The Nitrogenase FeMo‐Cofactor Precursor Formed by NifB Protein: A Diamagnetic Cluster Containing Eight Iron Atoms

The biological activation of N₂ occurs at the FeMo‐cofactor, a 7Fe–9S–Mo–C–homocitrate cluster. FeMo‐cofactor formation involves assembly of a Fe_6–8–S_X–C core precursor, NifB‐co, which occurs on the NifB protein. Characterization of NifB‐co in NifB is complicated by the dynamic nature of the assembly process and the presence of a permanent [4Fe–4S] cluster associated with the radical SAM chemistry for generating the central carbide. We have used the physiological carrier protein, NifX, which has been proposed to bind NifB‐co and deliver it to the NifEN protein, upon which FeMo‐cofactor assembly is ultimately completed. Preparation of NifX in a fully NifB‐co‐loaded form provided an opportunity for Mössbauer analysis of NifB‐co. The results indicate that NifB‐co is a diamagnetic (S=0) 8‐Fe cluster, containing two spectroscopically distinct Fe sites that appear in a 3:1 ratio. DFT analysis of the ⁵⁷Fe electric hyperfine interactions deduced from the Mössbauer analysis suggests that NifB‐co is either a 4Fe²⁺–4Fe³⁺ or 6Fe²⁺–2Fe³⁺ cluster having valence‐delocalized states.     

Enzymatic and catalytic reduction of dinitrogen to ammonia: Density functional theory characterization of alternative molybdenum active sites

We used density functional calculations to model dinitrogen reduction by a FeMo cofactor containing a central nitrogen atom and by a Mo‐based catalyst. Plausible intermediates, reaction pathways, and relative energetics in the enzymatic and catalytic reduction of N₂ to ammonia at a single Mo center are explored. Calculations indicate that the binding of N₂ to the Mo atom and the subsequent multiple proton–electron transfer to dinitrogen and its protonated species involved in the conversion of N₂ are feasible energetically. In the reduction of N₂ the Mo atom experiences a cycled oxidation state from Mo(IV) to Mo(VI) by nitrogenase and from Mo(III) to Mo(VI) by the molybdenum catalyst, respectively, tuning the gradual reduction of N₂. Such a wide range of oxidation states exhibited by the Mo center is crucial for the gradual reduction process via successive proton–electron transfer. Present results suggest that the Mo atom in the N‐centered FeMo cofactor is a likely alternative active site for dinitrogen binding and reduction under mild conditions once there is an empty site available at the Mo site. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005     

Synthesis and ring‐opening (co)polymerization of L‐lysine N‐carboxyanhydrides containing labile side‐chain protective groups

This contribution describes the synthesis and ring‐opening (co)polymerization of several L ‐lysine N‐carboxyanhydrides (NCAs) that contain labile protective groups at the ?‐NH₂ position. Four of the following L ‐lysine NCAs were investigated: N^?‐trifluoroacetyl‐L ‐lysine N‐carboxyanhydride, N^?‐(tert‐butoxycarbonyl)‐L ‐lysine N‐carboxyanhydride, N^?‐(9‐fluorenylmethoxycarbonyl)‐L ‐lysine N‐carboxyanhydride, and N^?‐(6‐nitroveratryloxycarbonyl)‐L ‐lysine N‐carboxyanhydride. In contrast to the harsh conditions that are required for acidolysis of benzyl carbamate moieties, which are usually used to protect the ?‐NH₂ position of L ‐lysine during NCA polymerization, the protective groups of the L ‐lysine NCAs presented here can be removed under mildly acidic or basic conditions or by photolysis. As a consequence, these monomers may allow access to novel peptide hybrid materials that cannot be prepared from ?‐benzyloxycarbonyl‐L ‐lysine N‐carboxyanhydride (Z‐Lys NCA) because of side reactions that accompany the removal of the Z groups. By copolymerization of these L ‐lysine NCAs with labile protective groups, either with each other or with γ‐benzyl‐L ‐glutamate N‐carboxyanhydride or Z‐Lys NCA, orthogonally side‐chain‐protected copolypeptides with number‐average degrees of polymerization ≤20 were obtained. Such copolypeptides, which contain different side‐chain protective groups that can be removed independently, are interesting for the synthesis of complex polypeptide architectures or can be used as scaffolds for the preparation of synthetic antigens or protein mimetics. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1167–1187, 2003     

Graphitic C3N4 Decorated with CoP Co‐catalyst: Enhanced and Stable Photocatalytic H2 Evolution Activity from Water under Visible‐light Irradiation

In this work, graphitic C₃N₄ decorated with a CoP co‐catalyst (g‐C₃N₄/CoP) is reported for photocatalytic H₂ evolution reaction based on two‐step hydrothermal and phosphidation method. The structure of g‐C₃N₄/CoP is well confirmed by XRD, FTIR, TEM, XPS, and UV/Vis diffuse reflection spectra techniques. When the weight percentage of CoP loading is 3.4 wt % (g‐C₃N₄/CoP‐3.4 %), the highest H₂ evolution amount of 8.4×10² μmol g⁻¹ is obtained, which is 1.1×10³ times than that over pure g‐C₃N₄. This value also is comparable with that of g‐C₃N₄ loaded by the same amount of Pt. In cycling experiments, g‐C₃N₄/CoP‐3.4 % shows a stable photocatalytic activity. In addition, g‐C₃N₄/CoP‐3.4 % is an efficient photocatalyst for H₂ evolution under irradiation with natural solar light. Based on comparative photoluminescence emission spectra, photoelectrochemical I –t curves, EIS Nyquist plots, and polarization curves between g‐C₃N₄/CoP‐3.4 % and pure g‐C₃N₄, it is concluded that the presence of the CoP co‐catalyst accelerates the separation and transfer of photogenerated electrons of g‐C₃N₄, thus resulting in improved photocatalytic activity in the H₂ evolution reaction.     

Controlled Incorporation of Nitrides into W‐Fe‐S Clusters

Incorporation of monatomic 2p ligands into the core of iron–sulfur clusters has been researched since the discovery of interstitial carbide in the FeMo cofactor of Mo‐dependent nitrogenase, but has proven to be a synthetic challenge. Herein, two distinct synthetic pathways are rationalized to install nitride ligands into targeted positions of W‐Fe‐S clusters, generating unprecedented nitride‐ligated iron–sulfur clusters, namely [(Tp*)₂W₂Fe₆(μ₄‐N)₂S₆L₄]^2? (Tp*=tris(3,5‐dimethyl‐1‐pyrazolyl)hydroborate(1?), L=Cl^? or Br^?). ⁵⁷Fe Mössbauer study discloses metal oxidation states of W^IV₂Fe^II₄Fe^III₂ with localized electron distribution, which is analogous to the mid‐valent iron centres of FeMo cofactor at resting state. Good agreement of Mössbauer data with the empirical linear relationship for Fe–S clusters indicates similar ligand behaviour of nitride and sulfide in such clusters, providing useful reference for reduced nitrogen in a nitrogenase‐like environment.     

Highly Dispersed and Small‐Sized Nickel(II) Hydroxide Co‐Catalyst Prepared by Photodeposition for Hydrogen Production

Photodeposition has been widely used as a mild and efficient synthetic method to deposit co‐catalysts. It is also worth studying how to synthesize non‐noble metal photocatalysts with uniform dispersion. Different synthetic conditions in photodeposition have a certain influence on particle size distribution and photocatalytic activity. Therefore, we designed experiments to prepare the inexpensive composite photocatalyst Ni(OH)₂/g‐C₃N₄ by photodeposition. The Ni(OH)₂ co‐catalysts disperse uniformly with particle sizes of about 10 nm. The photocatalytic hydrogen production rate of Ni(OH)₂/g‐C₃N₄ reached about 19 mmol g^?1 h^?1, with the Ni(OH)₂ deposition amount about 1.57 %. During 16 h stability testing, the rate of hydrogen production did not decrease significantly. The composite catalyst also revealed a good hydrogen production performance under sunlight. The Ni(OH)₂ co‐catalyst enhanced the separation ability of photogenerated carriers, which was proved by surface photovoltage and fluorescence analysis.     

An Efficient Catalyst System at Mild Reaction Conditions Containing Rare Earth Metal Complexes

An efficient rare earth metal complex‐catalyzed cycloaddition reaction of CO₂ with propylene oxide using Hdpza (di(2‐pyrazyl)amine) as a N‐donor ligand has been accomplished in good to excellent yields with high selectivity. The effects of different rare earth metal salts, ligands and reaction conditions were examined. Catalytic reaction tests demonstrated that the incorporation of ErCl₃ and Hdpza can significantly enhance the catalytic reactivity of the TBAB (nBu₄NBr, tetra‐n‐butyl ammonium bromide) towards cycloaddition reaction of CO₂ and propylene oxide that produce cyclic carbonates under mild conditions without any co‐solvent.     

Surface Functionalization of g‐C3N4: Molecular‐Level Design of Noble‐Metal‐Free Hydrogen Evolution Photocatalysts

A stable noble‐metal‐free hydrogen evolution photocatalyst based on graphite carbon nitride (g‐C₃N₄) was developed by a molecular‐level design strategy. Surface functionalization was successfully conducted to introduce a single nickel active site onto the surface of the semiconducting g‐C₃N₄. This catalyst family (with less than 0.1 wt % of Ni) has been found to produce hydrogen with a rate near to the value obtained by using 3 wt % platinum as co‐catalyst. This new catalyst also exhibits very good stability under hydrogen evolution conditions, without any evidence of deactivation after 24 h.     

A Zwitterionic Phosphonio‐1, 2, 4‐Diazaphospholide and Neutral 1, 2, 4‐Diazaphosphole — A Comparative Study of Molecular Structures and Co‐ordination Properties

The bis‐phosphonio‐1, 2, 4‐diazaphospholide salt ( 1 [Cl]) reacts with complex boron hydrides under selective extrusion of one PPh₃ moiety to give borane adducts of a novel zwitterionic phosphonio‐1, 2, 4‐diazaphospholide. Both the Et₃B adduct 2b and the free zwitterionic heterocycle 3 , which was liberated by further reaction of 2b with NEt₃, were characterized by spectroscopic data and 2b , as well, by a single crystal X‐ray diffraction study. The comparison of the structural data with those of a neutral 1, 2, 4‐diazaphosphole and a lithium‐1, 2, 4‐diazaphospholide which was formed by deprotonation of the parent 1, 2, 4‐diazaphosphole 4a discloses trends in endocyclic bonding distances which can be rationalized in terms of a charge dependent shift in the π‐electron distribution. First studies of the co‐ordination properties reveal for both 2b and 4a a marked preference to bind two M(CO)₅‐fragments (M = Cr, W) via the lone‐pairs of the phosphorus and one nitrogen atom; mononuclear complexes with P‐co‐ordinated heterocycles are formed as intermediates. A single crystal X‐ray diffraction study of the dinuclear complex [Cr₂(CO)₁₀(μ₂‐C₂H₃N₂P‐κP, κN)] ( 10a ) together with spectroscopic studies (including ¹⁸³W NMR studies of tungsten complexes) suggests that M→L back donation is more efficient for P‐ than for N‐bound metal fragments. No evidence for π‐co‐ordination of the 1, 2, 4‐diazaphosphole ring to a Cr(CO)₃ fragment was obtained.     

CO Adsorption on N2‐Precovered NaY Faujasite: A FTIR Analysis of the Resulting Adsorbed Species

To productively complete the information regarding the reversible adsorption of a gas mixture on the micropores of cationic zeolites, the adsorption of the two gases N₂ and CO on NaY faujasite is taken as a model case study. We analyze herein CO adsorption (77 K) on two distinct N₂‐precovered NaY sets (low and medium). We outline the continuous desorption of N₂ adducts during CO admittance to full N₂ desorption for the highest CO loadings. These features contrast with preceding results obtained for N₂ loading on CO‐precovered NaY. By comparing these results with the sole CO admission and combining both studies regarding the co‐adsorption sets, we demonstrate the influence of the basic strength of the two gases regarding the nature of the surface‐adsorbed species formed. We also propose and discuss a hypothesis regarding the formation of adsorbed mixed species having both N₂ and CO as ligands. These new findings strengthen the statistical response of IR signatures as a helpful proposal for analyzing adsorbed species and their assignments. This survey completes the molecular understanding of gas‐mixture adsorption that lacks experimental data to date.     

The Coordination Chemistry of Iron with the 1,4‐Bis(2‐pyridyl‐methyl)piperazine Ligand

The behaviour of Fe^II and Fe^III ions in combination with the potential ligand 1,4‐bis(2‐pyridyl‐methyl)piperazine (BPMP) under anhydrous conditions has been investigated. BPMP has been reacted with FeCl₂, FeCl₃ and [Fe(OTf)₂(MeCN)₂]. This led to the isolation of four new complexes, which were fully characterized and structurally investigated by single crystal X‐ray diffraction. It turned out that in the presence of chloride co‐ligands Fe^III favours the tetradentate coordination mode of BPMP with the piperazine unit in a boat configuration, like for instance in [BPMP(Cl)Fe(μ‐O)FeCl₃] or [BPMP‐FeCl₂][FeCl₄], ( 1 ). However, the employment of FeCl₂ leads to the formation of a coordination polymer [BPMP‐FeCl₂]_n, ( 2 ), containing the piperazine ring in a chair configuration binding to two iron centres each. 2 can only be dissolved in very polar solvents like dmf which is capable of breaking up the polymeric structure under formation of [Cl₂(dmf)Fe(μ‐BPMP‐1κ²N,N:2κ²N,N))Fe(dmf)Cl₂]·2 dmf, ( 3 ). In contrast, using [Fe(OTf)₂(MeCN)₂] instead of FeCl₂ as the starting material leads to a mononuclear Fe^II complex with BPMP bound in the desirable tetradentate fashion: [BPMP‐Fe(OTf)₂], ( 4 ). Unlike other complexes with tetradentate N/py ligands the two residual ligands in 4 are bound almost trans to each other with the potential to adopt a cis orientation under oxidising conditions, and it will be interesting to exploit its catalytic properties in future.     

Synthesis and characterization of fluorene‐based oligomers and polymers incorporating N‐arylphenothiazine‐S,S‐dioxide units

A series of 3,7‐bis(9,9‐di‐n‐hexylfluoren‐2‐yl)‐N‐arylphenothiazine‐S,S‐dioxide trimers and (9,9‐di‐n‐octylfluorene‐2,7‐diyl‐co‐N‐arylphenothiazine‐S,S‐dioxide) co‐polymers, with varying ratios of phenothiazine‐S,S‐dioxide units, have been prepared in good yields by palladium‐catalyzed cross‐coupling reactions. The materials are deep blue emitters and show no solvatochromism or evidence for an intramolecular charge‐transfer state. The photoluminescence quantum yields of the trimers are ?_PL 15–30% in solution and 14–25% in films. The polymers demonstrated very high values in solution (?_PL 74–84%) and ?_PL values in films of 28–47%. The estimated HOMO energy levels are between ?5.64 and ?5.62 eV for the polymers with 15% incorporation of the phenothiazine‐S,S‐dioxide units. An analogous N‐arylphenothiazine co‐polymer shows significantly red shifted absorption and emission. Solution electrochemical data and density functional theory calculations are also presented. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

A new cardo bisphenol monomer containing pendant azido group and the resulting aromatic polyesters

Expanding on our strategy to synthesize aromatic step‐growth polymers containing pendant clickable azido groups via functional monomer approach, we have now designed and synthesized a new cardo bisphenol, viz., 2‐(2‐azidoethyl)‐3, 3‐bis(4‐hydroxyphenyl) isoindolin‐1‐one (PPH‐N₃). PPH‐N₃ was conveniently synthesized starting from commercially available phenolphthalein by a three‐step route in an overall yield of 65% using simple organic transformations. Aromatic (co)polyesters bearing pendant azido groups were synthesized by low‐temperature solution polycondensation of PPH‐N₃ or different molar ratios of PPH‐N₃ and bisphenol‐A (BPA) with aromatic diacid chlorides in dry dichloromethane in the presence of triethylamine (TEA) as a base. The formation of medium to reasonably high‐molecular‐weight (co)polyesters was evidenced from intrinsic viscosity and number‐average molecular‐weight measurements that were in the range 0.52–0.85 dL/g and 16,700–28,200, respectively. Tough, transparent, and flexible films could be cast from chloroform solutions of these (co)polyesters. (Co)polyesters were characterized using FTIR, ¹H NMR, ¹³C NMR spectroscopy, XRD, and TGA. The thermal curing reaction of (co)polyesters involving decomposition of azido groups was studied by DSC analysis. The chemical modification of a representative copolyester containing pendant azido groups was carried out quantitatively using catalyst‐free azide‐maleimide cycloaddition reaction with two maleimides, namely, N‐methylmaleimide and N‐hexylmaleimide. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1516–1526     

Efficient Solar‐Driven Nitrogen Fixation over Carbon–Tungstic‐Acid Hybrids

Ammonia synthesis under mild conditions is of supreme interest. Photocatalytic nitrogen fixation with water at room temperature and atmospheric pressure is an intriguing strategy. However, the efficiency of this method has been far from satisfied for industrialization, mainly due to the sluggish cleavage of the N≡N bond. Herein, we report a carbon–tungstic‐acid (WO₃ ? H₂O) hybrid for the co‐optimization of N₂ activation as well as subsequent photoinduced protonation. Efficient ammonia evolution reached 205 μmol g^?1 h^?1 over this hybrid under simulated sunlight. Nitrogen temperature‐programmed desorption revealed the decisive role of carbon in N₂ adsorption. Photoactive WO₃ ? H₂O guaranteed the supply of electrons and protons for subsequent protonation. The universality of carbon modification for enhancing the N₂ reduction was further verified over various photocatalysts, shedding light on future materials design for ideal solar energy utilization.     

Exploring the conformational space of cobalt(III)–salen catalyst for CO2/epoxide copolymerization: Effect of quaternary ammonium salts on preference of alternative isomers

Model catalysts for CO₂/epoxide copolymerization based on Co(III) complexes were studied, with focus on the preference of their alternative isomers, cisβ vs. trans. The systems range from model structures without the co‐catalyst, as derived from crystallographic data, to complex models with two  (CH₂)₄N⁺R₃ co‐catalyst chains (R = Me, Bu) grafted onto a Co(III)–salcy core. To explore the conformational space of the latter complexes, a computational protocol was developed, combining a systematic model‐building approach with static and molecular dynamics calculations, and multilevel energy assessment (PM7 and DFT). Results demonstrate an influence of the co‐catalyst on the relative stability of the isomers. The cisβ isomer is preferred for complexes without N⁺‐chains and the cisβ ↔ trans isomerization is feasible. Five‐coordinate species and open‐shell electronic configurations are energetically disfavored. The cisβ preference decreases with the introduction and enlargement of  (CH₂)₄N⁺R₃: both isomers can be populated for R = Me, while the trans isomer is visibly preferred for R = Bu. © 2018 Wiley Periodicals, Inc.     

N‐Benzoyl‐N′,N′‐dibutylselenourea and its palladium(II) complex

The crystal and molecular structures of N‐benzoyl‐N′,N′‐dibutylselenourea (HL), C₁₆H₂₄N₂OSe, and the corresponding complex bis(N‐benzoyl‐N′,N′‐dibutylselenoureato‐κ²Se,O)palladium(II), [Pd(C₁₆H₂₃N₂OSe)₂], are reported. The selenourea molecule is characterized by intermolecular hydrogen bonds between the selenoamidic H atom and the Se atom of a neighbouring molecule forming a dimer, presumably as a consequence of resonance‐assisted hydrogen bonding or π‐bonding co‐operativity. A second dimeric hydrogen bond is also described. In the palladium complex, the typical square‐planar coordination characteristic of such ligands results in a cis‐[Pd(L‐Se,O)₂] complex.     

High‐Pressure Synthesis of Metal–Inorganic Frameworks Hf4N20⋅N2, WN8⋅N2, and Os5N28⋅3 N2 with Polymeric Nitrogen Linkers

Polynitrides are intrinsically thermodynamically unstable at ambient conditions and require peculiar synthetic approaches. Now, a one‐step synthesis of metal–inorganic frameworks Hf₄N₂₀?N₂, WN₈?N₂, and Os₅N₂₈?3 N₂ via direct reactions between elements in a diamond anvil cell at pressures exceeding 100 GPa is reported. The porous frameworks (Hf₄N₂₀, WN₈, and Os₅N₂₈) are built from transition‐metal atoms linked either by polymeric polydiazenediyl (polyacetylene‐like) nitrogen chains or through dinitrogen units. Triply bound dinitrogen molecules occupy channels of these frameworks. Owing to conjugated polydiazenediyl chains, these compounds exhibit metallic properties. The high‐pressure reaction between Hf and N₂ also leads to a non‐centrosymmetric polynitride Hf₂N₁₁ that features double‐helix catena‐poly[tetraz‐1‐ene‐1,4‐diyl] nitrogen chains [?N?N?N=N?]_∞.     

Photocatalytic Reduction of Carbon Dioxide by Hydrous Hydrazine over Au–Cu Alloy Nanoparticles Supported on SrTiO3/TiO2 Coaxial Nanotube Arrays

Efficient photocatalytic conversion of CO₂ into CO and hydrocarbons by hydrous hydrazine (N₂H₄?H₂O) is achieved on SrTiO₃/TiO₂ coaxial nanotube arrays loaded with Au–Cu bimetallic alloy nanoparticles. The synergetic catalytic effect by the Au–Cu alloy nanoparticles and the fast electron‐transfer in SrTiO₃/TiO₂ coaxial nanoarchitecture are the main reasons for the efficiency, while N₂H₄?H₂O as the H source and electron donor provides a reducing atmosphere to protect the surface Cu atoms from oxidation, therefore maintaining the alloying effect which is the basis for the high photocatalytic activity and stability. This approach opens a feasible route to enhance the photocatalytic efficiency, which also benefits the development of photocatalysts and co‐catalysts.     

Covalent‐assisted supramolecular synthesis: the effect of hydrogen bonding in cocrystals of 4‐tert‐butylbenzoic acid with isoniazid and its derivatized forms

A series of cocrystals of isoniazid and four of its derivatives have been produced with the cocrystal former 4‐tert‐butylbenzoic acid via a one‐pot covalent and supramolecular synthesis, namely 4‐tert‐butylbenzoic acid–isoniazid, C₆H₇N₃O·C₁₁H₁₄O₂, 4‐tert‐butylbenzoic acid–N′‐(propan‐2‐ylidene)isonicotinohydrazide, C₉H₁₁N₃O·C₁₁H₁₄O₂, 4‐tert‐butylbenzoic acid–N′‐(butan‐2‐ylidene)isonicotinohydrazide, C₁₀H₁₃N₃O·C₁₁H₁₄O₂, 4‐tert‐butylbenzoic acid–N′‐(diphenylmethylidene)isonicotinohydrazide, C₁₉H₁₅N₃O·C₁₁H₁₄O₂, and 4‐tert‐butylbenzoic acid–N′‐(4‐hydroxy‐4‐methylpentan‐2‐ylidene)isonicotinohydrazide, C₁₂H₁₇N₃O₂·C₁₁H₁₄O₂. The co‐former falls under the classification of a `generally regarded as safe' compound. The four derivatizing ketones used are propan‐2‐one, butan‐2‐one, benzophenone and 3‐hydroxy‐3‐methylbutan‐2‐one. Hydrogen bonds involving the carboxylic acid occur consistently with the pyridine ring N atom of the isoniazid and all of its derivatives. The remaining hydrogen‐bonding sites on the isoniazid backbone vary based on the steric influences of the derivative group. These are contrasted in each of the molecular systems.     

Facile Dinitrogen and Dioxygen Cleavage by a Uranium(III) Complex: Cooperativity Between the Non‐Innocent Ligand and the Uranium Center

Activation of dinitrogen (N₂, 78 %) and dioxygen (O₂, 21 %) has fascinated chemists and biochemists for decades. The industrial conversion of N₂ into ammonia requires extremely high temperatures and pressures. Herein we report the first example of N₂ and O₂ cleavage by a uranium complex, [N(CH₂CH₂NPⁱPr₂)₃U]₂(TMEDA), under ambient conditions without an external reducing agent. The N₂ triple bond breaking implies a U^III–P^III six‐electron reduction. The hydrolysis of the N₂ reduction product allows the formation of ammonia or nitrogen‐containing organic compounds. The interaction between U^III and P^III in this molecule allows an eight‐electron reduction of two O₂ molecules. This study establishes that the combination of uranium and a low‐valent nonmetal is a promising strategy to achieve a full N₂ and O₂ cleavage under ambient conditions, which may aid the design of new systems for small molecules activation.