Single crystal of Li2Zn2（MoO4）3 has been grown from a flux of Li2MoO4 by the top-seeded solution-growth method, and its stnicture was refined by the Rietveld method. It belongs to the orthorhombic system, space grou...Single crystal of Li2Zn2（MoO4）3 has been grown from a flux of Li2MoO4 by the top-seeded solution-growth method, and its stnicture was refined by the Rietveld method. It belongs to the orthorhombic system, space group Pnma with a = 5.1114, b = 10.4906 and c = 17.6172A. Good agreement between the experimental and calculated profile （Rp = 6.69%, Rwp = 9.73% and Rexp = 6.58%） was reached.展开更多
A single crystal of Li3Ba2Ho3（WO4）8 was obtained from a flux of Li2WO4 under an air atmosphere. The structure of the pure crystal was determined by single-crystal X-ray diffraction method. It crystallizes in the mon...A single crystal of Li3Ba2Ho3（WO4）8 was obtained from a flux of Li2WO4 under an air atmosphere. The structure of the pure crystal was determined by single-crystal X-ray diffraction method. It crystallizes in the monoclinic system, space group C2/c with a = 5.240（4）, b = 12.790（10）, c = 19.247（15）, β = 91.921（15）°, V = 1289.1（18）3, Z = 2, Mr = 2773.09, Dc = 7.144 g/cm3, μ = 47.732 mm-1, Rint = 0.0693, F（000） = 2340, the final R = 0.0472 and wR = 0.1221 for 1535 observed reflections （I 2σ（I））. The Li3Ba2Ho3（WO4）8 has a high structure disorder with one 8f site shared by Li（1） and Ho ions with occupancy of 0.25 and 0.75, respectively. The fundamental structure is constituted by distorted square antiprisms Ho/Li（1）O8 with C1 symmetry, distorted Li（2）O6 octahedra and BaO10 polyhedra. The optical properties were investigated by IR and absorption spectroscopy, and the emission cross sections and gain cross sections of 5I7 → 5I8 of Ho3＋ were calculated.展开更多
This paper reported the crystal growth and spectroscopy characters of Cr^3＋：Li2Mg2（MoO4）3. The refractive index of Cr^3＋：Li2Mg2（MoO4）3 crystal is 1.87 and the hardness is 270 I-IV. This crystal shows broadband...This paper reported the crystal growth and spectroscopy characters of Cr^3＋：Li2Mg2（MoO4）3. The refractive index of Cr^3＋：Li2Mg2（MoO4）3 crystal is 1.87 and the hardness is 270 I-IV. This crystal shows broadband absorption property with peak wavelength at about 495 and 699 nm. The absorption crosssection is 14.75 × 10^-20 cm^2 at 495 nm and 9.63 ×10^-20 cm^2 at 699 nm, respectively. The crystal field strength and energy levels of Cr^3＋ ion were calculated based on the spectroscopic data. The Cr^3＋：Li2Mg2（MoO4）3 crystal shows broadband emission extending from 750 to 1300 nm even excited at 10 K. The room temperature emission cross section is 72×10^-20 cm^2 at 926 nm. A discussion of the relation between the spectroscopic properties and crystal field parameters of Cr^3＋：Li2Mg2（MoO4）3 crystal was presented based on the solid state spectroscopytheory.展开更多
Synthesis of complexes（η;-CH;C;H;）M（CO）;NO（M=Mo,I;M=W,II）and clusters（η;-CH;C;H;）M（μ;-NH）(μ;-NO) （μ;-CO）Fe;（CO）;（M=Mo,III:M=W,IV）,based on the reaction of （η;-C5;）M（CO）;Cl with Na[Fe（CO）;NO...Synthesis of complexes（η;-CH;C;H;）M（CO）;NO（M=Mo,I;M=W,II）and clusters（η;-CH;C;H;）M（μ;-NH）(μ;-NO) （μ;-CO）Fe;（CO）;（M=Mo,III:M=W,IV）,based on the reaction of （η;-C5;）M（CO）;Cl with Na[Fe（CO）;NO] at room tem-perature,have been demonstrated,The crystal structures of II and IV arealso presented.展开更多
The crystal structure of a new type arylarsonic polytungstate[C(NH_)_]_4[p-NH_3C_6H_4As)_2- W_6O_(25)]·4H_O was determined by single-crystal X-ray diffraction analysis.It belongs to triclinic,space group P,with c...The crystal structure of a new type arylarsonic polytungstate[C(NH_)_]_4[p-NH_3C_6H_4As)_2- W_6O_(25)]·4H_O was determined by single-crystal X-ray diffraction analysis.It belongs to triclinic,space group P,with cell dimensions a=12.863(3),b=18.912(3),c=21.383(4)α=91.14(2)°,β= 93.65(3)°,γ=92.25(3)°,V=5185.9~3,Z=4,D_c=2.753g/cm^3.The intensity data were collected on an Enraf-Nonius CAD4 diffractometer with Mo Kα radiation.The positions of all tungsten and arsenic atoms were determined by direct method.The other non-hydrogen atoms were revealed by difference Fourier synthesis.The structure was refined by fullmatrix least-squares procedure to a final R value of 0.070.The crystal structure contains two similar but nonidentical molecules.Two similar anions consist of a ring of six WO_6 octahedra,which are connected with one face-sharing,two corner-sharings and three edge-sharings,and two p-aminophenylarsonic tetrahedra capped above and below the ring. In each WO_6 ring,four tungsten atoms,which are joined with edge-sharing oxygen atoms,are almost coplanar,while the two others,which are joined with face-sharing oxygen atoms,protrude out of the ring towards the same side.The two arsenic atoms in each anion are not equivalent in their bonding manner.In each anion,all non-hydrogen atoms of each organic group are in the same plane.Each molecule contains one anion,four C(NH_2)_3^+ cations and four water molecules.There are many hydrogen bonds between cations and anions throughout the whole crystal.The amino groups can accept protons,so that the charge of the resulting anion decreases and[(RAs)_2W_6O_(25)]^(4-)type complexes are formed.展开更多
基金the National Natural Science Foundation of China (No. 50672123)
文摘Single crystal of Li2Zn2（MoO4）3 has been grown from a flux of Li2MoO4 by the top-seeded solution-growth method, and its stnicture was refined by the Rietveld method. It belongs to the orthorhombic system, space group Pnma with a = 5.1114, b = 10.4906 and c = 17.6172A. Good agreement between the experimental and calculated profile （Rp = 6.69%, Rwp = 9.73% and Rexp = 6.58%） was reached.
基金supported by the National Natural Science Foundation of China(20971123,51002153,21007070,51102232,61106004 and 21103191)
文摘A single crystal of Li3Ba2Ho3（WO4）8 was obtained from a flux of Li2WO4 under an air atmosphere. The structure of the pure crystal was determined by single-crystal X-ray diffraction method. It crystallizes in the monoclinic system, space group C2/c with a = 5.240（4）, b = 12.790（10）, c = 19.247（15）, β = 91.921（15）°, V = 1289.1（18）3, Z = 2, Mr = 2773.09, Dc = 7.144 g/cm3, μ = 47.732 mm-1, Rint = 0.0693, F（000） = 2340, the final R = 0.0472 and wR = 0.1221 for 1535 observed reflections （I 2σ（I））. The Li3Ba2Ho3（WO4）8 has a high structure disorder with one 8f site shared by Li（1） and Ho ions with occupancy of 0.25 and 0.75, respectively. The fundamental structure is constituted by distorted square antiprisms Ho/Li（1）O8 with C1 symmetry, distorted Li（2）O6 octahedra and BaO10 polyhedra. The optical properties were investigated by IR and absorption spectroscopy, and the emission cross sections and gain cross sections of 5I7 → 5I8 of Ho3＋ were calculated.
基金supported by the National Natural Science Foundation of China(Nos.61308085 and 61475158)
文摘This paper reported the crystal growth and spectroscopy characters of Cr^3＋：Li2Mg2（MoO4）3. The refractive index of Cr^3＋：Li2Mg2（MoO4）3 crystal is 1.87 and the hardness is 270 I-IV. This crystal shows broadband absorption property with peak wavelength at about 495 and 699 nm. The absorption crosssection is 14.75 × 10^-20 cm^2 at 495 nm and 9.63 ×10^-20 cm^2 at 699 nm, respectively. The crystal field strength and energy levels of Cr^3＋ ion were calculated based on the spectroscopic data. The Cr^3＋：Li2Mg2（MoO4）3 crystal shows broadband emission extending from 750 to 1300 nm even excited at 10 K. The room temperature emission cross section is 72×10^-20 cm^2 at 926 nm. A discussion of the relation between the spectroscopic properties and crystal field parameters of Cr^3＋：Li2Mg2（MoO4）3 crystal was presented based on the solid state spectroscopytheory.
文摘Synthesis of complexes（η;-CH;C;H;）M（CO）;NO（M=Mo,I;M=W,II）and clusters（η;-CH;C;H;）M（μ;-NH）(μ;-NO) （μ;-CO）Fe;（CO）;（M=Mo,III:M=W,IV）,based on the reaction of （η;-C5;）M（CO）;Cl with Na[Fe（CO）;NO] at room tem-perature,have been demonstrated,The crystal structures of II and IV arealso presented.
文摘The crystal structure of a new type arylarsonic polytungstate[C(NH_)_]_4[p-NH_3C_6H_4As)_2- W_6O_(25)]·4H_O was determined by single-crystal X-ray diffraction analysis.It belongs to triclinic,space group P,with cell dimensions a=12.863(3),b=18.912(3),c=21.383(4)α=91.14(2)°,β= 93.65(3)°,γ=92.25(3)°,V=5185.9~3,Z=4,D_c=2.753g/cm^3.The intensity data were collected on an Enraf-Nonius CAD4 diffractometer with Mo Kα radiation.The positions of all tungsten and arsenic atoms were determined by direct method.The other non-hydrogen atoms were revealed by difference Fourier synthesis.The structure was refined by fullmatrix least-squares procedure to a final R value of 0.070.The crystal structure contains two similar but nonidentical molecules.Two similar anions consist of a ring of six WO_6 octahedra,which are connected with one face-sharing,two corner-sharings and three edge-sharings,and two p-aminophenylarsonic tetrahedra capped above and below the ring. In each WO_6 ring,four tungsten atoms,which are joined with edge-sharing oxygen atoms,are almost coplanar,while the two others,which are joined with face-sharing oxygen atoms,protrude out of the ring towards the same side.The two arsenic atoms in each anion are not equivalent in their bonding manner.In each anion,all non-hydrogen atoms of each organic group are in the same plane.Each molecule contains one anion,four C(NH_2)_3^+ cations and four water molecules.There are many hydrogen bonds between cations and anions throughout the whole crystal.The amino groups can accept protons,so that the charge of the resulting anion decreases and[(RAs)_2W_6O_(25)]^(4-)type complexes are formed.
