Quantum-Chemical Investigation of Structure and Vibration Spectrum of [C(NPCl<Subscript>3</Subscript>)<Subscript>3</Subscript>]<Superscript>+</Superscript> Cation

Structural parameters of the cation [C(NPCl₃)₃]⁺ in vacuum and in acetonitrile are calculated by the methods RHF/6-311G(3d₆), RHF/6-31(3d₅) and B3LYP/6-311(3d₅f₇). Formation energy of the free adduct (MeCN) 2[C(NPCl₃)₃]⁺ is calculated and nonspecific character of interaction of the cation with liquid acetonitrile is established. Vibration spectrum of the cation is calculated and theoretical interpretation of IR and Raman spectra of the salt [C(NPCl₃)₃]⁺[SbCl₆]^? is refined.     

Die Schwingungsspektren der Reihe [NPCl2]3 ċ [NCCl]3

Vibrational Spectra of the Series [NPCl₂]₃ ? [NCCl]₃ The vibrational spectra of the six-membered ring systems [NPCl₂]₂[NCCl] and [NPCl₂][NCCl]₂ are reported and discussed together with the spectra of [NPCl₂]₃ and [NCCl]₃.     

Oligomeric hydroxy-aryloxy phosphazene based on cyclic chlorophosphazenes

Reaction of hexachlorocyclotriphosphazene and a mixture of cyclic chlorophosphazene [NPCl₂] _{n = 3–8} with an excess of diphenylolpropane under different conditions affords corresponding oligomeric hydroxy-aryloxy phosphazenes, which were characterized by gas chromatography-mass spectrometry, laser mass spectrometry, ³¹P and ¹H NMR spectroscopy. Side reactions was found with participation of decomposition products of diphenylolpropane.     

[Cl3PNPCl3][MoNCl4], eine Verbindung mit strangartig assoziierten Anionen

[Cl₃PNPCl₃][MoNCl₄], a Compound having Columns of Stacked Anions The title compound is formed by the reaction of [Cl₃PNPCl₃]Cl with MoNCl₃ in CH₂Cl₂ and subsequent precipitation with CCl₄ in from of orange-red crystals. According to the ³¹P-NMR spectrum, the compound exists as its isomer phosphaneiminate [Cl₅Mo(NPCl₂NPCl₃)] in CD₂Cl₂/CH₃CN solution. The crystal structure of [Cl₃PNPCl₃][MoNCl₄] is isotypic with that of [Cl₃PNPCl₃][MoOCl₄] and shows the same kind of two-dimensional disorder. X-ray diffraction patterns show planes of diffuse scattering as well as Bragg reflexions. The latter correspond to an averaged structure with a = 1590.0, b = 1141.6, c = 418.0 pm, space group Pba2, Z = 2. In the averaged structure (606 reflexions, R = 0.071) the atom sites have fractional occupation. The real structure consists of square-pyramidal [MoNCl₄]^? ions stacked to form columns with alternating MoN distances of 175 and 243 pm. The packing of the columns is disordered in that the [MoNCl₄]^? pyramids point either in the +c or ?c direction. The [Cl₃PNPCl₃]⁺ ions are stacked in the c direction and show two types of disorder, namely a displacement parallel to c and a rotation by 120° about the P? P axis.     

Über die Kronenetherkomplexe [K(15-Krone-5)2]3[Sb3I12], [TeCl3(15-Krone-5)][TeCl5] und [TeCl3(15-Krone-5)]2[TeCl6]

On the Crown Ether Complexes [K(15-Crown-5)₂]₃[Sb₃I₁₂], [TeCl₃(15-Crown-5)][TeCl₅], and [TeCl₃(15-Crown-5)]₂[TeCl₆] Orange-coloured crystals of [K(15-crown-5)₂]₃[Sb₃I₁₂] are formed in the reaction of potassium iodide with antimony triiodide and 15-crown-5 in acetonitrile solution. An X-ray structure determination reveals severe disorder of the crown ether molecules, which coordinate to the potassium atoms in a sandwich array; so only the [Sb₃I₁₂]^3? ion and the potassium positions were ascertained. The anion is a centrosymmetric trimer (symmetry C_2h), which can be understood as central SbI₆^3? ion, coordinated by two SbI₃ molecules. (Space group C2/m), Z = 2, 3263 observed, independent reflections, R = 0.06, lattice dimensions at 20°C: a = 2541.1 pm, b = 1441.7 pm, c = 1588.4 pm, β = 113.33°. The tellurium complexes [TeCl₃(15-crown-5)] [TeCl₅] and [TeCl₃(15-crown-5)]₂[TeCl₆] are prepared by reaction of TeCl₄ with 15-crown-5 in acetonitrile solution, forming yellow-green crystals sensitive to moisture. They are characterized by their i.r. spectra.     

Improved synthesis of cyclic and polymeric phosphazenes based on facile chlorine substitution with phenols promoted by cesium carbonate

In this report we describe a very convenient synthetic method for the preparation in high yields and purity of cyclic [N₃P₃(OCH₂CF₃)₆] and [N₃P₃(OC₆H₄R)₆] (R = Br, CN, CHO, COC₆H₅, COCH₃, H, OCH₃), and polymeric [NP(OC₆H₄R)₂]_n (R = Br, CHO, COC₆H₅, H, Bu^t) phosphazenes from the direct reaction of the trimer [N₃P₃Cl₆] or the high polymer [NPCl₂]_n and the alcohol HO CH₂CF₃ or the para-substituted phenols HO C₆H₄R, using Cs₂CO₃ as proton abstractor and acetone or tetrahydrofuran as solvent.     

Nitration of rhodium(III) sulfates

Nitration of sulfate complexes of rhodium has been investigated by NMR ¹⁰³Rh, ¹⁴N, ¹⁵N, and ¹⁷O NMR. At high pH, [Rh(NO₂)₆]^3?, dimer [Rh₂(μ-OH)₂(NO₂)₈]^4?, and trimer [Rh₃(μ-OH)₄(OH)(NO₂)₉]^5? are the dominant species in solutions.     

Mechanism of the controlled hydrolysis of (NPCl2)2NSOCl: Crystal and molecular structure of [KC12H24O6]+[NHPO2NPCl2NSOCl]−

The reaction mechanism of controlled hydrolysis of the inorganic ring system (NPCl₂)₂NSOCl in the presence of KCl and 18-crown-6 has been revised and is explained from steric constraints rather than from electronic considerations. The X-ray structure of one of the hydrolysis products, [KC₁₂H₂₄O₆]⁺-[NHPO₂NPCl₂NSOCl]⁻, shows a dimeric structure of two centrosymmetrically related formula units kept together by hydrogen bridges and K … O coordination. Crystals are monoclinic, space group C2/c with a = 25.698(5), b = 8.223(2), c = 23.665(4) Å, β = 106.03(1)°, V = 4806(2) ų, and Z = 8. The final R and R_w values are 0.048 and 0.044, respectively.     

Eugenol derivatives of higher chlorocyclophosphazenes and related epoxy oligomers

The synthesis of eugenol derivatives of octachlorocyclotetraphosphazene and mixtures of oligomer chlorocyclophosphazenes [NPCl₂]_3–8 was performed. Not yet described octakis(4-allyl-2-methoxyphenoxy)cyclotetraphosphazene was isolated in the crystalline form and identified via ³¹P and ¹H NMR spectroscopy, laser mass spectrometry, DSC, and TGA. Oligomers with epoxy numbers of 15–16% and molecular masses from 1400 to 1800 were prepared via epoxidation of the synthesized eugenol derivatives with m-chloroperbenzoic acid. Some assumptions on the nature of side reactions occurring in the course of epoxidation were made.     

Elucidation of the Reaction Products of Acetonitrile with Phosphorus Pentachloride

Abstract

The reaction of acetonitrile with PCl, results in the ionic compounds (1) to (4) containing the trichloro[2-chloro-2-[(trichlorophosphoranyli-dene)amino]ethenyl]phosphorus cations and not in the compounds [CH2?C?NPCl₃]PCl₆1 or trichloro[2-chloro-1 -[(trichlorophosphoranyli-dene)amino] ethenyl]phosphorus hexachlorophosphate (5) as assumed from ³¹P-NMR spectra [2, 3]. The crystal structures of the compounds (1) to (4) were determined with X-rays at 95K. As observed for the CI-C(NPCl₃); cation all the cations show cis-trans conformations with respect to their CI-C-X-P torsion angles. The wcl3 groups of the cations have two different orientations with one C?N?P?CI torsion angle of about 0° (cis) as in (1) or about 180° (trans) as in (3) and (4). In the salt (2) there are two formula units in the asymmetric unit with one cation showing the cis and the other showing the tram conformation.     

Bis(hinokitiolato)copper(II): modification (III)

Bis(hinokitiolato)copper(II), Cu(hino)₂, exhibits both antibacterial and antiviral properties, and has been previously shown to exist in two modifications. A third modification has now been confirmed, namely tetrakis(μ₂‐3‐isopropyl‐7‐oxocyclohepta‐1,3,5‐trien‐1‐olato)bis(3‐isopropyl‐7‐oxocyclohepta‐1,3,5‐trien‐1‐olato)tricopper(II)–bis(μ₂‐3‐isopropyl‐7‐oxocyclohepta‐1,3,5‐trien‐1‐olato)bis[(3‐isopropyl‐7‐oxocyclohepta‐1,3,5‐trien‐1‐olato)copper(II)] (1/1), [Cu(C₁₀H₁₁O₂)₂]₃·[Cu(C₁₀H₁₁O₂)₂]₂, where 3‐isopropyl‐7‐oxocyclohepta‐1,3,5‐trien‐1‐olate is the systematic name for the hinokitiolate anion. This new modification is composed of discrete [cis‐Cu(hino)₂]₂[trans‐Cu(hino)₂] trimers and [cis‐Cu(hino)₂]₂ dimers. The Cu atoms are bridged by μ₂‐O atoms from the hinokitiolate ligands to give distorted square‐pyramidal and distorted octahedral Cu^II coordination environments. Hence, the Cu^II environments are CuO₅/CuO₆/CuO₅ for the trimer and CuO₅/CuO₅ for the dimer. Each trimer and dimer has crystallographically imposed inversion symmetry. The trimer has never been observed before, the dimer has been seen only once before, and the combination of the two together in the same lattice is unprecedented. The CuO₅ cores exhibit four strong basal Cu—O bonds [1.915 (2)–1.931 (2) Å] and one weak apical Cu—O bond [2.652 (2)–2.658 (2) Å]. The CuO₆ core exhibits four strong equatorial Cu—O bonds [1.922 (2)–1.929 (2) Å] and two very weak axial Cu—O bonds [2.911 (3) Å]. The bite angles for the chelating hinokitiolate ligands range from 83.13 (11) to 83.90 (10)°.     

A fast atom bombardment mass spectrometric study of room-temperature 1-ethyl-3-methylimidazolium chloroaluminate(III) ionic liquids. Evidence for the existence of the decachlorotrialuminate(III) anion

Previous studies of 1-ethyl-3-methylimidazolium chloride–aluminium(III) chloride ([emim]Cl–AlCl₃) ionic liquids have been hampered by significant contamination of these liquids by oxide impurities. Treatment of these liquids with phosgene removes the oxide impurities, and the use of a specially constructed sample inlet system for air-sensitive materials permitted them to be studied by fast atom bombardment mass spectrometry. The ions Cl^?, [Cl₂]^?, [AlCl₄]^?, [Al₂Cl₇]^?, [emim]⁺ and [(emim)₂X]⁺ (X = Cl or AlCl₄) were observed for the basic ionic liquid. In addition, the anion [Al₃Cl₁₀]^? was observed for the acidic composition. Within the mass spectrometer, the hydrolyses of [Al₃Cl₁₀]^? to produce [Al₃C_l8O]^? and of [Al₂Cl₇]^? to produce [Al₂Cl₅O]^? were observed. Comparison of these results with published ¹⁷O NMR data suggests that the primary hydrolysis products in acidic ionic liquids are [Al₃Cl₈O]^? and [Al₂Cl₅O]^? and that the principal secondary hydrolysis product is [Al₂Cl₆(OH)]^?.     

High nuclearity PtRh carbonyl clusters. Synthesis and X-ray characterization of the [Pt2Rh9(CO)22]3− trianion

The new mixed PtRh cluster trianion [Pt₂Rh₉(CO)₂₂]^3? has been isolated as a minor product of the pyrolysis of [PtRh₅(CO)₁₅]^?, and has been characterized by X-ray diffraction. The metal skeleton, which has ideal D_3h symmetry, consists of three face-to-face condensed octahedra, as previously found in the isoelectronic species [Rh₁₁CO)₂₃]^3?, with the Pt atoms on the three-fold axis, in the positions of maximum MM connectivity.     

Theoretical study on nonlinear optical properties of the Li+[calix[4]pyrrole]Li−dimer,trimer and its polymer with diffuse excess electrons

The static (hyper)polarizabilities of the dimer and trimer with diffuse excess electrons, [Li⁺[calix[4]pyrrole]Li^?]_n, are firstly investigated by the DFT(B3LYP) method in detail. For the dimer and trimer, a Li atom inside each calix[4]pyrrole unit is ionized to form a diffuse excess electron. The results show that the dimer and trimer containing two and three excess electrons, respectively, have very large first hyperpolarizablities as 2.3 × 10⁴ and 4.0 × 10⁴ au, which are 30 and 40 times larger than that of the corresponding [calix[4]pyrrole]_n (n = 2, 3) without Li atom. Also, β values of dimer and trimer are twice and four times as large as that of monomer containing one excess electron. Obviously, not only excess electron but also the number of excess electron plays an important role in increasing the first hyperpolarizability. Moreover, the (hyper)polarizabilities of the [Li⁺[calix[4]pyrrole]Li^?]_n polymer are investigated at ab initio level by using the elongation finite‐field (elongation FF) method. All the oligomers of the [Li⁺[calix[4]pyrrole]Li^?]_n with many excess electrons exhibit very large first hyperpolarizability and large second hyperpolarizability. The present investigation shows that by introducing several and more excess electrons into the nonlinear optical (NLO) materials will be an important strategy for improving their NLO properties, which will be helpful for design of NLO materials. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2010     

HPLC Method for the Determination of the Purity of K[Pt(NH3)Cl3], a Precursor of the Platinum Complexes with Cytostatic Activity

K[Pt(NH₃)Cl₃], a valuable precursor for the preparation of platinum complexes with cytostatic activity, e.g. satraplatin, picoplatin, LA-12 and cycloplatam, is currently prepared from cis-[Pt(NH₃)₂Cl₂] or K₂[PtCl₄] and these are the usual impurities in the final product. A simple, selective and sensitive HPLC-UV analytical method for the determination of the purity of K[Pt(NH₃)Cl₃] and the quantification of the impurities has been developed and validated. The platinum complexes present in the final product were separated on a strong base ion exchange column by the gradient elution with detection at 213 nm. Intra-assay precisions for the platinum complexes respective to their ions ([PtCl₄]^2?, [Pt(NH₃)Cl₃]^? and cis-[Pt(NH₃)₂Cl₂]) were between 0.1 and 2.0% (relative standard deviation); intermediate precisions were between 1.4 and 2.0% and accuracies were between 98.6 and 101.4%. Limits of detection of [PtCl₄]^2?, [Pt(NH₃)Cl₃]^? and cis-[Pt(NH₃)₂Cl₂] were 6 µg · ml^?1, 13 mg · ml^?1 and 5 µg · ml^?1 respectively, limits of quantification of [PtCl₄]^2?, [Pt(NH₃)Cl₃]^? and cis-[Pt(NH₃)₂Cl₂] were 51 µg · ml^?1, 55 mg · ml^?1 and 20 µg · ml^?1 respectively.     

Die Fällung des PdII als [Pd(NH3)2Cl2] sowie das Verhalten verschiedener Begleitelemente

Precipitation of Pd^II as [Pd(NH₃)₂Cl₂] and the Behaviour of Various Impurities The dependence of [Pd(NH₃)₂Cl₂] precipitation upon reaction conditions (pH, Cl^? content, reaction time, temperature) has been studied. The dependence of residual Pd content in the mother liquor upon these parameters was found to be significant only for the precipitation temperature (c_Pd at 20°C: 1.65 ± 0.11 mM; at 50°C: 6.70 ± 0.58 mM). The increase of Pd concentration was due to the formation of Pd(NH₃)Cl₃^?. Among the impurities studied Cr, Ru, and Au were largely precipitated in the NH₃ medium. In subsequent precipitation of [Pd(NH₃)₂Cl₂] the following order of coprecipitation was found: The first four elements could be separated only incompletely by repeated reprecipitation. The coprecipitation of the platinum-group metals and of Au was highly dependence upon preceding formation of ammine complexes of these elements. The considerable coprecipitation of Pt^IV is presumably due to the formation of mixed Pd/Pt compounds, whereas the other impurities are adsorbed by [Pd(NH₃)₂Cl₂].     

Syntheses of [BpBut,Me]AlMe2 and [BpBut,Me]GaMe2: structural comparison of a pair of bis(pyrazolyl)hydroborato aluminum and gallium methyl complexes

The aluminum and gallium dimethyl complexes, [Bp^But,Me]AlMe₂ and [Bp^But,Me]GaMe₂, are readily obtained by the reactions of [Bp^But,Me]Tl with Me₃Al and Me₃Ga, respectively. [Bp^But,Me]AlMe₂ and [Bp^But,Me]GaMe₂ have been structurally characterized by X-ray diffraction, which indicates that the most noticeable difference in these otherwise very similar structures is the C–M–C bond angle, which increases from 118.9(3)° for [Bp^But,Me]AlMe₂ to 124.0(2)° for [Bp^But,Me]GaMe₂.     

Mixed-Valence BN-Doped Corannulene Trimer Radical Cations

Mixed-valence (MV) dimers have been extensively investigated, however, the structure and properties of purely organic MV trimers based on open-shell polycyclic aromatic hydrocarbons remain elusive. Herein, unprecedented MV BN-doped corannulene radical cations [ BN-Cor1 ]₃⋅⋅²⁺ ⋅ 2[BAryl^F₄]⁻ and [ BN-Cor2 ]₃⋅⋅²⁺ ⋅ 2[BAryl^F₄]⁻ were synthesized via chemical oxidation, and their structures were unambiguously confirmed by single-crystal X-ray diffraction. These uncommon radical cations consist of three corannulene cores and two [BAryl^F₄]⁻ anions, and three corannulene motifs [ BN-Cor1 ]₃⋅⋅²⁺ and [ BN-Cor2 ]₃⋅⋅²⁺ in the unit cell exhibit a trimer structure with a slipped π-stacking configuration. Detailed structural analyses further revealed that the corannulene cores exhibit an infinite layered self-assembly configuration, allowing their potential applications as building blocks for molecular conductors. The detection of a forbidden transition (Δm_s=±2) by electron paramagnetic resonance (EPR) spectroscopy further confirmed the existence of two unpaired electrons in the π-trimers and the MV characteristic of these two species. Variable-temperature EPR and conductivity measurements suggested that the BN-doped π-trimers exhibited antiferromagnetic coupling and conductivity properties.     

1H, 13C and 15N NMR spectra of [1,2-15N2]pyrazole derivatives

The chemical shifts and coupling constants of [1,2-¹⁵N₂]pyrazole, 2-(1-[1,2- ¹⁵N₂]pyrazolyl)-2-[l,3-²H₆]propanol, 1-nitro[1,2¹⁵N₂] and 3-nitro[1,2-¹⁵N₂]pyrazole are reported.     

Synthesis,Crystal Structure and Thermal Behavior of Gadolinium Dicyanamide Dihydrate Gd[N(CN)2]3 · 2 H2O

Gadolinium dicyanamide dihydrate Gd[N(CN)₂]₃ · 2 H₂O was prepared by ion exchange in aqueous solution followed by evaporation of the solvent at room temperature. Gd[N(CN)₂]₃ · 2 H₂O was characterized by single‐crystal structure analysis, FTIR spectroscopy and DSC analysis. In the crystal there are three crystallographically independent [N(CN)₂]^? ions and Gd³⁺ which are coordinated by six N atoms from six different [N(CN)₂]^? ions and two O atoms from two water molecules forming an irregular quadratic antiprism. Four H bonds have been identified in the structure of Gd[N(CN)₂]₃ · 2 H₂O, two of them running to terminal N atoms and two to the bridging N atoms of dicyanamide ions (Gd[N(CN)₂]₃ · 2 H₂O: P2₁/n (no. 14), a = 7.4845(15) Å, b = 11.529(2) Å, c = 13.941(3) Å, β = 93.98(3)°, Z = 4, 1948 reflections, 175 parameters, R1 = 0.0493). The DSC analysis indicates that Gd[N(CN)₂]₃ · 2 H₂O looses the crystal water at temperatures around 130 – 140 °C forming anhydrous Gd[N(CN)₂]₃, the structure of which has been refined by the Rietveld method based on X‐ray powder diffraction data. Gd[N(CN)₂]₃ was found to be isotypic with Ln[N(CN)₂]₃ (Ln = La, Ce, Pr, Nd, Sm and Eu) which previously have been described in the literature.