(V_1-xCr_x)₂O₃ nano-powders have been synthesized successfully for the first time in powder form by pyrolising polycrystalline Cr-doped precursors, Cr-doped (NH₄)₅[(VO)₆(CO₃)₄(OH)₉]·10H₂O in H₂ atmosphere at 1373 K. Development of single-crystal of the Cr-doped precursor showed that Cr (III) possibly entered the precursor lattice or a solid solution formed in the precursor. Comparing the ratio of Cr/V in the raw materials (VOCl₂ solution) to the Cr/V in the polycrystalline Cr-doped precursor indicated that the chemical doping method was feasible and Cr content in the precursor was controlled easily. The lattice parameters of Cr-doped V₂O₃ powders determined by X-ray diffraction (XRD) were consistent with those of single-crystalline Cr-doped V₂O₃, revealing that Cr (III) entered the V₂O₃ lattice. Both the results of differential scanning calorimetry (DSC) and magnetic susceptibility of the (V_1-xCr_x)₂O₃ demonstrated that the Cr-doped V₂O₃ powders exhibit intrinsic phase transition properties. Homogeneously distributed spherical (V_1-xCr_x)₂O₃ powders with a particle size of about 40 nm have been obtained.

Liuya Wei;向峰 储;Deming Lei;Chenmou Zheng;小明 陈

Materials Science and Engineering B: Solid-State Materials for Advanced Technology

2006-7-15

A two-dimensional coordination network, 2∞[Fe^III (OH)(e,a-cis-1,4-chdc)] (1,4-chdc: cyclohexane-1,4-dicarboxylate), featuring one-dimensional iron(iii)-hydroxy chains that are transversely bridged by 1,4-chdc in its pure e,a-cis conformation have been isolated. The magnetic study shows a typical spin-5/2 Heisenberg chain above 20 K, but canted antiferromagnetic ordering at lower temperatures.

Yan Zhen Zheng;小明 陈

Dalton Transactions

2012-10-21

Binding of four bipyridyl ligands, 2,2′-bipyridine (L1), 1,10-phenanthroline (L2), 1,4,8,9-tetraazatriphenylene (L3), and dipyrido[3,2-a:2′,3′-c]phenazine (L4) with Cdq₂/Znq ₂ complexes (q = 8-hydroxyquinoline) gave four neutral, mononuclear CdII/ZnII complexes, namely [Cdq₂L1]·H₂O· CH₃OH (1), [Cdq₂L₃]·3H₂O (2), [Cdq₂L4]·2H₂O (3), and [Znq₂L4] ·2CH₃OH (4). These mixed-ligand compounds were taken as models for investigating the interfacial effect at the electron-transfer layer/light-emitting layer junction in OLEDs by combination of X-ray diffraction, fluorophotometric titration, cyclic voltammetry, and time-dependent density functional theory (TDDFT) calculations. The results shows the formation of these compounds is favorable to energy transition on the contact surface.

Fan Yue;Ai Xin Zhu;Shao Liang Zheng;小明 陈

European Journal of Inorganic Chemistry

2008-11

Bis(pyridine betaine) hydrochloride monohydrate, 2C₅H₅NCH₂COO·HCl·H₂O, crystallizes in space group Pnna (No. 52), with a=15.623(3), b=19.707(3), c=5.069(1) Å, and Z=4. The structure has been refined to R_F=0.067 for 1207 observed (|F₀|>6σ|F₀|) MoKα data. The carboxylate groups of a pair of pyridine betaine molecules are bridged by a proton to form a centrosymmetric dimer featuring a very strong hydrogen bond of length 2.436(6) Å. The crystal structure comprises a packing of such [(C₅H₅NCH₂COO)₂H]⁺ moieties and hydrogen-bonded (Cl^-{dH₂O}_∞) zigzag chains running parallel to the c axis.

小明 陈;Thomas C.W. Mak

Journal of Molecular Structure

1990-4-30

The surface area, pore volume and adsorption characteristics of metal-organic frameworks (MOFs) are significantly affected by preparation and activation procedures. In this work, we explore one such key synthesis parameter influencing the characteristic of Cu-BTC. We used a solvothermal method to synthesize copper based MOFs (Cu-BTC) using six different solvents (chloroform, dichloromethane, acetone, ethanol, methanol and water) in the activation process. The effects of different activation solvents on the thermal stability, porous structure and CO₂ adsorption of Cu-BTC were investigated. Using methanol as an activation solvent will produce a highly crystalline and nearly solvent-free Cu-BTC, leading to the largest pore volume (0.823 cm ³ g^-1) and greatest CO₂ adsorption (6.95 mmol g^-1 at 25 °C and 132 kPa).

Ying Yang;Pradeep Shukla;Shaobin Wang;Victor Rudolph;小明 陈;Zhonghua Zhu

RSC Advances

2013-10-14

A polydentate ligand comprising imidazole donor 1,3-bis[(4-methyl-5-imidazol-1-yl)ethylideneamino]propane (BIP) was synthesized, and the crystal structure of its Zn(II) complex [Zn(BIP)(H₂O)₂](ClO₄)₂ has been reported, in which the Zn(II) atom adopts a distorted octahedral coordination geometry with the equatorial positions occupied by four nitrogen atoms of BIP and the axial positions by two aqua molecules. The effect of hydrogen bonding of the aqua ligand on the coordination geometry is discussed.

La Sheng Long;小明 陈;Liang Nian Ji

Inorganic Chemistry Communication

1999-5-1

To investigate the influence of the size of the aromatic chelate ligands on the frameworks of metal dicarboxylate polymers, four new coordination compounds [Co(phen)(oba)]_n·0.5nH₂O (1), [Ni(phen)(oba)] _n·0.5nH₂O (2), [Co₂(H ₂O)(TATP)₂(oba)₂]_n·2nH ₂O (3), and [Ni₂(H₂O)(TATP)₂(oba) ₂]_n·2nH₂O (4) (phen = 1,10-phenanthroline, TATP = 1,4,8,9-tetranitrogen-trisphene, oba = 4,4′-oxybis(benzoate)) have been synthesized under similar conditions and structurally characterized by elemental analysis, IR, and X-ray crystallography. In the isomorphous 1 and 2, the metal centers are linked by bridging oba ligand to form 1-D helical chains, whereas the isomorphous 3 and 4 have extended 2-D arrays. The differences among these structures indicate that the size of the rigid aromatic chelate ligands have important effects on the structures of their complexes.

Zheng Bo Han;Xiao Ning Cheng;小明 陈

Crystal Growth and Design

2005-3

The first thiocyanate-bridged double perovskite-type coordination polymer [NH₄]₂[NiCd(SCN)₆] is reported here, which undergoes a reversible structural phase transition at around 120 K. An order-disorder mechanism for this transition is disclosed by X-ray structural analyses, dielectric measurement, as well as molecular dynamics simulations.

Kai Ping Xie;Wei Jian Xu;Chun Ting He;Bo Huang;Zi Yi Du;Yu Jun Su;Wei Xiong Zhang;小明 陈

CrystEngComm

2016

Four novel non-interpenetrating metal-organic co-ordination networks of the Cd^II-L-NCS^- system have been prepared using potentially bridging nicotinic acid derivatives L [nicotinic acid (HL¹), nicotinamide (L²), isonicotinamide (L³), or isonicotinate (L⁴)]. Their crystal structures were determined by X-ray diffraction. In [Cd(SCN)₂(HL¹)₂]·HL¹ 1 each pair of cadmium(II) ions is bridged by two inversely related μ-NCS ^--N,S ligands to form infinite chains with the remaining two trans positions of six-co-ordinated Cd atoms being occupied by two HL¹ ligands, which form head-to-head double hydrogen bonds using the unco-ordinated carboxyl groups between adjacent chains to form two-dimensional layers. Weak S⋯S interactions between the NCS^- ligands extend the layers into a three-dimensional framework with the channels enclosing HL¹ guest molecules, which are interlinked into chains through O-H⋯N hydrogen bonds. [Cd(SCN)₂(L₂)₂]·H₂O 2 and [Cd(SCN)₂(L³)₂] 3 are interesting in that they contain unprecedented 16-membered [Cd₄(μ-SCN-N,S) ₄] rings in the two-dimensional sheets. Between the sheets N-H⋯O amide-amide hydrogen bonds extend the two-dimensional layers to three-dimensional structures. [Cd(SCN)(L⁴)(H₂O)] 4 exhibits two-dimensional wave-like networks with bridging NCS^- and L⁴ ligands using both ends in co-ordination. The results demonstrate that the structures of the Cd^II-L-NCS system deeply depend on the nature of the nicotinic acid derivatives L.

Guang Yang;Huai Gang Zhu;Bing Hua Liang;小明 陈

Journal of the Chemical Society. Dalton Transactions

2001

The synthesis and crystal structures of two new NLO-active coordination polymers, [Zn(2-pc)(4-pc)] and [Cd(2-pc)(4-pc)(H₂O)]· N ₂H₄ (2-pc = 2-pyridine carboxylate, 4-pc = 4-pyridine carboxylate), bridged by in situ generated mixed ligands under solvothermal treatment is described.

Yong Tao Wang;Hai Hua Fan;He Zhou Wang;小明 陈

Inorganic Chemistry

2005-6-13