In the version of this article initially published,the supporting information was incorrectly uploaded,which was a mistake not attributable to the authors.The correct version has now been replaced.
The direct transformation of dinitrogen(N_(2)) into nitrogen-containing organic compounds holds substantial importance.In this work,we report a titanium-promoted method for the conversion of N_(2) to N-methylimides.In...The direct transformation of dinitrogen(N_(2)) into nitrogen-containing organic compounds holds substantial importance.In this work,we report a titanium-promoted method for the conversion of N_(2) to N-methylimides.Initially,the N_(2)-bridging end-on dititanium side-on dipotassium complex[{(Tren^(TMS))Ti}_(2)(μ-η^(1):η^(1):η^(2):η^(2)-N_(2)K_(2))] underwent simultaneous disproportionation and N-methylation reactions in the presence of methyl trifluoromethanesulfonate(Me OTf),yielding [{(N^(Me,TMS)NN^(TMS)_(2))Ti}(μ-NMe)]_(2) with complete cleavage of the N≡N bond.The nucleophilicity of the N-methylated intermediate allowed it to react with electrophilic reagents such as trimethylchlorosilane(TMSCl) to form heptamethyldisilazane,or with acyl chlorides to generate N-methylimides.Moreover,nitrogen-15(^(15)N) labeled experiments provided a novel approach to synthesizing ^(15)N-labeled methylimides.展开更多
A nonsymmetrical PNN pincer ligand[6-(^(t)Bu_(2)PNH)C_(5)H_(4)N-2-(3-Mes)C_(3)H_(2)N_(2)]and its corresponding cobalt-N_(2)complex were synthesized and characterized.By the stoichiometric reaction of the PNN ligand li...A nonsymmetrical PNN pincer ligand[6-(^(t)Bu_(2)PNH)C_(5)H_(4)N-2-(3-Mes)C_(3)H_(2)N_(2)]and its corresponding cobalt-N_(2)complex were synthesized and characterized.By the stoichiometric reaction of the PNN ligand lithium salt with CoCl_(2),the complex 3,(PNN)CoCl,was obtained.Then,reduction of 3 with NaBHEt3under a dinitrogen atmosphere yielded complex 5,(PNN)Co(Ⅰ)(η^(1)-N_(2)).Single-crystal X-ray analysis,IR spectrum,and DFT calculations revealed that the dinitrogen in 5 was only weakly reduced by the cobalt center.The reactions of 5 with carbon monoxide and 2,6-dimethylphenyl isocyanide gave carbonyl and isocyanide complexes 6 and 7 with the release of N_(2),respectively.Furthermore,these cobalt complexes,especially complex 5,demonstrated the capacity to convert dinitrogen to N(TMS)_(3)with moderate efficiency.展开更多
A series of structurally well-defined iron-dinitrogen complexes(LFe-N2)bearing cyclopentadienylphosphine ligands(L)were synthesized and analyzed by single-crystal X-ray structural analysis,IR/Raman spectra,magnetometr...A series of structurally well-defined iron-dinitrogen complexes(LFe-N2)bearing cyclopentadienylphosphine ligands(L)were synthesized and analyzed by single-crystal X-ray structural analysis,IR/Raman spectra,magnetometry,Mössbauer spectroscopy,and elemental analysis.The conversion relationship and the change of the spin states among the iron complexes with different valences were studied in detail.展开更多
Iron sites in both nitrogenase enzymes and chemical catalysts for N_(2) fixation are typically at constrained distances and angles.Herein,we report a one-electron reduction reaction realized by constrained diiron dini...Iron sites in both nitrogenase enzymes and chemical catalysts for N_(2) fixation are typically at constrained distances and angles.Herein,we report a one-electron reduction reaction realized by constrained diiron dinitrogen cores.Using the semicircular bis(β-diketiminate)ligand,a series of diiron dinitrogen complexes were synthesized,in which the N_(2) groups were allowed to bind with Fe-Ct_(N2)-Fe angles ranging from 154°to 158°(Ct_(N2)=centroid of N_(2)).One-electron reduction of complex 2a[LFe(μ-N_(2))Fe(Et_(2)O)]gave dimer product 3a[LFe(μ-N_(2))FeK]_(2)(μ-N_(2))or monomer 3b[LFe(μ-N_(2))Fe(DMAP)K].Based on superconducting quantum interference device measurements and density functional theory calculations,2a,3a,and 3b exhibited ground spin states of S=3,S=5,and S=5/2,respectively.In addition,complex 3 underwent N_(2)derivatization via a silylation pathway followed by an acidic cleavage to yield N_(2)H_(4)as the product.展开更多
The conversion of N_(2)to NH_(3)holds great importance due to the essential role of NH_(3)in fertilizer production,energy storage and the synthesis of key industrial chemicals.Development of novel methods for N_(2)tra...The conversion of N_(2)to NH_(3)holds great importance due to the essential role of NH_(3)in fertilizer production,energy storage and the synthesis of key industrial chemicals.Development of novel methods for N_(2)transformation is a worthwhile goal and researchers have turned their attention to electrochemical N_(2)reduction as a potentially sustainable solution.The development of molecular electrocatalysts has gained considerable momentum over the last decades,and this review focuses on the advances and challenges in the field of molecular electrochemical nitrogen fixation and aims to inspire further research into the realm of nitrogen fixation chemistry from an electrochemical perspective.展开更多
文摘In the version of this article initially published,the supporting information was incorrectly uploaded,which was a mistake not attributable to the authors.The correct version has now been replaced.
基金Financial supports from the National Natural Science Foundation of China (Nos.22025109,22371283)the National Key R&D Program of China (No.2023YFA1507902)+1 种基金CAS Project for Young Scientists in Basic Research (No.YSBR-050)the State Key Laboratory of Fine Chemicals,Dalian University of Technology (No.KF2102) are gratefully acknowledged。
文摘The direct transformation of dinitrogen(N_(2)) into nitrogen-containing organic compounds holds substantial importance.In this work,we report a titanium-promoted method for the conversion of N_(2) to N-methylimides.Initially,the N_(2)-bridging end-on dititanium side-on dipotassium complex[{(Tren^(TMS))Ti}_(2)(μ-η^(1):η^(1):η^(2):η^(2)-N_(2)K_(2))] underwent simultaneous disproportionation and N-methylation reactions in the presence of methyl trifluoromethanesulfonate(Me OTf),yielding [{(N^(Me,TMS)NN^(TMS)_(2))Ti}(μ-NMe)]_(2) with complete cleavage of the N≡N bond.The nucleophilicity of the N-methylated intermediate allowed it to react with electrophilic reagents such as trimethylchlorosilane(TMSCl) to form heptamethyldisilazane,or with acyl chlorides to generate N-methylimides.Moreover,nitrogen-15(^(15)N) labeled experiments provided a novel approach to synthesizing ^(15)N-labeled methylimides.
基金supported by the National Natural Science Foundation of China(Nos.21988101 and 22201013)Beijing Natural Science Foundation(No.2222008)supported by the High-performance Computing Platform of Peking University。
文摘A nonsymmetrical PNN pincer ligand[6-(^(t)Bu_(2)PNH)C_(5)H_(4)N-2-(3-Mes)C_(3)H_(2)N_(2)]and its corresponding cobalt-N_(2)complex were synthesized and characterized.By the stoichiometric reaction of the PNN ligand lithium salt with CoCl_(2),the complex 3,(PNN)CoCl,was obtained.Then,reduction of 3 with NaBHEt3under a dinitrogen atmosphere yielded complex 5,(PNN)Co(Ⅰ)(η^(1)-N_(2)).Single-crystal X-ray analysis,IR spectrum,and DFT calculations revealed that the dinitrogen in 5 was only weakly reduced by the cobalt center.The reactions of 5 with carbon monoxide and 2,6-dimethylphenyl isocyanide gave carbonyl and isocyanide complexes 6 and 7 with the release of N_(2),respectively.Furthermore,these cobalt complexes,especially complex 5,demonstrated the capacity to convert dinitrogen to N(TMS)_(3)with moderate efficiency.
基金supported by the Basic Science Center of Transformation Chemistry of Key Components of Air,National Natural Science Foundation of China(no.21988101).
文摘A series of structurally well-defined iron-dinitrogen complexes(LFe-N2)bearing cyclopentadienylphosphine ligands(L)were synthesized and analyzed by single-crystal X-ray structural analysis,IR/Raman spectra,magnetometry,Mössbauer spectroscopy,and elemental analysis.The conversion relationship and the change of the spin states among the iron complexes with different valences were studied in detail.
基金supported by National Natural Science Foundation of China(grant nos.21988101,22201013,92161204)China Postdoctoral Science Foundation(grant no.2020M670016)Beijing Natural Science Foundation(grant no.2222008).
文摘Iron sites in both nitrogenase enzymes and chemical catalysts for N_(2) fixation are typically at constrained distances and angles.Herein,we report a one-electron reduction reaction realized by constrained diiron dinitrogen cores.Using the semicircular bis(β-diketiminate)ligand,a series of diiron dinitrogen complexes were synthesized,in which the N_(2) groups were allowed to bind with Fe-Ct_(N2)-Fe angles ranging from 154°to 158°(Ct_(N2)=centroid of N_(2)).One-electron reduction of complex 2a[LFe(μ-N_(2))Fe(Et_(2)O)]gave dimer product 3a[LFe(μ-N_(2))FeK]_(2)(μ-N_(2))or monomer 3b[LFe(μ-N_(2))Fe(DMAP)K].Based on superconducting quantum interference device measurements and density functional theory calculations,2a,3a,and 3b exhibited ground spin states of S=3,S=5,and S=5/2,respectively.In addition,complex 3 underwent N_(2)derivatization via a silylation pathway followed by an acidic cleavage to yield N_(2)H_(4)as the product.
基金supported by the National Natural Science Foundation of China(21988101)。
文摘The conversion of N_(2)to NH_(3)holds great importance due to the essential role of NH_(3)in fertilizer production,energy storage and the synthesis of key industrial chemicals.Development of novel methods for N_(2)transformation is a worthwhile goal and researchers have turned their attention to electrochemical N_(2)reduction as a potentially sustainable solution.The development of molecular electrocatalysts has gained considerable momentum over the last decades,and this review focuses on the advances and challenges in the field of molecular electrochemical nitrogen fixation and aims to inspire further research into the realm of nitrogen fixation chemistry from an electrochemical perspective.
