AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Polyoxometalates (POMs) are a class of unique inorganic oxide macromolecules with nanosized geometry. Recently, organoimido derivatives of POMs have received increasing interest in the supramolecular chemistry and chemistry of materials, since they are valuable building blocks for constructing novel nanostructured organic-inorganic hybrid molecular materials with the so-called "value-adding properties" and possible synergistic effects, including unique catalytic, photo and electronic properties dramatically different from the corresponding parent materials, which results from the pi electrons in the organic component of such molecules may extend their conjugation to the inorganic framework and dramatically modify the electronic structure and redox properties of the corresponding parent POMs. The surface modification of POMs, that is, the substitution of one or more terminal or bridged oxo groups with organoimido ligand, is the fundamental method to synthesize organoimido derivatives of POMs via common organic chemistry reactions. In this chapter of the book, the synthetic chemistry of organoimido derivatives of POMs using different organic reagents will be reviewed, of which the novel DCC-dehydrating protocol to prepare organoimido derivatives of POMs recently developed by us and co-authors will be concentrated. As it can be expected, the reaction chemistry of organoimido derivatives of POMs stands for the fascinating future of the chemistry of organoimido derivatives of POMs since it opens not only a new road to the chemical modification of POMs, but also an exciting research arena where a variety of hybrid materials containing covalently bonded POM clusters and organic conjugated segments can be prepared in a more controllable and rational manner. Hence, in the rest of this chapter, Pd-catalyzed coupling reactions of the functionalized organoimido derivatives of POMs will be introduced in detail for this purpose. Especially, different rationally assembled hybrid macromolecules and polymers where the organic molecules and inorganic clusters are bonded together by an imido nitrogen atom will then be highlighted.

The space group of the crystal of the title compound is P2/a, with unit cell constants a=12.006, b = 8.398, c= 14.261? ,β= 93.98°. the cell contains two formula units of [phCH2CH(NH3)+CO2C2H5]2? [PtCl4]. The structre was determined from 1759 observed reflections and refined by the block-diagonal least-squares method to R = 0.038. The platinum atoms occupy one set of symmetrical center special positions. The [PtCl4]2- ion is coplanar with Pt-Cl bond, the bond lengths are 2.304(3) and 2.294(3)?, The discreate phenylalanine ethyl ester does not coordinate to the platinum atoms. The [PtCl4]2- ion and [phCH2CH(NH3)+CO2C2H5] ions are connected by ionic fores and hydrogen bonds between the nitrogen and chlorine atoms. Therefore this compound is an adduct of phenylalanine ethylester with anion of chloropladnite.

Two novel low-dimensional framework materials, [Ni(en)2]2[Ni(en)2MoVI6VVI10O40(VIVO4)]·4H2O (1) and [en]0.5[Cu(en)2]2[Cu(en)2MoVI6MoV2VIV8O40(MoIVO4)]·0.5H2O (2), assembled hydrothermally, are constructed from the mixed Mo/V tetra-capped Keggin structure clusters linked through M(en)2(M=Ni,Cu) groups.

A three-dimensional neutral framework of a novel decavanadate ion [VIV8VV2O26(μ-H 2O)] containing an AsO4 tetrahedral bridge has been synthesized hydrothermally and structurally characterized by X-ray diffraction.

The title compound is formed by controlled hydrolytic polymerization in nonaqueous solution of simple oxo-bridged binuclear ferric salts under the presence of carboxylate ligands. The rhombohedral crystalline form of the cluster with six imidazole molecules, which has crystallographically required C-3V symmetry, will be reported. The largest Fe-Fe distance in the undecairon oxo-hydroxo cluster is about 0.68 nm and the cluster has a diameter near 2 nm, which implies that this cluster leaches a nanometer-sized dimension.

Lead (II)-binding properties of rabbit liver thionein 2 (apo-MT2) have been studied. Two kinds of complexes, Pb-7-MT and Pb-7-MT', are observed upon the binding of Pb2+ to ape-MT at different pH. From their characteristic peaks in UV and CD spectra, it is deduced that Pb2+ in Pb-7-MT is coordinated by four sulfhydryl groups in Td microsymmetry, while multiple coordination types including two-coordination maybe present in Pb-7-MT'.

The one-dimensional polymer catena-poly[[aqua-manganese(II)-μ-[N-(2-hydroxyethyl)iminodiacetato]-O 1 ,O 2 ,O N ,N:O 1' ] hydrate], {[Mn II (Hheidi)(H 2 O)]-H 2 O} n [Hheidi is N-(2-hydroxyethyl)iminodiacetate, C 6 H 9 NO 5 ], was synthesized in aqueous solution. The polymeric [Mn II (Hheidi)(H 2 O)] segment is totally chiral and is connected into a three-dimensional structure by hydrogen bonds.

Lead(II)-binding behaviors of rabbit liver thionein2 (apo-MT2) has been studied by monitoring the changes of their electronic absorption(UV) and circular dichroism(CD) spectra, Two MT species, Pb-7-MT and Pb-7-MT', are observed upon the binding of Pb to ape-MT at different pH. The formation of Pb-7-MT or Pb-7-MT' is closely related to the amount of deprotoned sulfhydryl groups. Pb-7-MT is formed only at high pH characterized by UV 340 nm shoulder and CD 245 nm band. Then the formation of a new lead-metallothionein complex. namely Pb MT', is observed at low pH (pH < 6). This new species is characterized by a strong circular dichroism(CD) cotton effect at 395 nm(-), 310 nm(-) peaks and 350 nm (+), 250 nm (+) double-hump and a unique electronic absorption(UV) spectrum at 325 nm, 375 nm and 400 nm shoulder. From their characteristic peaks in UV and CD spectra, it is deduced that Pb2+ in Pb-7-MT is coordinated by four sulfhydryl groups in Td microsymmetry, while multiple Pb2+ coordination including two-coordination maybe present in Pb-7-MT', This is a novel structure motif that was not found previously for MT species.

The tide compound is formed by controlled hydrolytic polymerization in nonaqueous solution of simple oxo-bridged binuclear ferric salts under the presence of carboxylate ligands. The rhombohedral crystalline form of the cluster with six imidazole molecules, which has crystallographically required C3v symmetry, will be reported. The largest Fe-Fe distance in the undecairon oxo-hydroxo cluster is about 0.68 nm and the cluster has a diameter near 2 nm, which implies that this cluster reaches a nanometer-sized dimension.

Reduction of an acidified solution of Na2MoO4. 2H(2)O by iron powder results in the formation of the title compound [Mo176O16O480(OH)(32)(H2O)(80)]; the compound is tyre shaped and consists of sixteen {Mo-8} subunits being linked by forty-eight MoO6 octahedra; remarkable features are the size and mass (which is of the order of a protein) and its nano-dimensional cavity of ca. 3 nm in diameter.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Tetragonal crystals of hen egg white lysozyme were cross-linked and subjected to X-ray diffraction study in acetonitrile–water media with different acetonitrile concentrations. Crystals in neat acetonitrile did not scatter X-ray well. Structures of crystals in neat water, in 90% and 95% acetonitrile, and crystal back-soaked from acetonitrile to water, were determined to about 2 Å resolution. For crystals in both 90% and 95% acetonitrile, only one protein-bond acetonitrile molecule is found in the active site cleft, and its location and binding-protein mode is similar to the C subunit of polysaccharide. The alteration in conformation and hydrogen-bond pattern involving water as solvent causes the reduction of the protein's flexibility in organic media. The back-soaked crystal regained its ordinary three-dimensional structure in water.

In the crystals of C14H22N4O4, the molecule has a crystallographic inversion center and the methylene chain is fully extended.

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTToward Quantum Line−Self-Assembly Process of Nanomolecular Building Blocks Leading to a Novel One-Dimensional Nanomolecular Polymer: Single-Crystal X-ray Structure of {[H3O]+12{(H2O)MoO2.5[Mo36O108(NO)4(H2O)16]- O2.5Mo(H2O)}12-}nShi-Wei Zhang, Yong-Ge Wei, Qing Yu, Mei-Cheng Shao, and You-Qi TangView Author Information Department of Chemistry, Peking University Beijing 100871, People's Republic of China Cite this: J. Am. Chem. Soc. 1997, 119, 27, 6440–6441Publication Date (Web):July 9, 1997Publication History Received15 May 1996Revised26 October 1996Published online9 July 1997Published inissue 1 July 1997https://doi.org/10.1021/ja961637eCopyright © 1997 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views456Altmetric-Citations47LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit Read OnlinePDF (99 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information SUBJECTS:Anions,Crystals,Nanomaterials,Self organization,Vinyl Get e-Alerts

The novel oxo-centered dinuclear iron complex K4[Fe2O(IDA)4] (1) (IDA = iminodiacetate) was synthesized by the air-oxidation of ferrous iron in an aqueous solution in the presence of iminodiacetate and characterized by IR, magnetic susceptibility, and X-ray crystallography methods. The structure contains dimeric units where the two crystallographically equivalent iron centers are linked by a μ2-oxo bridge at a symmetric center of crystallography, forming a stick-like core, [Fe2O]4+, and have distorted octahedral environments each with one tridentate and one “bidentate-like” IDA ligands completing the coordination sphere. The iron centers are antiferromagnetically coupled in the cluster since they are bridged by the μ2-oxo oxygen atom in the center of symmetry and this was confirmed by the magnetic susceptibility study.

The first dodecanuclear manganese aggregate containing heterocarboxylate ligands [Mn12O12(O2CMe)4(O2CEt)12(H2O)4] (1) has been prepared and structurally characterized. The single crystal X-ray diffraction of 1 shows that it is similar to [Mn12O12(O2CR)16(H2O)4] (2a, R = Me or 2b, R = Ph) in its skeletal structure but it has a different crystal structure. Primary magnetism studies imply that 1 has an S = 9 spin ground state. A clear hysteresis loop was also observed for a polycrystalline sample of 1 · 2H2O · 4EtCOOH, but there was no anomaly in susceptibility down to 1.5 K. The cluster 1 represents another example of nanometre-sized molecular superparamagnets without particle size distribution.

A mixed-valence MnIII, MnII, MnIII malonate polymeric cluster having a trimeric repeat unit, {[MnII (H2O)4] [Mn(malonate)2 (H2O)]2}n, which is the first example of mixed-valence manganese carboxylate polymeric complex, has been prepared and characterized structurally. This complex behaves as an antiferromagnet and has a Neel temperature of ca 10 K.