According to a uniform and simple method of calculating spin-lattice coupling coefficients and the pert1rbation formulas of gi factors and hyperfine structure constants Ai based on the cluster approach for 3d7 ions in...According to a uniform and simple method of calculating spin-lattice coupling coefficients and the pert1rbation formulas of gi factors and hyperfine structure constants Ai based on the cluster approach for 3d7 ions in cubic,tetragonal and trigonal octahedral crystal fields, the spin-lattice coupling coefficients Fij (F11, Fl2, F44), Zij (Z11, Z12,Z44) and also g factor and hyperfine constant A for MgO:Co2+ are calculated by using the parameters obtained from the optical spectra without adjustable parameters. The calculated results show good agreement with the observed values.The difiiculty in explaining the coeficients Fij and Zij is therefore removed.展开更多
The electron paramagnetic spectra of trigonal Mn^(2+) centers in[Co(H_(2)O)_(6)]SiF6,[Co(H_(2)O)_(6)]SnF6,and[Co(H_(2)O)_(6)]PtCl6 crystals were studied on the basis of the complete energy matrices for a d5 configurat...The electron paramagnetic spectra of trigonal Mn^(2+) centers in[Co(H_(2)O)_(6)]SiF6,[Co(H_(2)O)_(6)]SnF6,and[Co(H_(2)O)_(6)]PtCl6 crystals were studied on the basis of the complete energy matrices for a d5 configuration ion in a trigonal ligand field.When Mn^(2+) is doped in the[Co(H_(2)O)_(6)]SiF6,[Co(H_(2)O)_(6)]SnF6,and[Co(H_(2)O)_(6)]PtCl6 crystals crystals,there is a similar local distortion.The experimental results show that the local lattice structure around a trigonal Mn^(2+) center has an elongation distortion along the crystalline C3 axis.From the EPR calculation,the local lattice structure parameters R=2.278A,θ=52.6406? for[Co(H_(2)O)_(6)]SiF6,R=2.280,θ=52.4936° for[Co(H_(2)O)_(6)]SnF6 and R=2.244A,θ=53.0616? for[Co(H_(2)O)_(6)]PtCl6 were determined.展开更多
The electron paramagnetic resonance(EPR) spectra of trigonal Mn^(2+) centers in Zn(ClO4)2·6(H2O) and Mg(ClO4)2·6(H2O) crystals were studied on the basis of the complete energy matrices for a d^5...The electron paramagnetic resonance(EPR) spectra of trigonal Mn^(2+) centers in Zn(ClO4)2·6(H2O) and Mg(ClO4)2·6(H2O) crystals were studied on the basis of the complete energy matrices for a d^5 configuration ion in a trigonal ligand field. It was demonstrated that the local lattice structure around a trigonal Mn^(2+) center has an compressed distortion along the crystalline c3 axis, and when Mn^(2+) is doped in the Zn(ClO4)2·6(H2O) and Mg(ClO4)2·6(H2O) crystals, there is a similar local distortion. From the EPR calculation, the local lattice structure parameters R=2.183 2 ?, for Zn(ClO4)2·6(H2O), R=2.130 2 ?, for Mg(ClO4)2·6(H2O) have been determined.展开更多
By extending the usual DV-X<sub>α</sub> calculation and applying Bird’s ligand-field theory, wepresent a theoretical method for calculating d-d ligand-field spectra of transition-metal com-plexes. Compar...By extending the usual DV-X<sub>α</sub> calculation and applying Bird’s ligand-field theory, wepresent a theoretical method for calculating d-d ligand-field spectra of transition-metal com-plexes. Comparison between the calculated d-d ligand-field spectrum and the experimental (orother theoretical) results of cluster (CrF<sub>6</sub>)<sup>3-</sup> shows that this method is convenient and ef-fective.展开更多
Protecting clusters from coalescing by ligands has been universally adopted in the chemical synthesis of atomically precise clusters.Apart from the stabilization role,the effect of ligands on the electronic properties...Protecting clusters from coalescing by ligands has been universally adopted in the chemical synthesis of atomically precise clusters.Apart from the stabilization role,the effect of ligands on the electronic properties of cluster cores in constructing superatoms,however,has not been well understood.In this letter,a comprehensive theoretical study about the effect of an organic ligand,methylated N-heterocyclic carbene(C_(5)N_(2)H_(8)),on the geometrical and electronic properties of the aluminum-based clusters XAl_(12)(X=Al,C and P)featuring different valence electron shells was conducted by utilizing the density functional theory(DFT)calculations.It was observed that the ligand can dramatically alter the electronic properties of these aluminum-based clusters while maintaining their structural stability.More intriguingly,different from classical superatom design strategies,the proposed ligation strategy was evidenced to possess the capability of remarkably reducing the ionization potentials(IP)of these clusters forming the ligated superalkalis,which is regardless of their shell occupancy.The charge transfer complex formed during the ligation process,which regulates the electronic spectrum through the electrostatic Coulomb potential,was suggested to be responsible for such an IP drop.The ligation strategy highlighted here may provide promising opportunities in realizing the superatom synthesis in the liquid phase.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
文摘According to a uniform and simple method of calculating spin-lattice coupling coefficients and the pert1rbation formulas of gi factors and hyperfine structure constants Ai based on the cluster approach for 3d7 ions in cubic,tetragonal and trigonal octahedral crystal fields, the spin-lattice coupling coefficients Fij (F11, Fl2, F44), Zij (Z11, Z12,Z44) and also g factor and hyperfine constant A for MgO:Co2+ are calculated by using the parameters obtained from the optical spectra without adjustable parameters. The calculated results show good agreement with the observed values.The difiiculty in explaining the coeficients Fij and Zij is therefore removed.
基金Funded by the National Natural Science Foundation of China (Nos. 11804285 and 61601384)。
文摘The electron paramagnetic spectra of trigonal Mn^(2+) centers in[Co(H_(2)O)_(6)]SiF6,[Co(H_(2)O)_(6)]SnF6,and[Co(H_(2)O)_(6)]PtCl6 crystals were studied on the basis of the complete energy matrices for a d5 configuration ion in a trigonal ligand field.When Mn^(2+) is doped in the[Co(H_(2)O)_(6)]SiF6,[Co(H_(2)O)_(6)]SnF6,and[Co(H_(2)O)_(6)]PtCl6 crystals crystals,there is a similar local distortion.The experimental results show that the local lattice structure around a trigonal Mn^(2+) center has an elongation distortion along the crystalline C3 axis.From the EPR calculation,the local lattice structure parameters R=2.278A,θ=52.6406? for[Co(H_(2)O)_(6)]SiF6,R=2.280,θ=52.4936° for[Co(H_(2)O)_(6)]SnF6 and R=2.244A,θ=53.0616? for[Co(H_(2)O)_(6)]PtCl6 were determined.
基金Funded in Part by the National Natural Science Foundation of China(No.61601384)
文摘The electron paramagnetic resonance(EPR) spectra of trigonal Mn^(2+) centers in Zn(ClO4)2·6(H2O) and Mg(ClO4)2·6(H2O) crystals were studied on the basis of the complete energy matrices for a d^5 configuration ion in a trigonal ligand field. It was demonstrated that the local lattice structure around a trigonal Mn^(2+) center has an compressed distortion along the crystalline c3 axis, and when Mn^(2+) is doped in the Zn(ClO4)2·6(H2O) and Mg(ClO4)2·6(H2O) crystals, there is a similar local distortion. From the EPR calculation, the local lattice structure parameters R=2.183 2 ?, for Zn(ClO4)2·6(H2O), R=2.130 2 ?, for Mg(ClO4)2·6(H2O) have been determined.
基金Project supported by the National Natural Science Foundation of China.
文摘By extending the usual DV-X<sub>α</sub> calculation and applying Bird’s ligand-field theory, wepresent a theoretical method for calculating d-d ligand-field spectra of transition-metal com-plexes. Comparison between the calculated d-d ligand-field spectrum and the experimental (orother theoretical) results of cluster (CrF<sub>6</sub>)<sup>3-</sup> shows that this method is convenient and ef-fective.
基金supported by the Innovation Project of Jinan Science and Technology Bureau(No.2021GXRC032)the Taishan Scholars Project of Shandong Province(No.ts201712011)+4 种基金the National Natural Science Foundation of China(NSFC,Nos.92161101,21603119)the Natural Science Foundation of Shandong Province(No.ZR2020ZD35)the Shandong University Multidisciplinary Research and Innovation Team of Young Scholars(No.2020QNQT015)the Young Scholars Program of Shandong University(YSPSDU,No.2018WLJH48)the Fundamental Research Funds of Shandong University(No.2017TB003).
文摘Protecting clusters from coalescing by ligands has been universally adopted in the chemical synthesis of atomically precise clusters.Apart from the stabilization role,the effect of ligands on the electronic properties of cluster cores in constructing superatoms,however,has not been well understood.In this letter,a comprehensive theoretical study about the effect of an organic ligand,methylated N-heterocyclic carbene(C_(5)N_(2)H_(8)),on the geometrical and electronic properties of the aluminum-based clusters XAl_(12)(X=Al,C and P)featuring different valence electron shells was conducted by utilizing the density functional theory(DFT)calculations.It was observed that the ligand can dramatically alter the electronic properties of these aluminum-based clusters while maintaining their structural stability.More intriguingly,different from classical superatom design strategies,the proposed ligation strategy was evidenced to possess the capability of remarkably reducing the ionization potentials(IP)of these clusters forming the ligated superalkalis,which is regardless of their shell occupancy.The charge transfer complex formed during the ligation process,which regulates the electronic spectrum through the electrostatic Coulomb potential,was suggested to be responsible for such an IP drop.The ligation strategy highlighted here may provide promising opportunities in realizing the superatom synthesis in the liquid phase.
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.