Structure of the organic crystallite unit in coal as determined by X-ray diffraction

X-ray diffraction （XRD） was used to study the structure of the organic crystallite unit （La, Lo doo2） in coals collected from Henan and Shanxi Provinces. XRD patterns of coal were collected in a step-scan mode （0.1 °/step） over an angular range of 2-90° （20）, allowing 8 s at each step. The structure of the crystallite unit was determined from the Scherrer equation and peak parameters deduced from whole pattern fitting. The results show that the structure of the crystallite unit in coal is mainly controlled by the coal rank. As the coal rank increases the average diameter of a coal crystallite unit （La） increases, the interlayer spacing （doo2） decreases slightly, and the average height of a coal crystallite unit （Lc） increases at first but then decreases. A new diffraction peak from the crystallite unit in coal was found at a low scattering angle in the XRD pattern （2-10~）. This suggests a structure with an inter-layer spacing from 1.9 to 2.8 nm exists in coal crystallites.

Synthesis and Characterization of New Palladium（ll） Complexes Containing 4,5-dimethyl-2,2＇-bipyridine： X-ray Crystal Structure of Bis（4-methyl pyrdine）-4,5- dimethyl-2,2＇-bipyridine palladium （11） Perchlorate

New heteroleptic and homoleptic complexes of the type[Pd（4,5-dmbipy）C12], [Pd（4,5-dmbipy）L2], and [Pd（4,5-dimebipy）2]2＋ （L = Pyridine or 4-methylpyridine（4-picoline）, bipy = 2,2＇-bipyridine, and 4,5-dimebipy = 4,5-dimethyl-2,2＇-bipyridine） were synthesized and characterized by IH NMR and elemental analysis. The crystal structure of bis（4-methylpyridine）-4,5- dimethyl-2,2＇-bipyridinepalladium（II）perchlorate [Pd（4,5-dmbipy）（4-pic）2]（CIO4）2 was also determined by single crystal X-ray diffraction. This complex crystallized in the triclinic crystal system and space group PI with a = 9.562 （2）, b = 11.326 （4）, c = 15.0120 （10） A°; α = 70.940°, β= 77.60 （2）, γ= 67.86 （2） and z = 4. The Pd （II） in square planar environment showed a small distortion towards tetrahedral through one coordinated bipyridine ring twisting with respect to the other.

头孢唑林钠水合物新晶体及其理化特性的研究

One kind of new cefazolin sodium hydrate crystal was obtained in the isopropyl alcohol-water system.There are two symmetry independent molecules in the asymmetric unit,both being well ordered in the lattice,and ten independent water positions but generally four to six(mean five)water molecules and one sodium ion present in the unit cell structure.Huge solvent tunnels can be found.Again there are two general regions of water molecules,those in the large solvent tunnels and those in proximity of the sodium ion and the tetrazole moieties of the drug molecule.The physical and chemical characteristics of the new cefazolin sodium hydrate crystal are similar to that of the α-form cefazolin sodium crystal,and the new crystal has better chemical stability than amorphous cefazolin sodium powder.

乙基四甲基环戊二烯基铁羰基化合物的合成及晶体结构

将C5Me4HCH2CH3和Fe(CO)5在二甲苯中加热回流,合成了一个新的双核配合物[(η5-C5Me4CH2CH3)Fe(CO)(μ-CO)]2.通过元素分析、红外光谱、核磁共振氢谱对其结构进行了表征.用X线单晶衍射法测定了该配合物的结构,结果表明:晶体属于单斜晶系,C2/m空间群,a=1.170 4(5)nm,b=1.217 9(5)nm,c=0.930 4(4)nm,α=90°,β=115.842(4)°,γ=90°,V=1.193 6(9)nm3,Dc=1.445g/cm3,μ=1.245mm-1,F(000)=542,Z=2,R1=0.024 2,wR2=0.062 0.CCDC号为839243.

天然产物绝对构型的确定方法

天然产物的物理、化学、生物及药物学性质与其绝对构型紧密相关,而天然产物绝对构型的确定一直都是天然产物化学中面临的巨大挑战,受到科研工作者的广泛关注。人们已经总结出多种确定方法,如X线单晶衍射、基于手性试剂化学反应和核磁共振(NMR)的Mosher法、光谱法(如圆二色谱)及有机合成等方法,对于不同结构特点天然产物的绝对构型确定,这些方法各有利弊。本文综述了这些常用方法的原理、优势和局限性。

A Reflectron Time-of-Flight Mass Spectrometer with a Nano-Electrospray Ionization Source for Study of Metal Cluster Compounds

An experiment facility has been set up for the study of metal cluster compounds in our laboratory, which consists of a nano-electrospray ionization source, an ion transmission and focus system, and a reflectron time-of-fight mass spectrometer. Taking advantage of the nano-electrospray ionization source, polyvalent ions are usually produced in the ＂ionization＂ process and the obtained mass resolution of the equipment is over 8000. The molecular ion peaks of metal cluster compounds [Au20（PPhpy2）10Cl2]（SbF6）4, where PPhpy2=bis（2- pyridyl）phenylphosphine, and [AuaAg2（C）L6]（BF4）4, where L=2-（diphenylphosphino）-5- methylpyridine, are distinguished in the respective mass spectrum, accompanied by some fragment ion peaks. In addition, the mass-to-charge ratios of the parent ions are determi- nated. Preliminary results suggest that the device is a powerful tool for the study of metal cluster compounds. It turns out that the information obtained by the instrumentation serves as an essential supplement to single crystal X-ray diffraction for structure characterization of metal cluster compounds.

对称5,5′-二苯亚胺基二吡咯甲烷化合物及其Ni(Ⅱ)配合物的合成与晶体结构

从二吡咯甲烷出发,合成2种对称5,5′-二亚胺苯基二吡咯甲烷化合物配体(H2L1,H2L2),利用该配体与NiCl2·6H2O反应,分别得到2种新的配合物(NiL1,NiL2).X线单晶衍射结果表明,镍配合物NiL1和NiL2均属于单斜晶系、P2(1)/c空间群.NiL1的晶胞参数为a=0.865 61(18)nm,b=1.050 70(2)nm,c=2.758 2(5)nm,α=γ=90°,β=94.799(4)°,V=2.499 7(9)nm3,Z=4;NiL2的晶胞参数为a=1.615 43(5)nm,b=1.182 23(4)nm,c=1.407 15(5)nm,α=γ=90°,β=112.319 0(10)°,V=2.486 06(14)nm3,Z=4.在晶体结构中,Ni(II)离子分别与配体中的2个吡咯N以及2个亚胺N原子配位,形成平面四边形构型模式,其通过π…π及C—H…π作用形成二维结构.

The Paramagnetic 2D Chiral-porous Polymer of L-Phenylalanine and Manganese

Mn(L-Phe)2稨2O]n (Phe=phenylalanine) with a single stranded coordination poly- mer has been synthesized by self-assembly of manganese salt and phenylalanine and characterized by X-ray single-crystal diffraction method. The complex crystallizes in the orthorhombic, space group P212121 with a = 6.0911(1), b = 10.3642(1), c = 30.4321(7) ? V = 1921.16(6) ?, Z = 4, Dc = 1.387 g/cm3, C18H22N2O5Mn, Mr = 401.32, F(000) = 836 and m(MoKa) = 0.717 mm-1. The final R = 0.0614 and wR = 0.1412 for 2291 observed reflections with I > 2s(I). The magnetic behavior study shows that there exist super-exchange antiferromagnetic interactions between the magnetic centers through the effective exchange pathway of the carboxylate group.

Synthesis and Crystal Structure of Bis(nitrate)- bis(N,N'-dimethyl-N,N'-dibenzenyl-urea)uranyl(Ⅱ)

The new uranyl complex UO2(NO3)2[PhN(CH3)C(O)(CH3)NPh]2 was synthesized and its crystal structure has been determined by single-crystal X-ray diffraction. Crystal data: C30H32N6O10U, triclinic, space group P with a = 7.772(1), b = 9.267(1), c = 12.644(1) ? a = 68.246(8), b = 73.871(9), g = 84.99(1)o, V = 812.4(2) ?, Mr = 874.65, Z = 1, Dc = 1.788 g/cm3, F(000) = 426, m = 5.062 mm-1, the final R = 0.022 and wR = 0.059 for 3571 observed reflections (I > 2s(I)). The central uranyl ion is coordinated by six oxygen atoms, two from the carbonyl groups of N,N-dimethyl-N,N-dibenzenyl-urea molecules and the other four from two nitrate groups.

Effect of Crystallization Conditions on Polymorphic Diversity of Malic Acid RS-Racemate

Enantiomers （R （＋） and S（-））, RS-racemate mixture of enantiomers） of malic acid C4H605 have been （double compound） and （R ＋ S） -conglomerate （mechanical investigated by means of X-ray diffractometry and high tern- perature X-ray diffraction method. The RS-racemate was found to be able to form three polymorphic modifications, which we denominated as M1 （monoclinic, space group P21/c）, M2 （monoclinic, space group Cc）, and Tc （triclinic, space group P-l ）, the latter modification having been unknown before. Modification Tc was also described, and its X- ray diffraction characteristics, including interplanar spacings d, hkl indices, unit cell parameters, were defined. In addi- tion, X-ray diffraction characteristics for both reported earlier M1 and M2 monoclinic polymorphic modifications were measured with higher accuracy. The ability of RS-racemate to form one of the above three modifications （MI, M2, and Tc） or their mixtures containing various proportions and combinations of the components （M1 ＋ M2, M1 ＋ Tc, or M2 ＋ Tc） was found to depend on the type of crystallization medium （a melt, aqueous medium, ethanol or acetone solu- tion）, crystallization rate （from 2--3 minutes to 4 months）, and crystallization temperature. Heating S-enantiomer and M1 RS-racemate up to their respective melting points （100 ℃ and 124 ℃, correspondingly） only made them undergo thermal deformations, while heating （R ＋ S） -conglomerate in the temperature range of 96--110 ℃ resulted in its homogenization to form M2 RS-racemate, which, near the melting point （118 ℃）, namely, in the range of 112-116 ℃, was transformed into MI RS-racemate. Keywords： polvmorDhism; racemic, chiral

Syntheses, structures and magnetic properties of three Co(Ⅱ)coordination architectures based on a flexible multidentate carboxylate ligand and different N-donor ligands

Three new cobalt complexes, {[Co5（tci）2（bimb）3（μ3-O）2（H2O）2]·3DMF·4H2O}n（1）, {[Co3（tci）2（bib）]·2DMF·2H2O}n （2） and {[Co（Htci）（bpea）0.5]-H2O}n （3） （H3tci = tris（2-carboxyethyl）isocyanurate, bimb = 4,4＇-bis（imidazol-l-yl）biphenyl, bib = 1,4-bis（imidazol-l-yl）benzene, bpea = 1,2-bis（4-pyridyl）ethane, DMF = N,N＇-dimethylformamide）, have been successfully synthesized through the assembly of Co（If） ions, H3tci and different N-donor ligands, respectively. All complexes were structurally characterized by single crystal X-ray diffraction, elemental analyses, IR spectra, thermogravimetric （TG） analyses and X-ray powder diffraction （XRPD）. Complex 1 exhibits a 3D three-fold parallel interpenetrated 3D · 3D structure with （65.8） CdSO4 topology. Complex 2 is built from [Co3（μ/2-Ocarboxyl）2（CO2）4] clusters and linear bib ligands, displaying a two-fold par- allel interpenetrated （3,8）-connected （4^3）2（4^6.6^18·8^4） topology, while complex 3 is a 3D pillar-layered structure involving an in- finite -Co-（μ2-Ocarboxyl）（CO2）-Co-chain. The diverse structures of the three complexes indicate that the skeletons of different N-donor ligands play an important role in the assembly of such different frameworks. In addition, magnetic investigation indi- cates that besides spin-orbit coupling of Co（II） ions, there exist antiferromagnetic exchange interactions in Co5 and Co3 clus- ters of 1 and 2, respectively.

Solvent-and metal-directed lanthanide-organic frameworks based on pamoic acid:observation of slow magnetization relaxation,magnetocaloric effect and luminescent sensing

Two types of lanthanide coordination polymers, namely, [Ln（PA）（NO3）（DMA）3]n （Ln=Gd （1）, Dy （2）, Eu （3）, Tb （4）） （type I）, and {[Ln2（PA）3（DMF）4]＇2DMF} （Ln=Eu （5）, Tb （6）） （type II） （PA=Pamoic acid, DMA=dimethylacetamide, DMF=N,N-dimethylformamide）, have been synthesized by the reaction of Ln（NO3）a-6H20 with pamoic acid through layer diffusion method. These complexes were characterized by single crystal X-ray diffraction, infrared spectroscopy （IR）, thermogravimetric analysis （TGA）, fluorescence and magnetic measurements. Solvents and lanthanide atoms in the reaction play an important role in controlling different structures. Type I demonstrated 1-D linear chain structure connected by Ln atoms and PA ligands. Type II exhibited non-interpenetrating 3-D 6-connected 43612 nets based on binuclear [Ln2（CO2）6（DMF）4] cores. Magnetic properties of complexes 1-4 were investigated in details. Complex 1 shows significant magnetocaloric effect with -△Sm=20.37 J kg^-1 K^-1 at 3.0 K and 7 T. Complex 2 exhibits slow relaxation of the magnetization. Complexes 3-6 exhibit both ligand- and metal-centered fluorescent properties. Complex 6 demonstrates fluorescent sensing of DMF and Cu^2＋ ion.

Antimicrobial, anticancer and DNA binding studies of transition metal(Ⅱ)complexes containing 2-phenyl-4-selenazole carboxylic acid

Three novel transition metal complexes [ML2（phen）]＇H20 （M= Mn, Co, Zn; HL= C10H702NSe, 2-phenyl-4-selenazole carboxylic acid, phen= 1,10-phenanthroline） 1-3 were synthesized and characterized by elemental analysis, IR spectra. Their crystal structures were deterimined by single-crystal X-ray diffraction method. The antibacterial activities of the complexes against five species of bacteria, Escherichia coli （E. coli）, Staphylococcus epidermidis （S. epidermidis）, Staphylococcus aureus （S. au- reus）, Acinetobacter baumanii （A. baumanii） and Streptococcus viridans （S. viridans）, were tested respectively. The anticancer activities of the complexes against human pancreatic cancer line PANC-28 and human hepatocarcinoma line HuH7 were also studied. The interactions between the complexes and DNA were studied by ethidium bromide （EB） fluorescent probe.

Thermal expansion behaviors of Mn(Ⅱ)-pyridylbenzoate frameworks based on metal-carboxylate chains

Solvothermal reactions of MnCl2with pyridylbenzoic acids gave three-dimensional metal-carboxylate frameworks(MCFs),named MCF-34,MCF-43,and MCF-44,based on one-dimensional Mn-carboxylate chains.The crystal structure,stability,porosity,and framework flexibility of the new compound MCF-44 were studied in detail and compared with its analogs.Depending on their shapes and the bridging angles of the ligands,these compounds possess different network connectivities and porosities.Considering the pyridylbenzote ligands and Mn(II)ions as,respectively,3-and 6-connected nodes,they resemble either the anatase(ant)or rutile(rtl)polymorph of TiO2.Variable-temperature single-crystal X-ray diffraction studies revealed large thermal expansion coefficients for these compounds,which are probably related to the relatively flexible edge-sharing polyhedral structure of their Mn-carboxylate chains.Interestingly,the new compound MCF-44,with its highly porous rtl structure exhibits the largest thermal expansion coefficienct among the coordination polymers reported so far.

Crystal structures and thermal decomposition mechanism of four lanthanide complexes with halogen-benzoic acid and 1,10-phenanthroline

This paper describes syntheses and structure determination of four lanthanide complexes [Nd(2-Cl-4-FBA) 3 phen] 2 (1, 2-Cl-4-FBA = 2-chloro-4-fluorobenzoate, phen = 1,10-phenanthroline), [Ln(2,5-DClBA) 3 phen] 2 (Ln = Sm(2) and Tb(3), 2,5-DClBA = 2,5-dichlorobenzoate) and [Sm(2-Cl-4,5-DFBA) 3 (phen)(H 2 O)] 2 (4, (2-Cl-4,5-DFBA = 2-chloro-4,5-difluorobenzo- ate). The complexes were characterized by elemental analysis, infrared and ultraviolet spectra, and X-ray single-crystal diffraction. In the molecular structures of 1 4, two Ln 3+ ions are linked by four carboxyl groups, with two of them in a bridging bidentate mode and the other two in a bridging-chelating tridentate mode, forming four binuclear molecules. In addition, each Ln 3+ ion is also chelated to one phen molecule and one carboxyl group in the complexes, except each Sm 3+ ion in 4 which is bonded to one carboxyl group by unidentate mode and one H 2 O molecule. There are two different coordination polyhedrons for each Nd 3+ ion in the two similar molecular structures of 1 and they are a distorted monocapped square antiprismatic and a distorted tricapped triangular prism conformation, respectively. The coordination polyhedron for each Ln 3+ ion in 2 4 is a nine-coordinated distorted mono-capped square antiprismatic conformation. The complex 3 exhibits green luminescence under the radiation of UV light. The thermal decomposition behaviors of the complexes have been discussed by simultaneous TG/DSC-FTIR technique. The 3D surface graphs for the FTIR spectra of the evolved gases were recorded and the gaseous products were identified by the typical IR spectra obtained at different temperatures from the 3D surface graphs. Meanwhile, we discussed the nonisothermal kinetics of 1 4 by the integral isoconversional non-linear (NL-INT) method.

An inverted triplesalen ligand by a convergent synthesis and its influence on trinuclear Fe_3~Ⅲ complexes

The inverted triplesalen ligand H6feldMe has been synthesized from 2,4,6-triformyl-phloroglucinol and a ketimine salen half-unit in a convergent synthesis. NMR, IR, and UV-vis spectroscopy reveal that this ligand is not in the O-protonated tau- tomer but in the N-protonated tautomer with substantial heteroradialene contribution. This ligand and the conventional triple- salen ligand H6talent-au2 have been used to synthesize the trinuclear Fem complexes [（feldMe）（FeCl）3] and [（talent-Bu2）（FeC1）3], respectively. The molecular structures of these complexes were obtained by single-crystal X-ray diffraction. Two trinuclear Fem complexes of [（feldMe）（FeCl）3] dimerize via two Fe-phenolate bonds, whereas due to steric hindrance no dimerization is observed for [（talent-Bu2）（FeC1）3]. The structural data also reveal some heteroradialene contribution in the trinuclear complexes. Whereas UV-vis and MOlSbauer spectroscopy are not suitable to distinguish between the two complexes, FT-IR spectra show characteristic features due to the different substitution patterns of the conventional and the inverted triplesalen ligands. Another handle is provided by electrochemistry. Whereas both complexes exhibit an irreversible oxidation wave （0.94 V vs. Fc＋/Fc for [（feldMe）（FeC1）3] and 0.84 V vs. Fc~/Fc for [（talent-Bu2）（FeC1）3]）, which is assigned to the oxidation of the central backbone, higher potential oxidations are reversible for [（talent-Bu2）（FeC1）3]） but irreversible for [（feldMe）（FeC1）3]. This is attributed to the reversible oxidation of the terminal phenolates in the di-tert-butyl substituted [（talentBu2）（FeCl）3] in contrast to the mono-methyl-substituted phenolates in [（feld^ae）（FeC1）3]. The magnetic properties of [（talen^-Bu2）（FeC1）3] reveal a very small ferromagnetic coupling with significant zero-field splitting of the Feul S = 5/2 ions. In contrast, the dimerization of two trinu- clear complexes in [（feldMe）（FeCl）3] results in antiferromagnetic interactions between the two phenolate-bridged FeIII ions, which mask the intra-trinuclear interactions transmitted by the central phloroglucinol backbone.

Discovery of a novel 112-type iron-pnictide and La-doping induced superconductivity in Eu_(1-x)La_xFeAs_2(x=0–0.15)

We report the discovery and characterization of a novel 112-type iron pnictide EuFeAs2, with La-doping induced superconductivity in a series of Eu1- xLaxFeAs2. The polycrystalline samples were synthesized through solid state reaction method only within a very narrow temperature window around 1073 K. Small single crystals were also grown from a flux method with the size about 100μm. The crystal structure was identified by single crystal X-ray diffraction analysis as a monoclinic structure with space group of P2 1/m. From resistivity and magnetic susceptibility measurements, we found that the parent compound EuFeAs2 shows distinct anomalies probably due to the Fe2＋ related antiferromagnetic/structural phase transition near 110K and the Eu2＋ related antiferromagnetic phase transition near 40K. La-doping suppressed both phase transitions to lower temperatures and induced superconducting transitions with a Tc - 11 K for Eu0.85La0.15FeAs2.

Orthorhombic HoMnO_3/Nb-doped SrTiO_3 epitaxial heterojunctions fabricated by pulsed laser deposition

Orthorhombic HoMnO 3 films with a-axis orientations were prepared epitaxially on Nb-1.0wt%-doped SrTiO 3 single crystal substrates by using the pulsed laser deposition technique to fabricate all-oxide heterojunctions.X-ray diffraction and atomic force microscopy were then used to characterize the films.The temperature dependent current-voltage measurement displayed diode-like rectifying behavior,and the forward current was perfectly fitted using the thermionic emission model.The ideality factor and built-in potential were suggested.

Reactivity study of a hydroxyl coordinated osmium vinyl complex OsCl_2(PPh_3)_2 [CH=C(PPh_3)CHPh(OH)]

We studied the reactivity of an osmium vinyl complex containing a coordinated hydroxyl group OsC12（PPh3）2[CH=C（PPh3）- CHPh（OH）] （1） toward bidentate ligand 1,4-bis（diphenylphosphino）butane （DPPB）, acid ligand （CO）, base （Cs2CO3） and heat. Two osmium vinyl complexes OsC12（dppb）[CH=C（PPh3）CHPh（OH）] （2） and OsCI2（CO）2（PPh3）[CH=C（PPh3）CHPh（OH）] （3）, as well as two relatively rare phosphonium-containing osmafuran complexes Os（q2-OCOO）（PPha）z[CHC（PPha）CPhO] （4） and OsClz（PPh3）z[CHC（PPh3）CPhO] （5）, were obtained in high yields from these reactions. All products were characterized by NMR spectroscopy, elemental analysis, and their structures were further confirmed by single crystal X-ray diffraction.

Ba4M（CO3）2（BO3）2（M=Ba, Sr）: two borate-carbonates synthesized by open high temperature solution method

Two borate-carbonates Ba4M(CO3)2(BO3)2(M =Ba, Sr) have been successfully synthesized in the open air representing the first examples of borate-carbnate complex.Their structures were determined by single crystal X-ray diffraction and they both crystallize in same space group, Pnma.Their structures feature a Ba/Sr-based three dimensional framework composed of the BaO8 polyhedra(the SrO8 polyhedra), isolated BO3 and CO3 triangles. Detailed structure analysis shows that the intergrowth of [Ba3(BO3)2]/[Ba2Sr(BO3)2] and [BaCO3] layers favors the formation of these two borate-carbonates. In addition, their syntheses, spectroscopic properties and thermal behaviors were investigated.