The formation mechanism for the body-centred regular octahedral structure of Li7 cluster is proposed. The curve of the total energy versus the separation R between the nucleus at the centre and nuclei at the apexes fo...The formation mechanism for the body-centred regular octahedral structure of Li7 cluster is proposed. The curve of the total energy versus the separation R between the nucleus at the centre and nuclei at the apexes for this structure of Li7 has been calculated by using the method of Gou＇s modified arrangement channel quantum mechanics （MACQM）. The result shows that the curve has a minimal energy of-52.169 73 a.u. at R = 5.06ao. When R approaches infinity, the total energy of seven lithium atoms has the value of-51.996 21 a.u. So the binding energy of Li7 with respect to seven lithium atoms is 0.173 52 a.u. Therefore the binding energy per atom for Li7 is 0.024 79 a.u. or 0.674 eV, which is greater than the binding energy per atom of 0.453 eV for Li2, the binding energy per atom of 0.494 eV for Li3 and the binding energy per atom of 0.632 eV for Li5 calculated previously by us. This means that the Li7 cluster may be formed stably in a body-centred regular octahedral structure with a greater binding energy.展开更多
The complex Na2 [CrW3O4(O2CCH3)8]2·H2O (Mr = 2343. 80) crystallizes in monoclinic, space group P21/n with a=11. 206 (4 ), b=18. 016 (9), c=14. 465 (5) A, β=98. 00(3)°, V=2891. 9 A, Z=2, Dc=2. 69 g/cm3, F(00...The complex Na2 [CrW3O4(O2CCH3)8]2·H2O (Mr = 2343. 80) crystallizes in monoclinic, space group P21/n with a=11. 206 (4 ), b=18. 016 (9), c=14. 465 (5) A, β=98. 00(3)°, V=2891. 9 A, Z=2, Dc=2. 69 g/cm3, F(000) =2168. Final R= 0.043, Rw=0.049 for 3144 independent reflections with I>3σ(I).The complex anion contains two W3O4 core which were connected by two Cr atomsthrough four μ3-O atoms and eight bridging CH3COO- groups. Each of the Cr atomsand the W atoms is coordinated by six oxygen atome. The amons are linked by Na+cations to form one-dimensional infinite chain structure. The infrared spetrum of thecompound has been measured and rationally assigned.展开更多
The reaction of dipropargyl phthalate C6H41,2(CO2CH2C2H)2 1 with octacarbonyldicobalt 2 resulted in the formation of red complex C6H41,2(CO2CH2C2H)2Co2(CO)62 3, in which each Co2(CO)6 group coordinates to one of t...The reaction of dipropargyl phthalate C6H41,2(CO2CH2C2H)2 1 with octacarbonyldicobalt 2 resulted in the formation of red complex C6H41,2(CO2CH2C2H)2Co2(CO)62 3, in which each Co2(CO)6 group coordinates to one of the two CC bonds of 1. Molecular structure of complex 3 was determined by single crystal Xray analyses. The crystal belongs to the monoclinic system, space group P21/a with the following crystallographic parameters: a=8.521(2), b=29.143(6), c=12.918(7) , = 100.12(3),V=3158(2) 3, Z=4, Mr=814.09, Dc=1712 g.cm-3, F(000)=1608, (MoK)=21.37 cm-1 and final R=0.044 for 3151 observations.展开更多
The first mixed alkali-metal gallium iodate-fluoride,namely,LiGaF2(IO3)2,was successfully obtained under hydrothermal conditions.The structure of LiGaF2(IO3)2 features a novel two-dimensional(2D)[GaF2(IO3)2]layer comp...The first mixed alkali-metal gallium iodate-fluoride,namely,LiGaF2(IO3)2,was successfully obtained under hydrothermal conditions.The structure of LiGaF2(IO3)2 features a novel two-dimensional(2D)[GaF2(IO3)2]layer composed of[Ga2F4(IO3)6]4 dimers further bridged by(IO3)groups.LiGaF2(IO3)2 exhibits a wide band gap of 4.33 eV,corresponding to the ultraviolet(UV)absorption edge of 230 nm.Calculations of linear optical property revealed that LiGaF2(IO3)2 has a remarkably large birefringence of 0.181@1064 nm and 0.206@532 nm,indicating that it is a potential birefringent material that could be used from visible to UV region.This study provides a new method for the future discovery of promising optical crystals.展开更多
Nanomagnetic CoPt truncated octahedral nanoparticles （TONPs） were successfully synthesised through a facile one-pot strategy. These single crystal CoPt TONPs with an average size of about 8 nm exhibit excellent elec...Nanomagnetic CoPt truncated octahedral nanoparticles （TONPs） were successfully synthesised through a facile one-pot strategy. These single crystal CoPt TONPs with an average size of about 8 nm exhibit excellent electrocatalytic performance of both activity and stability for methanol oxidation reaction （MOR）. The mass and specific activities of CoPt TONPs is 8 and 6 times higher than that of standard commercial Pt/C, respectively. After accelerated durability test （ADT）, the loss of electrochemical surface area （ECSA） for CoPt TONPs is only 18.5%, which is significantly less than that of commercial Pt/C （68.2%）, indicating that CoPt TONPs possess much better stability than commercial Pt/C in the prolonged operation. The Curie temperature of CoPt TONPs down to 8 nm is as high as 350 K with weak ferromagntism at room temperature （RT）, which is greatly valuable for recycling in the eletrocatalytic applications.展开更多
基金The project supported by National Natural Science Foundation of China under Grant No. 19974027
文摘The formation mechanism for the body-centred regular octahedral structure of Li7 cluster is proposed. The curve of the total energy versus the separation R between the nucleus at the centre and nuclei at the apexes for this structure of Li7 has been calculated by using the method of Gou＇s modified arrangement channel quantum mechanics （MACQM）. The result shows that the curve has a minimal energy of-52.169 73 a.u. at R = 5.06ao. When R approaches infinity, the total energy of seven lithium atoms has the value of-51.996 21 a.u. So the binding energy of Li7 with respect to seven lithium atoms is 0.173 52 a.u. Therefore the binding energy per atom for Li7 is 0.024 79 a.u. or 0.674 eV, which is greater than the binding energy per atom of 0.453 eV for Li2, the binding energy per atom of 0.494 eV for Li3 and the binding energy per atom of 0.632 eV for Li5 calculated previously by us. This means that the Li7 cluster may be formed stably in a body-centred regular octahedral structure with a greater binding energy.
文摘The complex Na2 [CrW3O4(O2CCH3)8]2·H2O (Mr = 2343. 80) crystallizes in monoclinic, space group P21/n with a=11. 206 (4 ), b=18. 016 (9), c=14. 465 (5) A, β=98. 00(3)°, V=2891. 9 A, Z=2, Dc=2. 69 g/cm3, F(000) =2168. Final R= 0.043, Rw=0.049 for 3144 independent reflections with I>3σ(I).The complex anion contains two W3O4 core which were connected by two Cr atomsthrough four μ3-O atoms and eight bridging CH3COO- groups. Each of the Cr atomsand the W atoms is coordinated by six oxygen atome. The amons are linked by Na+cations to form one-dimensional infinite chain structure. The infrared spetrum of thecompound has been measured and rationally assigned.
文摘The reaction of dipropargyl phthalate C6H41,2(CO2CH2C2H)2 1 with octacarbonyldicobalt 2 resulted in the formation of red complex C6H41,2(CO2CH2C2H)2Co2(CO)62 3, in which each Co2(CO)6 group coordinates to one of the two CC bonds of 1. Molecular structure of complex 3 was determined by single crystal Xray analyses. The crystal belongs to the monoclinic system, space group P21/a with the following crystallographic parameters: a=8.521(2), b=29.143(6), c=12.918(7) , = 100.12(3),V=3158(2) 3, Z=4, Mr=814.09, Dc=1712 g.cm-3, F(000)=1608, (MoK)=21.37 cm-1 and final R=0.044 for 3151 observations.
基金the National Natural Science Foundation of China(21875248,21921001,and 21975256)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB20000000)the 100 Talents Project of Fujian Province。
文摘The first mixed alkali-metal gallium iodate-fluoride,namely,LiGaF2(IO3)2,was successfully obtained under hydrothermal conditions.The structure of LiGaF2(IO3)2 features a novel two-dimensional(2D)[GaF2(IO3)2]layer composed of[Ga2F4(IO3)6]4 dimers further bridged by(IO3)groups.LiGaF2(IO3)2 exhibits a wide band gap of 4.33 eV,corresponding to the ultraviolet(UV)absorption edge of 230 nm.Calculations of linear optical property revealed that LiGaF2(IO3)2 has a remarkably large birefringence of 0.181@1064 nm and 0.206@532 nm,indicating that it is a potential birefringent material that could be used from visible to UV region.This study provides a new method for the future discovery of promising optical crystals.
基金supported by the National Basic Research Program of China(2015CB921401)the National Instrument Program of China(2012YQ120048)+2 种基金the National Natural Science Foundation of China(51625101,51431009,51471183,51331002,51371015,11274371 and 11674023)the Instrument Development Program of Chinese Academy of Sciences(YZ201345)the Fundamental Research Funds for the Central Universities(FRF-BR-15-009B)
文摘Nanomagnetic CoPt truncated octahedral nanoparticles （TONPs） were successfully synthesised through a facile one-pot strategy. These single crystal CoPt TONPs with an average size of about 8 nm exhibit excellent electrocatalytic performance of both activity and stability for methanol oxidation reaction （MOR）. The mass and specific activities of CoPt TONPs is 8 and 6 times higher than that of standard commercial Pt/C, respectively. After accelerated durability test （ADT）, the loss of electrochemical surface area （ECSA） for CoPt TONPs is only 18.5%, which is significantly less than that of commercial Pt/C （68.2%）, indicating that CoPt TONPs possess much better stability than commercial Pt/C in the prolonged operation. The Curie temperature of CoPt TONPs down to 8 nm is as high as 350 K with weak ferromagntism at room temperature （RT）, which is greatly valuable for recycling in the eletrocatalytic applications.
