3-(1H-Imidazol-1-yl)propane­nitrile

The title compound, C6H7N3, has an ethyl­ene group connecting an imidazole ring and a –CN group. These groups are in a staggered conformation. The shortest inter­molecular contact is found between the imidazole N atom and a –CH2– group of a neighboring mol­ecule

New Low-Melting Triply Charged Homoleptic Cr(III)-Based Ionic Liquids in Comparison to Their Singly Charged Heteroleptic Analogues

A series of new low-melting triply charged homoleptic Cr(III)-based ionic liquids of the general formula (RMIm)3[Cr(NCS)6] (R = methyl, ethyl, n-butyl, benzyl) is reported. Their syntheses and properties are described in comparison to their singly charged heteroleptic analogues of the general formula (RMIm)[Cr(NCS)4L2] (R = methyl, ethyl, n-butyl, benzyl; L = pyridine, γ-picoline). In total, sixteen new Reineckate related salts with large imidazolium cations are described. Out of these, five compounds were crystallized, and their structures determined by single-crystal X-ray structure analyses. They all consisted of discrete anions and cations with octahedrally coordinated Cr(III) ions. In the structures, various hydrogen contacts interconnect the entities to build up hydrogen bonded networks. Thermal investigations showed relatively low melting points for the homoleptic complexes. The compounds with the [Cr(NCS)6]3− anion melt without decomposition and are stable up to 200 K above their melting points. The complex salts with the [Cr(NCS)4L2]− anion, in contrast, start to decompose and lose L molecules (Pyr or Pic) already at the melting point

On the Borderline of Pauling\u27s Bond Order Concept: Metal-Metal Bonding in Icosahedral Chains of Metal-Rich Tantalum Sulfides

Metal-metal bonding in the icosahedral metal-rich sulfides of Ta is considered from the point of view of extended Hückel calculations via Mullikan overlap populations and from the point-of-view of Pauling bond order. It is found that the two approaches are generally consistent, but that the overlap populations provide a more sensitive estimate of reaction energies. The results are consistent with a strong stabilization of the icosahedral clusters by central atom to icosahedral metal atom bonding and a weak destabilization (relative to the disproportionation products) by the icosahedral metal atom bonds

Hexanuclear Niobium Cluster Compounds with Protonated N‐Base Cations

Octahedral clusters of the [M6X12] type offer numerous possibilities to form structural arrangements through different choices of bonding situations. In this paper a series of new cluster compounds of the transition metal niobium is described, which consist of the [Nb6Cl18]2–, and in one case [Nb6Cl18]3–, anion and protonated N‐base cations ([MIm‐H]+, [nPr3N‐H]+, [TMGu‐H]+, and [Tzn‐H]+). They all are prepared using water scavenger compounds [SOCl2 or (Ac)2O] under oxidising conditions, resulting in two‐electron (or one‐electron, respectively) oxidized cluster units with respect to the starting material [Nb6Cl14(H2O)4]·4H2O. Of five members of this group single‐crystal X‐ray structures were determined. The cluster anions exist in all structures as discrete units. The acidic H atoms of all N‐bases are hydrogen bonded to H acceptors, in 4 cases to outer, exo bonded Cl atoms of the cluster unit and in one case to the O atom of a co‐crystallized THF molecule. In [TMGu‐H]2[Nb6Cl18] chains of cluster anions exist hydrogen‐bonded through bridging [TMGu‐H]+ cations. ESI mass spectra of [MIm‐H]2[Nb6Cl18]·2SOCl2 and [TMGu‐H]2[Nb6Cl18] show the expected isotopic distribution patterns for the anions together with other peaks associated to chloride mass losses and/or reduction processes

Разработка технологии изготовления червяка двухзаходного симметричного

Выпускная квалификационная работа на тему: Разработка технологии изготовления детали "Червяк двухзаходный симметричный" включает в себя разработанную операционную технологию механической обработки, размерный анализ детали, расчет режимов резания и норм времени. В конструкторском разделе спроектировано две разрезные втулки для фрезерной и токарной операций. Так же рассмотрены вопросы профессиональной и экологической безопасности и безопасность при ЧС. Выполнены оценки экономических аспектов разработки технологии изготовления.The final qualifying work on the topic: Development of the technology for the manufacture of the part "Double-start symmetric worm" includes the developed operating technology of machining, dimensional analysis of the part, calculation of cutting conditions and time norms. In the design section, two split bushings have been designed for milling and turning operations. The issues of professional and environmental safety and safety in case of emergency are also considered. Estimates of the economic aspects of the development of manufacturing technology have been carried out

Low-melting manganese(II)-based ionic liquids: syntheses, structures, properties and influence of trace impurities

The synthesis of more than 10 new magnetic ionic liquids with [MnX4]2 anions, X = Cl, NCS, NCO, is presented. Detailed structural information through single-crystal X-ray di raction is given for (DMDIm)[Mn(NCS)4], (BnEt3N)2[Mn(NCS)4], and {(Ph3P)2N}2[Mn(NCO4)] 0.6H2O, respectively. All compounds consist of discrete anions and cations with tetrahedrally coordinated Mn(II) atoms. They show paramagnetic behavior as expected for spin-only systems. Melting points are found for several systems below 100 C classifying them as ionic liquids. Thermal properties are investigated using di erential scanning calorimetry (DSC) measurements. The physicochemical properties of density, dynamic viscosity, electrolytic conductivity, and surface tension were measured temperature-dependent of selected samples. These properties are discussed in comparison to similar Co containing systems. An increasing amount of bromide impurity is found to a ect the surface tension only up to 3.3%

Synthesis and Molecular Structure of 2-(Diphenylphosphano)phenyl Benzoate Borane Adduct

The crystal and molecular structure of 2-(diphenylphosphano)phenyl benzoate borane adduct are reported. The title compound crystallizes from a petroleum ether/ethyl acetate mixture in the triclinic space group P  with two molecules in the unit cell. The unit cell parameters are: a = 8.67(1) Å, b = 9.202(1) Å, c = 14.224(2) Å; α = 72.600(7)°, β = 73.577(7)°, γ = 84.349(7)° and V = 1039.5(2) Å3. Bond lengths and angles are typical for this phosphane borane adduct

Tetrakis(triethylenediamin-1-ium) dodeca-μ2-chlorido-hexakis(thiocyanato-κN)hexa-octahedro-niobate

The crystal structure of the cluster complex salt, (C6H13N2)4[Nb6(NCS)6Cl12] or (H-DABCO)4[Nb6Cl12(NCS)6] (DABCO = triethylenediamine or 1,4-diazabicyclo[2.2.2]octane), comprises octahedral Nb6 cluster cores, which are μ2-coordinated by 12 chloride ligands (bridging the octahedral edges, inner ligand sphere). Furthermore, each Nb atom is N-bonded to a terminal thiocyanate ligand (outer ligand sphere). The discrete clusters carry a charge of −4, which is compensated by four monoprotonated DABCO molecules. These are arranged in rows, which are N—H...Cl and N—H...N hydrogen bonded to the anions and among each other

(C7H6NS)2[Nb6Cl18]·2C4H8O: first niobium cluster with an N,S-heterocyclic cation

The title compound bis(benzothiazolium) dodeca-μ-chlorido-hexachlorido-octahedro-hexaniobium(12 Nb—Nb) tetrahydrofuran disolvate, (C7H6NS)2[Nb6Cl18]·2C4H8O or (HBTh)2[Nb6Cl18]·2THF, is the first known niobium cluster compound to contain an N,S-heterocyclic cation. The synthesis takes place within a few hours as an one-pot reaction at room temperature of the cluster precursor compound [Nb6Cl14(H2O)4]·4H2O with SOCl2 in the presence of BTh (benzothiazole) in very high yield. The stabilization of the acidic proton of the cation is achieved by the use of tetrahydrofuran as a co-solvent and by the formation of hydrogen bonds