We have synthesized two copper nanoclusters(NCs)with a protection of the same ligand diphenylphosphino-2-pyridine(C_(17)H_(14)NP,dppy for short),formulated as Cu_(4)(dppy)_(4)Cl_(2)and Cu21(dppy)10,respectively.The fo...We have synthesized two copper nanoclusters(NCs)with a protection of the same ligand diphenylphosphino-2-pyridine(C_(17)H_(14)NP,dppy for short),formulated as Cu_(4)(dppy)_(4)Cl_(2)and Cu21(dppy)10,respectively.The former one bears a distorted tetrahedron Cu4 core with its six edges fully protected by chlorine and dppy ligands,while the latter presents a symmetric Cu_(21)core on which ten dppy molecules function as monolayer protection via well-organized monodentate or bidentate coordination.Interestingly,the Cu_(4)(dppy)_(4)Cl_(2)cluster exhibits a strong yellow emission at∼577 nm,while Cu_(21)(dppy)_(10)displays dual emissions in purple(∼368 nm)and green(∼516 nm)regions respectively.In combination with TD-DFT calculations,we demonstrate the origin of altered emissions and unique stability of the two copper nanoclusters pertaining to the ligand coordination and metallic superatomic states.展开更多
The distinctive electronic bonding properties of actinide-containing clusters have made them the subject of increased attention. Herein, we use density functional theory calculations to examine a unique actinide-encap...The distinctive electronic bonding properties of actinide-containing clusters have made them the subject of increased attention. Herein, we use density functional theory calculations to examine a unique actinide-encapsulated U@B40 cage structure, revealing that it exhibits a 32-electron （1S2P61Dl01FTM） closed-shell singlet configuration in which all s, p, d, and f shells of the U atom are filled. Furthermore, the binding energy of 8.22 eV calculated for this cluster implies considerable stability, and the simulated infrared and Raman spectra feature U-B40 stretching and pure B40 breathing vibration modes, respectively. These spectral characteristics may aid future experimental investigations. Thus, this work not only describes a new member of the superatomic family, but also provides a method of encapsulating radioactive actinides.展开更多
Actinide elements encaged in a superatomic cluster can exhibit unique properties due to their hyperactive valence electrons. Herein, the electronic and spectroscopic properties of Th@Au14 are predicted and compared wi...Actinide elements encaged in a superatomic cluster can exhibit unique properties due to their hyperactive valence electrons. Herein, the electronic and spectroscopic properties of Th@Au14 are predicted and compared with that of the isoelectronic entities [Ac@Au14]- and [Pa@Au14]＋ using density functional theory. The calculation results indicate that these clusters all adopt a closed- shell superatomic 18-electron configuration of the 1S21p61D10 Jellium state. The absorption spectrum of Th@Au14 can be interpreted by the Jelliumatic orbital model. In addition, calculated spectra of pyridine-Th@Au14 complexes in the blue laser band exhibit strong peaks attributable to charge transfer （CT） from the metal to the pyridine molecule. These charge-transfer bands lead to a resonant surface-enhanced Raman scattering （SERS） enhancement of -104. This work suggests a basis for designing and synthesizing SERS substrate materials based on actinide-embedded gold superatom models.展开更多
Magnetic materials could realize the intriguing quantum anomalous Hall effect and metal-to-insulator transition when combined with band topology or electronic correlation,which have broad prospects in quantum informat...Magnetic materials could realize the intriguing quantum anomalous Hall effect and metal-to-insulator transition when combined with band topology or electronic correlation,which have broad prospects in quantum information,spintronics,and valleytronics.Here,we propose the approach of designing novel two-dimensional(2D)magnetic states via d-orbital-based superatomic lattices.Specifically,we chose triangular zirconium dichloride disks as superatoms to construct the honeycomb superatomic lattices.Using first-principles calculations,we identified a series of 2D magnetic states with varying sizes of superatoms.We found the non-uniform stoichiometries and geometric effect of superatomic lattice give rise to spin-polarized charges arranged in different magnetic configurations,containing ferromagnetic coloring triangles,antiferromagnetic honeycomb,and ferromagnetic kagome lattices.Attractively,these magnetic states are endowed with nontrivial band topology or strong correlation,forming an ideal Chern insulator or antiferromagnetic Dirac Mott insulator.Our work not only reveals the potential of d-orbital-based superatoms for generating unusual magnetic configurations,but also supplies a new avenue for material engineering at the nanoscale.展开更多
Superatoms are considered as promising building blocks for customizing superatomic molecules and cluster-assembly nanomaterials due to their tunable electronic structures and functionalities.Electron counting rules,wh...Superatoms are considered as promising building blocks for customizing superatomic molecules and cluster-assembly nanomaterials due to their tunable electronic structures and functionalities.Electron counting rules,which mainly adjust the shell-filling of clusters,are classical strategies in designing superatoms.Here,by employing the density functional theory(DFT)calculations,we proved that the 1,4-phenylene diisocyanide(CNC_(6)H_(4)NC)ligand could dramatically reduce the adiabatic ionization potentials(AlPs)of the aluminum-based clusters,which have 39,40,and 41 valence electrons,respectively,to give rise to superalkali species without changing their shell-filling.Moreover,the rigid structure of the ligand can be used as a bridge firmly linking the same or different aluminum-based clusters to form superatomic molecules and nanowires.In particular,the bridging process was observed to enhance their nonlinear optical(NLO)responses,which can be further promoted by the oriented external electric field(OEEF).Also,the stable cluster-assembly XAl_(12)(CNC_(6)H_(4)NC)(X=Al,C,and P)nanowires were constructed,which exhibit strong absorption in the visible light region.These findings not only suggest an effective ligand-field strategy in superatom design but also unveil the geometrical and electronic evolution from the CNC_(6)H_(4)NC-based superatoms to superatomic molecules and nanomaterials.展开更多
Exploring metal cluster reactivity with alkyl halides enables to understand the related chemical mechanism of metal surfaces in terms of active sites.Here we report a study of Ag_(n)^(+)(n=1-27)clusters reacting with ...Exploring metal cluster reactivity with alkyl halides enables to understand the related chemical mechanism of metal surfaces in terms of active sites.Here we report a study of Ag_(n)^(+)(n=1-27)clusters reacting with iodomethane by a flow tube apparatus in tandem with a customized triple quadrupole mass spectrometer.Strong even/odd alternation of the Ag_(n)^(+)is observed in their reactions with CH_(3)I,where silver clusters with even-number,Ag_(2n)^(+),find favorable products of Ag_(2n)I_(1,3)^(+)series,while the Ag_(2n−1)^(+)clusters form Ag_(2n−1)I_(2,4)^(+)products.Interestingly,Ag_(9)^(+)shows up with prominent mass abundance but allows for the formation of Ag_(9)I_(2)^(+),which finds an echo with the formation of Ag_(10)I_(3)^(+).We illustrate the enhanced stability of Ag_(9)I_(2)^(+)and Ag_(10)I_(3)^(+)by showing their significantly enlarged highest occupied molecular orbital(HOMO)-lowest unoccupied molecular orbital(LUMO)gaps and balanced charge distribution compared with the bare metal clusters,respectively.Also elucidated,is the superatomic nature of these bare and iodinated silver clusters,especially Ag_(9)I_(2)^(+)which mimics the rare-gas compound XeF_(2).This study expands a vivid example of special and general superatoms,and enriches the general knowledge on how a ligand stabilizes a metal cluster.展开更多
In this study,the size of the titanium organic cage was controlled to achieve the restricted growth from a single Ag(I)atom(Ag@Ti_(5))to rare all-carboxylate-protected superatomic Ag cluster(Ag6@Ti_(6)).The classical ...In this study,the size of the titanium organic cage was controlled to achieve the restricted growth from a single Ag(I)atom(Ag@Ti_(5))to rare all-carboxylate-protected superatomic Ag cluster(Ag6@Ti_(6)).The classical octahedral Ag_(6)^(4+) cluster with two delocalized electrons(2e)has been encapsulated in a Ti6 organic cage,which shows high stability in air and dimethyformamide(DMF).Furthermore,larger 2e nested double-tetrahedra Ag clusters(Ag_(8)^(6+) and Ag_(9)^(7+))protected using a tetrahedral hollow metalloligand framework(Ag_(8)@Ti_(4) and Ag_(9)@Ti_(4))were obtained.Electrospray ionization mass spectrometry(ESI-MS)and density functional theory(DFT)calculations confirmed that there are two delocalized electrons on these small Ag clusters.This study provides a new form of protection for superatomic Ag clusters and provides a feasible strategy for the development of stable Ag clusters.展开更多
Boron allotropes are known to be predominately constructed by icosahedral B_(12) cages,while icosahedral-B_(12) stuffing proves to effectively improve the stability of fullerene-like boron nanoclusters in the size ran...Boron allotropes are known to be predominately constructed by icosahedral B_(12) cages,while icosahedral-B_(12) stuffing proves to effectively improve the stability of fullerene-like boron nanoclusters in the size range between B_(98)–B_(102).However,the thermodynamically most stable core-shell borospherenes with a B_(12) icosahedron at the center still remains unknown.Based on the structural motif of D5h C_(70) and extensive first-principles theory calculations,we predict herein the high-symmetry C5v B111+(3)which satisfies the Wade’s n+1 and n+2 skeletal electron counting rules exactly and the approximately electron sufficient Cs B_(111)(4),Cs B_(112)(5),Cs B_(113)(6),and Cs B_(114)(7)which are the most stable neutral core-shell borospherenes with a B_(12) icosahedron at the center reported to date in the size range between B_(68)–B_(130),with Cs B112(5)being the thermodynamically most favorite species in the series.Detailed orbital and bonding analyses indicate that these spherically aromatic species all contain a negatively charged icosahedral B_(122)−core at the center which exhibits typical superatomic behaviors in the electronic configuration of 1S21P61D101F8,with its dangling valences saturated by twelve radial B-B 2c-2eσbonds between the B_(12) inner core and the B_(70) outer shell.The infrared(IR)and Raman spectra of the concerned species are computationally simulated to facilitate their future characterizations.展开更多
Due to challenges in preparing pure metal clusters and in controlling reactions,the oxides produced by metal clusters reacting with oxygen are often different from traditional ion-molecule products in the gas phase an...Due to challenges in preparing pure metal clusters and in controlling reactions,the oxides produced by metal clusters reacting with oxygen are often different from traditional ion-molecule products in the gas phase and their reactivity pattern is also largely unveiled yet.In this work,utilizing a customized Re-TOFMS having a home-made cluster source and a flow tube reactor,we have observed the gaseous reactions of Nin±clusters with oxygen and found magic clusters of Ni_(13)O_(8)±that dominate the mass distributions.By quantum chemistry calculations,we find that both Ni_(13)O_(8)−and Ni_(13)O_(8)+clusters bear a regular cubic structure with 8 oxygen anchoring the eight angles,however,they have rather different spin accommodations.The Ni_(13)O_(8)−clusters have 15 unpaired spin-up electrons exhibiting cubic aromaticity and decent ferromagnetism,while the Ni_(13)O_(8)+clusters take a lower-spin ground state(11 unpaired electrons),with spin-down population on the central Ni atom pertaining to ferrimagnetism.This is a class of metalloxocube clusters that hold properties of aromaticity and ferromagnetism/ferrimagnetism charcterized by a few spin electrons,which embodies the bonding nature of superatomic compounds and enables to develop cluster-genetic materials of multi-functionality.展开更多
5f-elements encaged in a gold superatomic cluster are capable of giving rise to unique optical properties due to their hyperactive valence electrons and great radial components of 5f/6d orbitals. Herein, we review our...5f-elements encaged in a gold superatomic cluster are capable of giving rise to unique optical properties due to their hyperactive valence electrons and great radial components of 5f/6d orbitals. Herein, we review our first-principles studies on electronic structures and spectroscopic properties of a series of actinide-embedded gold superatomic clusters with different dimensions. The three-dimensional（3D） and two-dimensional（2D） superatom clusters possess the 18-electron configuration of 1S21P61D10 and 10-electron configuration of 1S21P41D4, respectively. Importantly, their electronic absorption spectra can also be effectively explained by the superatom orbitals. Specifically, the charge transfer（CT） transitions involved in surface-enhance Raman spectroscopy（SERS） spectra for 3D and 2D structures are both from the filled 1D orbitals, providing the enhancement factors of the order of ～ 10^4 at 488 nm and ～ 10^5 at 456 nm, respectively. This work implies that the superatomic orbital transitions involved in 5f-elements can not only lead to a remarkable spectroscopic performance, but also a new direction for optical design in the future.展开更多
Utilizing a facile top-down synthetic procedure, here we report the finding of a chlorine-passivated Al_(37) superatom cluster. It is demonstrated that the presence of electrophilic groups, severing as protecting liga...Utilizing a facile top-down synthetic procedure, here we report the finding of a chlorine-passivated Al_(37) superatom cluster. It is demonstrated that the presence of electrophilic groups, severing as protecting ligands, alters the valence electron count of the metallic core and stabilize the as-prepared aluminum clusters especially when even-numbered chlorine atoms are located at equilibrium positions. Following the discussion regarding their reasonable stabilities, we illustrate the feasible reaction pathways in forming such chlorine-passivated Al_(37) superatom clusters which bear delocalized superatomic orbitals with five valence 3P^5 electrons shifting to the chlorine ligands indicative of a closed electron shell 2F^(14) of the metal core. The successful synthesis of such chlorine-protected aluminum clusters evidences the compatibility of general theory of cluster chemistry in both gas phase and wet chemistry. Such simple-ligand-protected aluminum clusters exhibit reverse-saturated-absorption(RSA) nonlinear optical property pertaining to electronic transitions within the discrete energy states of cluster materials.展开更多
Assembly is an effective way to realize the functionalization potential of boron-based superatoms. Here we study the interaction between typical boron-based B40 superatoms using the density functional theory. Our resu...Assembly is an effective way to realize the functionalization potential of boron-based superatoms. Here we study the interaction between typical boron-based B40 superatoms using the density functional theory. Our results reveal that different oligomers constructed by modulating the arrangement of two B40 superatoms still retain some of the superatomic properties associated with their monomeric form despite possessing different electronic structures. While the inner shell superatomic orbitals maintain their electronic localization, the valence shell superatomic orbitals cannot maintain their original shape due to bonding and antibonding hybridization. Furthermore, the decreasing of band gap means that the B40 oligomers could achieve a transformation from insulators to semiconductors. The decreased band gap is possibly due to the disappearance of the superatomic orbitals with the principal quantum number of two. Our findings highlight that superatom–superatom interactions could induce synergy effects that differ from their monomers. Therefore, this research will aid in the development of new materials and devices that are constructed from superatoms.展开更多
We present an improved version of the superatom(SA)model to examine the slow-light dynamics of a few-photons signal field in cold Rydberg atoms with van der Waals(vdW)interactions.A main feature of this version is tha...We present an improved version of the superatom(SA)model to examine the slow-light dynamics of a few-photons signal field in cold Rydberg atoms with van der Waals(vdW)interactions.A main feature of this version is that it promises consistent estimations on total Rydberg excitations based on dynamic equations of SAs or atoms.We consider two specific cases in which the incident signal field contains more photons with a smaller detuning or less photons with a larger detuning so as to realize the single-photon-level light storage.It is found that vdW interactions play a significant role even for the slow-light dynamics of a single-photon signal field as distributed Rydberg excitations are inevitable in the picture of dark-state polariton.Moreover,the stored(retrieved)signal field exhibits a clearly asymmetric(more symmetric)profile because its leading and trailing edges undergo different(identical)traveling journeys,and higher storage/retrieval efficiencies with well preserved profiles apply only to weaker and well detuned signal fields.These findings are crucial to understand the nontrivial interplay of single-photon-level light storage and distributed Rydberg excitations.展开更多
基金the National Natural Science Foundation of China(Nos.22003072 and 21722308),the Ministry of Science and Technology of the People’s Republic of China(No. 2020YFA0714602).
文摘We have synthesized two copper nanoclusters(NCs)with a protection of the same ligand diphenylphosphino-2-pyridine(C_(17)H_(14)NP,dppy for short),formulated as Cu_(4)(dppy)_(4)Cl_(2)and Cu21(dppy)10,respectively.The former one bears a distorted tetrahedron Cu4 core with its six edges fully protected by chlorine and dppy ligands,while the latter presents a symmetric Cu_(21)core on which ten dppy molecules function as monolayer protection via well-organized monodentate or bidentate coordination.Interestingly,the Cu_(4)(dppy)_(4)Cl_(2)cluster exhibits a strong yellow emission at∼577 nm,while Cu_(21)(dppy)_(10)displays dual emissions in purple(∼368 nm)and green(∼516 nm)regions respectively.In combination with TD-DFT calculations,we demonstrate the origin of altered emissions and unique stability of the two copper nanoclusters pertaining to the ligand coordination and metallic superatomic states.
文摘The distinctive electronic bonding properties of actinide-containing clusters have made them the subject of increased attention. Herein, we use density functional theory calculations to examine a unique actinide-encapsulated U@B40 cage structure, revealing that it exhibits a 32-electron （1S2P61Dl01FTM） closed-shell singlet configuration in which all s, p, d, and f shells of the U atom are filled. Furthermore, the binding energy of 8.22 eV calculated for this cluster implies considerable stability, and the simulated infrared and Raman spectra feature U-B40 stretching and pure B40 breathing vibration modes, respectively. These spectral characteristics may aid future experimental investigations. Thus, this work not only describes a new member of the superatomic family, but also provides a method of encapsulating radioactive actinides.
基金Acknowledgements We would like to thank Drs. Jun Liu and Lei Chen for the stimulating discussions. We would also like to acknowledge the support of the National Natural Science Foundation of China （No. 11374004） and the Science and Technology Development Program of Jilin Province of China （No. 20150519021JH）. Z. W. also acknowledges the Fok Ying Tung Education Foundation （No. 142001） and High Performance Computing Center of Jilin University.
文摘Actinide elements encaged in a superatomic cluster can exhibit unique properties due to their hyperactive valence electrons. Herein, the electronic and spectroscopic properties of Th@Au14 are predicted and compared with that of the isoelectronic entities [Ac@Au14]- and [Pa@Au14]＋ using density functional theory. The calculation results indicate that these clusters all adopt a closed- shell superatomic 18-electron configuration of the 1S21p61D10 Jellium state. The absorption spectrum of Th@Au14 can be interpreted by the Jelliumatic orbital model. In addition, calculated spectra of pyridine-Th@Au14 complexes in the blue laser band exhibit strong peaks attributable to charge transfer （CT） from the metal to the pyridine molecule. These charge-transfer bands lead to a resonant surface-enhanced Raman scattering （SERS） enhancement of -104. This work suggests a basis for designing and synthesizing SERS substrate materials based on actinide-embedded gold superatom models.
基金supported in part by the Key R&D of the Ministry of Science and Technology(No.2022YFA1204103).
文摘Magnetic materials could realize the intriguing quantum anomalous Hall effect and metal-to-insulator transition when combined with band topology or electronic correlation,which have broad prospects in quantum information,spintronics,and valleytronics.Here,we propose the approach of designing novel two-dimensional(2D)magnetic states via d-orbital-based superatomic lattices.Specifically,we chose triangular zirconium dichloride disks as superatoms to construct the honeycomb superatomic lattices.Using first-principles calculations,we identified a series of 2D magnetic states with varying sizes of superatoms.We found the non-uniform stoichiometries and geometric effect of superatomic lattice give rise to spin-polarized charges arranged in different magnetic configurations,containing ferromagnetic coloring triangles,antiferromagnetic honeycomb,and ferromagnetic kagome lattices.Attractively,these magnetic states are endowed with nontrivial band topology or strong correlation,forming an ideal Chern insulator or antiferromagnetic Dirac Mott insulator.Our work not only reveals the potential of d-orbital-based superatoms for generating unusual magnetic configurations,but also supplies a new avenue for material engineering at the nanoscale.
基金supported by the Taishan Scholars Project of Shandong Province(No.ts201712011)the National Natural Science Foundation of China(NSFC)(Nos.21603119 and 21705093)+3 种基金the Natural Science Foundation of Jiangsu Province(No.BK20170396)the Natural Science Foundation of Shandong Province(No.ZR2020ZD35)the Young Scholars Program of Shandong University(YSPSDU)(No.2018WLJH48)the Qilu Youth Scholar Funding of Shandong University.
文摘Superatoms are considered as promising building blocks for customizing superatomic molecules and cluster-assembly nanomaterials due to their tunable electronic structures and functionalities.Electron counting rules,which mainly adjust the shell-filling of clusters,are classical strategies in designing superatoms.Here,by employing the density functional theory(DFT)calculations,we proved that the 1,4-phenylene diisocyanide(CNC_(6)H_(4)NC)ligand could dramatically reduce the adiabatic ionization potentials(AlPs)of the aluminum-based clusters,which have 39,40,and 41 valence electrons,respectively,to give rise to superalkali species without changing their shell-filling.Moreover,the rigid structure of the ligand can be used as a bridge firmly linking the same or different aluminum-based clusters to form superatomic molecules and nanowires.In particular,the bridging process was observed to enhance their nonlinear optical(NLO)responses,which can be further promoted by the oriented external electric field(OEEF).Also,the stable cluster-assembly XAl_(12)(CNC_(6)H_(4)NC)(X=Al,C,and P)nanowires were constructed,which exhibit strong absorption in the visible light region.These findings not only suggest an effective ligand-field strategy in superatom design but also unveil the geometrical and electronic evolution from the CNC_(6)H_(4)NC-based superatoms to superatomic molecules and nanomaterials.
基金supported by the Ministry of Science and Technology of China(2020YFA0714602)the National Natural Science Foundation of China(21722308,22003072)CAS Instrument Development Project(Y5294512C1)。
文摘Exploring metal cluster reactivity with alkyl halides enables to understand the related chemical mechanism of metal surfaces in terms of active sites.Here we report a study of Ag_(n)^(+)(n=1-27)clusters reacting with iodomethane by a flow tube apparatus in tandem with a customized triple quadrupole mass spectrometer.Strong even/odd alternation of the Ag_(n)^(+)is observed in their reactions with CH_(3)I,where silver clusters with even-number,Ag_(2n)^(+),find favorable products of Ag_(2n)I_(1,3)^(+)series,while the Ag_(2n−1)^(+)clusters form Ag_(2n−1)I_(2,4)^(+)products.Interestingly,Ag_(9)^(+)shows up with prominent mass abundance but allows for the formation of Ag_(9)I_(2)^(+),which finds an echo with the formation of Ag_(10)I_(3)^(+).We illustrate the enhanced stability of Ag_(9)I_(2)^(+)and Ag_(10)I_(3)^(+)by showing their significantly enlarged highest occupied molecular orbital(HOMO)-lowest unoccupied molecular orbital(LUMO)gaps and balanced charge distribution compared with the bare metal clusters,respectively.Also elucidated,is the superatomic nature of these bare and iodinated silver clusters,especially Ag_(9)I_(2)^(+)which mimics the rare-gas compound XeF_(2).This study expands a vivid example of special and general superatoms,and enriches the general knowledge on how a ligand stabilizes a metal cluster.
基金This work was supported by the National Science Fund for Distinguished Young Scholars(No.21825106)the National Natural Science Foundation of China(Nos.21975065 and 21671175)+1 种基金the Program for Science&Technology Innovation Talents in Universities of Henan Province(No.164100510005)the Program for Innovative Research Team(in Science and Technology)in Universities of Henan Province(No.19IRTSTHN022)and Zhengzhou University.
文摘In this study,the size of the titanium organic cage was controlled to achieve the restricted growth from a single Ag(I)atom(Ag@Ti_(5))to rare all-carboxylate-protected superatomic Ag cluster(Ag6@Ti_(6)).The classical octahedral Ag_(6)^(4+) cluster with two delocalized electrons(2e)has been encapsulated in a Ti6 organic cage,which shows high stability in air and dimethyformamide(DMF).Furthermore,larger 2e nested double-tetrahedra Ag clusters(Ag_(8)^(6+) and Ag_(9)^(7+))protected using a tetrahedral hollow metalloligand framework(Ag_(8)@Ti_(4) and Ag_(9)@Ti_(4))were obtained.Electrospray ionization mass spectrometry(ESI-MS)and density functional theory(DFT)calculations confirmed that there are two delocalized electrons on these small Ag clusters.This study provides a new form of protection for superatomic Ag clusters and provides a feasible strategy for the development of stable Ag clusters.
基金This work was supported by the National Natural Science Foundation of China(Nos.21720102006 and 21973057 to S.-D.Li and 21473106 to H.-G.Lu).
文摘Boron allotropes are known to be predominately constructed by icosahedral B_(12) cages,while icosahedral-B_(12) stuffing proves to effectively improve the stability of fullerene-like boron nanoclusters in the size range between B_(98)–B_(102).However,the thermodynamically most stable core-shell borospherenes with a B_(12) icosahedron at the center still remains unknown.Based on the structural motif of D5h C_(70) and extensive first-principles theory calculations,we predict herein the high-symmetry C5v B111+(3)which satisfies the Wade’s n+1 and n+2 skeletal electron counting rules exactly and the approximately electron sufficient Cs B_(111)(4),Cs B_(112)(5),Cs B_(113)(6),and Cs B_(114)(7)which are the most stable neutral core-shell borospherenes with a B_(12) icosahedron at the center reported to date in the size range between B_(68)–B_(130),with Cs B112(5)being the thermodynamically most favorite species in the series.Detailed orbital and bonding analyses indicate that these spherically aromatic species all contain a negatively charged icosahedral B_(122)−core at the center which exhibits typical superatomic behaviors in the electronic configuration of 1S21P61D101F8,with its dangling valences saturated by twelve radial B-B 2c-2eσbonds between the B_(12) inner core and the B_(70) outer shell.The infrared(IR)and Raman spectra of the concerned species are computationally simulated to facilitate their future characterizations.
基金We thank Peter Livens for personal communication.Financial support for this work was partially provided by the National Natural Science Foundation of China(Nos.91536105,21722308 and 21802146)the National Project Development of Advanced Scientific Instruments Based on Deep Ultraviolet Laser Source(No.Y31M0112C1)+1 种基金the Beijing Natural Science Foundation(No.2192064)the Key Research Program of Frontier Sciences(CAS,No.QYZDBSSW-SLH024).
文摘Due to challenges in preparing pure metal clusters and in controlling reactions,the oxides produced by metal clusters reacting with oxygen are often different from traditional ion-molecule products in the gas phase and their reactivity pattern is also largely unveiled yet.In this work,utilizing a customized Re-TOFMS having a home-made cluster source and a flow tube reactor,we have observed the gaseous reactions of Nin±clusters with oxygen and found magic clusters of Ni_(13)O_(8)±that dominate the mass distributions.By quantum chemistry calculations,we find that both Ni_(13)O_(8)−and Ni_(13)O_(8)+clusters bear a regular cubic structure with 8 oxygen anchoring the eight angles,however,they have rather different spin accommodations.The Ni_(13)O_(8)−clusters have 15 unpaired spin-up electrons exhibiting cubic aromaticity and decent ferromagnetism,while the Ni_(13)O_(8)+clusters take a lower-spin ground state(11 unpaired electrons),with spin-down population on the central Ni atom pertaining to ferrimagnetism.This is a class of metalloxocube clusters that hold properties of aromaticity and ferromagnetism/ferrimagnetism charcterized by a few spin electrons,which embodies the bonding nature of superatomic compounds and enables to develop cluster-genetic materials of multi-functionality.
基金supported by the National Natural Science Foundation of China(Grant No.11374004)the Science and Technology Development Program of Jilin Province,China(Grant No.20150519021JH)+1 种基金the Fok Ying Tung Education Foundation,China(Grant No.142001)the Support from the High Performance Computing Center(HPCC)of Jilin University,China
文摘5f-elements encaged in a gold superatomic cluster are capable of giving rise to unique optical properties due to their hyperactive valence electrons and great radial components of 5f/6d orbitals. Herein, we review our first-principles studies on electronic structures and spectroscopic properties of a series of actinide-embedded gold superatomic clusters with different dimensions. The three-dimensional（3D） and two-dimensional（2D） superatom clusters possess the 18-electron configuration of 1S21P61D10 and 10-electron configuration of 1S21P41D4, respectively. Importantly, their electronic absorption spectra can also be effectively explained by the superatom orbitals. Specifically, the charge transfer（CT） transitions involved in surface-enhance Raman spectroscopy（SERS） spectra for 3D and 2D structures are both from the filled 1D orbitals, providing the enhancement factors of the order of ～ 10^4 at 488 nm and ～ 10^5 at 456 nm, respectively. This work implies that the superatomic orbital transitions involved in 5f-elements can not only lead to a remarkable spectroscopic performance, but also a new direction for optical design in the future.
基金supported by the Key Research Program of Frontier Sciences (QYZDB-SSW-SLH024)the National Natural Science Foundation of China (21722308)the National Thousand Youth Talents Program
文摘Utilizing a facile top-down synthetic procedure, here we report the finding of a chlorine-passivated Al_(37) superatom cluster. It is demonstrated that the presence of electrophilic groups, severing as protecting ligands, alters the valence electron count of the metallic core and stabilize the as-prepared aluminum clusters especially when even-numbered chlorine atoms are located at equilibrium positions. Following the discussion regarding their reasonable stabilities, we illustrate the feasible reaction pathways in forming such chlorine-passivated Al_(37) superatom clusters which bear delocalized superatomic orbitals with five valence 3P^5 electrons shifting to the chlorine ligands indicative of a closed electron shell 2F^(14) of the metal core. The successful synthesis of such chlorine-protected aluminum clusters evidences the compatibility of general theory of cluster chemistry in both gas phase and wet chemistry. Such simple-ligand-protected aluminum clusters exhibit reverse-saturated-absorption(RSA) nonlinear optical property pertaining to electronic transitions within the discrete energy states of cluster materials.
基金supported by the National Natural Science Foundation of China (11674123 and 11374004)
文摘Assembly is an effective way to realize the functionalization potential of boron-based superatoms. Here we study the interaction between typical boron-based B40 superatoms using the density functional theory. Our results reveal that different oligomers constructed by modulating the arrangement of two B40 superatoms still retain some of the superatomic properties associated with their monomeric form despite possessing different electronic structures. While the inner shell superatomic orbitals maintain their electronic localization, the valence shell superatomic orbitals cannot maintain their original shape due to bonding and antibonding hybridization. Furthermore, the decreasing of band gap means that the B40 oligomers could achieve a transformation from insulators to semiconductors. The decreased band gap is possibly due to the disappearance of the superatomic orbitals with the principal quantum number of two. Our findings highlight that superatom–superatom interactions could induce synergy effects that differ from their monomers. Therefore, this research will aid in the development of new materials and devices that are constructed from superatoms.
基金supported by the National Natural Science Foundation of China(Nos.11534002 and 12074061)the Cooperative Program by the Italian Ministry of Foreign Affairs and International Cooperation(No.PGR00960)the National Natural Science Foundation of China(No.11861131001).
文摘We present an improved version of the superatom(SA)model to examine the slow-light dynamics of a few-photons signal field in cold Rydberg atoms with van der Waals(vdW)interactions.A main feature of this version is that it promises consistent estimations on total Rydberg excitations based on dynamic equations of SAs or atoms.We consider two specific cases in which the incident signal field contains more photons with a smaller detuning or less photons with a larger detuning so as to realize the single-photon-level light storage.It is found that vdW interactions play a significant role even for the slow-light dynamics of a single-photon signal field as distributed Rydberg excitations are inevitable in the picture of dark-state polariton.Moreover,the stored(retrieved)signal field exhibits a clearly asymmetric(more symmetric)profile because its leading and trailing edges undergo different(identical)traveling journeys,and higher storage/retrieval efficiencies with well preserved profiles apply only to weaker and well detuned signal fields.These findings are crucial to understand the nontrivial interplay of single-photon-level light storage and distributed Rydberg excitations.
