Synthese und Koordinationschemie von Diisocyanmethan

Synthesis and Coordination Chemistry of Disocyanomethane Disocyanomethane ( 1 ) was synthesized starting from bis(formylamido)methane by the Ugi method. 1 decomposes vigourously above its melting point (−15 °C) into a brown insoluble solid. The isocyanide can be stabilized by coordination to a transition metal complex fragment. The complexes (CO)₅Cr(CN‐CH₂‐NC) ( 2 ), (CO)₅Cr(CN‐CH₂‐NC)Cr(CO)₅ ( 3 ), CpMn(CO)₂(CN‐CH₂‐NC) ( 4 ), CpMn(CO)₂(CN‐CH₂‐NC)(CO)₂MnCp ( 5 ), CpMn(CO)₂‐(CN‐CH₂‐NC)Cr(CO)₅ ( 6 ), CpMn(CO)₂(CN‐CH₂‐NC)Cu(pz*)₃BH ( 7 ) and (CO)₅Cr(CN‐CH₂‐NC)Cu(pz*)₃BH ( 8 ) (pz* = 3, 5‐dimethylpyrazolyl) were synthesized and characterized spectroscopically. The structures of bis(formylamido)methane, monoclinic, P2₁/c, a = 9.189(5), b = 6.881(3), c = 7.616(2)Å, β = 91.24(4)°, R₁ = 0.0475, wR₂ = 0.1748, and the diisocyanomethane complexes 2 , monoclinic, C2/c, a = 24.996(7), b = 5.882(2), c = 20.572(6)Å, β = 134.62(2)°, R₁ = 0.0582, wR₂ = 0.1357, 4 , monoclinic, P2₁/a, a = 12.143(4), b = 5.848(2), c = 14.301(5)Å, β = 97.77(3)°, R₁ = 0.0355, wR₂ = 0.0972, 6 monoclinic, P2₁/c, a = 11.537(7), b = 12.248(5), c = 12.54(2)Å, β = 102.75(8), R₁ = 0.1333, wR₂ = 0.3024 and 7 , triclinic, P1¯, a = 9.8841(9), b = 9.9517(9), c = 16.2479(15)Å, α = 104.790(2), β = 90.530(2), γ = 98.213(2)°, R₁ = 0.0416, wR₂ = 0.1198 were determined by single crystal X‐ray diffraction.     

Elektrochemische Synthese von Ag5Pb2O6

Electrochemical Synthesis of Ag₅Pb₂O₆ Ag₅Pb₂O₆ was prepared by anodic oxidation of silver in a PbO₂ suspension in an aqueous KOH solution. Phase purity was checked by a Rietveld‐fit of the X‐ray powder pattern, thermal and chemical analysis. The compound exhibits ionic conductivity. It' anisotropy leads to an orientation of the crystallites on the silver anode.     

Synthese,Strukturuntersuchung und Koordinationschemie von Isocyanacetonitril

Synthesis, Structure, and Coordination Chemistry of Isocyanoacetonitrile Isocyanoacetonitrile 1 was synthesized starting from aminoacetonitrile by the Ugi method. The structure and relative energies of 1 were calculated by ab initio methods (MP2/6‐31G**) in comparison with malonodinitrile and diisocyanomethane. 1 crystallizes on cooling below –14 °C forming a colourless solid, monoclinic, Pn, a = 614.9(2), b = 756.3(1), c = 786.4(3) pm, β = 98.99(4)°, Z = 4, R = 0.054, wR₂ = 0.132, with two molecules representing the asymmetric unit. 1 polymerizes readily at ambient temperature forming a dark‐brown almost insoluble solid 2 . 1 can be stabilized by coordination to metal fragments. The metal complexes (CO)₅M(CNCH₂CN) ( 3 ) ( a , M = Cr; b , M = W), CpMn(CO)₂(CNCH₂CN) ( 4 ) and fac‐(CO)₃W(CNCH₂CN)₃ ( 5 ) were synthesized and characterized by spectroscopic methods. The structures of 3 a , monoclinic, C2/c, a = 2481.4(7), b = 582.2(2), c = 2053.3(6) pm, β = 134.57(2)°, R₁ = 0.0368, wR₂ = 0.1001, and 4 , monoclinic, P2₁/a, a = 1223.7(2), b = 586.0(1), c = 1446.3(3) pm, β = 97.81(2)°, R₁ = 0.0459, wR₂ = 0.1190, were determined by single crystal X‐ray diffraction.     

Synthese von Dimethoxyethan‐ und Tetrahydrofuran‐Komplexen der Selten‐Erd‐Nitrate – Festkörperstruktur von Pr(NO3)3(thf)4

Synthesis of Dimethoxyethane and Tetrahydrofuran Complexes of Rare‐Earth Nitrates – Solid State Structure of Pr(NO₃)₃(thf)₄ The solvated rare‐earth nitrates Ln(NO₃)₃(thf)_n (Ln = Pr, n = 4 ( 1 ); Ln = Ho ( 2 ), Yb ( 3 ), n = 3 and Ln(NO₃)₃(dme)₂; Ln = Pr ( 4 ), Ho ( 5 )) were obtained from Ln(NO₃)₃(H₂O)_x and HC(OCH₃)₃. Pale green thermally labile crystals of 1 were characterized by X‐ray crystallography. The praseodymium atoms in two independent monomeric molecules show capped trigonal prismatic and pentagonal bipyramidal coordination, respectively.     

Synthesis,Characterization, and Photoluminescence Properties of a Planar Copper Triazolate Coordination Polymer with Cyanide as Co‐Ligand

A new copper coordination polymer [Cu₃(CN)(dmtz)₂] ( 1 ) (Hdmtz = 3,5‐dimethyl‐1,2,4‐triazole) was solvothermally synthesized and characterized by IR spectroscopy, X‐ray power diffraction, and single‐crystal X‐ray diffraction. The single‐crystal diffraction analysis shows that compound 1 belongs to the orthorhombic space group Pmmn, and exhibits a 2D planar framework constructed by the ligand dmtz and cyanide anions, in which the cyanide anion was generated from in situ decomposition of acetonitrile. The photoluminescent study indicates that 1 emits strong blue‐green luminescence with long emission lifetimes in the solid state at room temperature.     

3D Coordination Polymer Incorporating Discrete Molecular Octahedra

Copper(II) oxalate coordination polymer [{Cu₄(C₂O₄)₄(L)₄}₃ · {Cu₃(C₂O₄)₃(L)₆}₂ · 3L · 25H₂O]_n (L = 3,3′,5,5′‐tetramethyl‐4,4′‐bipyrazole) reveals a structure that is related to the Pt₃O₄ net topology. The 3D linkage is sustained with copper‐oxalate squares and copper‐bipyrazole triangles sharing vertices. The framework supports giant icosahedral cages and entraps discrete molecular octahedra formed by two molecular complexes Cu₃(C₂O₄)₃(L)₆ associated by means of NH‐‐‐N hydrogen bonding. The coexistence of the discrete and 3D portions formed by the same components suggests self‐templation as a key feature of the system. Simpler copper oxalate compounds [Cu(C₂O₄)(L)₂(H₂O)] · CH₃OH · 3.75H₂O and [Cu₂(C₂O₄)₂(L)₅] · L · 11H₂O are concomitant products of the reaction mixture and they exist in the form of molecular mono‐ and binuclear complexes.     

Synthese und strukturelle Charakterisierung von Borsubphthalocyaninaten

Synthesis and Structural Characterization of Boron Subphthalocyaninates Halosubphthalocyaninatoboron, [B(X)_spc] (X = F, Cl, Br) is obtained by heating phthalonitrile with boron trihalide in quinoline (X = F) or the corresponding halobenzene, resp. [B(C₆H₅)_spc] is prepared from phthalonitrile and tetraphenylborate or tetraphenyloboron oxide, resp. [B(OR)_spc] (R = H, CH(CH₃)₂, C(CH₃)₃, C₆H₅) is synthesized by bromide substitution of [B(Br)_spc] in pyridine/HOR. Substitution of [B(Br)_spc] in carboxylic acids yields [B(OOCR)_spc] (R = H, CX₃ (X = H, Cl, F), CH₂X (X = Cl, C₆H₅), C₆H₅). All subphthalocyaninates are characterized electrochemically and by UV‐VIS, IR/FIR, resonance Raman, and ¹H/¹⁰B‐NMR spectroscopy. Typical B–X stretching vibrations are at 622 (X = Br), 950 (Cl), 1063 (F), 1096 cm^–1 (OH) as well as between 1119 and 1052 cm^–1 (OR) resp. 985 and 1028 cm^–1 (OOCR). The difference ν(C=O)–ν(C–O) > 400 cm^–1 confirms the unidentate coordination of the carboxylato ligands. According to the crystal structure analysis of [B(OH)_spc], [B(OH)_spc] · 2 H₂O, [B(C₆H₅)_spc], [B(OC(CH₃)₃)_spc], [B(OOCCH₃)_spc] · 0.5 H₂O · C₂H₅OH and [B(OOCCH₃)_spc] · 0.4 H₂O · 1.1 C₅H₅N the _spc ligand is concavely distorted. This saucer shaped conformation is independent of the acido ligands and the presence of solvate. The outermost C atomes are vertically displaced in part by more than 2 Å from the N_i plane. The B atom is in a distorted tetrahedral coordination geometry. It is displaced by ca 0.64 Å out of the N_i plane towards the acido ligand. The average B–N distance is 1.500 Å, and the B–O distances range from 1.418(5) to 1.473(2) Å.     

Supramolecular Complexes Based on [M(CN)8]4– (M = Mo,W) and Aliphatic Amine CuII Tectons

Three heterometallic supramolecular complexes [Cu₂(pn)₄(Mo(CN)₈)·4H₂O] (pn = diaminopropane) ( 1 ), [Cu₂(pn)₄(W(CN)₈)·4H₂O] ( 2 ) and [Cu₂(1,2‐pn)₄(H₂O) (W(CN)₈)·3H₂O] ( 3 ) have been synthesized and structurally characterized by single‐crystal X‐ray diffraction studies. Complexes 1 – 3 exhibit three different networks. In 1 , the copper(II) ion is pentacoordinate with a distorted square‐pyramidal arrangement and the network is formed by the incorporation of coordinative linkage between the μ₂ bridge of [Mo(CN)₈]^4– and copper(II) ions and hydrogen‐bonding interactions. In 2 , the copper(II) ion exhibits a distorted square‐pyramidal arrangement and the network is formed by the hydrogen bonded trinuclear complexesof [Cu₂(pn)₂(W(CN)₈)]. In 3 , the copper(II) ions show twodifferent distorted octahedral arrangements. The network structure of 3 is formed by the hydrogen‐bonded complex chains of [Cu₂(1,2‐pn)₂(W(CN)₈)].     

Elektrochemische Synthese von Perowskiten im System K/Ba/Pr/Bi/O

Electrochemical Synthesis of Perovskites in the System K/Ba/Pr/Bi/O An easy procedure for the synthesis of well crystalline samples of (K,Ba)(Pr,Bi)O₃ is provided by anodic oxidation of melts consisting of Ba(OH)₂ / KOH / Pr(NO₃)₃ / Bi(NO₃)₃, at comparatively low temperatures of about 220 °C. We have explored the influence of different parameters like temperature, potential of the working electrode, and composition of the electrolyte. Chemical and thermal analyses were performed. Products obtained at different experimental conditions revealed different Ba/K and Pr/Bi ratios with a large homogeneity range. X‐Ray powder diffraction and single crystal structure analyses of K_xBa_1?xPr_yBi_1?yO₃ proved these compounds to be cubic perovskites. Barium and potassium ions are disordered occupying the A‐sites while praseodym and bismuth ions share the B‐sites or are ordered, as indicated by a doubling of the lattice parameter. The composition x and y can independently be altered. XPS analysis and physical properties are reported and discussed.     

Synthese und Kristallstruktur von Calcium-Kupfer-Diarsenat CaCuAs2O7

Synthesis and Crystal Structure of the Calcium Copper Diarsenate CaCuAs₂O₇ Solid state reactions led to single crystals of CaCuAs₂O₇. X-ray investigations revealed monoclinic symmetry, space group C⁵_2h-P2₁/c, lattice constants a = 7.272(1); b = 8.946(2); c = 9.307(2) Å; β = 109.48(2)°; Z = 4. CaCuAs₂O₇ is characterized by ¹_∞[CaO₆] chains, connected by As₂O₇ double tetrahedra and elongated square CuO₅ pyramids. The hitherto unknown crystal structure shows relationships to CaCuP₂O₇ but not to CaCuV₂O₇.     

Elektrochemische Deintercalation von Ag2PbO2

Electrochemical Deintercalation of Ag₂PbO₂ Ag₂PbO₂ was electrochemically deintercalated. The electrochemical reactions were studied in a two electrode swagelock teflon laboratory cell. A silver metal foil was used as negative electrode, and a pellet of the educt phase Ag₂PbO₂ (diameter 9 mm, thickness ca. 0.5 mm) without any graphite or binder was used as positive electrode. Silvernitrate, dissolved in acetonitrile (0.1 mol), was applied as liquid electrolyte. The electrotitration was carried out with a constant charge density of 6 μA/cm². Periods of working potential (48 h) alternated with periods of the open cell potential (3 h). The development of the cell voltage at decreasing silver content shows a continuous change of slope without any extended plateau. The Ag₂PbO₂ cell was totally charged, and the resulting product of deintercalation was proven to be binary PbO₂ in the stable α‐modification. The Rietveld evaluation of the powder diffraction data of intermediate deintercalated phases gave conclusive support to a two phase mode mechanism of deintercalation during which α‐PbO₂ was continuously separated without forming Ag_xPbO₂ solid solutions.     

Synthese und Kristallstruktur von ACu4As2 (A: Ca–Ba,Eu)

Synthesis and Crystal Structure of A Cu₄As₂ ( A : Ca–Ba, Eu) Steel‐gray single crystals of ACu₄As₂ with A = Ca–Ba and Eu respectively were synthesized by heating mixtures of the elements at about 900 °C. Structure determinations with X‐ray diffractometry data revealed, that the isotypic compounds crystallize in the rhombohedral CaCu₄P₂ type structure (R3m; Z = 3) (hexagonal axes see ”︁Inhaltsübersicht”︁”︁). Measurements of the susceptibility of EuCu₄As₂ showed divalent Eu and ferromagnetic order at 35 K.     

Synthese und Charakterisierung von Natriumcyanamid

Synthesis and Characterization of Sodium Cyanamide The synthesis of Na₂CN₂ was carried out by reaction of sodium amide with sodium hydrogen cyanamide at 200 °C, in vacuum. Single crystals were obtained while heating the product (500 °C, 8 days) in silver crucibles. The title compound was characterised by single crystal X‐ray diffraction and IR‐spectroscopy (C2/m; Z = 2, a = 5.0456(3), b = 5.0010(3), c = 5.5359(3) Å; β = 110.078(5)°; R1 = 3.18%, wR2 = 6.35%, GOF = 1.078). The CN₂^2– units are linear exhibiting a C–N bond length of 1.236(1) Å, while sodium is coordinated by five nitrogen atoms forming a square pyramid. The structural relationships to aristotypic Na₂HgO₂ are pointed out.     

Synthesis and Crystal Structures of Copper Zinc Phenylthiolate and the First Copper Zinc Selenolate and Tellurolate Complexes

Five copper zinc phenylchalcogenolate complexes [(iPr₃PCu)₃(ZnMe₂)₂(SPh)₃] ( 1 ), [(iPr₃PCu)₂(ZnPh)₄(SPh)₆] ( 2 ), [(iPr₃PCu)₂(ZnEt)₄(SPh)₆] ( 3 ), [(iPr₃PCu)₃(ZnEt)(SePh)₄] ( 4 ), and [(iPr₃PCu)₃Cu(iPr₃PZn)(TePh)₆] ( 5 ) were synthesized by the reaction of phosphine stabilized copper phenylchalcogenolate complexes with ZnR₂ (R = Me, Et, Ph) with and without additional chalcogenol. The novel mixed metal compounds were characterized by single‐crystal X‐ray structure analysis and NMR spectroscopy. 4 and 5 are the first examples of compounds with a Zn–Se–Cu or a Zn–Te–Cu linkage, respectively.     

Synthese und Kristallstruktur von [(Me3Si)2BiCu(PMe3)3], dem ersten Komplex mit einer Bismut—Kupfer‐Bindung

Synthesis and Crystal Structure of [(Me₃Si)₂BiCu(PMe₃)₃] — the First Complex with a Bismuth—Copper Bond The reaction of CuO^t Bu with PMe₃ and Bi(SiMe₃)₃ in hexane yields the phosphine‐stabilized complex [(Me₃Si)₂Bi‐Cu( PMe₃)₃]. This synthesis gave rise to the first binuclear Bi—Cu compound to be structurally characterized by X‐ray crystallography.     

Bis(2,4,6‐trimethylphenyl)tellurium(IV) Dicyanide: the First Crystal Structure for a Tellurium Cyanide of the Type R2Te(CN)2

The reaction of Mes₂TeF₂ (Mes = 2,4,6‐trimethylphenyl) with trimethylsilyl cyanide yields the corresponding tellurium(IV) dicyanide Mes₂Te(CN)₂. Isolation of suitable crystals allows the determination of the first crystal structure of a compound of the type R₂Te(CN)₂.     

Crystal Structure and Structural Transformation of [(CH3)3NH]2[CuZn(CN)5]

A newly synthesized coordination polymer, [(CH₃)₃NH]₂[CuZn(CN)₅], was investigated using ¹³C and ⁶³Cu solid‐state NMR techniques and single‐crystal X‐ray diffractometry. It consists of a three‐dimensional (3D) net composed of tetrahedral Cu^I and Zn^II ions and CN^– ligands bridging between the two metal ions. (CH₃)₃NH⁺ ions are trapped in the inner space of the 3D net. Three coordination sites of each metal ion are used for the formation of the 3D net and the remaining site is occupied by a unidentate CN^– ligand. The structure of the 3D net is chiral and categorized as srs in the notation of the Reticular Chemistry Structure Resource (RCSR). In water vapor or open air at room temperature under ambient pressure, a powder of [(CH₃)₃NH]₂[CuZn(CN)₅] showed a structural transformation to [(CH₃)₃NH][CuZn(CN)₄] · 1.5H₂O, which is a known compound with a diamond‐like 3D net of [CuZn(CN)₄]^– composed of tetrahedral Cu^I and Zn^II ions and bridging CN^– ligands. ⁶³Cu solid‐state NMR spectroscopy revealed that the Cu‐CN‐Zn orientation of the bridging CN^– ligands was conserved after the structural transformation.