Metal nitride cluster fullerenes(NCFs)are the most intensively studied endohedral fullerenes due to their exceptional structural variety.It is commonly understood that in NCFs,small clusters such as Sc_(3)N favor C_(8...Metal nitride cluster fullerenes(NCFs)are the most intensively studied endohedral fullerenes due to their exceptional structural variety.It is commonly understood that in NCFs,small clusters such as Sc_(3)N favor C_(82) and smaller cages,while large clusters(e.g.,Tb_(3)N and Gd_(3)N)favor C_(84)and larger cages.Endohedral structures with small nitride clusters encaged inside large carbon cages(e.g.,C_(84)and C_(86)).展开更多
Two missing cage isomers of C_(86)have been successfully stabilized by the encapsulation of the actinide ion Th.The two novel isomers of Th@C_(86)were synthesized using the arc-discharge method and characterized using...Two missing cage isomers of C_(86)have been successfully stabilized by the encapsulation of the actinide ion Th.The two novel isomers of Th@C_(86)were synthesized using the arc-discharge method and characterized using mass spectrometry,single-crystal X-ray crystallography,UV-vis-NIR spectroscopy and DFT calculations.The molecular structures of the two isomers were unambiguously assigned to Th@C_(2)(14)-C_(86)and Th@C_(3)(18)-C_(86)by crystallographic analysis.Both of these cage isomers of C_(86)have been predicted by computational studies but have never been experimentally confirmed until now.DFT computation reveals that both Th@C_(2)(14)-C_(86)and Th@C_(3)(18)-C_(86)present closed-shell electronic configurations with formally Th(Ⅳ),consistent with other previously reported Th based mono-metallofullerenes.Th@C_(2)(14)-C_(86)has emerged as the third lowest-energy isomer with significant predicted abundance at temperatures of fullerene formation.Th@C_(3)(18)-C_(86),on the other hand,represents an unexpected isomer with low thermodynamic stability,but significant abundance.Its formation was further rationalized as a kinetically trapped intermediate obtained from the lowest-energy and abundant Th@C_(2)(8)-C_(84),by a C_(2)insertion and a single Stone-Wales transformation.This study highlights the unique impact of actinides on the stabilization of fullerene cage isomers and also provides a more in-depth understanding into the stabilization mechanism of fullerene cage isomers.展开更多
Endohedral clusterfullerenes featuring encapsulation of metal clusters which transfer electrons to the outer fullerene cages show intriguing chemical properties different from empty fullerenes.Despite the extensive st...Endohedral clusterfullerenes featuring encapsulation of metal clusters which transfer electrons to the outer fullerene cages show intriguing chemical properties different from empty fullerenes.Despite the extensive studies on the chemical properties of empty fullerenes,especially C60,chemical functionalization of endohedral clusterfullerenes has been less explored,and previous reports are primarily limited to the well-known metal nitride and carbide clusterfullerenes.Herein,we report the first chemical functionalization of an emerging endohedral clusterfullerene μ_(3)-carbido clusterfullerene(abbreviated as μ_(3)-CCF)bearing central μ_(3)-C and Ti(Ⅳ)atoms forming a TivC double bond.A μ_(3)-CCF Dy_(2)TiC@I_(h)-C_(80) is synthesized,and its molecular structure is unambiguously determined by single-crystal X-ray diffraction for the first time.A photochemical cycloaddition reaction of Dy_(2)TiC@I_(h)-C_(80) with 2-adamantane-2,3-[3H]-diazirine(abbreviated as AdN_(2))is then carried out and only one monoadduct Dy_(2)TiC@I_(h)-C_(80)-Ad is obtained,indicating its high regioselectivity.According to the X-ray single-crystal structure of Dy_(2)TiC@Ih-C_(80)-Ad,the Ad moiety selectively attacks the[6,6]-bond(conjunction of two fused hexagons),which is adjacent to the Ti^(4+)ion instead of the two Dy^(3+)ions,affording a[6,6]-open addition pattern.Theoretical calculations unveil that the Ti(IV)ion plays a decisive role in high regioselectivity,and the formation of[6,6]-open Dy_(2)TiC@Ih-C_(80)-Ad is thermodynamically preferred.Contrarily,a similar reaction of a Ti(Ⅲ)-containing nitride clusterfullerene Y_(2)TiN@C_(80) with AdN_(2) is predicted to generate a different type of adduct with the addition sites adjacent to the Y^(3+)ion instead of the Ti^(3+)ion.This reveals the peculiarity of the chemical property of μ_(3)-CCF resulting from the existence of the non-rare earth metal Ti with a high oxidation state.展开更多
Metal−nitrogen double bonds have been commonly reported for conventional metal complexes,but the coexistence of both transition metal−nitrogen and lanthanide−nitrogen double bonds bridged by nitrogen within one compou...Metal−nitrogen double bonds have been commonly reported for conventional metal complexes,but the coexistence of both transition metal−nitrogen and lanthanide−nitrogen double bonds bridged by nitrogen within one compound has never been reported.Herein,by encapsulating a ternary transition metallanthanide heteronuclear dimetallic nitride into a C_(84) fullerene cage,transition metal−nitrogen and lanthanide-nitrogen double bonds are costabilized simultaneously within the as-formed clusterfullerene TiCeN@C_(1)(12)-C_(84),which is a representative heteronuclear dimetallic nitride clusterfullerene.Its molecular structure was unambiguously determined by single-crystal X-ray diffraction,revealing a slightly bentμ2-bridged nitride cluster with short Ti−N(1.761Å)and Ce−N(2.109Å)bond lengths,which are comparable to the corresponding Ti=N and Ce=N double bonds of reported metal complexes and consistent with the theoretically predicted values,confirming their coexistence within TiCeN@C_(1)(12)-C_(84).Density functional theory(DFT)calculations unveil three-center two-electron(3c-2e)bonds delocalized over the entire TiCeN cluster,which are responsible for costabilization of Ti�N and Ce�N double bonds.An electronic configuration of Ti4+Ce^(3+)N^(3−)@C_(84)^(4−)is proposed featuring an intramolecular four-electron transfer,drastically different from the analogous actinide dimetallic nitride clusterfullerene(U_(2))^(9+)N^(3−)@C_(80)^(6−)and trimetallic nitride clusterfullerene(Sc_(2))^(6+)Ti^(3+)^(N3−)@C_(80)^(6−),indicating the peculiarity of 4-fold negatively charged fullerene cage in stabilizing the heteronuclear dimetallic nitride cluster.展开更多
Comprehensive Summary The experimental investigation of rare-earth metal-metal bonds remains a challenge in the study of chemical bonds.Herein,we report the synthesis and characterization of a novel heteronuclear di-m...Comprehensive Summary The experimental investigation of rare-earth metal-metal bonds remains a challenge in the study of chemical bonds.Herein,we report the synthesis and characterization of a novel heteronuclear di-metallofullerene,ScY@C_(3v)(8)-C_(82),which contains a mixed rare-earth metal-metal bond.ScY@C_(3v)(8)-C_(82)was successfully synthesized by arc-discharging method and characterized by mass spectrometry,UV-vis-NIR spectroscopy and single-crystal X-ray diffraction crystallography,which unambiguously determined its molecular structure.Theoretical calculations were also performed to study the optimized positions of Sc-Y metallic dimer and the electronic configuration.The combined experimental and theoretical results confirmed that both Sc and Y atoms transfer two electrons to the C_(3v)(8)-C_(82)cage,i.e.,(ScY)4+@(C_(3v)(8)-C_(82))4-.In particular,a covalent Sc-Yσ2 bond,which has never been reported before,is proven to be formed inside C_(3v)(8)-C_(82)fullerene cage.This work presents a novel di-metallofullerene containing mixed rare-earth metal-metal bond and expands the understanding of metal-metal bonding of rare earth elements.展开更多
The precise identification of metal-metal bonds is critical to fully understanding the nature of metal-metal bonding but remains a fundamental challenge.Herein,we show the essence of Sc-Sc bonds with a metal-metal dis...The precise identification of metal-metal bonds is critical to fully understanding the nature of metal-metal bonding but remains a fundamental challenge.Herein,we show the essence of Sc-Sc bonds with a metal-metal distance of 3.36 Å in a C_(3v)(8)-C_(82) fullerene cage using crystallography.展开更多
基金National Science Foundation China(NSFC nos 52172051 and 91961109)the Natural Science Foundation of Jiangsu Province(BK20200041)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘Metal nitride cluster fullerenes(NCFs)are the most intensively studied endohedral fullerenes due to their exceptional structural variety.It is commonly understood that in NCFs,small clusters such as Sc_(3)N favor C_(82) and smaller cages,while large clusters(e.g.,Tb_(3)N and Gd_(3)N)favor C_(84)and larger cages.Endohedral structures with small nitride clusters encaged inside large carbon cages(e.g.,C_(84)and C_(86)).
基金National Natural Science Foundation of China(NSFC no.52172051)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)+1 种基金the Spanish Ministry of Science and Innovation(grant PID2020-112762GB-I00 funded by MCIN/AEI/10.13039/501100011033)the Generalitat de Catalunya(grant 2021SGR00110)and the URV for support.
文摘Two missing cage isomers of C_(86)have been successfully stabilized by the encapsulation of the actinide ion Th.The two novel isomers of Th@C_(86)were synthesized using the arc-discharge method and characterized using mass spectrometry,single-crystal X-ray crystallography,UV-vis-NIR spectroscopy and DFT calculations.The molecular structures of the two isomers were unambiguously assigned to Th@C_(2)(14)-C_(86)and Th@C_(3)(18)-C_(86)by crystallographic analysis.Both of these cage isomers of C_(86)have been predicted by computational studies but have never been experimentally confirmed until now.DFT computation reveals that both Th@C_(2)(14)-C_(86)and Th@C_(3)(18)-C_(86)present closed-shell electronic configurations with formally Th(Ⅳ),consistent with other previously reported Th based mono-metallofullerenes.Th@C_(2)(14)-C_(86)has emerged as the third lowest-energy isomer with significant predicted abundance at temperatures of fullerene formation.Th@C_(3)(18)-C_(86),on the other hand,represents an unexpected isomer with low thermodynamic stability,but significant abundance.Its formation was further rationalized as a kinetically trapped intermediate obtained from the lowest-energy and abundant Th@C_(2)(8)-C_(84),by a C_(2)insertion and a single Stone-Wales transformation.This study highlights the unique impact of actinides on the stabilization of fullerene cage isomers and also provides a more in-depth understanding into the stabilization mechanism of fullerene cage isomers.
基金partially supported by the National Key Research and Development Program of China(2017YFA0402800)the National Natural Science Foundation of China(52172053,51925206,21772189,U1932214,21773181,21573172 and 91961113).
文摘Endohedral clusterfullerenes featuring encapsulation of metal clusters which transfer electrons to the outer fullerene cages show intriguing chemical properties different from empty fullerenes.Despite the extensive studies on the chemical properties of empty fullerenes,especially C60,chemical functionalization of endohedral clusterfullerenes has been less explored,and previous reports are primarily limited to the well-known metal nitride and carbide clusterfullerenes.Herein,we report the first chemical functionalization of an emerging endohedral clusterfullerene μ_(3)-carbido clusterfullerene(abbreviated as μ_(3)-CCF)bearing central μ_(3)-C and Ti(Ⅳ)atoms forming a TivC double bond.A μ_(3)-CCF Dy_(2)TiC@I_(h)-C_(80) is synthesized,and its molecular structure is unambiguously determined by single-crystal X-ray diffraction for the first time.A photochemical cycloaddition reaction of Dy_(2)TiC@I_(h)-C_(80) with 2-adamantane-2,3-[3H]-diazirine(abbreviated as AdN_(2))is then carried out and only one monoadduct Dy_(2)TiC@I_(h)-C_(80)-Ad is obtained,indicating its high regioselectivity.According to the X-ray single-crystal structure of Dy_(2)TiC@Ih-C_(80)-Ad,the Ad moiety selectively attacks the[6,6]-bond(conjunction of two fused hexagons),which is adjacent to the Ti^(4+)ion instead of the two Dy^(3+)ions,affording a[6,6]-open addition pattern.Theoretical calculations unveil that the Ti(IV)ion plays a decisive role in high regioselectivity,and the formation of[6,6]-open Dy_(2)TiC@Ih-C_(80)-Ad is thermodynamically preferred.Contrarily,a similar reaction of a Ti(Ⅲ)-containing nitride clusterfullerene Y_(2)TiN@C_(80) with AdN_(2) is predicted to generate a different type of adduct with the addition sites adjacent to the Y^(3+)ion instead of the Ti^(3+)ion.This reveals the peculiarity of the chemical property of μ_(3)-CCF resulting from the existence of the non-rare earth metal Ti with a high oxidation state.
基金National Natural Science Foundation of China(51925206,U1932214,52302052,22301288)Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0450301)+2 种基金Anhui Provincial Natural Science Foundation(2308085MB33,2308085MB31)Fundamental Research Funds for the Central Universities(20720220009,WK2060000051)National Synchrotron Radiation Laboratory(KY2060000240).
文摘Metal−nitrogen double bonds have been commonly reported for conventional metal complexes,but the coexistence of both transition metal−nitrogen and lanthanide−nitrogen double bonds bridged by nitrogen within one compound has never been reported.Herein,by encapsulating a ternary transition metallanthanide heteronuclear dimetallic nitride into a C_(84) fullerene cage,transition metal−nitrogen and lanthanide-nitrogen double bonds are costabilized simultaneously within the as-formed clusterfullerene TiCeN@C_(1)(12)-C_(84),which is a representative heteronuclear dimetallic nitride clusterfullerene.Its molecular structure was unambiguously determined by single-crystal X-ray diffraction,revealing a slightly bentμ2-bridged nitride cluster with short Ti−N(1.761Å)and Ce−N(2.109Å)bond lengths,which are comparable to the corresponding Ti=N and Ce=N double bonds of reported metal complexes and consistent with the theoretically predicted values,confirming their coexistence within TiCeN@C_(1)(12)-C_(84).Density functional theory(DFT)calculations unveil three-center two-electron(3c-2e)bonds delocalized over the entire TiCeN cluster,which are responsible for costabilization of Ti�N and Ce�N double bonds.An electronic configuration of Ti4+Ce^(3+)N^(3−)@C_(84)^(4−)is proposed featuring an intramolecular four-electron transfer,drastically different from the analogous actinide dimetallic nitride clusterfullerene(U_(2))^(9+)N^(3−)@C_(80)^(6−)and trimetallic nitride clusterfullerene(Sc_(2))^(6+)Ti^(3+)^(N3−)@C_(80)^(6−),indicating the peculiarity of 4-fold negatively charged fullerene cage in stabilizing the heteronuclear dimetallic nitride cluster.
基金the National Science Foundation China(NSFC No.52172051)the NSF of Jiangsu Province(BK20200041)+2 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)A.R.-F.and J.M.P.thank the Spanish Ministry of Science(grant PID2020-112762GB-I00 funded by MCIN/AEl/10.13039/501100011033)the Generalitat de Catalunya(grant 2021 SGR 00110)and the URV for support.
文摘Comprehensive Summary The experimental investigation of rare-earth metal-metal bonds remains a challenge in the study of chemical bonds.Herein,we report the synthesis and characterization of a novel heteronuclear di-metallofullerene,ScY@C_(3v)(8)-C_(82),which contains a mixed rare-earth metal-metal bond.ScY@C_(3v)(8)-C_(82)was successfully synthesized by arc-discharging method and characterized by mass spectrometry,UV-vis-NIR spectroscopy and single-crystal X-ray diffraction crystallography,which unambiguously determined its molecular structure.Theoretical calculations were also performed to study the optimized positions of Sc-Y metallic dimer and the electronic configuration.The combined experimental and theoretical results confirmed that both Sc and Y atoms transfer two electrons to the C_(3v)(8)-C_(82)cage,i.e.,(ScY)4+@(C_(3v)(8)-C_(82))4-.In particular,a covalent Sc-Yσ2 bond,which has never been reported before,is proven to be formed inside C_(3v)(8)-C_(82)fullerene cage.This work presents a novel di-metallofullerene containing mixed rare-earth metal-metal bond and expands the understanding of metal-metal bonding of rare earth elements.
基金Financial support for this research was provided by the National Natural Science Foundation of China(nos.92061204,21771152,and 21721001).
文摘The precise identification of metal-metal bonds is critical to fully understanding the nature of metal-metal bonding but remains a fundamental challenge.Herein,we show the essence of Sc-Sc bonds with a metal-metal distance of 3.36 Å in a C_(3v)(8)-C_(82) fullerene cage using crystallography.
