Thiochlorowolframate von Wolfram(V) und -(VI). Die Kristallstrukturen von PPh4[WSCl4] und (PPh4)2[WS2Cl4] · 2 CH2Cl2

Thiochlorowolframates with Tungsten(V) and (VI). Crystal Structures of PPh₄[WSCl₄] and (PPh₄)₂[WS₂Cl₄] · 2 CH₂Cl₂ Diamagnetic (NEt₄)₂[WSCl₄]₂, having tungsten atoms linked via sulfur atoms, is obtained by the reaction of WCl₅ with NEt₄SH as well as by the reduction of WSCl₄ with NEt₄I in dichloromethane. If the reduction is performed with PPh₄I, PPh₄[WSCl₄] with monomer anions is formed. Reaction of WCl₆ with H₂S in dichloromethane yields brown, insoluble WS₂Cl₂ which has terminal W?S groups and bridging W? S? W groups according to its IR spectrum. WS₂Cl₂ and PPh₄Cl react to afford PPh₄[WS₂Cl₃] · 2 CH₂Cl₂ and (PPh₄)₂[WS₂Cl₄] · 2 CH₂Cl₂. IR spectra are reported. The crystal structures of PPh₄[WSCl₄] and (PPh₄)₂[WS₂Cl₄] · 2 CH₂Cl₂ were determined by X-ray diffraction. PPh₄[WSCl₄]: tetragonal, space group P4/n, Z = 2, a = 1292.3 pm, c = 763.2 pm; R = 0.054 for 898 observed reflexions. The [WSCl₄]^? ion has the structure of a square pyramid with a rather short W?S bond of 206 pm length. (PPh₄)₂[WS₂Cl₄] · 2 CH₂Cl₂: triclinic, space group P1 , a = 1017.7, b = 1114.5, c = 1243.4 pm, α = 70.61, β = 79.73, γ = 80.80°; R = 0.076 for 1804 reflexions. The [WS₂Cl₄]^2? has cis configuration; as it is situated on an inversion center it shows positional disorder.     

Thiochloroanionen von Molybdän(IV). Die Kristallstruktur von (NEt4)3[Mo3(μ3-S)(μ-S2)3Cl6]Cl · CH2Cl2 Kristallstruktur,EPR-Spektrum und magnetische Eigenschaften von (NEt4)2[Mo2(μ-S2)(μ-Cl)2Cl6]

Thiochloro Anions of Molybdenum (IV). Crystal Structure of (NEt₄)₃[Mo₃(μ₃-S)(μ-S₂)₃Cl₆]Cl μ CH₂Cl₂. Crystal Structure, Magnetic Properties, and EPR-Spectrum of (NEt₄)₂ [Mo₂(μ-S₂)(μ-Cl)₂Cl₆] From molybdenum pentachloride and tetraethylammonium hydrogensulfide in CH₂Cl₂ an insoluble product of composition (NEt₄)₂[Mo₂S₃Cl₉] was obtained along with a brown solution, from which (NEt₄)₂[Mo₂(S₂)Cl₈] was crystallized. The insoluble product and NEt₄Cl react in CH₂Cl₂ to yield, among others, (NEt₄)₃[Mo₃(S)(S₂)₃Cl₆]Cl · CH₂Cl₂. The latter crystallizes in the orthorhombic space group Pnma, a = 2495.8, b = 1501.2, c = 1295.6 pm, Z = 4. According to the crystal structure determination (3070 observed reflexions, R = 0.049) the [Mo₃(S)(S₂)₃Cl₆]^2? ion consists of an Mo₃ triangle with Mo? Mo bonds, each side of the triangle is bridged by disulfido groups and one sulfur atom is capped over the Mo₃ triangle; the single chloride ion is looseley associated to three S atoms. (NEt₄)₂[Mo₂(S₂)Cl₈] also crystallizes in the space group Pnma, a = 1425.6, b = 1129.9, c = 2004.7 pm, Z = 4; structure determination with 1703 observed reflexions, R = 0.061. In the [Mo₂(S₂)Cl₈]^2? ion the Mo atoms are bridged via one disulfido group and two chlorine atoms. There is a Mo? Mo bond, but according to the magnetic properties and the EPR spectrum each Mo atom still possesses one unpaired electron.     

A new carbonylhydridorhenium cluster

The preparation and properties of new polynuclear carbonylhydrido complexes (NEt₄)₃[H₄Re₄(OCH₃)(CO)₁₆] (I) and (NEt₄)₂[H₄Re₄(CO)₁₅] (II) are reported. Infrared and NMR spectra of these compounds are presented and discussed. The structure of compound II has been established by X-ray crystallographic analysis.     

Thiohalogeno-Verbindungen von Niob und Tantal: NbSCl3, TaSCl3, [NbSCl5]2−, [TaSCl5]2−, [NbSBr4]− Die Kristallstrukturen von (PPh4)2[NbSCl5] · 2 CH2Cl2 und NEt4[NbCl6]

Thiohalo Compounds of Niobium and Tantalum: NbSCl₃, TaSCl₃, [NbSCl₅]^2?, [TaSCl₅]^2?, [NbSBr₄]^?. Crystal Structures of (PPh₄)₂[NbSCl₅] · 2 CH₂Cl₂ and NEt₄[NbCl₆] NbSCl₃ can be obtained from NbCl₅ by reaction with H₂S or bistrimethylsilyl sulfide in a suspension of CCl₄ or CH₂Cl₂, respectively; in the latter case the product contains a rest of trimethylsilyl groups. This also applies for TaSCl₃, NbSBr₃ and TaSBr₃, which are formed from the metal pentahalides and S(SiMe₃)₂. NEt₄[NbSCl₄] is formed together with NEt₄[NbCl₆] in the reaction of NbCl₅ with NEt₄SH in CH₂Cl₂. PPh₄[NbCl₆] reacts with S(SiMe₃)₂ in dichloromethane yielding (PPh₄)₂[NbSCl₅] · 2 CH₂Cl₂, whereas PPh₄[NbSBr₄] is obtained from PPh₄[NbBr₆] and S(SiMe₃) under the same conditions. (PPh₄)₂[TaSCl₅] · 2 CH₂Cl₂ was obtained from TaSCl₃ and PPh₄Cl in CH₂Cl₂. According to an X-ray crystal structure determination (PPh₄)₂[NbSCl₅] · 2 CH₂Cl₂ crystallizes in the β-(AsPh₄)₂[UCl₆] · 2 CH₂Cl₂ type with positionally disordered, octahedral anions. Crystal data: a = 1 021.7, b = 1120.4, c = 1 243.3 pm, α = 70.77, β = 80.24, γ = 80.54°, space group P1 , Z = 2; 2462 unique observed reflexions, R = 0.036. NEt₄[NbCl₆] crystallizes isotypic to NEt₄[WCl₆], a = 723.5, b = 1 018.0, c = 1 174.6 pm, β = 100.07°, space group P2₁/n, Z = 2; 1 875 reflexions, R = 0.075.     

Thermal transformations of complexes Co2(μ-OOCBut)4(NEt3)2 and Co3(μ-OOCBut)2(μ-OOCBut)4(NEt3)2

The features of thermal transformations of trimethylacetatocobalt complexes Co₂(μ-OOCBu^t)₄(NEt₃)₂ and Co₃(μ-OOCBu^t)₂(μ-OOCBu^t)₄(NEt₃)₂ with attendant geometric alterations are considered as dependent on temperature on the basis of single-crystal X-ray diffraction, magnetochemical, and thermochemical investigations.     

Electrochemical study of (NEt4)2Cl2FeS2MoS2 and (NEt4)2Cl2FeS2MoS2FeCl2

Summary The ability of [MoS₄]^2–, anions to be used as ligands for transition metal ions has been widely demonstrated, especially with Fe²⁺. The present study has been restricted to linear complexes such as (NEt₄)₂ [Cl₂FeS₂MoS₂] and (NEt₄)₂[Cl₂FeS₂MoS₂FeCl₂]. Their electrochemical properties are described: upon electrochemical reduction, these compounds yield MoS₂, as a black precipitate, and an iron complex in solution, assumed to be [SFeCl₂]^2–. The electrochemical reduction goes through two electron transfers, coupled with the breakdown of the molecular skeleton: a DISPl and an ECE mechanism. Depending on the solvent, the following equilibrium may be observed: [Cl₄Fe₂MoS₄]^2–[Cl₂FeMoS₄]^2–+FeCl₂. The equilibrium constant, K_D, was evaluated by differential pulse polarography. K_D is tightly related to the donor number of the solvent.     

(PPh4)[(ReO2S2)CuI] und (NEt4)2[(ReOS3)Cu3Cl4]: Fixierung der bisher nicht isolierten Ionen [ReO2S2]− und [ReOS3]− durch Ausnutzung der Stabilität der CuS2(Re)- und Cu3S3(Re)-Fragmente

(PPh₄)[(ReO₂S₂)CuI] and (NEt₄)₂[ReOS₃)Cu₃Cl₄]: Fixation of the up to now not Isolated Ions [ReO₂S₂]^? and [ReOS₃]^? Utilizing the Stability of the CuS₂(Re) and Cu₃S₃(Re) Fragments (PPh₄)[(ReO₂S₂)CuI] ( 1 ) and (NEt₄)₂[ReOS₃)Cu₃Cl₄] ( 2 ) containing the up to now not isolated oxothioperrhenate ions [ReO₂S₂]^? and [ReOS₃]^? as ligands, have been prepared by the reaction of (NEt₄)[ReS₄] with PPh₃ and CuI in acetone in the presence of (PPh₄)I (( 1 )) or with CuCl in CH₂Cl₂ in the presence of (NEt₄)Cl (( 2 )), respectively. 1 and 2 have been characterized by X-ray structure analysis, elemental analysis and spectroscopic studies (IR, UV/Vis). The electronic spectra show bands which can approximately be assigned to interesting low-energy charge-transfer-transitions of the type d(Cu) → d(Re). For crystal data see Inhaltsübersicht.     

Halfsandwich Complexes Containing the Tetrathiotungstate Chelate Ligand. Crystal and Molecular Structure of Cp*Rh(PMe3)[(μ‐S)2WS2] (Cp* = η5‐Pentamethylcyclopentadienyl)

The reactions of Cp*M(PMe₃)Cl₂ (M = Rh ( 1a ), Ir ( 1b )) with (NEt₄)₂[WS₄] led to the heterodimetallic sulfido‐bridged complexes Cp*M(PMe₃)[(μ‐S)₂WS₂] (M = Rh ( 2a ), Ir ( 2b )), whereas the dimers [Cp*MCl(μ‐Cl)]₂ (M = Rh ( 4a ), Ir ( 4b )) reacted with (NEt₄)₂[WS₄) to give the known trinuclear compounds [Cp*M(Cl)]₂(μ‐WS₄) (M = Rh ( 5a ), Ir ( 5b )). Hydrolysis of the terminal W=S bonds converts 2a, b into Cp*M(PMe₃)[(μ‐S)₂WO₂] (M = Rh ( 3a ), Ir ( 3b )). Salts of a heterodimetallic anion, A[CpMo(I)(NO)(WS₄)] ( 6 ) (A⁺ = NEt₄⁺, NPh₄⁺) were obtained by reactions of [CpMo(NO)I₂]₂ with tetrathiotungstates, A₂[WS₄]. The complexes were characterized by IR and NMR (¹H, ¹³C, ³¹P) spectroscopy, and the X‐ray crystallographic structure of Cp*Rh(PMe₃)[(μ‐S)₂WS₂] ( 2a ) has been determined. The bond lengths and angles in the coordinations spheres of Rh and W in 2a (Rh···W 288.5(1) pm) are compared with related complexes containing terminal [WS₄^2—] chelate ligands.     

Synthesis and crystal structure of tetraethylammonium-μ-trichloro-heptachloro-diaqua-trirhenate(III)-dihydrate,NEt4[Re3Cl10(H2O)2] · 2 H2O

NEt₄[Re₃Cl₁₀(H₂O)₂] · 2 H₂O ( 1 ) was obtained from hydrochloric acid solutions of ReCl₃ and tetraethylammonium chloride, NEt₄Cl, by isothermal evaporation as dark red crystals. 1 crystallizes in the orthorhombic crystal system, space group Pnma, Z = 4, with a = 1838,7(2), b = 1456.9(1), c = 972.08(7) pm, V_m = 391.81(6) cm³ · mol^?l. The crystal structure consists of [Re₃Cl₁₀(H₂O)₂]^? anions that are arranged in the fashion of a hexagonal closest-packing of spheres. These are held together by partially disordered NEt₄⁺ cations and are bound into a hydrogen bonding system with the crystal water.     

Synthesis and characterisation of [tris(1,3-dithiole-2-thione-4,5-dithiolato)-stannate]2−, [Q]2[Sn(dmit)3], [tris(1,3-dithiole-2-one-4,5-dithiolato)stannate]2−, [Q]2[Sn(dmio)3] and [tris(1,3-dithiole-2-thione-4,5-selenolato)stannate]2−, [Q]2[Sn(dsit)3], complexes: Analysis of the structural variations of the [Sn(dmit)3]2− and [Sn(dmio)3]2− dianions

[Tris(1,3-dithiole-2-thione-4,5-dithiolato)stannate]²⁻, [Q]₂[Sn(C₃S₅)₃], [tris(1,3-dithiole-2-one-4,5-dithiolato)stannate]²⁻, [Q]₂[Sn(C₃S₄O)₃], and [tris(1,3-dithiole-2-thione-4,5-diselenolato)stannate]²⁻ [Q]₂[Sn(C₃S₃Se₂)₃], complexes, have been synthesised and characterised. Crystal structure determinations of [Q]₂[Sn(C₃S₅)₃] (Q=1,4-dimethylpyridinium, monoclinic and orthorhombic forms; NMe₄, NEt₄, and PPh₄) and [NEt₄]₂[Sn(C₃S₄O)₃] revealed variations in the overall dianion structures. The geometry about tin in each case is essentially octahedral with the chelate bite angles in the range 80.7(5)–87.45(4)°: the range of Sn–S distances is 2.5207(18)–2.571(17) Å. A statistical analysis, carried out on the crystal structure data for the six complexes, indicated that the most critical factors in controlling the overall shape of the dianion were the distances of the Sn atom from the dithiolate ligand planes [Sn–OOP]. Interanionic S⋯S interactions, within the sum of the van der Waals’ radii for two S atoms, are affected by the size of the cation, Q; the secondary connectivity is 3-dimensional for the smallest cations, Q=1,4-dimethylpyridinium and NMe₄, in chains for the somewhat larger cation, NEt₄ and is absent for the still larger, PPh₄ cation.     

Unravelling the Role of the Pentafluoroorthotellurate Group as a Ligand in Nickel Chemistry

The pentafluoroorthotellurate group (teflate, OTeF₅) is able to form species, for which only the fluoride analogues are known. Despite nickel fluorides being widely investigated, nickel teflates have remained elusive for decades. By reaction of [NiCl₄]²⁻ and neat ClOTeF₅, we have synthesized the homoleptic [Ni(OTeF₅)₄]²⁻ anion, which presents a distorted tetrahedral structure, unlike the polymeric [NiF₄]²⁻. This high-spin complex has allowed the study of the electronic properties of the teflate group, which can be classified as a weak/medium-field ligand, and therefore behaves as the fluoride analogue also in ligand-field terms. The teflate ligands in [NEt₄]₂[Ni(OTeF₅)₄] are easily substituted, as shown by the formation of [Ni(NCMe)₆][OTeF₅]₂ by dissolving it in acetonitrile. Nevertheless, careful reactions with other conventional ligands have enabled the crystallization of nickel teflate complexes with different coordination geometries, i.e. [NEt₄]₂[trans-Ni(OEt₂)₂(OTeF₅)₄] or [NEt₄][Ni(bpyMe₂)(OTeF₅)₃].     

The decomposition kinetics of [Et4N]2[M(dmit)2] (M = Ni, Pd) in a nitrogen atmosphere using thermogravimetry

Thermal properties and thermal decompositions of [NEt₄]₂[M(dmit)₂] (M = Ni(II), Pd(II), dmit = 1,3-dithiole-2-thione-4,5-dithiolate) have been studied by thermogravimetry (TG). The TG analysis has shown that the complexes are thermally stable up to 460 K and the decomposition of the complexes occurs in three consecutive stages up to 873 K. A thermal stability scale for [M(dmit)₂]ⁿ⁻ anions was based on the thermal properties. Kinetics parameters, such as activation energy, E_a, and kinetic apparent pre-exponential factor, ln A_app, have been calculated from the thermogravimetric data at heating rates of 10, 15, 20 and 25 K/min involving differential (Friedman's equation) and integral (Flynn-Wall-Ozawa's equation) methods.     

Isothiocyanat-Komplexe von Kupfer (II) mit quadratisch-planarer und tetragonal-pyramidaler Koordination: Struktur,Phasenumwandlungen und Redoxverhalten

Isothiocyanate Complexes of Copper(II) with Square-Planar and Tetragonal-Pyramidal Coordination: Structure, Phase Transitions, and Redox-Properties In dependence on the kind and size of the counter-cations Cu²⁺-ions form isothiocyanate complexes with different coordination number and geometry. The structures of compounds with square-planar coordination [(NEt₄)₂[Cu(NCS)₄] · CHCl₃ (brown): Space group 14/mmm, Z = 2; a = 1204.3(2) pm, c = 1154.2(3) pm] and with tetragonal-pyramidal polyhedra [(NEt₄)₃[Cu(NCS)₅] · SM (green, SM: unidentified solvent molecule): Space group P2₁/c, Z = 4; a = 1154.2(6) pm, b = 2291.6(10) pm, c = 1739.9(9) pm, ß = 95.98(5)°] are reported. The green complex transforms into a brown compound at room-temperature; the transformation is (partly) reversibly. Solutions of NCS-anions and Cu²⁺ are redox unstable. The structure of a resulting product: (PPh₄)₂[Cu₂(NCS)₂] [Space group C2/c, Z = 4; a = 1235.4(1) pm, b = 1347.1(2) pm, c = 2953.4(11) pm, ß = 99.36(2)°] with Cu(I) dimers and two bridging NCS^- ligands is also reported.     

Reactivity of tetrathiometalates with alkynes. Synthesis and characterisation of dithiolene complexes of Mo,W, and V by ESMS and XRD

The reaction of DMA (C₂(CO₂Me)₂) with MoS₄²⁻, WS₄²⁻, and VS₄³⁻ led to six dithiolene compounds. (NEt₄)₂[Mo₂(X)₂(μ-S) ₂(η²-S₂C₂(CO₂Me)₂)₂] 1, (X = O or S), (NEt₄)₂[V(η²-S₂C₂(CO₂Me)₂)₃] 2a, (NEt₄)₂[V(O)(η²-S₂C₂(CO₂Me)₂)₂] 2b, (NEt₄)₂[W₂(S)₂(μ-S)₂(η²-S₂C₂(CO₂Me)₂)₂] 3, (NEt₄)₂[W(O)(η²-S₂C₂(CO₂Me)₂)₂] 4 and (NEt₄)₂[W₂(μ-S)₂(η² -S₂C₂(CO₂Me)₂)₄] 5 were isolated in the solid state. The structures of 2a, 3, 4 and 5 were determined by single crystal X-ray diffraction study. The compounds 1 and 2b were characterised in solution by ESMS (Electrospray Mass Spectrometry) and in the solid state by IR spectroscopy. ESMS data also allowed proposal of a reaction scheme which rationalizes the formation of the different species present in solution.     

Einstieg in die Chemie einfacher Rhenium-Schwefel-Komplexe und -Cluster. Darstellung und Kristall-Struktur von R[ReS4], R′[ReS9], (NH4)4[Re4S22]·2H2O,R′2[Cl2Fe(MoS4)FeCl2]x [Cl2Fe(ReS4)FeCl2]1-x′ R′2 [(ReS4)Cu3l4] und RR′2[(ReS4)Cu5Br7] (R  NEt4; R′  PPh4; x = 0,3, 0,5)

Entry to the Chemistry of Simple Rhenium Sulfur Complexes and Clusters. Preparation and Crystal Structures of R′[ReS₄], R′[ReS₉], (NH₄)₄[Re₄S₂₂]·2H₂O, R′₂[Cl₂Fe(MoS₄)FeCl₂]_1-x, R′₂[(ReS₄)Cu₃I₄] and RR′₂[(ReS₄)Cu₅Br₇] (R ? NEt₄; R′ ? PPh₄, x = 0.3, 0.5) The compounds R[ReS₄] ( 1 ), R′[ReS₉] ( 2 ), (NH₄)₄[Re₄S₂₂]·2 H₂O ( 3 ), R′₂[Cl₂Fe(MoS₄) FeCl₂]_x[Cl₂Fe(ReS₄)FeCl₂] _1-x (x = 0.3 ( 4 ), 0.5), R′₂[(ReS₄)Cu₃I₄] ( 5 ) and R′₂[(ReS₄)Cu₅Br₇] ( 6 ) (R ? NEt₄; R′ ? PPh₄) have been prepared by reaction of perrhenates or rhenium(VII)oxide with S_x^2? solutions (under different conditions) or by reactions of metal-halides with [ReS₄]^?-ions. All compounds have been characterized by complete X- ray structure analysis. For further details see Inhaltsübersicht.     

Kinetics of substitution on chloro-1,1,7,7-tetraethyldiethylene-triaminegold(III) in methanol-water mixtures

Summary Rate constants are reported for the replacement of chloride by bromide in the complex [Au(Et₄dien-H)⁺ in methanol-water mixtures. This reaction follows the usual two-term rate law = (k_obs = k₁ + K₂[Br^–1]) for square planar complexes in all the mixtures studied. The logarithms of the rate constants correlate with Grunwald-Winstein solvent Y values and yield slopes of 0.32 (k₁) and 0.15 (k₂). The results suggest that both reaction paths are associative.Dien complexes of gold(III) yield conjugate base species at low pH; Et₄dien-H = Et₂NCH₂CH₂NCH₂CH₂NEt₂.     

Reactive E=C(p‐p)π‐Systems. 55. [1] Ligand Properties of 1‐Trifluoromethyl‐2‐diethylamino‐2‐fluoro‐1‐arsaethene,F3CAs=C(F)NEt2

Due to the mesomeric interaction of the nitrogen lone pair with the As=C double bond, the perfluoroarsapropene derivative F₃CAs=C(F)NEt₂ ( 1 ) is sufficiently stable to serve as a ligand in transition metal carbonyl complexes. 1 was coordinated to chromium by reaction with the photochemically generated labile complex Cr(CO)₅(THF), yielding the monosubstituted pentacarbonyl derivative Cr(CO)₅[F₃CAs=C(F)NEt₂] ( 2 ). Already at room temperature, this is slowly transformed into the binuclear complex [F₃CAs=C(F)NEt₂][Cr(CO)₅]₂ ( 3 ) by replacing 1 from a neighbouring molecule by the stronger donor 2 . In a closed system 3 obviously exists in an equilibrium with 1 and 2 . Both complexes are related to the previously studied derivatives of the 2‐dimethylamino‐perfluoro‐1‐phosphapropene ligand. The products were identified by spectroscopic (IR, NMR) investigations and comparison with the related phosphaalkene complexes.     

Silicon‐ and Tin‐Containing Open‐Chain and Eight‐Membered‐Ring Compounds as Bicentric Lewis Acids toward Anions

Herein, we report the syntheses of silicon‐ and tin‐containing open‐chain and eight‐membered‐ring compounds Me₂Si(CH₂SnMe₂X)₂ ( 2 , X=Me; 3 , X=Cl; 4 , X=F), CH₂(SnMe₂CH₂I)₂ ( 7 ), CH₂(SnMe₂CH₂Cl)₂ ( 8 ), cyclo‐Me₂Sn(CH₂SnMe₂CH₂)₂SiMe₂ ( 6 ), cyclo‐(Me₂SnCH₂)₄ ( 9 ), cyclo‐Me_(2?n)X_nSn(CH₂SiMe₂CH₂)₂SnX_nMe_(2?n) ( 5 , n=0; 10 , n = 1, X= Cl; 11 , n=1, X= F; 12 , n=2, X= Cl), and the chloride and fluoride complexes NEt₄[cyclo‐ Me(Cl)Sn(CH₂SiMe₂CH₂)₂Sn(Cl)Me?F] ( 13 ), PPh₄[cyclo‐Me(Cl)Sn(CH₂SiMe₂CH₂)₂Sn(Cl)Me?Cl] ( 14 ), NEt₄[cyclo‐Me(F)Sn(CH₂SiMe₂CH₂)₂Sn(F)Me?F] ( 15 ), [NEt₄]₂[cyclo‐Cl₂Sn(CH₂SiMe₂CH₂)₂SnCl₂?2 Cl] ( 16 ), M[Me₂Si(CH₂Sn(Cl)Me₂)₂?Cl] ( 17 a , M=PPh₄; 17 b , M=NEt₄), NEt₄[Me₂Si(CH₂Sn(Cl)Me₂)₂?F] ( 18 ), NEt₄[Me₂Si(CH₂Sn(F)Me₂)₂?F] ( 19 ), and PPh₄[Me₂Si(CH₂Sn(Cl)Me₂)₂?Br] ( 20 ). The compounds were characterised by electrospray mass‐spectrometric, IR and ¹H, ¹³C, ¹⁹F, ²⁹Si, and ¹¹⁹Sn NMR spectroscopic analysis, and, except for 15 and 18 , single‐crystal X‐ray diffraction studies.     

Luminescence determination of sodium and potassium using molecular sensors on the basis of terbium(III) complexes of 4-carboxybenzocrown ethers

The spectral luminescent properties of terbium(III) complexes of 4-carboxybenzo-15-crown-5 (L₁) and 4-carboxybenzo-18-crown-6 (L₂) are studied. The quenching of the luminescence of lanthanide by alkali metal ions is discovered, which is referred to as the formation of mixed Tb(III)-L₁-Na⁺ and Tb(III)-L₂-K⁺ complexes. The complexes are useful as molecular sensors for the luminescence determination of Na⁺ and K⁺ with the detection limits 1.5 and 25.0 μg/mL. Using the Tb(III)-L₁ complex, sodium can be determined in the presence of a 1000-fold excess of potassium. The developed procedures are utilized for the determination of KCl in the Kalipoz medication in tablet form and the total sodium salts (NaCl, NaHCO₃) in the Trisol solution for infusions.     

Tricarbonylrhenium(I) and manganese(I) complexes of 2-(pyrazolyl)-4-toluidine

A series of tricarbonyl rhenium(I) and manganese(I) complexes of the electroactive 2-(pyrazolyl)-4-toluidine ligand, H(pzAn^Me), has been prepared and characterized including by single crystal X-ray diffraction studies. The reactions between H(pzAn^Me) and M(CO)₅Br afford fac-MBr(CO)₃[H(pzAn^Me)] (M = Mn, 1a; Re, 1b) complexes. The ionic species {fac-M(CH₃CN)(CO)₃[H(pzAn^Me)]}(PF₆) (M = Mn, 2a; Re, 2b) were prepared by metathesis of 1a or 1b with TlPF₆ in acetonitrile. Complexes 1a and 1b partly ionize to {M(CH₃CN)(CO)₃[H(pzAn^Me)]⁺}(Br⁻) in CH₃CN but retain their integrity in less donating solvents such as acetone or CH₂Cl₂. Each of the four metal complexes reacts with (NEt₄)(OH) in CH₃CN to give poorly-soluble crystalline [fac-M(CO)₃(μ-pzAn^Me)]₂ (M = Mn, 3a; Re, 3b). The solid state structures of 3a and 3b are of centrosymmetric dimeric species with bridging amido nitrogens and with pyrazolyls disposed trans- to the central planar M₂N₂ metallacycle. In stark contrast to the diphenylboryl derivatives, Ph₂B(pzAn^Me), none of the tricarbonyl group 7 metal complexes are luminescent.