THE CRYSTAL STRUCTURE OF RARE EARTH COMPLEX WITH AMINO ACIDS Ⅱ The Crystal Structure of Gtutamate Comptex of Erbium Perchtorate

The crystat structure of {[Er;（L—Glu）;（H;O）;]（ClO;）;·3H;O);has been studied by X-ray diffraction. The crystal is monoctinic with space group P2;and cell parameters a=19.987（3） , b=16.505（3） , c=11.040（2） , β=104.69（1）;, V=3538（1） , Z=2, Dc=2.29 g. cm;, μ=53.2 cm;, F（000）=2384. The asymmetric unit contains two complex motecules and four centre ions. Each erbium （Ⅲ） is coordinated by five oxygen donors from four different glutamates and four oxygen donors from the aqua ligand to form a nine coordination potyhedron. The mean distances of Er—0 （carboxylate） and Er—Ow are 2.439 and 2.41 respectivety. The finat R and Rw are 0.043 and 0. 058, respectivety.

On the Crystal Structure of [Cu(OH)_2(H_2O)_2(4-C_5H_4NCOOH)_2]

The compound described as [Cu(OH)2(H2O)2(4-C5H4NCOOH)2] in Chin. J. Struct. Chem., 2001, 20: 478-480 is instead the compound [Cu(H2O)4(4-C5H4NCOO)2], whose crystal structure has already been published elsewhere.

THE CRYSTAL STRUCTURE OF [Co(TPPO)_4][Co (NCS)_3TPPO]_2

The title complex [Co(TPPO)_4] [Co(NCS)_2TPPO]_2 (TPPO=triphenylphosphine oside) was prepared by solvent evaporation method. Its crystal structure was determined by x-ray diffraction method. The crystal is rhombohedral with space group R3. The unit cell parameters are presented and the structure has been refined to a final R of 0.064.

SPECTRAL VARIATION AND CHARACTERISTICS OF LOW VALENCY RARE EARTH IONS IN COMPLEX OXIDESⅢ.EFFECT OF THE CRYSTAL ENVIRONMENT AND CHEMICAL FACTORS ON LUMINESCENCE PROPERTIES OF EUROPIUM (Ⅱ) ION

In this paper,the influence of crystal-field on the Luminescence properties of Eu^(2+) in complex oxides are studied theoretically by using purely electrostatic model,the dependence of the 4f^65d levels on Eu-O bond distance is given.Quantum chemistry calculation shows that the splitting extent of 4f^65d energy band in cubic or in octahedral fields will be inversely proportional to R^5,where R is the distance of Eu^(2+) to oxygen ligand.The value of R affects slightly the location of the centre of 4f^65d energy band.According to the exper- imental spectrum data,we have discussed the influence of the host chemical composition,the replaced sites of Eu^(2+) and degree of covalency of Eu-O bond on luminescence properties of Eu^(2+).Some regularity of fluorescence spectrum was observed. In alkali-alkaline earth-phosphates,the splitting extent of 4f^65d band (△E) becomes smaller as the Eu-O bond distance (R) increases.In Na_(3-x)(PO_4)_(1-x)(SO_4)_x and Na_(2-x)CaSi_(1-x)P_xO_4 hosts,d-d emission peak of Eu^(2+) will shift to shorter wavelength with the increase of x's value. The crystal structure data show that Eu^(2+) in K_2Mg_2(SO_4)_3 is affected more strongly by crystal-field and covalancy than in KMgF_3,so K_2Mg_2(SO_4)_3:Eu^(2+) emits blue light (E_(em)~m=400nm) and KMgF_3:Eu^(2+) produces ultraviolet fluorescence.

The crystal structure of pearls and related shellfish's shells

In this article we explored the crystal structure of a few pearls and shellfish's shell of fresh water and sea water, and found that pearls and nacreous layer (perhaps and prismatic layer) of shells are all the same: CaCO3, orthorhombic system, aragonite structure and the value of lattice spacings are almost identical. This shows that the pearls of fresh water and sea water are all the same in nature.

Redetermination of the Crystal Structure of Vesignieite

Vesignieite, Cu_3Ba(VO_4)_2(OH)_2, crystallizes in space group C_2 / m with a°=1.0270(2), b°=0.5911(1),c°=0.7711(2)nm and β=116.42(3)°. The intensity data were collected with the RIGAKU RASA-IISsingle-crystal four-circle diffractometer. The structure was determined by Patterson and Fourier methods andrefined by the least-square technique to a final R index of 0.051 for 614 independent diffraction points with|F? |>3σ|F?|. The crystal structure analysis shows that vesignieite has a layer structure parallel to (001). The powder diffraction lines were reindexed.

Ionization of Atoms and the Thomas－Fermi Model for the Electric Field in Crystal Planar Channels

The electric field in the crystal planar channels is studied by the Thomas-Fermi method. The Thomas-Fermi equation and the corresponding boundary conditions are derived for the crystal planar channels. The numerical solution for the electric field in the channels between (110) planes of the single crystal silicon and the critical angles of channelling protons in them arc shown. Reasonable agreements with the experimental data are obtained. The results show that the Thomas-Fermi method for the crystal works well in this study, and a microscopic research of the channel electric field with the contribution of all atoms and the atomic ionization being taken into account is practical.

EFFECT OF VACUUM ON THE CRYSTAL FORM AND MORPHOLOGY OF THE EVAPORATED FILM OF COPPER PHTHALOCYANINE

In a previous paper, we have reported the relationship between the crystallite orientation of the evaporated film of copper phthalacyanine （PcCu） （α-form） and the incident angle of molecular beam at 10-5 torr. In this paper, we shall show some research results about vacuum effects on the crystal forms and the morphology of the evaporat-

The crystal structure of a new gossypol derivative-8,8’-dibromo-6,6’7,7’-tetramethoxy-5,5’-diisopropyl-3,3’-oxydimethylene dinaphtho[2,1-b:2’,l’-d]furan

8,8′-Dibromo-6,6′, 7,7′-tetramethoxy-5,5′-diisopropyl-3,3′-oxydimethylene dinaphtho[2,1- b:2′, 1′-d]furan, C_(32)H_(30)Br_2O_; M. W.=670; triclinic; space group P1; a=8.896(2), b=10.216(1), c= 10.423(1)A, α=108.48(1), β=119.36(1), γ=99.26(1); V=723.5A^3; Z=1, D_(cal.)=1.479 g.cm^(-3). Mo K_α=28.11cm^(-1), F(000)=326, T=293K. The structure was solved by direct method and full-matrix least-squares refinement converged at R=0.034 for 2377 observed reflections. The oxygen atom in seven-membered ring exists in a disordered arrangement. Both bisnaphthalene and oxygen-containing five-membered ring have planar conformations with dihedral angle 6°, showing marked aromatic feature.

The reactivities of Mo cluster——A selective substitution reaction of the bridging(dtp)ligand and the crystal structure of{Mo_3S_4(μ-O_2CR)(dtp)_3(Py)}

The reaction of trinuclear molybdenum cluster{Mo_3S_4(μ-dtp)(dtp)_3(H_2O)}1[dtp= S_2P(OEt)_2]with RCO_2Na(R=H,CH_3)in the presence of Py gave the black compounds{Mo_3S_4(μ- O_2CR)(dtp)_3(Py)}(2,R=H,3,R=CH_3).Both compounds are characterized by X-ray crystallo- graphy.It is shown that crystals 2 and 3 belong to space group P with Z=2 and a=10.519(2),b= 12.121(2),c=15.757(2),α=93.27(1),β=94.63(1),γ=105.22(1)°,V=1925~3 for crystal 2,whereas a=9.556(2),b=14.067(7),c=15.914(9),α=101.41(4),β=101.44(4),γ=74.26(3)°,V=1994~3 for crystal 3.The final R factors are 0.041 and 0.048 for crystal 2 and 3 respectively.The structure analysis indicates that(O_2CR)^- ligand selectively substitutes the bridging(dtp)ligand.This type of Mo_3 cluster molecule where structure contains two species of bidentate ligand is for the first time to be obtained by us.

A new route to prepare the mixed oxo-ethylidynecapped trinuclear tungsten(Ⅳ)cluster and the crystal structure of H_2Na_3[W_3O(CCH_3)(O_2CCH_3)_6(H_2O)_3][H_2W_(12)O_(40)]·13.5H_2O

The synthesis and the structural characterization of the title compound HNa[WO（CCH）-（OCCH）（HO）][HWO]·13.5 HO are described.It is known that the mixed oxo-ethylidyne-capped tritungsten cluster can be obtained by Zn dust reduction of NaWO·2HO in acetic anhydride.The title compound has been characterized by X-ray diffraction,UV/VIS andH NMR spectra.The tungsten atoms in the cluster cation and anion are in the oxidation states of W（IV）and W（VI）respectively.The crystal is rhombohedral with the space group R32,a=17.058（3）,c=49.665（9）,γ=120°,V=12516（9）,Z=6,final R=0.037 for 2071 reflections with I≥3σ（I）.Boththe cluster cation and anion have a Csymmetry.The important interatomic distances in angstroms forthe cluster cation are:W—W,2.730（2）;W—μ-O,2.00;W—O（carboxyl）,2.12;W—O,2.18（2）.

The crystal structure and conformation of N-[2,2-dimethyl-3-(2-methylpropenyl)-cyclopropylcarbonyl]-5-methylisoxazolin-3-one

The title compound has been synthesized and its crystal structure was determined by X-ray crystallographic method.The crystal is triclinic,space group P-1,with unit cell dimensions a=6.146 (5),b=8.473(6),c=14.383(5)(?);a=77.47(4),β=82.84(4),γ=69.00(8)°and Z=2.The results obtained reveal that the molecule of the title compound keeps a long conjugative system in- volving C=C double bond,cyclopropane ring,carbonyl group and isoxazolinone ring and adopts a low energy conformation including s-trans of C=C double bond,s-cis of carbonyl group with respect to the three-membered ring and like-s-trans of carbonyl group with the carbonyl group within the heterocyclic moiety.

The determination of the crystal struoure of tetra-potassium uranyl tricarbonate by powder X-ray diffraction method

A uranyl compound, K_4UO_2(CO_3)_3 has been characterized by powder X-ray diffraction method. M. W.=606.46, monoclinic, C2/c (No. 15), a=1.0240(7), b=0.9198(4), c=1.2222(12)nm, β=95.12(4)°,V=1.1466(5)nm^3, Z=4, D_m=3.468g/cm^3, D_c=3.513g/cm~, λ(Cu Kα_1)=O.1540598nm, T=298K. The structure was solved by heavy atom method and Fourier synthesis, and refined by full- matrix least-squares method to R=0.1185 for 275 reflections. The uranium (Ⅵ) atom is in an eight-coordinate distorted hexagonal-bipyramidal environment with creasy fan shape. The linear uranyl group approaches to perpendicular to the equatorial plane in which three carbonate groups are chelated. U(Ⅵ) has two linear oxygen atoms closer to it (U-O=0.1767 (5) nm) than six other neighbours (U-O ranging from 0.2516 to 0.2568nm). The distances between carbon atoms and uncoordinated oxygen atoms are 0.122 (1) and 0.123(1) nm, which are distinctly different from those between carbon and coordinated oxygen atoms (mean 0.134(6) nm). This fact reveals the non-eq- uivalence of one oxygen atom to the other two in each carbonate. In K_4UO_2(CO_3)_3, the O-O dis- tance for the adjacent carbonate groups is 0.2794(4)nm approaching to the sum of Van der Waals radii of two oxygen atoms. The K-O distances vary between 0.2667 and 0.3131nm, and each anion is immediately surrounded by six potassium ions, only four of which can be considered to belong to the same structural formula unit, and they are symmetrically located above and below the equatorial plane.

The crystal structure and conformation of 15phenyl-bicyclo[10.3.0]pentadec-1(12)-en-13-one

The title compound has been synthesized and its crystal structure determined by X-ray crystal- lographic method.The crystal is monoclinic,space group C2/c,with unit cell dimensions a=19.260 (3),b=11.217(1),c=15.997(1)(?);β=92.08(2)°and Z=8. This is the first crystal structure determined in the series of bicyclo[10.3.0]pentadec-1(12)-en- 13-one derivatives.The structure and the conformation of the cis-cyclododecene moiety in this compound is demonstrated to be closely similar to the lowest energy conformer[lene 2333].