power density (173.6 mW cm-2) and stability than Pt/C in DEGFCs. Density functional theory calculations revealed that oxophilic Mo species promoted the EGOR kinetics. This work provides new possibilities for designing advanced Pt-based nanomaterials to improve DEGFC performance.

Targeting P2Y14R protects against necroptosis of intestinal epithelial cells through PKA/CREB/RIPK1 axis in ulcerative colitis.

Purinergic signaling plays a causal role in the pathogenesis of inflammatory bowel disease. Among purinoceptors, only P2Y14R is positively correlated with inflammatory score in mucosal biopsies of ulcerative colitis patients, nevertheless, the role of P2Y14R in ulcerative colitis remains unclear. Here, based on the over-expressions of P2Y14R in the intestinal epithelium of mice with experimental colitis, we find that male mice lacking P2Y14R in intestinal epithelial cells exhibit less intestinal injury induced by dextran sulfate sodium. Mechanistically, P2Y14R deletion limits the transcriptional activity of cAMP-response element binding protein through cAMP/PKA axis, which binds to the promoter of Ripk1, inhibiting necroptosis of intestinal epithelial cells. Furthermore, we design a hierarchical strategy combining virtual screening and chemical optimization to develop a P2Y14R antagonist HDL-16, which exhibits remarkable anti-colitis effects. Summarily, our study elucidates a previously unknown mechanism whereby P2Y14R participates in ulcerative colitis, providing a promising therapeutic target for inflammatory bowel disease.

Fine-tuning of thermally induced SCO behaviors of trinuclear cyanido-bridged complexes by regulating the electron donating ability of CCN-terminal fragments.

To achieve fine regulation of FeII SCO behavior, a series of trinuclear cyanido-bridged complexes trans-[CpMen(dppe)MII(CN)]2[Fe1II(abpt)2](OTf)2 (1-4) (1, M = Fe2 and n = 1; 2, M = Fe2 and n = 4; 3, M = Fe2 and n = 5; 4, M = Ru and n = 5; CpMen = alkyl cyclopentadienyl with n = 1, 4, 5; dppe = 1,2-bis-(diphenylphosphino)ethane; abpt = 4-amino-3,5-bis-(pyridin-2-yl)-1,2,4-triazole and OTf = CF3SO3-) were synthesized and fully characterized by using elemental analysis, X-ray crystallography, magnetic measurements, variable-temperature IR spectroscopy and Mössbauer spectroscopy. It is worth mentioning that different from many mononuclear Fe(abpt)2X2 (X = NCS, NCSe, N(CN)2, C(CN)3, (NC)2CC(OCH3)C(CN)2, (NC)2CC(OC2H5)C(CN)2, C16SO3 and Cl) complexes with more than one polymorph, only one polycrystalline form was found in complexes 1-4. Moreover, the thermally induced SCO behaviors of these four complexes are independent of intermolecular π-π interactions. The electron-donating ability of the CCN-terminal fragment of CpMen(dppe)MIICN can be flexibly regulated by changing the methyl number (n) of the cyclopentadiene ligand or metal ion type (MII). These investigations indicate that the electron-donating ability of the CCN-terminal fragment has an influence on the SCO behavior of Fe1II. The spin transition temperature (T1/2) of the complexes decreases with the increase of the electron-donating ability of the fragment CpMen(dppe)MII. This study provides a new strategy to predict and precisely regulate the behaviors of SCO complexes.

Fe,Co co-implanted dendritic CeO2/CeF3 heterostructure@MXene nanocomposites as structurally stable electrocatalysts with ultralow overpotential for the alkaline oxygen evolution reaction.

Exploring low-cost, high-activity, and structurally stable nonprecious metal electrocatalysts for sluggish oxygen evolution reaction (OER) is paramount for water electrolysis. Herein, we successfully prepare a novel Fe,Co-CeO2/CeF3@MXene heterostructure with Fe-Co dual active sites and oxygen vacancies for alkaline OER using an energy-free consumption co-deposition method. Impressively, Fe,Co-CeO2/CeF3@MXene achieves an ultralow overpotential of 192 mV and a long-term stability of 110 h at 10 mA cm-2 without structural changes, thereby outperforming the commercial IrO2 (345 mV). In addition, Fe,Co-CeO2/CeF3@MXene exhibits much superior activity (271 mV) and durability to IrO2 (385 mV) in the real seawater OER. Wind- and solar energy-assisted water electrolysis devices show their promising prospects for sustainable green hydrogen production. Characterization techniques and theoretical calculations reveal that the Fe,Co co-implanted CeO2/CeF3 heterostructure effectively degrades the energy barrier of the OER and optimizes the adsorption strength of *OH, *O, and *OOH intermediates. It exhibits the dual coupling mechanism of the adsorbed evolution and lattice oxygen mechanisms, which synergistically improves the OER performance. This work provides a facile and efficacious strategy for synthesizing a new class of heterostructures to achieve significant enhancement in the activity and stability of OER catalysts.

Azo-Cyanamide Bridged Dinuclear Iron Complexes Exhibiting no Electronic Coupling but Moderate Magnetic Coupling between the two Iron Centers.

To investigate the effect of long-distance organic ligand on electronic coupling between metallic atoms, the mononuclear and dinuclear complexes [Cp(dppe)Fe(apc)] (1), [{Cp(dppe)Fe}2(µ-adpc)] (2), [{CpMe5(dppe)Fe}2(µ-adpc) (3) and their oxidized complexes [Cp(dppe)Fe(apc)][PF6] (1[PF6]), [{Cp(dppe)Fe}2(µ-adpc)][PF6] (2[PF6]2), [{CpMe5(dppe)Fe}2(µ-adpc)][PF6]2 (3[PF6]2) (Cp=1,3-cyclopentadiene, CpMe5=1,2,3,4,5-pentamethylcyclopentadiene, dppe=1,2-bis(diphenylphosphino)ethane), apc-=4-azo(phenylcyanamido)benzene and adpc2-=4,4'-azodi(phenylcyanamido)) were synthesized and characterized by cyclic voltammetry, UV-vis, single-crystal X-ray diffraction and Mössbauer spectra. Electrochemical measurements showed no electronic coupling between the two terminal Fe units, However, the investigation results of the magnetic properties of the two-electron oxidized complexes indicate the presence of moderate antiferromagnetic coupling across 18 Šdistance.

Syntheses, crystal structures and MMCT properties of diruthenium-based cyanido-bridged RuV/VI2-NC-RuII complexes.

The goal of this study was to investigate how the electron-donating capability around the lower valent metal ion and the electron-accepting capability of the higher valent metal ion influence metal to metal charge transfer (MMCT) properties in mixed-valence complexes. A series of trinuclear ruthenium complexes represented as [Ru2(ap-4-Me)3(CH3COO)NCRuCpMex(dppe)][PF6] (CpMex = polymethylcyclopentadienyl, x = 0, 1, and 5; and dppe = 1, 2-bis(diphenylphosphino)ethane, ap-4-Me = 2-anilino-4-methylpyridine) and their one-electron oxidized products were synthesized and fully characterized. The UV-vis-NIR spectra confirmed that as the electron donor character of the CpMex(dppe)RuCN fragment enhanced or the electron-accepting capability of the higher valent diruthenium cluster increased, the RuII → RuV2 or RuVI2 Ru2 MMCT bands shifted to lower energies, which was supported by TDDFT calculations.

Delayed Leaf Senescence Improves Radiation Use Efficiency and Explains Yield Advantage of Large Panicle-Type Hybrid Rice.

Super hybrid rice with predominantly large panicle types has achieved remarkable success in enhancing crop yield. However, when compared with multi-panicle-type varieties, the yield stability of large panicle-type varieties remains a challenge, and limited information is available on the comparative advantages of multi-panicle types. Consequently, a two-year experiment was conducted to evaluate the grain yield, biomass production, leaf area index (LAI), and radiation use efficiency (RUE) of large panicle-type hybrid rice (Y-liangyou 900, YLY900) and multi-panicle-type hybrid rice (C-liangyouhuazhan, CLYHZ) under three nitrogen (N) treatments (0, 180, 270 kg N ha-1). The effects of increased N fertilization were more pronounced in the large panicle-type varieties. YLY900 outperformed CLYHZ in terms of average yield (6% higher), and its yield advantage was attributed to higher spikelets per panicle (28%). Due to YLY900's RUE being 9% higher than CLYHZ, it results in a 12% greater accumulation of dry matter than CLYHZ. Furthermore, YLY900 exhibited significant improvements of 16%, 4%, and 14% in specific leaf weight, effective leaf area ratio, and LAI at 20 days after the heading stage (20DAH), respectively, compared with CLYHZ. YLY900 also demonstrated a stronger correlation between rice yield and intercepted photosynthetically active radiation (IPAR) compared with CLYHZ, with R2 values of 0.80 and 0.66, respectively. These findings highlight the superior performance of YLY900, resulting from higher light interception percentage (IP) and IPAR values, which consequently led to enhanced RUE and grain yield. Our research reveals that delayed leaf senescence by increasing LAI at the post-heading stage for large panicle-type hybrid rice, thereby contributing to greater RUE, led to higher biomass production and grain yield.

Different delocalized ranges in mixed valence cyanido-metal-bridged Fe-Ru-Fe complexes controlled by terminal ligand substitution modification.

In order to investigate the properties of metal to metal charge transfer (MMCT) influenced by the relative energy level between the bridging unit and the terminal unit, two groups of heterotrimetallic cyanido-metal-bridged complexes, trans-[Cp(dppe)Fe-CN-Ru(MeOpy)4-NC-Fe(dppe)Cp][X]n (1[X]n; n = 2, 3, or 4; X = PF6 or BF4) (Cp = cyclopentadiene, dppe = 1,2-bis(diphenylphosphino)ethane, MeOpy = 4-methoxypyridine) and [Cp*(dppe)Fe-CN-Ru(MeOpy)4-NC-Fe(dppe)Cp*] [X]n (2[X]n; Cp* = 1,2,3,4,5-pentamethylcyclopentadiene; n = 2, 3, or 4; X = PF6 or BF4) were synthesized and fully characterized. The crystallography data suggest different oxidation sites in the ground state for one-electron oxidation products 13+ and 23+, and the electrochemical and Mössbauer spectra suggest that in the one-electron oxidation compounds 13+, the charge is delocalized all along the trimetal backbone Fe-Ru-Fe, while in 23+, the charge is rather delocalized between the two metal parts Fe-Ru. Further oxidation of N3+ gives N4+ (N = 1 or 2), during which a spin transfer towards the terminal units is observed in both series.

Integration of MnO2 Nanosheets with Pd Nanoparticles for Efficient CO2 Electroreduction to Methanol in Membrane Electrode Assembly Electrolyzers.

It remains a challenge to design a catalyst with high selectivity at a large current density toward CO2 electrocatalytic reduction (CO2ER) to a single C1 liquid product of methanol. Here, we report the design of a catalyst by integrating MnO2 nanosheets with Pd nanoparticles to address this challenge, which can be implemented in membrane electrode assembly (MEA) electrolyzers for the conversion of CO2ER to methanol. Such a strategy modifies the electronic structure of the catalyst and provides additional active sites, favoring the formation of key reaction intermediates and their successive evolution into methanol. The optimal catalyst delivers a Faradaic efficiency of 77.6 ± 1.3% and a partial current density of 250.8 ± 4.3 mA cm-2 for methanol during CO2ER in an MEA electrolyzer by coupling anodic oxygen evolution reaction with a full-cell energy efficiency achieving 29.1 ± 1.2% at 3.2 V. This work opens a new avenue to the control of C1 intermediates for CO2ER to methanol with high selectivity and activity in an MEA electrolyzer.

Two new baccharane triterpenes isolated from Rhus chinensis.

Two new baccharane triterpenes, 17,24-epoxy-23-en-baccharan-3-one (1) and 17,24(S)-epoxy-25-en-21-hydroxy-baccharan-3-one (2) were isolated from Rhus chinensis Mill. The structures were established on the basis of UV, IR, HR-ESI-MS, 1D and 2D NMR spectroscopy and X-ray diffraction analysis.

Ag+ -Doped InSe Nanosheets for Membrane Electrode Assembly Electrolyzer toward Large-Current Electroreduction of CO2 to Ethanol.

It is an appealing approach to CO2 utilization through CO2 electroreduction (CO2 ER) to ethanol at high current density; however, the commonly used Cu-based catalysts cannot sustain large current during CO2 ER despite their capability for ethanol production. Herein, we report that Ag+ -doped InSe nanosheets with Se vacancies can address this grand challenge in a membrane electrode assembly (MEA) electrolyzer. As revealed by our experimental characterization and theoretical calculation, the Ag+ doping, which can tailor the electronic structure of InSe while diversifying catalytically active sites, enables the formation of key reaction intermediates and their sequential evolution into ethanol. More importantly, such a material can well work for large-current conditions in MEA electrolyzers with In2+ species stabilized via electron transfer from Ag to Se. Remarkably, in an MEA electrolyzer by coupling cathodic CO2 ER with anodic oxygen evolution reaction (OER), the optimal catalyst exhibits an ethanol Faradaic efficiency of 68.7 % and a partial current density of 186.6 mA cm-2 on the cathode with a full-cell ethanol energy efficiency of 26.1 % at 3.0 V. This work opens an avenue for large-current production of ethanol from CO2 with high selectivity and energy efficiency by rationally designing electrocatalysts.

Metal-Metal Charge Transfer Properties of a Series of Trinuclear Fe2 Ru and Corresponding Pentanuclear Fe2 Ru2 Ag Cyanido-Bridged Complexes.

A series of trimetallic cyanidometal-bridged compounds [Men Cp(dppe)FeII -(µ-NC)-RuII (MeOpy)4 -(µ-CN)-FeII (dppe)CpMen ] - [PF6 ]2 (N[PF6 ]2 , n=0, N =1; n=1, N=2; n=3, N=3; Cp=cyclopentadiene, dppe=1,2-bis(diphenylphosphino)ethane, MeOpy=4-methoxypyridine) and their one- and two-electron oxidized compounds N3+ and N4+ were synthesized and characterized. Meanwhile, a series of corresponding linear cyanido-bridged pentanuclear compounds [Men Cp(dppe)FeIII -(µ-NC)-RuII (MeOpy)4 -(µ-NC)-AgI -(µ-CN)-RuII (MeOpy)4 -(µ-CN)-FeIII (dppe)CpMen ][BF4 ]5 (M[BF4 ]5 , n=0, M=4; n=1, M=5; n=3, M=6) were also obtained and well characterized. The investigations suggest that in the trinuclear system there exists remote interaction between the two Fe centers, but no significant interactions exist across the central silver unit between the metals on the two sides of the silver center in the pentanuclear system. In both the trinuclear N4+ and the pentanuclear M5+ complexes, there exists the neighboring RuII →FeIII MM'CT transitions, and the MM'CT energy in the corresponding trinuclear system is higher than those in the pentanuclear system in which no remote metal-metal interaction occurs. Meanwhile, as the substituted methyl groups on the cyclopentadiene increases, the redox potential of the ruthenium in the trinuclear N4+ series increases, but that in the pentanuclear M5+ complexes decreases.

Al-Doped Core-Shell-Structured Ni@Mesoporous Silica for Highly Selective Hydrodeoxygenation of Lignin-Derived Aldehydes.

Selective deoxygenation of chemicals using non-noble metal-based catalysts poses a significant challenge toward upgrading biomass-derived oxygenates into advanced fuels and fine chemicals. Herein, we report a bifunctional core-shell catalyst (Ni@Al3-mSiO2) consisting of Ni nanoparticles closely encapsulated by the Al-doped mesoporous silica shell that achieves 100% vanillin conversion and >99% yield of 2-methoxy-4-methylphenol under 1 MPa H2 at 130 °C in water. Due to the unique mesoporous core-shell structure, no significant decrease in catalytic activity was observed after 10 recycles. Furthermore, incorporating Al atoms into the silica shell significantly increased the number of acidic sites. Density functional theory calculations reveal the reaction pathway of the vanillin hydrodeoxygenation process and uncover the intrinsic influence of the Al sites. This work not only provides an efficient and cost-effective bifunctional hydrodeoxygenation catalyst but also offers a new synthetic protocol to rationally design promising non-noble metal catalysts for biomass valorization or other widespread applications.

Low-Pt Octahedral PtCuCo Nanoalloys: "One Stone, Four Birds" for Oxygen Reduction and Methanol Oxidation Reactions.

To find a low-Pt electrocatalyst that is functionally integrated and superior to the state-of-the-art single-Pt electrocatalyst is expectedly a challenge. We have in this study found that the reactivity of the oxygen reduction reaction (ORR) and the methanol oxidation reaction (MOR), in both acidic and alkaline electrolytes (viz., four half-cell reactions), can be modified and greatly enhanced by the electronic and/or synergistic effects of a low-Pt octahedral PtCuCo alloy. For the ORR, the mass activity (MA) of Pt0.23Cu0.64Co0.13/C in an acidic or alkaline electrolyte was 14.3 or 10.7 times that of the commercial Pt/C. For the MOR, the MA of Pt0.23Cu0.64Co0.13/C in an acidic or alkaline electrolyte was 7.2 or 3.4 times that of the commercial Pt/C. In addition, Pt0.23Cu0.64Co0.13/C exhibited an increased durability and CO tolerance, as compared with the commercial Pt/C. Density functional theory calculations demonstrated that the PtCuCo(111) surface can effectively optimize the O* binding energy. This work has successfully shown an example of how both acidic and alkaline ORR and MOR activities can be significantly synchronously enhanced.

Electronic Transition and Magnetic Coupling Regulation in Trimetallic Complexes Featuring a New Bridging Ligand Obtained by Oxidative Addition.

A series of trimetallic complexes [FeIII(µ-L)(py)]2MII(py)n (n = 2, MII = MnII, 1; FeII, 2; CoII, 3; ZnII, 4; n = 3, MII = CdII, 5) with a new bridging ligand L4- (deprotonated 1,2-N1,N2-bis(2-mercaptoanil) oxalimidic acid) were synthesized and fully characterized by elemental analysis, single-crystal X-ray crystallography, IR, and Mössbauer spectra. Interestingly, the bridging ligand was obtained by oxidative addition of the (gma•)3- ligand from the mononuclear precursor Fe(gma)py (gma = glyoxal-bis(2-mercaptoanil)). In the obtained complexes, the bridging ligand L4- coordinates to the terminal FeIII ions (intermediate-spin with SFe = 3/2) by the N, S atoms, and coordinate to the central metal MII ion by the four O atoms. The resonance structure of the bridging ligand can be described as the two 4π-electron delocalized systems connected by one single-bond (C1-C2), which is different from the electronic structure of the precursor Fe(gma)py. Remarkably, the magnetic coupling interaction can be regulated through the central metal. The ferromagnetic coupling constant J gradually decreases as MII changes from FeII to CoII and MnII, while the paramagnetic behaviors are presented when MII = ZnII and CdII, confirmed by the magnetic susceptibility measurements and further supported by using the PHI program. Furthermore, the bridging ligand to the terminal FeIII charge transfer (LMCT) transitions emerged in all complexes but the central FeII to terminal FeIII charge transfer (MMCT) only presented in complex 2, strongly supported by the UV/vis-NIR electronic spectra and TDDFT calculations.

Triphenylamine-Functionalized Coordination Cage as a Supramolecular Fluorescence Sensor for Sequential Detection of Aluminum Ions and Nitrofurantoin.

Coordination cages with a well-defined nanocavity are a class of promising supramolecular materials for molecular recognition and sensing. However, their applications in sequential sensing of multiple types of pollutants are highly desirable yet extremely limiting and challenging. Herein, we demonstrate a convenient strategy to develop a supramolecular fluorescence sensor for sequentially detecting environmental pollutants of aluminum ions and nitrofurantoin. A coordination cage (Ni-NTB), adopting an octahedral structure with triphenylamine chromophores occupying on the faces, is weakly emissive in solution due to the intramolecular rotations of the phenyl rings. Ni-NTB exhibits sensitive and selective fluorescence "off-on-off" processes during consecutive sensing of Al3+ and nitrofurantoin, an antibacterial drug. These sequential detection processes are highly interference-tolerant and visually observable with the naked eye. Mechanism studies reveal that the fluorescence switch is controllable by tuning the degree of intramolecular rotations of the phenyl rings and the pathway of intermolecular charge transfer, which is associated with the host-guest interaction. Moreover, the fabrication of Ni-NTB on test strips enabled a quick naked-eye sequential sensing of Al3+ and nitrofurantoin in seconds. Hence, this novel supramolecular fluorescence "off-on-off" sensing platform provides a new approach to developing supramolecular functional materials for monitoring environmental pollution.

Subnanoscale Dual-Site Pd-Pt Layers Make PdPtCu Nanocrystals CO-Tolerant Bipolar Effective Electrocatalysts for Alcohol Fuel Cell Devices.

Finding a high-performance low-Pt bipolar electrocatalyst in actual direct alcohol fuel cells (DAFCs) remains challenging and desirable. Here, we developed a crystalline PdPtCu@amorphous subnanometer Pd-Pt "dual site" layer core-shell structure for the oxygen reduction reaction (ORR) and alcohol (methanol, ethylene glycol, glycerol, and their mixtures) oxidation reaction (AOR) in an alkaline electrolyte (denoted D-PdPtCu). The prepared D-PdPtCu/C achieved a direct 4-electron ORR pathway, a full oxidation pathway for AOR, and high CO tolerance. The ORR mass activity (MA) of D-PdPtCu/C delivered a 52.8- or 59.3-fold increase over commercial Pt/C or Pd/C, respectively, and no activity loss after 20000 cycles. The D-PdPtCu/C also exhibited much higher AOR MA and stability than Pt/C or Pd/C. Density functional theory revealed the intrinsic nature of a subnanometer Pd-Pt "dual site" surface for ORR and AOR activity enhancement. The D-PdPtCu/C as an effective bipolar electrocatalyst yielded higher peak power densities than commercial Pt/C in actual DAFCs.

Four sesquiterpenes isolated from Taraxacum mongolicum.

One new sesquiterpene, (6S,7R,11S)-13-carboxy-1(10)-en-dihydroartemisinic acid (1), together with three known sesquiterpenes, ainsliaea acid B (2), mongolicumin B (3), and 11ß,13-dihydroxydeacetylmatricarin (4) were isolated from Taraxacum mongolicum Hand.-Mazz. The structures were established on the basis of UV, IR, HR-ESI-MS, 1D and 2D NMR spectroscopy, ECD spectroscopy, and X-ray diffraction analysis. Compound 1 was found to have potential anti-inflammatory activity and could reduce LPS-induced NO levels in murine macrophage, with inhibitory rate of 37%.

Coexistence of Three Different Spin States in a Cyanido-Bridged Trinuclear Iron(III) Complex with an Unusual FeIII to Ligand Charge Transfer.

We report a trinuclear iron(III) cyanido-bridged complex trans-[CpMe3 FeIII (dppe)(CN)]2 [FeIII (LN4 )][PF6 ]4 (2[PF6 ]4 ) as the oxidation product of binuclear complex [CpMe3 (dppe)FeII CN-FeIII (LN4 )][PF6 ] (1[PF6 ]) (CpMe3 =1, 2, 4-trimethyl-1,3-cyclo-pentadienyl, dppe=1,2-bis(diphenylphosphino)ethane, LN4 =pentane-2,4-dione-bis(S-methylisothiosemicarbazonato). Complex 1[PF6 ] possesses an intermediate-spin five-coordinated FeIII (S=3/2) which couples antiferromagnetically to the π-radical ligand (L⋅N4 )2- and shows a LMCT (ligand to metal charge transfer) transition from (L⋅N4 )2- to FeIII and the FeII →FeIII MMCT transition. Upon oxidation of 1[PF6 ], (L⋅N4 )2- loses one electron to be the strong electron-attracting ligand (LOx N4 )- and the intermediate-spin five-coordinated FeIII (S=3/2) becomes a low-spin six-coordinated FeIII (S=1/2) in 2[PF6 ]4 . Also interestingly, 2[PF6 ]4 presents the coexistence of three different spin states (one S=3/2 and two S=1/2) and an uncommon FeIII →(LOx N4 )- MLCT transition, confirmed by the experimental results and supported by the TDDFT calculations.