A theoretical study on the dynamics of the gas phase reaction of NH<Subscript>2</Subscript>(<Superscript>2</Superscript>B<Subscript>1</Subscript>) with HO<Subscript>2</Subscript>(<Superscript>2</Superscript>A″)

Quasi-classical trajectory calculations and stochastic one-dimensional chemical master equation simulation methods are used to study the dynamics of the reaction of amidogen radical [NH₂(²B₁)] with hydroperoxyl radical [HO₂(²A″)] on the lowest singlet electronic state. The title complex reaction takes place on a multi-well multichannel potential energy surface consisting of three deep potential wells and one van der Waals complex. In quasi-classical trajectory calculations a new analytical potential energy surface based on CCSD(T)/aug-cc-pVTZ//MPW1K/6-31+G(d,p) ab initio method was driven and used to study the dynamics of the title reaction. In quasi-classical trajectory calculations, the reactive cross sections and reaction probabilities are determined for 200–2000 K relative translational energies to calculate the rate constants. The same ab initio method was used to have the necessary data for solving the one-dimensional chemical master equation to calculate the rate constants of different channels. In solving the master equation, the Lennard-Jones potential model was used to form the collision between the collider gases. The fractional populations of different intermediates and products in the early stages of the reaction were examined to determine the role of the energized intermediates and the van der Waals complex on the dynamics of the title reaction. Although the calculated total rate constants from both methods are in good agreement with the reported experimental values in the literature, the quasi-classical trajectory simulation predicts the formation of NH₂O + OH as the major channel in the title reaction in accordance with the previous studies (Sumathi and Peyerimhoff, Chem. Phys. Lett., 263:742–748, 1996), while the stochastic master equation simulation predicts the formation of HNO + H₂O as the major products.     

Isothermal solubility diagram of the 2Na<Superscript>+</Superscript>,Mg<Superscript>2+</Superscript>‖2Cl<Superscript>−</Superscript>, 2ClO<Stack><Subscript>3</Subscript><Superscript>‒</Superscript></Stack>-H<Subscript>2</Subscript>O quaternary system at 20 and 100°C

The solubility in the 2Na⁺,Mg²⁺‖2Cl⁻, 2ClO₃⁻-H₂O system was studied at 20 and 100°C and the solubility diagrams were plotted. New compounds were not found to form in the title quaternary reciprocal system. The sodium chloride field was observed to expand with rising temperature.     

Blue and green upconversion luminescence modification of Tb<Superscript>3+</Superscript>–Yb<Superscript>3+</Superscript> co-doped Ca<Subscript>5</Subscript>(PO<Subscript>4</Subscript>)<Subscript>3</Subscript>F inverse opal

Tb³⁺–Yb³⁺ co-doped Ca₅(PO₄)₃F inverse opal photonic crystals were prepared by a self-assembly technique in combination with a sol–gel method. Upconversion luminescence characteristics of the inverse opals were investigated. The results indicate that photonic band gap has a significant effect on upconversion luminescence of Tb³⁺–Yb³⁺ co-doped Ca₅(PO₄)₃F inverse opal. Significant inhibition of the green or blue upconversion luminescence was inspected if the photonic band gap overlapped with the emission band of Tb³⁺ ions.     

UV-sensitized nanomaterial semiconductor catalytic reduction of Co<Superscript>III</Superscript>(N–N)<Subscript>3</Subscript><Superscript>3+</Superscript>/nm-TiO<Subscript>2</Subscript> and Co:TiO<Subscript>2</Subscript> formation: SEM-EDX and HRTEM analyses

Interfacial electron transfer induced by 254 nm light at nanomaterial (nm) titanium dioxide/Co^III(N–N)₃ ³⁺ interface in binary mixed solvent media such as water/methanol (or 1,4-dioxane) has been probed. The distinct photo reduction of cobalt(III) complexes, Co^III(N–N)₃ ³⁺; (N–N)=(NH₃)₂, en (1,2-diamino ethane), pn (1,2-diamino propane), tn (1,3-diamino propane), and bn (1,4-diamino butane), by excited nm-TiO₂ particles: Co^III + nm-TiO₂ + hν → TiO₂ (h⁺;e⁻) + Co^III → nm-TiO₂ (h) + Co^II is solvent controlled. The electron transfer from the conduction band of TiO₂ (e⁻, CB) onto the metal centre of the complex consists of (i) electron transport from CB into surface-adsorbed species A: Co^III(N–N)₃ ³⁺ (ii) solution phase species B: Co^III(N–N)₃ ³⁺ _(sol.), accumulated at the surface of the nanoparticle. In addition, UV irradiation of Co^III(N–N)₃ ³⁺ stimulates generation of \textCo_\textaq^\textII {\text{Co}}_{\text{aq}}^{\text{II}} ion, due to charge transfer transition, in solution phase. After UV irradiation, cobalt-implanted nm-TiO₂ separated as gray ultrafine particles, which were isolated. Photo efficiency of the formation of Co^II ion was estimated and the cobalt implanted nanomaterial crystals isolated from the photolyte solutions were subjected to SEM-EDX, X-ray mapping, and HRTEM-SAED analyses. Solvent medium was found to contribute in both the formation of Co^II ion and interstitial insertion of cobalt into the lattice of nm-TiO₂.     

Mercury complex [(HOCH<Subscript>2</Subscript>)<Subscript>3</Subscript>CNH<Subscript>3</Subscript>]<Stack><Subscript>2</Subscript><Superscript>+</Superscript></Stack> [HgI<Subscript>4</Subscript>]<Superscript>2−</Superscript>: Synthesis and structure

The complex [(HOCH₂)₃CNH₃] ₂ ⁺ [HgI₄]^2? (I) was synthesized by reacting (trioxymethyl)methylammonium iodide with mercury dioide (2: 1 mol/mol) in acetone. X-ray crystallography shows that the complex consists of two types of crystallographically independent [(HOCH₂)₃CNH₃]⁺ cations and tetrahedral anions [HgI₄]^2? (IHgI, 106.49(2)°–113.99(4)°; Hg-I, 2.7849(8)-2.8105(8) Å. [(HOCH₂)₃CNH₃]⁺ cations are linked via hydrogen bonds O…H-N and O-H…N (O…N, 2.84–2.92 Å) to form polymer chains, which are cross-linked with one another via anions (I…H, 2.81, 2.82 Å).     

Framework coordination polymer based on the [Re<Subscript>3</Subscript>Mo<Subscript>3</Subscript>S<Subscript>8</Subscript>(CN)<Subscript>6</Subscript>]<Superscript>6–</Superscript>heterometallic cluster anions and Cd<Superscript>2+</Superscript> cations

A new coordination polymer, [Cd(NH₃)₄]₂{Cd[Re₃Mo₃S₈(CN)₆]}·1.5H₂O (I), was prepared by the reaction between solutions of Cd(CH₃COO)₂ · 2H₂O in aqueous ammonia and CaK₄[Re₃Mo₃S₈(CN)₆] · 8H₂O in water. The crystals are cubic, space group Fm3m (Prussian blue structural type); a = 15.0268(4) Å (CIF file CSD no. 431555). According to ESR data, compound I is paramagnetic, g-factor is 2.298. Thermal stability investigation by TGA and powder X-ray diffraction showed that elimination of coordinated NH₃ molecules is accompanied by sample amorphization.     

Phase diagrams and physicochemical properties of Li<Superscript>+</Superscript>,K<Superscript>+</Superscript>(Rb<Superscript>+</Superscript>)//borate–H<Subscript>2</Subscript>O systems at 323 K

The phase and physicochemical properties diagrams of Li⁺,K⁺(Rb⁺)//borate–H₂O systems at 323 K were constructed using the experimentally measured solubilities, densities, and refractive indices. The Schreinemakers’ wet residue method and the X-ray diffraction were used for the determination of the compositions of solid phase. Results show that these two systems belong to the hydrate I type, with no solid solution or double salt formation. The borate phases formed in our experiments are RbB₅O₆(OH)₄ · 2H₂O, Li₂B₄O₅(OH)₄ · H₂O, and K₂B₄O₅(OH)₄ · 2H₂O. Comparison between the stable phase diagrams of the studied system at 288, 323, and 348 K show that in this temperature range, the crystallization form of salts do not changed. With the increase in temperature, the crystallization field of Li₂B₄O₅(OH)₄ · H₂O salt at 348 K is obviously larger than that at 288 K. In the Li⁺,K⁺(Rb⁺)//borate–H₂O systems, the densities and refractive indices of the solutions (at equilibrium) increase along with the mass fraction of K₂B₄O₇ (Rb₂B₄O₇), and reach the maximum values at invariant point E.     

Experimental Determination of the Isotherm at 15°C of the System Mg<Superscript>2+</Superscript>/Cl<Superscript>−</Superscript>, SO<Subscript>4</Subscript><Superscript>2</Superscript>–H<Subscript>2</Subscript>O

Summary.  The diagram of the ternary system Mg²⁺/Cl⁻, SO₄ ²⁻–H₂O was established at 15°C by means of analytical and conductimetric measurements. Three compounds were found in this diagram, which are MgSO₄·6H₂O, MgSO₄·7H₂O, and MgCl₂·6H₂O. The solubility field of MgSO₄·7H₂O is important whereas those of MgSO₄·6H₂O and MgCl₂·6H₂O are small. The compositions (mass-%) of the two invariant points determined by the two methods are: MgSO₄:MgCl₂=2.73:33.80 and MgSO₄: MgCl₂=3.38:28.91. Both the measured and the calculated isotherm at 15°C have been used for modelling of the diagram Mg²⁺/Cl⁻, SO₄ ²⁻–H₂O between 0 and 35°C. The polythermal invariant point was approximately located between 15 and 10°C.  Corresponding author. E-mail: ariguib@planet.tn Received October 16, 2002; accepted (revised) December 3, 2002 Published online April 24, 2003 RID="a" ID="a" Dedicated to Prof. Dr. Heinz Gamsj?ger on the occasion of his 70^th birthday     

Study on the thermal behavior of the complexes of the type [PdX<Subscript>2</Subscript>(tdmPz)] (X = Cl<Superscript>−</Superscript>, Br<Superscript>−</Superscript>, I<Superscript>−</Superscript>, SCN<Superscript>−</Superscript>)

Four new mononuclear Pd(II) complexes of the type [PdX₂(tdmPz)] {X = Cl⁻ (1); Br⁻ (2); I⁻ (3); SCN⁻ (4); tdmPz = 1-thiocarbamoyl-3,5-dimethylpyrazole} have been synthesized and characterized by elemental analysis, IR spectroscopy, ¹H and ¹³C{¹H}-NMR experiments. The thermal behavior of the complexes 1–4 has been investigated by means of thermogravimetry (TG) and differential thermal analysis (DTA). From the initial decomposition temperatures, the thermal stability of the complexes can be ordered in the sequence: 3 < 4 ≡ 2 < 1. The final products of the thermal decompositions were characterized as metallic palladium by X-ray powder diffraction.     

Extractive separation of Cu<Superscript>2+</Superscript>–Co<Superscript>2+</Superscript> and Ni<Superscript>2+</Superscript>–Co<Superscript>2+</Superscript> mixtures using <Emphasis Type="Italic">N</Emphasis>-salicylideneaniline

A study on the extraction of copper(II), cobalt(II), and nickel(II) from solutions containing ions of both metals with N-salicylideneaniline(SAN) in chloroform has been realized. Distribution of the metal ions in wide range of pH has been studied. Extraction of copper(II) was always favored over that of cobalt(II). Extraction of copper(II) from binary metal solution is selective and it can be quantitatively separated from cobalt(II). The equilibrium constant of the extraction of cobalt and nickel from an aqueous solution containing both metals using SAN were evaluated. The separation factors for cobalt and nickel were expressed as a function of the distribution of nickel and cobalt. From these results, salicylideneaniline is an adequate extractant for extractive separation of such mixtures.     

Stereo-dynamics study of O + HCl → OH + Cl reaction on the <Superscript>3</Superscript>A″, <Superscript>3</Superscript>A′, and <Superscript>1</Superscript>A′ states

Using three accurate potential energy surfaces of the ³A″, ³A′, and ¹A′ states constructed recently, we present a quasi-classical trajectory (QCT) calculation for O + HCl (v = 0, j = 0) → OH + Cl reaction at the collision energies (E _col) of 14.0–20.0 kcal/mol. The three angular distribution functions—P(q_r ) P(\theta_{r} ) , P(j_r ) P(\varphi_{r} ) , and P(q_r ,j_r ) P(\theta_{r} ,\varphi_{r} ) , together with the four commonly used polarization-dependent differential cross-sections, \frac2ps \fracds₀₀ dw_t , \frac2ps \fracds₂₀ dw_t , \frac2ps \fracds_{22 +} dw_t , \textand \frac2ps \fracds_{21 -} dw_t {\frac{2\pi }{\sigma }}\,{\frac{{d\sigma_{00} }}{{d\omega_{t} }}},\,{\frac{2\pi }{\sigma }}\,{\frac{{d\sigma_{20} }}{{d\omega_{t} }}},\,{\frac{2\pi }{\sigma }}\,{\frac{{d\sigma_{22 + } }}{{d\omega_{t} }}},\,{\text{and}}\,{\frac{2\pi }{\sigma }}\,{\frac{{d\sigma_{21 - } }}{{d\omega_{t} }}} are exhibited to get an insight into the alignment and the orientation of the product OH radical. There is a similar behavior of the tendency scattering direction for the two triplet electronic states (³A″ and ³A′)—backward scattering dominates, however, forward scattering prevails for the case of ¹A′ state. Also, obvious differences have been found in the stereo-dynamical information, which reveals the influences of the potential energy surface and the collision energy. The degrees of polarization and the influence of the collision energy on the stereo-dynamics characters of the title reaction are both demonstrated in the order of ³A′ > ³A″ > ¹A′.     

Syntheses and structures of six-coordinate K[Ga<Superscript>III</Superscript>(Cydta)] · 2H<Subscript>2</Subscript>O and K[Ga<Superscript>III</Superscript>(Pdta)] · 3H<Subscript>2</Subscript>O complexes

The title complexes, K[Ga^III(Cydta)] · 2H₂O(Cydta = trans-1,2-cyclohexanediaminetetraacetic acid) and K[Ga^III(Pdta)] · 3H₂O (Pdta = propylenediaminetetraacetic acid), were prepared, and their structures were studied by IR spectra, elemental analyses, NMR spectra, and single-crystal X-ray diffraction techniques. In the K[Ga^III(Cydta)] · 2H₂O complex, the Ga³⁺ is six-coordinated by the Cydta ligand yielding an octahedral conformation, and the complex crystallizes in the monoclinic system with the P2₁/c space group. The crystal data are as follows: a = 16.5039(19), b = 13.1499(16), c = 8.5204(10) Å, β = 101.650(2)°, V = 1811.0(4) ų, Z = 4, ρ = 1.757 g/cm³, μ = 1.805 mm^?1, F(000) = 984, R = 0.0291, and wR = 0.0698 for 3713 observed reflections with I ≥ 2σ(I). In the K[Ga^III(Pdta)] · 3H₂O complex, the Ga³⁺ is also six-coordinated by the Pdta ligand yielding an almost standard octahedral conformation, and the complex crystallizes in the orthorhombic system with P2₁2₁2₁ space group. The crystal data are as follows: a = 8.8913(10), b = 11.6181(13), c = 17.0227(19) Å, V = 1758.4(3) ų, Z = 4, ρ = 1.757 g/cm³, μ = 1.862 mm^?1, F(000) = 952, R = 0.0288, and wR = 0.0724 for 3556 observed reflections with I ≥ 2σ(I).     

Thermogravimetric analysis of wheatleyite Na<Subscript>2</Subscript>Cu<Superscript>2+</Superscript>(C<Subscript>2</Subscript>O<Subscript>4</Subscript>)<Subscript>2</Subscript>·2H<Subscript>2</Subscript>O

Evidence for the existence of primitive life forms such as lichens and fungi can be based upon the formation of oxalates. These oxalates form as a film like deposit on rocks and other host matrices. The anhydrous oxalate mineral moolooite CuC₂O₄ as the natural copper(II) oxalate mineral is a classic example. Another example of a natural oxalate is the mineral wheatleyite Na₂Cu²⁺(C₂O₄)₂·2H₂O. High resolution thermogravimetry coupled to evolved gas mass spectrometry shows decomposition of wheatleyite at 255°C. Two higher temperature mass losses are observed at 324 and 349°C. Higher temperature mass losses are observed at 819, 833 and 857°C. These mass losses as confirmed by mass spectrometry are attributed to the decomposition of tennerite CuO. In comparison the thermal decomposition of moolooite takes place at 260°C. Evolved gas mass spectrometry for moolooite shows the gas lost at this temperature is carbon dioxide. No water evolution was observed, thus indicating the moolooite is the anhydrous copper(II) oxalate as compared to the synthetic compound which is the dihydrate.     

Identification of Anionic Supramolecular Complexes of Sulfonamide Receptors with Cl<Superscript>−</Superscript>, NO<Stack><Subscript>3</Subscript><Superscript>−</Superscript></Stack>, Br<Superscript>−</Superscript>, and I<Superscript>−</Superscript> by APCI-MS

As part of a mass spectrometric investigation of the binding properties of sulfonamide anion receptors, an atmospheric pressure chemical ionization mass spectrometric (APCI-MS) method involving direct infusion followed by thermal desorption was employed for identification of anionic supramolecular complexes in dichloromethane (CH₂Cl₂). Specifically, the dansylamide derivative of tris(2-aminoethyl)amine (tren) (1), the chiral 1,3-benzenesulfonamide derivatives of (1R,2S)-(+)-cis-1-amino-2-indanol (2), and (R)-(+)-bornylamine, (3), were shown to bind halide and nitrate ions in the presence of (n−Bu)₄N⁺X⁻ (X⁻ = Cl⁻, NO₃⁻, Br⁻, I⁻). Solutions of receptors and anions in CH₂Cl₂ were combined to form the anionic supramolecular complexes, which were subsequently introduced into the mass spectrometer via direct infusion followed by thermal desorption. The anionic supramolecular complexes [M+X]⁻, (M=1–3, X⁻=Cl⁻, NO₃⁻, Br⁻, I⁻) were observed in negative mode APCI-MS along with the deprotonated receptors [M−H]⁻. Full ionization energy of the APCI corona pin (4.5 kV) was necessary for obtaining mass spectra with the best signal-to-noise ratios.     

Yb<Superscript>3+</Superscript> → Er<Superscript>3+</Superscript> energy transfer in Al<Subscript>2</Subscript>O<Subscript>3</Subscript> and temperature characteristic of near-infrared photoluminescence

For the Er³⁺–Yb³⁺ codoped Al₂O₃ powders, the strong near-infrared photoluminescence (PL) centered at 1.535 μm derived from the energy transfer (ET) from Yb³⁺ to Er³⁺ was detected by a 978 nm laser diode excitation. Compared with that of Er³⁺ doped Al₂O₃ powders, the PL intensity enhanced about 9 times, the full width at half maximum (FWHM) extended from 82 to 90 nm, and the lifetime increased from 3.22 to 4.17 ms for Er³⁺–Yb³⁺ codoped Al₂O₃ powders at room temperature. The ET coefficient of 2.18 × 10⁻¹⁸ cm³ s⁻¹ from Yb³⁺ to Er³⁺ was obtained based on the rate equations. The decrease of PL intensity with increasing temperature in the range of 298–733 K was observed, due to thermally enhanced nonradiative relaxation ⁴I_13/2 → ⁴I_15/2 dominated over thermally enhanced phonon-assisted ET in the Er³⁺–Yb³⁺ codoped Al₂O₃.     

CN (<Emphasis Type="Italic">B</Emphasis><Superscript>2</Superscript>Σ<Superscript>+</Superscript> → <Emphasis Type="Italic">X</Emphasis><Superscript>2</Superscript>Σ<Superscript>+</Superscript>) Violet System in a Cold Atmospheric-Pressure Argon Plasma Jet

\( {\text{CN}} (B^{2}\Sigma ^{ + } \to X^{2}\Sigma ^{ + } ) \) violet system was investigated using optical emission spectroscopy in a non-equilibrium microwave atmospheric-pressure plasma jet in argon expanding in air. From the analysis of the emission spectra of the discharge in the range of 380 and 400 nm, the violet system of CN was found to be overlapped with the \( {\text{N}}_{2}^{ + } \left( {B^{2}\Sigma _{u}^{ + } , v = 1 \to X^{2}\Sigma _{g}^{ + } , v = 1} \right) \) and \( {\text{N}}_{2} \left( {C^{3}\Pi _{u} \to B^{3}\Pi _{g} } \right) \) bands, sequence \( \Delta \upsilon = - \;3 \). A numerical disentangle technique, developed in this work, permitted to obtain a well resolved violet system from the different systems observed, namely the nitrogen First Negative and the Second Positive systems. The \( {\text{CN}} (B^{2}\Sigma ^{ + } \to X^{2}\Sigma ^{ + } ) \) band head intensity was determined and analysed as function of discharge powers between 30 and 150 W and fluxes between 2.5 and 10.0 slm. With aid of this numerical approach it was also possible to obtain the rotational temperature, from (1600 ± 100) to (2300 ± 100) K and vibrational temperature between (9000 ± 800) and (14,000 ± 800) K along the plasma jet. The kinetics of \( {\text{CN}} (B^{2}\Sigma ^{ + } ) \) state was analysed as well.     

Synthesis of substituted 1-thia-3-aza-λ<Superscript>5</Superscript>-phosphacyclohex-2-ene

The addition of dimethylamine to O-phenyl 2-chloropropylisothiocyanatophosphonate afforded the six-membered cyclic product, viz., 1-thia-3-aza-4⁵-phosphacyclohex-2-ene.Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1657–1659, August, 2004.     

Platinum–Ruthenium Cluster Complexes from the Reaction of Ru<Subscript>3</Subscript>(CO)<Subscript>12</Subscript> with Pt(PBu<Superscript>t</Superscript><Subscript>3</Subscript>)<Subscript>2</Subscript>

Three new platinum–ruthenium complexes: Pt₃Ru₃(PBu^t ₃)₃(CO)₁₂, 8, Pt₅Ru₃(PBu^t ₃)₃(CO)₁₂, 9 and PtRu₃(PBu^t ₃)₂(CO)₈(μ₃-PBu^t)(μ-H)₂, 10 were obtained from the reaction of Ru₃(CO)₁₂ with Pt(PBu^t ₃)₂. Compound 8 was obtained from this reaction when conducted at 25 °C. Compounds 9 and 10 were obtained when the reaction was conducted at 68 °C. The structure of 8 consists of a central triangular cluster of three ruthenium atoms with one Pt(PBu^t ₃) group bridging each of the three Ru–Ru bonds. The structure of 9 consists of a capped pentagonal bipyramidal cluster of eight metal atoms that is formed formally by the addition of two platinum atoms to 8. The structure of 10 contains a triangular cluster of three ruthenium atoms with a Pt(PBu^t ₃) group bridging one of the Ru–Ru bonds. A t-butyl phosphido ligand formed by degradation of a molecule of PBu^t ₃ bridges the three ruthenium atoms. This report is dedicated to the memory of Professor F. A. Cotton for his many pioneering contributions to inorganic and metal cluster chemistry.     

Synthesis and preliminary biological evaluation of [<Superscript>99m</Superscript>Tc(CO)<Subscript>3</Subscript>(IDA–PEG<Subscript>3</Subscript>–CB)]<Superscript>−</Superscript> for tumor imaging

This work reports the synthesis, radiolabeling and preliminary biodistribution results in tumor-bearing mice of [^99mTc(CO)₃(IDA–PEG₃–CB)]⁻. The novel chlorambucil derivative was successfully synthesized by conjugation of iminodiacetic acid (IDA) to chlorambucil via a pegylated linker. The ligand could be labeled by [^99mTc(CO)₃]⁺ core in high yield to get [^99mTc(CO)₃(IDA–PEG₃–CB)]⁻, which was very hydrophilic and was stable at room temperature. Biodistribution studies in tumor-bearing mice showed that [^99mTc(CO)₃(IDA–PEG₃–CB)]⁻ accumulated in the tumor with favorable uptake and retention. The good accumulation in tumor tissue with high tumor/muscle ratios warrants further research to improve tumor targeting efficacy and pharmacokinetic profile of radiolabeled chlorambucil derivative by structural modification.     

Low-melting salts with the [Cr<Superscript>III</Superscript>(NCS)<Subscript>4</Subscript>(1,10-phenanthroline)]<Superscript>−</Superscript> complex anion: Syntheses,properties, and structures

Four new low melting salts, “Ionic Liquids” consisting of the [Cr^III(NCS)₄(Phen)]^? complex monoanion and imidazolium based cations A, with A = 1-ethyl-3-methylimidazolium (EMIm), 1-butyl-3-methylimidazolium (BMIm), 1,3-dimethyl-2,4,5-triphenylimidazolium (DML), and 1,2,3,4,5-pentamethyl-imidazolium (PMIm), were investigated. Single-crystal X-ray investigations established the structures of the four compounds. (EMIm)[Cr(NCS)₄(Phen)] (I): triclinic, \(P\bar 1\), a = 8.1382(6), b = 10.4760(8), c = 16.003(1) Å, α = 90.330(4)°, β = 94.759(4)°, γ = 107.305(4)°, Z = 2, R ₁(F)/wR ₂(F ²) = 0.0650/0.1770; (BMIm)[Cr(NCS)₄(Phen)] (II): triclinic, \(P\bar 1\), a = 8.5545(4), b = 9.8620(4), c = 16.6762(6) Å, α = 92.503(2)°, β = 97.517(2)°, γ = 91.249(2)°, Z = 2, R ₁(F)/wR ₂(F ²) = 0.0393/0.0848; (DML)[Cr(NCS)₄(Phen)] · C₃H₆O (III): triclinic, \(P\bar 1\), a = 11.0475(9), b = 13.589(1), c = 14.582(1) Å, α = 83.013(4)°, β = 87.116(4)°, γ = 70.333(5)°, Z = 2, R ₁(F)/wR ₂(F ²) = 0.0407/0.1023; (PMIm)[Cr(NCS)₄(Phen)] · C₃H₆O (IV): orthorhombic, Pbca, a = 17.379(1), b = 16.514(1), c = 22.304(1) Å, Z = 8, R ₁(F)/wR ₂(F ²) = 0.0460/0.1107 (in addition III and IV contain co-crystallized acetone molecules). Each compound was characterized by elemental analysis, NMR, IR, und UV-Vis spectroscopy. Magnetic properties were derived from NMR investigations (EVANS method). All four compounds are paramagnetic with effective magnetic moments of spin-only Cr^III. Melting points were obtained from DSC measurements. All melting points are higher than required for “Ionic Liquids”, but nevertheless “low” for molten salts.