Synthesis and crystal structure of β-hexanitrohexaazaisowurtzitane

A polycyclic caged compound with high strain——hexanitrohexaazaisowurtzitane (HNIW)——has been synthesized via a three-step reaction: condensation, hydrogenolysis debenzylation and nitrolysis, starting with benzylmine and glyoxal. HNIW is the most powerful high energy density compound (HEDC) ever tested. β-HNIW possesses a caged structure consisting of two five-membered rings and one six-membered ring with a nitro group attached to each of the six bridging nitrogens. The nitro group lies basically within a plane. The lengths of C--C bonds of β-HNIW range from 0.156 nm to 0.159 nm, 0.002--0.005 nm longer than the sp~3 C-C bond. The β-HNIW's crystal belongs to orthorhombic system and space group Pca2_1 with parameters: a=0.9670 (2), b=1.1616 (2), c=1.3032 (3) nm; V=1.4638(5) nm~3, Z=4; D_c=1.989 g/cm~3 and D_m=1.982 g/cm~3.     

Hydrothermal Synthesis and Crystal Structure of Inorganic-organic Hybrid Compound [H3NC2H4NH2]VOPO4

An inorganic-organic hybrid compound, [H_3NC_2H_4NH_2]VOPO_4 was synthesized by means of the hydrothermal method. It was crystallized in a monoclinic system, a space group P2_1/c, with the crystal cell parameters: a=0.92285(11) nm, b=0.72994(9) nm, c=0.98495(11) nm, β=101.280(3)°, V=0.65067(13) nm~3, M_r=223.02 g/mol, D_c=2.277 g/cm~3, Z=4, R=0.0315, ωR=0.0865, GOF=1.085. The VO_5N octahedra chains are corner-linked by PO_4 tetrahedra; the VO_5N octahedra are all trans-linked with V—O bonds being alternately short and long. The monoprotonated ethylenediamine was intercalated between the layers with one end coordinating to V and the other end as an H-bond donor interacting with a terminal O atom of PO_4 from a neighboring sheet. The elementary analysis, infrared spectrum characters and thermal stability were also given.     

Molecular Chirality and Chiral Superlattice in Crystal of Tetrakis[（pyrrol-1-yl）methyl]methane

The crystal structure of tetrakis[(pyrrol-1-yl)methyl]methane was determined by X-ray diffraction measurement, and the result shows that it belongs to monoclinic crystal system, space group is P21/n, with a=0.9284(3) nm, b=1.0950(6) nm, c=1.8749(8) nm; α=γ= 90.00(4)°, β=103.63(3)°, V=1.8523(14) nm3, Z=4, ρcalcd.=1.192 kg/m3, μ=0.072 nm-1, F(000)=712, R1=0.0854, wR2=0.1884. It has been found that the molecules exist in two enantiomeric states. Enantioselective self-assemblies such as one-dimensional molecular stacks in a single handedness, homochiral monolayers and a chiral superlattice are specified in this racemic crystal. In addition, a simple technique is advocated to distinguish chiral states from tetrahedral molecules in the solid state. The present R/S nomenclature of the tetracooradinated carbon centers is used solely for its convenience to distinguish the two enantiomeric states, but not used to determine the absolute configurations.     

Synthesis,Crystal Structure and Anion Recognition Property of a Flexible Urea-functionalized Receptor

A flexible urea-functionalized receptor bearing two p-nitrobenzene units was designed and synthesized from the reaction of precursors 4-nitrophenyl isocyanate and 1,2-bis(2?-aminophenoxy) benzene. The receptor was characterized by ~1 H NMR, MS, FTIR and elemental analysis, and the crystal structure of the receptor was determined by X-ray diffraction analysis. The crystal belongs to the orthorhombic system, space group Pca21 with a = 12.740(2), b =14.133(3), c = 15.842(3) ?, V = 2852.4(9) ?~3, Z = 4, M_r = 620.57, D_c = 1.445 g/cm~3, F(000) = 1288,= 0.0585 and wR = 0.1032 for 3177 observed reflections(Ⅰ 2σ(Ⅰ)), and R = 0.1304 and wR =for all data. The results show that the receptor displays selective recognition ability for H_2PO_4~– in DMSO with a series of anions using UV-Vis absorption spectra technique. Furthermore, the coordination reaction of the receptor with H_2PO_4~– was investigated via UV-Vis spectra and ~1 H NMR.The stoichiometric ratio and the association constant(Ka) of the coordination reaction were obtained as well.     

Synthesis, Structure and Optical Properties of Cerium（Ⅲ） Triphosphate CeP3O9

The single crystal and crystallized powder of triphosphate CeP3O9 have been syn-thesized,and the space group of CeP3O9 has been determined to be C2221 with the cell parameters of a=8.6059,b=11.2437,c=7.3518 ,V=711.4(3) 3,Z=4,Dc=3.520 g/cm3,F(000)=700,R=0.0377 and wR=0.0930. The absorption and emission spectra have been measured,for which the strongest absorption and emission peaks are located at 280 and 320 nm,respectively. The density of state (DOS) and dielectric function have been calculated by the DFT method. The crystal is transparent provided the wavelength is larger than 341 nm,and the observed ultraviolet cut-off edge is at about 350 nm for a polycrystalline power sample. It is possible that the triphosphate CeP3O9 will become an ultraviolet emission material.     

An ab initio Study on the Structural and Bonding Properties of Li_2Si_3O_7

A theoretical study on the structural and electronic properties of Li2Si3O7 is performed by using density functional theory(DFT) method.The molecular structure of the crystal and two kinds of [SiO4]-tetrahedra with different number of non-bridging oxygen(Qn) are analyzed.The structure of crystal Li2Si3O7 can be considered as a framework of corner-sharing tetrahedra.From the band structure(BS),total density of state(TDOS) and projected density of state(PDOS) of the crystal,the structures of Q3,Q4,and LiO4 tetrahedra as well as their bonding characters are presented.For lithium trisilicate,we find the bond cation-NBO(nonbridging oxygen and oxygen atoms bonding to one silicon atom only) is stronger than the bond cation-BO(bridging oxygen and oxygen atoms bonding to two silicon atoms).By analyzing the ionicity of two different types of bonds of silicon-oxygen according to the Mulliken population analysis,we also find that the Si-NBO bonds have higher ionicity than Si-BO for crystalline lithium trisilicate,which agrees with other lithium silicates.     

A New Modification of Tellurite Phosphate: β-Te_3O_3(PO_4)_2

A new modification of tellurite phosphate, β-Te_3O_3(PO_4)_2, has been synthesized under hydrothermal conditions and its crystal structure was determined by single-crystal X-ray diffraction. It crystallizes in the monoclinic space group P2_1/n(No. 14), with a = 11.115(5), b = 4.7033(19), c = 17.287(7) ?, β = 106.086(5)°, V = 868.3(6) ?~3, Z = 4, P_2 Te_3 O_(11), M_r = 620.74, D_c = 4.748 g/cm~3, μ(Mo Kα) = 10.438 mm~(–1) and F(000) = 1096. The final full-matrix least-squares refinement converged to R = 0.0227, wR = 0.0534 for 1984 observed reflections with I 2σ(I), and R = 0.0240, w R = 0.0540 for all data(2070) and S = 1.117. β-Te_3O_3(PO_4)_2 is polymorphic with the known α-Te_3O_3(PO_4)_2(Weil H. M. et al. Z. Anorg. Allg. Chem. 2003, 629, 1068-1072). The crystal structure of β-Te_3O_3(PO_4)_2 features a three-dimensional(3D) network composed of Te_6 O_(22)~(20)-hexanuclear clusters interconnected by PO_4 groups. Te_6 O_(22) hexanuclear cluster is built from three Te_2 O_8 dimers(edge-sharing TeO_5 square pyramids) linked to each via sharing O-corners. The structure difference between α-and β-forms of Te_3O_3(PO_4)_2 lies in the polymerization of tellurite oxides Te_nO_m. 1D infinite ~1_∞{[Te_3 O_(11)]~(10-)} single chains are presented in α-Te_3O_3(PO_4)_2, while 0D discrete Te_6 O_(22) hexanuclear clusters are observed for β-Te_3O_3(PO_4)_2. Moreover, thermal analyses, infrared spectra and UV-Vis-NIR diffuse reflectance are also presented.     

The synthesis and crystal structure of heteronuclear complex of lanthanide with sulfo-salicylic acid [Na3YLa2(C7H3SO6)4.26H2O]n

The titled complex has been synthesized by the reaction of sodium sulfo-salicylate with lanthanum and yttrium perchlorate. The crystal structure has been determined by single crystal X-ray diffractometry. The crystal is monoclinic with space group C2/c. The unit cell parameters are as follows: a=16.289(8), b=18.323(8), c=22.044(8) A, β=106.34(2)°, V=6314(6) A3, Z=4 and Dc=1.764 g/cm3. The structure was solved by direct method. The least-square refinement based on 3776 observed reflections [F > 6σ(F)] converged to a final R=8.6% and F(000) is 3548. Yttrium ion with eight-coordinate is located in central of the molecule, the two lanthanum ions with ten-coordinate are located at the two sides of yttrium ion. There are two positions for Na in the molecule, one is in the C2 axis with six coordinate, the other one is in a general position with five-coordinate.     

Structure Analysis of Beta-alumina Synthesized by Solid State Reaction

The crystal structure of a solid electrolyte, beta-Al2O3, was investigated by XRD analysis and demonstrated by Diamond software. Its chemical formula was verified by the Ag ion molten salt exchange method and X-ray fluorescence analysis(XRF). The chemical formula of β-Al2O3 is Na2O·8.52Al2O3, and its crystal is of hexagonal, space group P63/mmc, with a = 5.5941  and c = 22.5300 . The chemical formula of β'-Al2 O is Na2O·6.03Al2O3, and its crystal is of trigonal, space group R 3 m, with a = 5.6017 and c = 33.6219 . The maximum span in the sodion migration of β'-phase(2.4283 ) is only about a third of that for the β'-phase(6.9037 ), so the β'-phase has higher ionic conductivity than the β-phase.     

Prominently Promoting the Formation of Poly(butylene adipate) α-Form Crystals by Coalescing from Inclusion Complex

We successfully use a co-precipitation method to prepare inclusion complex between poly(butylene adipate)(PBA) chains(guest component) and urea molecules(host component). The PBA/urea inclusion complex is confirmed to adopt a hexagonal crystal modification with lattice parameters of a = 8.14 ? and c = 10.92 ?, and the interaction between PBA chains and urea is van der Waals force. The singly isolated PBA chains are suggested to take some gauche conformation, which is different from the all-trans conformation in β-form PBA. Furthermore, we employ the isolated PBA chains which are uniformly pre-established in a specific conformation in urea channels to regulate the crystal form of PBA for the first time. After removing the host urea molecules, the coalesced PBA chains are found to solely crystallize into α-form crystals at different coalescing temperatures. By comparing the FTIR spectra, it is found that PBA chains in inclusion complex plausibly contain some similar conformers as those in α-form crystal, which is suggested to be the intrinsic reason for the sole formation of α-form crystals. This research proves that inclusion complex can be used as a very effective method to regulate polymorphism of semi-crystalline polymers.     

Synthesis,Single-crystal Structure,and Computational Studies of a Yavapaiite Structure Compound:Pb(Sb_(0.5)Fe_(0.5))(PO_4)_2

The single crystals and powder of a Yavapaiite Structure phosphate,namely,PbSb_(0.5)Fe_(0.5)(PO_4)_2,were synthesized by solid state method and characterized by X-ray single-crystal diffraction and powder diffraction.The title compound crystallizes in the monoclinic system,space group C2/c(No.15) with a = 16.716(4),b = 5.186(7),c = 8.130(2) ?,β = 114.93(6)o,Z = 4,R(I 2s(I)) = 0.0430,R indices(all data) = 0.0460,and T = 293(2) K.The title compound belongs to the Yavapaiite Structure A(Ⅱ)M(Ⅳ)(PO_4)_2 compounds,and the Sb1 atom and Fe1 atoms occupy the same site(M) and their occupancy factors are refined to be 0.5 and 0.5 having a sum occupancy factor of 1.0.Its structure consists of [M(PO)_4]_2 nn layers running parallel to the(b,c) plane built up of cornerconnected MO_6 octahedra and PO_4 tetrahedra.Additionally,the calculations of energy band structure,and density of states have been performed with the density functional theory method.The studies of computational calculation and UV experimental results show that the new compound is an indirect band-gap insulator.     

Syntheses and Structures of Sil abridged Hafnocene Dichlorides

The present paper covers three silabridged hafnocene dichlorides(1, 2 and 3) prepared by sequential reactions of α, ω-dichloropermethyl polysilane with cyclopentadienyl sodium, n-butyl lithium and hafnium tetrachloride. Their structures were characterized by elemental analyses, UV, 1H(13C) NMR and MS. Furthermore the crystal and molecular structures of 1 and 2 were determined by X-ray diffraction method. The crystal of 1 is monoclinic, space group C2/c with a=1. 3401(4), b=0. 9977(3), c = 1. 0922(4) nm; β=94. 07(1)° V=3. 6342 nm3, Z = 2, Dc = 2.155 g·cm-3. The final deviation factor R = 0. 064. The crystal of 2 is monoclinic, space group P21/c with a=0.0847(1), b=1.5181(1), c=2.9824(2) nm; β= 94. 07(1)°? V=3.634 nm3; Dc= l. 805 g·cm-3. The final deviation factor R = 0. 033. The relationship between the silabridged structure and spectral properties is also discussed.     

Growth and Spectroscopic Investigations of Disordered Nd3+:Li3Ba2La3(MoO4)8 Crystal

Nd3+: Li3Ba2La3(MoO4)8 crystal has been grown from a flux of Li2MoO4 by the top seeded solution growth method (TSSG) and its structure was confirmed by X-ray diffraction. The polarized absorption spectra, fluorescence spectra and fluorescence decay curve of the crystal were measured. The main spectral parameters were calculated by the Judd-Ofelt theory and compared with other Nd-doped crystals. The broad absorption bands and the large absorption cross sections around 805 nm indicate that the crystal is very suitable for diode-laser pumping. The broad emission bands around 1060 nm show that the crystal is a potential medium for tunable and short pulse lasers. The quantum efficiency of the crystal is up to 95%, which is higher than the value for Nd3+:YVO4 and Nd3+:YAG and comparable to that of other disordered molybdate crystals. The excellent spectroscopic properties show that Nd3+:Li3Ba2La3(MoO4)8 crystal may be regarded as a potential solid state laser host material for diode laser pumping.     

RESEARCH ON TRINUCLEAR MOLYBDENUM CLUSTER COMPOUNDS——CRYSTAL AND MOLECULAR STRUCTURE OF Mo_3(μ_3—O)(μ_2—S_2)_3[S_2P(OEt)_2]_3I

The title crystals are golden yellow rhomboic plates, belonging to the monoelinic system. The space group is P_(B_1)/n with unit cell parameters a=16.570(2), b=12.370(1), c=20.007(2), β=99.97(1)°, Z=4, D_c=1.938 g.cm~(-3). The crystal structure was solved mainly by the heavy atom method and refined by the full-matrix least-squares to a final R factor of 0.047 based on 4387 unique reflections with intensities I≥2σ(I). The results show that the crystal structure consists of neutral mono-oxo-capped trinuclear molybdenum cluster molecules with an average Mo-Mo bond length of 2.626(4) and an average Mo-O bond length of 2.036(2) respectively. Each pair of Mo atoms is further bridged by an S_2~(2-) radical, in which one S atom is essentially situated on the triangular plane formed by these three Mo atoms and the other one is situated on the side of the plane opposite to the μ_3-O atom. Besides, each Mo atom is coordinated to two S atoms belonging to an [S_2P(OEt)_2]~-radical so as to complete a nearly pen     

CRYSTAL AND MOLECULAR STRUCTURE OF N, N-PLATINUM-DIETHYL-DICHLORIDEDI-L-ASPARTATE

This paper reports the crystal and molecular structure of title compound. 3978 three-dimensional independent reflections were collected by Syntex R3 four circle diffractometer. The crystal is monoclinic with space group P2_1, a=8.074(1), b=11.309(4), c=27.793(9), β=106.84°(2), Z=4. The molecular formula is Pt(C_8 H_(15)O_4N)_a Cl_2. The crystal structure was solved by Patterson method and refined by block matrix least squares refinement techniques. The final R factor is 0.039.The result of crystal structure analysis shows that Pt(Ⅱ) has a dsp~2 hybrid orbital and square coordination. Two C1 atoms are located oppositely to two diethyi-dichloride-di-L-aspartare. N atoms have sp~3 tetrahedral hybrid configurations and form the coordinate bonds with Pt(Ⅱ) atom using their lone pair electrons. By reason of molecular packing and due to the formation of inner hydrogen bonds in the complex molecule, the configuration of L-aspartic acid in the title complex is more twisted than that of L-and DL-aspartic acid     

Crystal structural studies of destripeptide (B28-B30) insulin

Single crystals of destripeptide (B28-B30) insulin (DTRI) in three forms were obtained by hanging-drop vapor diffusion method. Form 1 belongs to P21 space group with cell parameters a-4.77 nm, b=6.19 nm, c=6.12 nm, β=110.3°. Form 2 belongs to P4122 or P4322 space group with cell parameters a= 6.45 nm, c=12.07 nm. Form 3 belongs to P212121 space group with cell parameters a=4.98 nm, b=5.16 nm, c=10.06 nm. The structure of form 1 crystal was determined by molecular replacement method and refined at 0.23 nm resolution. The R-factor of the final model is 18.8% with r.m.s. deviations of 0.001 5 nm and 3.3?for the bond lengths and the bond angles, respectively. Studies on the crystal structure show that the removal of B28 Pro has brought DTRI structural changes which made it dissociate more easily than native insulin although DTRI can still form a hexamer.     

Synthesis and Crystal Structure of trans(N)-(1,10-Phenanthroline)-bis (DL-Al aninato)-Cobalt( Ⅲ ) Chloridetrihydrate

The title compound was synthesized by the reaction of cis-[Co(phen)2Cl2]Cl·3H2O with DL-alanine at pH = 8, and isolated using a column chromatographic method. Its crystal structure was determined. The crystal structure belongs to mono-clinic system, space group P21/c, with a = 0. 9549(6) nm, b=2.3746(8) nm, c= 1.0782(4) nm, β=114.13(3)°? Z = 4, Dc= 1. 50 g/cm3. The final refinement converged to R = 0. 047 for 3246 independent observed reflections. In the octahedral coordination sphere formed by the cobalt atom and the coordinate atoms, N, O of DL-alan-inato ligands are in the configuration of trans-N ,N form.     

Synthesis and Crystal Structure of 5-Nitro-4-salicylideneamino-3-methyl-1,2,4-triazol-5-thione

The crystal structure of 5-nitro-4-salicylideneamino-3-methyl-1,2,4-triazole-5-thione ([C10H9N5O3S]·HCON(CH3)2, Mr=352.38)(CCDC No. 216094) was determined by the single crystal X-ray diffraction method. The crystal belongs to a triclinic system, the space group is P1 with unit cell constants a=0.6113(2) nm, b=1.0836(4) nm, c=1.3132(5) nm, α=74.523(7)°, β=117.68(3)°, γ= 79.769(7)°, V=0.8245(5) nm3, Z=2, Dc=1.419 g/cm3, μ=0.228 mm-1, F(000)=368, R and wR are 0.0579 and 0.1040, respectively, beasd on 3348 unique reflections of which 1925 reflections were observed[I>2σ(I)]. The results indicate that the title compound can be assigned to the thione tautomeric form rather than the thiol tautomeric form. It contains a five membered triazole ring and a phenyl ring with a dihedral angle of 4.35°. The intermolecular hydrogen bond N3-H3…S1, O1-H1…O4 can be observed.     

Synthesis and Crystal Structure of a New Dinuclear Manganese(Ⅱ) Manganese(Ⅲ) Complex of a Macrocyclic Ligand

A mixed-valence dinuclear manganese complex, [MnⅡMnⅢL](ClO4)·1/2MeOH, where L is a macrocyclic ligand derived from the cyclocondensation of sodium 2,6-diformyl-4-methylphenolate with N,N-bis(2-aminoethyl)-2-hydroxybenzyl amine, was obtained and its structure was determined by X-ray diffraction. The orange crystal is a monoclinic system with space group P21/c and lattice parameters a=1.1617(4), b=1.4005(3), c=1.4641(3) nm, β=113.03(2)°, and Z=2. The crystal structure shows that each pendant-arm is bonded in a bidentate fashion to the adjacent metal atom and that both the arms are on the same side of the macrocycle. The two Mn atoms are bridged by two μ2-phenoxy oxygen atoms of the tetra-imine macrocycle, and each Mn atom, locating in a trigonal prismatic coordination environment(N3O3), is six-coordinated by the two imine nitrogen atoms, one tertiary nitrogen atom and a pendant phenol moiety apart from the two oxygen atoms.     

THE CRYSTALLOGRAPHIC STRUCTURE OF THE PHOTOOXIDIZED PRODUCT OF HYPOCRELLIN A AND THE STUDY OF THE PHOTODYNAMIC ACTION MECHANISM

In attempting to study the phototherapeutic action and the photosensitized oxygenation mechanism, we have determined the crystal structure of the main oxidized product of hypocrellin A (HA). It was crystallized in monoclinic system with space group P2_1. The cell data are: a=10.030(3), b=8.877(3), c=15.764(5), β=104.50(2)°, Z=2. The crystal structure has been determined by direct method and refined to a final R of 0.055 based on the 1408 observed reflections with l>2.5σ(Ⅰ). The photooxidized product is composed of a heptacyclic aliphatic hydrocarbon connecting with two α-naphthoquinone derivatives as its skeletal molecule. No peroxidic linkage has been found. On the basis of the crystal structure determined, we have deduced part of the process of formation of the oxide, ⅰ. e. firstly, the peroxide was formed by photocycloaddition of oxygen molecule to Hypocrellin A, then thermodissociation took place to form a stable oxide.