Catalytic transformation of silicon tetraisocyanate Si(NCO)4 to a polymeric silylcarbodiimide

A new way for the preparation of inorganic polymeric carbodiimide‐based networks is presented which resembles the transformation of molecular isocyanates using 1‐phenyl‐3‐methyl‐2‐phospholene‐1‐oxide as a catalyst. The respective reaction sequence, well established in preparative organic chemistry, has been applied for the synthesis of carbodiimide‐based SiNC(O) materials. Starting from Si(NCO)₄ (silicon tetraisocyanate), a transformation to an insoluble extended inorganic array was achieved in boiling dodecan (T = 216 °C). Analysis of the polymer using X‐ray diffraction, FT‐IR, density measurement, matrix‐assisted laser desorption/ionization time of flight and TGA revealed that this highly moisture‐sensitive amorphous network consists of oligomers of high molar mass and exhibits a high density of around 1.5 g cm^?3, which corresponds quite well to the calculated density of crystalline Si(NCN)₂ reported in the literature. Degradation of this 'SiNC(O) phase' with the release of N₂ and (CN)₂ finally provided SiC as the only crystalline product. No indication of the formation of crystalline Si₃N₄ or intermediate crystalline 'SiC₂N₄', silicon carbodiimide (= Si(NCN)₂), was noticed. Copyright © 2013 John Wiley & Sons, Ltd.     

Preparation of57Fe enriched K4[Fe(CN)6] and K3[Fe(CN)6]

A simple method to prepare⁵⁷Fe enriched K₄[Fe(CN)₆] and K₃[Fe(CN)₆] is described. The yields of the products are much better than those reported in the literature so far. The enrichment is essential for⁵⁷Fe Mössbauer investigation in a variety of Prussiate type complexes and other inorganic compounds which are conveniently prepared from K₄[Fe(CN)₆] and K₃[Fe(CN)₆]. K₄[Fe(CN)₆] was obtained by reacting freshly prepared Fe(OH)₃ with glacial acetic acid and treating with iron acetate in boiling aqueous solution of KCN. The novel feature of the procedure to obtain K₃[Fe(CN)₆] is that the oxidation of K₄[Fe(CN)₆] has been carried out in the solid state by passing chlorine gas over the powdered specimen. K₃[Fe(CN)₆] was crystallised from alkaline solution of this oxidised powder. The compounds were characterised by Mössbauer spectroscopy.     

Cyanide‐Bridged Tetranuclear REIII2FeIII2 (RE = Y,Tb, Dy) Molecular Squares with 2, 2′:6′,2′′‐Terpyridine as a Capping Ligand

Self‐assembly reaction between hydrated rare‐earth (RE) nitrates RE(NO₃)₃ · 6H₂O with K₃Fe(CN)₆ in H₂O/DMF solution by employing the tridentate ligand 2, 2′:6′,2′′‐terpyridine (terpy) as a capping ligand has yielded three cyanide‐bridged compounds [RE(terpy)(DMF)(H₂O)₂][Fe(CN)₆] · 6H₂O [RE = Y ( 1 ), Tb ( 2 ), Dy ( 3 )]. FT‐IR spectra confirmed the presence of terpy ligands and cyanide groups in compounds 1 – 3 . Single‐crystal X‐ray structural analysis indicated that these compounds are isomorphous and adopt neutral [RE₂Fe₂] molecular squares, which are further linked through hydrogen bonding interactions to generate a three‐dimensional supramolecular network. Magnetic susceptibility measurements revealed that significant single ion magnetic anisotropy dominates the properties of these compounds.     

MÖSSBAUER- und Infrarotspektren von Addukten des K4[Fe(CN)6] mit Antimontrihalogeniden

Mössbauer- and IR Spectra from the Addition Compounds of K₄[Fe(CN)₆] with Antimony Trihalides By the reaction of K₄[Fe(CN)₆] with SbX₃ in the melt (X = Cl, Br) or in SO₂ solution (X = F) the addition compounds K₄[Fe(CNSbX₃)₆] (X = F, Cl) and K₄[Fe(CNSbX₃)₄(CN)₂] (X = Cl, Br) are formed. The IR spectra of these compounds have been interpreted. The MÖSSBAUER spectra are single lines which exhibit a slight broadening compared with K₄[Fe(CN)₆] · 3 H₂O. The values of the isomer shifts following the order of the LEWIS acid strengths of the SbX₃ molecules correspond to a small but significant increase of the s-electron density, which is explained by the increasing influence of the π-acceptor function of the ligands.     

Hydrothermal synthesis of the fist two‐dimensional folded layer formed by a cyano‐bridged one‐dimensional chain joined by Cu(I)?Cu(I) bonding

Two cyano‐bridged polymers, [Cu₃(CN)₃(phen)]_n ( 1 ) and [Cu(CN)(phen)]_n ( 2 ) (phen = 1,10‐phenphralonine), were synthesized by the hydrothermal reaction of Cu(NO₃)₂· 3H₂O, K₃[Fe(CN)₆] and phen and were characterized structurally by X‐ray, IR and ERSC methods. Compound 1 shows a two‐dimensional folded coordination network by Cu(I)? CN? Cu(I) and Cu(I)? Cu(I) interaction, while compound 2 exhibits an infinite helix chain by Cu(I)? CN linkages. Copyright © 2005 John Wiley & Sons, Ltd.     

Zero Thermal Expansion in K0.46Co1.27[Fe(CN)6]·5.5H2O

Thermal expansion of materials is a comparatively easy‐understood physical property. Prussian blue analogues are of particular interest in engineering as new zero thermal expansion materials. We investigated the thermal expansion in K_0.46Co_1.27[Fe(CN)₆] · 5.5H₂O by x‐ray powder diffraction. This compound is a good example of a zero thermal expansion material. The origin of zero thermal expansion is considered to be the low frequency transverse vibrational motion of the cyano bridges.     

Catalytic Activity of Bimetallic (Ruthenium/Palladium) Nano‐alloy Decorated Porous Carbons Toward Reduction of Toxic Compounds

Chicken feather‐derived high‐surface‐area porous activated carbon (CFAC) material was prepared using chemical activation. A new composite composed of Ru‐Pd nanoparticles supported on CFAC (Ru‐Pd@CFAC) has been prepared by microwave‐thermal reduction in the presence of the support. Characterization by XRD, Raman, BET, FE‐SEM/TEM, FT‐IR, TGA, XPS, HAADF‐STEM‐EDS, H₂‐chemisorption, H₂‐TPR, and ICP‐AES was used to analyze the catalyst. This catalyst is found to be efficient for the reduction of hexavalent chromium (Cr^VI), potassium ferricyanide (K₃[Fe(CN)₆]), 4‐nitrophenol (4‐NP), and pendimethalin (PDM), at room temperature, and remains stable, even after several repeated runs. Moreover, it showed excellent catalytic activity compared with the monometallic counterparts.     

A new method of synthesis of BiFeO<Subscript>3</Subscript> prepared by thermal decomposition of Bi[Fe(CN)<Subscript>6</Subscript>]·4H<Subscript>2</Subscript>O

In order to investigate the formation of the multiferroic BiFeO₃, the thermal decomposition of the inorganic complex Bismuth hexacyanoferrate (III) tetrahydrate, Bi[Fe(CN)₆]·4H₂O has been studied. The starting material and the decomposition products were characterized by IR spectroscopy, thermal analysis, laboratory powder X-ray diffraction, and microscopic electron scanning. The crystal structures of these compounds were refined by Rietveld analysis. BiFeO₃ were synthesized by the decomposition thermal method at temperature as low as 600 °C. There is a clear dependence of the type and amount of impurities that are present in the samples with the time and temperature of preparation.     

Three Distinct Silver(I) Coordination Polymers: Bridging‐­Ligand Directed Syntheses,Crystal Structures,Luminescence, and Nitrobenzene Sensing Properties

Three distinct Ag^I‐DMAP [DMAP = 4‐(dimethylamino)pyridine] coordination polymers [Ag₂I₂(DMAP)₂]_n ( 1 ), [Ag₂(CN)₂(DMAP)_2.5 · DMAP]_n ( 2 ), and [Ag(SCN)(DMAP)]_n ( 3 ) were constructed by monatomic I^–, diatomic CN^–, and triatomic SCN^– bridges, respectively. 1 – 3 were determined by FT‐IR spectroscopy, elemental analyses, TGA, powder and single‐crystal X‐ray diffraction. 1 exhibits a 1D wavelike chain structure, sustained by 3‐connected I^– bridges, whereas 2 shows a unique 1D single‐ and double‐strand alternating chain, supported by 3‐connected CN^– bridges. Compound 3 has a 2D 3‐connected network architecture, fabricated by 3‐connected SCN^– bridges, and exhibits a (4 · 8²) topology. The luminescence and nitrobenzene sensing properties of 1 – 3 were explored in 2‐propanol suspensions, which revealed that compounds 1 – 3 exhibit DMAP originated luminescence emissions and are highly sensitive for nitrobenzene detection.     

On the Lanthanide Ferrocyanides KLnFe(II)(CN)6·xH2O (Ln=La-Lu): Characterization and Thermal Evolution

The properties of a series of lanthanide hexacyanoferrate(II) n-hydrates were studied by thermal analysis, IR spectroscopy and X-ray diffraction. Thermal analysis results show that there are three kinds of complexes in this series, KLn[Fe(CN)₆]·4 H₂O (Ln=La-Nd), KSm[Fe(CN)₆]·3H₂O and KLn[Fe (CN)₆]·3.5H₂O (Ln=Eu-Lu). On the basis of IR spectra, only two different types of complexes show obvious differences. Indeed for the tetrahydrates, there is one OH stretching band; on the other hand, for the samarium phase and the 3.5 hydrates a splitting of HOH stretching mode is observed. The splitting of the H₂O band is correlated to a symmetry modification. The crystal structures of the three complexes KLn[Fe(CN)₆]·3.5H₂O (Ln=Eu, Er and Lu) were determined; they belong to orthorhombic symmetry (space group Cmcm). Heat-treated powders have been investigated by X-ray analysis which show the formation of thin needles of LnFeO₃ at 600°C.     

Synthesis,IR Spectrum,Thermal Analysis,and Crystal Structure of the Cyano‐bridged Heteronuclear Polymeric Complex: [Zn(teta)Ni(μ‐CN)2(CN)2]n

The heteronuclear polymeric complex, [Zn(teta)Ni(μ‐CN)₂(CN)₂]_n (teta: triethylenetetramine), was synthesized and characterized by elementel analysis, FT‐IR spectroscopy, thermal analysis and single crystal X–ray diffraction techniques. The complex crystallizes in the monoclinic system, space group P2₁/c and in which the Zn^II ion exhibits a distorted octahedral coordination by one tetradentate teta ligand and two bridging cyano groups as a trans position, whereas the Ni^II ion has square planer coordination and is coordinated by four cyano ligands. The decomposition reaction takes places in the temperature range 30–600 °C in the static air atmosphere.     

Synthesis, Characterization and Crystal Structure of the First Tri-nuclear MFe2（M = Cu and Ni） Complexes Based on Nitroprusside

IntroductionSince 184 8,whenPlayfairpublishedthefirstpaperrelatedtonitroprussides ,1thetransitionmetalpenta cyanonitrosylmetallatehydrateshavebeenwidelystudiedbecauseoftheirimportantrolesinmolecularsieves ,cationexchangers,electronscavengersandradionuclidesor bents .2 4 Thenitroprussides ,regardlessofthecationicmetal,arecurrentlyemployedasreversibleinhibitorsofagroupofenzymesknownassuperoxidedismutases .5Recently ,using [Fe(CN ) 5(NO) ]2 - asabuildingblock ,somenitroprusside bridgedpolymeri…     

Potassium bis(ethylenediamine)­copper(II) ferricyanide

The title compound, potassium bis(ethylenediamine‐N,N′)copper(II) hexacyanoferrate(III), K[Cu(C₂H₈N₂)₂]‐[Fe(CN)₆], contains [Cu(en)₂]²⁺ and [Fe(CN)₆]^3? complex ions, where en is ethylenediamine. The Fe^III and K⁺ ions lie on twofold axes and the Cu^II atom lies on an inversion center. The [Cu(en)₂]²⁺ ion has square‐planar coordination with a mean Cu—N distance of 1.992 (2) Å and the [Fe(CN)₆]^3? ion has distorted octahedral coordination with a mean Fe—C distance of 1.947 (2) Å.     

The three‐dimensional coordination polymer tetra­ethyl­ammonium (ethyl­ene­di­amine)­cadmium(II) hexa­cyano­ferrate(III), (Et4N){[Cd(en)]4[Fe(CN)6]3}

The title compound, tetra­ethyl­ammonium dodeca‐μ‐cyano‐hexa­cyano­tetrakis­(ethyl­ene­di­amine)­tetra­cadmium(II)­tri­fer­rate(III), (C₈H₂₀N)[Cd₄Fe₃(CN)₁₈(C₂H₈N₂)₄], was pre­pared from a reaction mixture containing CdCl₂, K₃[Fe(CN)₆], ethyl­ene­di­amine (en) and [Et₄N]Br in a 1:1:3:1 molar ratio. The crystal structure consists of a negatively charged three‐dimensional framework of {[Cd(en)]₄[Fe(CN)₆]₃} anions, with [Et₄N]⁺ cations located in the cavities of the framework. The Cd atom is octahedrally coordinated by one disordered chelating en mol­ecule [mean Cd—N = 2.35 (3) Å] and four N‐­bonded bridging cyano groups [Cd—N distances are in the range 2.283 (2)–2.441 (2) Å]. There are two crystallographically independent [Fe(CN)₆]³⁻ anions in the structure and in each the Fe atom lies on a twofold axis. In the first [mean Fe—C = 1.941 (5) Å], all the cyano groups are bridging ligands, while in the second [mean Fe—C = 1.945 (2) Å], there are two terminal cyano ligands in trans positions. The Cd—N—C angles range from 128.6 (2) to 172.8 (2)°.     

一个二维Honeycomb-like聚合簇合物 (Et4N)3{[MoS4Cu2(m-CN)]2(m’-CN)}·2MeCN的合成和晶体结构

采用一个预制的簇合物(Et₄N)₂[MoS₄(CuCN)₂]·H₂O(1)和HAc在MeCN中混合反应，生成了一个有趣的二维聚合簇合物(Et₄N)₃{[MoS₄Cu₂(m-CN)]₂(m’-CN)}·2MeCN (2)。通过元素分析，红外光谱及单晶X-射线衍射分析对簇合物2进行了表征。在2的结构中，前驱体1中的MoS₄Cu₂簇核得到了保留，并且此簇核作为三重连接点通过单一氰桥和其他相同的簇核相连，形成一个阴离子型的2D (6,3)（蜂窝状）网络。由预制的簇合物1通过醋酸诱导形成的超分子2表明这种简单的合成方法有可能应用到许多其他相关的体系。     

Die Kristallstruktur von BaHg(CN)4 · 4 Pyridin

Crystal Structure of BaHg(CN)₄ · 4 Pyridine The structure of the tetragonal BaHg(CN)₄ · 4 Pyridine (space group I4 , a = 1119.4(7), c = 1 057.9(7) pm, Z = 2, d_c = 1.87 g · cm^?3) contains tetrahedral Hg(CN)₄ and bisdisphenoide Ba(NC)₄(py)₄ groups, which are linked together by Hg? CN? Ba bridges. The BaHg(CN)₄ framework consists of a 3-dimensional network of all round edge-sharing tetrahedrons. The analogous strontium compound is isotype with a = 1 108.2(9) and c = 1 035.3(14) pm.     

Hexacyanopalladium(IV)-säure und Hexacyanopalladate(IV)

The preparation and the properties of the hexacyanopalladium(IV) acid (H₃O)₂[Pd(CN)₆] and of a number of metal hexacyanopalladates(IV) are described. UV, IR and Raman spectra are reported, force constants have been calculated and the bonding properties are discussed. K₂[Pd(CN)₆] crystallizes in a hexagonal lattice; a = 7.42, c = 6.65 Å, Z = 1.     

Complexation of Cyanine Dyes of the Tetrazolo[5,1-a]isoindole Series with Potassium Hexacyanoferrate(III) and Tetracyanonickelate(II)

The interaction of K₃[Fe(CN)₆] and K₂[Ni(CN)₄] with cyanine dyes of the tetrazoloisoindole series in nonaqueous media was established. This process involved both ion-exchange reactions and several other interactions. Four compounds were isolated and studied by electronic absorption spectroscopy, IR spectro-scopy, and mass spectrometry.     

Ag/Cu-mediated decarboxylative cyanation of aryl carboxylic acids with K4Fe(CN)6 under aerobic conditions

A method for facile synthesis of aryl nitriles has been well established via Ag/Cu-mediated decarboxylative cyanation of benzoic acids with K₄Fe(CN)₆ under aerobic conditions. The approach of using readily accessible aryl carboxylic acids and green K₄Fe(CN)₆ as starting material provides a feasible alternative to previous cyanation protocols. Control experiments revealed the key role of Cu for the process and excluded the possibility of a radical mechanism for the transformation.     

Synthesis of Isotope Enriched (CN3H6)2[57Fe(CN)5NO] starting from 57Fe

A high‐yield, mmolar‐scale synthesis of pure guanidinium nitroprusside, (CN₃H₆)₂[⁽⁵⁷⁾Fe(CN)₅NO] (GNP) from iron metal is described. The iron metal contained pieces of 95.3% ⁵⁷Fe together with normal iron so that an isotope enrichment in ⁵⁷Fe of 25% was achieved. Single‐crystals of GNP could be grown in cubic shape and dimensions of about 3 × 4 × 4 mm³. The purity of the GNP product and the intermediates K₄[⁽⁵⁷⁾Fe(CN)₆] · 3 H₂O and Na₂[⁽⁵⁷⁾Fe(CN)₅NO] · 2 H₂O was ascertained by ⁵⁷Fe Mössbauer spectroscopy as well as ¹³C, ¹⁴N and ⁵⁷Fe NMR spectroscopy. The ⁵⁷Fe NMR chemical shift for [⁽⁵⁷⁾Fe(CN)₅NO]^2– in GNP was detected at +2004.0 ppm [vs Fe(CO)₅].