Synthesis and structure of the mixed-ligand cobalt(III) complex [Co(DH)(Hthsc)2][SiF6] · 2.3H2O

The compound [Co(DH)(Hthsc)₂][SiF₆] · 2.3H₂O, where DH^? is a dimethylglyoxime residue and Hthsc is a thiosemicarbazide molecule, was synthesized and studied by X-ray diffraction. The coordination polyhedron of the central metal ion (distorted octahedron) is formed by two sulfur atoms, two nitrogen atoms of two Hthsc molecules coordinated in the bidentate mode, and two nitrogen atoms of the DH^? ligand. The positions of three metal rings are fixed by two intramolecular hydrogen bonds (N-H…O). A bifurcated system of intermolecular hydrogen bonds forms a framework structure in the crystal.     

Cheminformatics aspects of high throughput screening: from robots to models: symposium summary

The “Cheminformatics aspects of high throughput screening (HTS): from robots to models” symposium was part of the computers in chemistry technical program at the American Chemical Society National Meeting in Denver, Colorado during the fall of 2011. This symposium brought together researchers from high throughput screening centers and molecular modelers from academia and industry to discuss the integration of currently available high throughput screening data and assays with computational analysis. The topics discussed at this symposium covered the data-infrastructure at various academic, hospital, and National Institutes of Health-funded high throughput screening centers, the cheminformatics and molecular modeling methods used in real world examples to guide screening and hit-finding, and how academic and non-profit organizations can benefit from current high throughput screening cheminformatics resources. Specifically, this article also covers the remarks and discussions in the open panel discussion of the symposium and summarizes the following talks on “Accurate Kinase virtual screening: biochemical, cellular and selectivity”, “Selective, privileged and promiscuous chemical patterns in high-throughput screening” and “Visualizing and exploring relationships among HTS hits using network graphs”.     

Crystal structure of benzoylformic acid thiosemicarbazone

Institute of Applied Physics, Academy of Sciences of the Moldavian SSR. Institute of Chemistry, Academy of Sciences of the Moldavian SSR. Burevestnik [Stormy Petrel] Scientific-Industrial Association, Leningrad. Translated from Zhurnal Strukturnoi Khimii, Vol. 29, No. 5, pp. 166–169, September–October, 1988.     

Synthesis and structure of cobalt(III) dimethylglyoximate with [FeF<Subscript>5</Subscript>(H<Subscript>2</Subscript>O)]<Superscript>2−</Superscript> anion

A new complex [Co(DH)₂(Thio)₂]₂[FeF₅(H₂O)] · 2CH₃OH (where DH^? is dimethylglyoxime monoanion, Thio is thiourea molecule) was synthesized and its structure was determined. The coordination polyhedron of the Co(III) atoms in two centrosymmetric complex cations is an octahedron, formed by four N atoms of two dimethylglyoxime residues and two S atoms of coordinated Thio molecules. One of the Thio molecules is almost perpendicular to a metal cycle (the dihedral angle 87.8(1)°), which is responsible for realization of intermolecular hydrogen bond N-H···O (N···O 2.990(3) Å). The second Thio molecule is almost parallel to the equatorial CoN₄ fragment (the dihedral angle 159.4(1)°) to give rise to intramolecular π-π interaction between practically planar Thio molecule and one of the π-delocalized metal cycle. The Fe(III) coordination polyhedron is an octahedron, formed by five F atoms and by the O atom of coordinated water molecule. The key role in the crystal structure organization is played by intermolecular hydrogen bonds N-H···F, N-H···O, N-H···S, the intramolecular bonds O-H···O, formed by the donor NH₂ groups of a complex cation with the F atoms of the [FeF₅(H₂O)]^2? and the donor-acceptor groups of the Thio fragments.     

Structure of thiocarbamide-containing cobalt(III) dioximates with [BeF4]2− and [BF4]− anions

The crystal structure of the complexes [Co(DH)₂(Tu)₂]₂[BeF₄]·C₂H₅OH (I) and [Co(DfH)₂(Tu)₂][BF₄] 0.5H₂ (II) (where DH^? is the dimethylglyoxime monoanion, DfH^? is the α-benzyldioxime monoanion, and Tu is thiourea) has been determined by X-ray diffraction analysis. The coordination polyhedron of the Co³⁺ atom is an N₄S₂ octahedron formed by four nitrogen atoms of the dioxime molecule and two sulfur atoms of the fragments of thiourea (Tu); the latter have parallel and perpendicular orientations relative to the dioxime residue. The deviation of the cobalt atom from the four-angle plane (formed by the nitrogen atoms of the dimethylglyoxime residues) does not exceed 0.019 Å. The Co-N and Co-S distances vary from 1.877(3) Å to 1.901(3) Å and from 2.280(1) Å to 2.307(1) Å, respectively. The statistically disordered cations [BeF₄]^2? and [BF₄]^? play an important role in crystal formation — they form a complex system of hydrogen bonds.     

Synthesis,structure, and biological properties of mixed cobalt(III) dioximates with guanidine derivatives

Two Co(III) dioximates, cyanoguanidine complex {[Na₂(µ-H₂O)₂(L¹)₂(H₂O)₂]-[Co^III(DmgH)₂(N₃)₂]} _n [Co^III(DmgH)₂(N₃)₂] _n (L¹ = (H₂N)₂C=N–C=N) (I) and aminoguanidine complex [H₃L²][Co(DmgH)₂(N₃)₂] (H₂L² = H₂N–C(=NH)–NH–NH₂) (II), were synthesized from the [CoCl(DmgH)₂(H₂O)] structural unit (DmgH^– is the dimethylglyoxime monoanion). The implementation of the synthesis was confirmed by chemical analysis, IR spectroscopy, and X-ray diffraction (CIF files CCDC 1531845 (I), 1531846 (II)). Both compounds are ionic. Compound I consists of cations representing centrosymmetrical 2D coordination polymers, {[Na₂(µ-H₂O)₂(L¹)₂(H₂O)₂][Co^III(DmgH)₂(N₃)₂]} ⁿ⁺ _n , and monomeric [Co(DmgH)₂(N₃)₂]^– anions, while in II, the charge of the [Co(DmgH)₂(N₃)₂]^– complex anion is counterbalanced by the organic [H₃L²]⁺ cation. In I, L¹ is coordinated to the metal as a monodentate neutral ligand, while in II, H₂L² occurs in the complex as a protonated uncoordinated component. Since L¹ in I and H₂L² in II contain functional amine groups able to form intermolecular hydrogen bonds acting as proton donors, the component packing mode in the crystals was analyzed assuming various types of interactions, apart from electrostatic ones. The biological properties of the complexes were tested considering their effect on the biosynthesis of proteases by the micromycete Fusarium gibbosum CNMN FD 12 strain. Culturing the producer on a culture medium containing complex I in the selected optimal concentrations of 5–10 mg/L was found to increase the acid protease activity by 140–150%.     

面向并行设计的局部特征识别技术研究

为支持在并行设计过程中设计特征模型到加工特征模型的逐步转换，提出了局部特征识别的方法．在并行设计中，设计特征模型和加工特征模型通过面名历史图共享零件的实体模型，设计特征的变动通过局部特征识别自动地转换为相应的加工特征．局部特征识别是由基于最小条件子图特征识别方法改进来的，它以零件的局部区域为识别对象，通过搜索匹配局部区域构成的边界模式，识别出该局部区域中所包含的加工特征．局部特征识别方法的特点是只对设计中发生变动的区域进行识别．     

Cobalt(III) dimethylglyoximates containing selenourea and an unusual diselenourea ligand: Synthesis and structures

The complexes [Co(DH)₂(Seu) _y (Se-Seu) _z ]₂X · mSolv (DH is the dimethylglyoxime monoanion, Seu is selenourea, and X is [TiF₆]²⁻, [ZrF₆]²⁻) were obtained from the system CoX · 6H₂O-DH₂-Seu in DMF-MeOH or MeOH-H₂O and examined by UV, IR, and NMR spectroscopy and X-ray diffraction. Unexpectedly, the ligand Se-Seu (the oxidized form of selenourea) was detected on the axial coordinate, partially replacing selenourea. The complexes were formulated as [Co(DH)₂(Seu)_1.75(Se-Seu)_0.25]₂[TiF₆] · H₂O (I) and [Co(DH)₂(Seu)(Se-Seu)]₂[ZrF₆] · 3H₂O (II). The complex cations in I and II have trans-octahedral structures. Their crystal structures are made up of the complex Co³⁺ cations and the outer-sphere MF₆²⁻ anions (M = Ti(IV) (I) and Zr(IV) (II)) held together by electrostatic interactions and hydrogen bonds; water of crystallization is also involved in hydrogen bonding.