Die Massenspektren von Pd6Cl12, Pt6Cl12 und PdnPt6−nCl12

Mass Spectra of Pd₆Cl₁₂, Pt₆Cl₁₂, and Pd_nPt_6?nCl₁₂ Pd₆Cl₁₂, and Pt₆Cl₁₂ and both together are volatilised in a mass spectrometer. 3 Cl and 1 Pd have approximately the same mass, therefore isotopes of Pd and Pt are used (¹⁰⁸Pd, ₁₉₄Pt). With an ionisation energy of 50 eV part of the vapourised molecules is strongly fragmented. With a lower ionisation energy the molecule ions Pd₆Cl₁₂⁺, Pt₆Cl₁₂⁺ and Pd_nPt_6?nCl₁₂⁺ are only observed.     

Pt6Cl12·(1,2,4‐C6H3Cl3), a Structurally Characterized Cocrystallization Product of Pt6Cl12

The reaction of platinum(II) chloride with 1,2,4‐trichlorobenzene gives the novel platinum complex Pt₆Cl₁₂·(1,2,4‐C₆H₃Cl₃). It is the first example of an cocrystallization product of platinum(II) chloride and organic molecules whose crystal structure has been established.     

Der Ligandenaustausch im Kristallgitter von (PyH)2[Ta6Br12]Cl6

Ligand Replacement in the Crystal Lattice of (PyH)₂[Ta₆Br₁₂]Cl₆ Solid (PyH)₂[Ta₆Br₁₂ⁱ]Cl₆^a transforms exothermically at 210°C. In this way the Cl^a atoms outside of the complex are going instead of Brⁱ into the inside position; e.g. [Ta₆Br₁₂]Cl₆^2? → [Ta₆Br₆Cl₆]Br₆^2?. After each transformation Cl is brought in the outside position of the complex by recrystallization from a solution containing HCl. One gets in the following transformation step [Ta₆Br₃Cl₉]⁴⁺ and finally in the third step [Ta₆Br_1.5Cl_10.5]⁴⁺. Both formula are empirical formula. They consist of [Ta₆Br₆Cl₆]⁴⁺ and [Ta₆Br₂Cl₁₀]⁴⁺; and [Ta₆Br₆Cl₆]⁴⁺, [Ta₆Br₂Cl₁₀]⁴⁺ and [Ta₆Cl₁₂]⁴⁺, respectively. This result is in agreement with the theory.     

Caesiumchloropalladat(II)‐hydrate – zwei neue Verbindungen mit kondensierten [Pd2Cl6]‐Baugruppen

Caesiumchloropalladate(II)‐hydrates – Two New Compounds with Condensed [Pd₂Cl₆] Groups We were able to synthesize two caesiumchloropalladate(II)‐hydrates in the CsCl/PdCl₂/H₂O system by hydrothermal methods. Both compounds show combination of monomeric and dimeric Pd–Cl groups. We characterized the crystal structures by single‐crystal X‐ray diffraction. Cs₆Pd₅Cl₁₆ · 2 H₂O ( I ) crystallizes triclinic in space group type P1 (Nr. 2) with a = 8.972(1) Å, b = 11.359(1) Å, c = 18.168(1) Å, α = 83.61(1)°, β = 76.98(1)°, γ = 76.39(1)° and Z = 2, Cs₁₂Pd₉Cl₃₀ · 2 H₂O ( II ) monoclinic, space group type C2/m (No. 12) with a = 19.952(1) Å, b = 14.428(1) Å, c = 14.411(1) Å, β = 125.29(1)°, and Z = 2.     

Die Gasmolekeln Pd2Al2Cl10 und PdAlCl5 als Begleiter von PdAl2Cl8

Gas Molecules Pd₂Al₂Cl₁₀ and PdAlCl₅ as Accompanists of PdAl₂Cl₈ Mass spectrometric observations using a double cell showed that the reaction of gaseous Al₂Cl₆ with solid PdCl₂ besides the known gaseous complex PdAl₂Cl₈ gives PdAlCl₅ and the unexpected complex Pd₂Al₂Cl₁₀. For the equilibrium (with ΔCp? ?1 cal/K) ΔH°(298) = 7.5 kcal/Mol and ΔS°(298) = 5.3 ± 2 cl have been obtained.     

Die Umwandlung [W6X8]X4 [W6X12]X6 (X = Cl,Br)

Transformation of [W₆X₈]X₄ + 3 X₂ = [W₆X₁₂]X₆ (X = Cl, Br) The transformation of [W₆X₈]X₄ + 3 X₂ = [W₆X₁₂]X₆ (X = Cl, Br) has been investigated by changing the relation Cl₂/Br₂ and the temperature. In this way the compounds [W₆Br_12?nCl_n]Cl_6?mBr_m are isolated. All of the products are isotypic with W₆Cl₁₈ and W₆Br₁₈. Most often n equals 6, however compounds with other relations of Cl/Br are also observed (e. g. n = 4.8) The 6 ligands standing outside of the brackets are replaced by Cl or Br. The substitution of [W₆Br₆Cl₆]Cl₆ by means of bromine leads to the cluster [W₆Br₁₂]X₆. The backward transformation of the cluster compound [W₆Br₁₂]Br₆ happens by decomposition on the thermobalance, e. g. according to Gl. (1) (See Inhaltsübersicht). By analogy [W₆Br₁₂]Cl₆ is decomposed to [W₆Br₈]Cl₂Br₂, which by treatment with conc. HCl is transformed into [W₆Br₈]Cl₄ · 2 H₂O.     

Tl4Pd3Cl10 – eine Verbindung mit neuartiger [(PdCl2Cl2/2)4]4–‐Baugruppe

Tl₄Pd₃Cl₁₀ – A Compound with a New [(PdCl₂Cl_2/2)₄]^4– Group Single crystals of Tl₄Pd₃Cl₁₀ can be obtained by hydrothermal synthesis. They show tetragonal symmetry with lattice parameters a = 15.956(1) Å and c = 14.146(1) Å, Z = 8 and space group I42d (No. 122). The atomic arrangement of Tl₄Pd₃Cl₁₀ is explored by X‐ray crystal structure analysis. Tl₄Pd₃Cl₁₀ is the first example of a new structural type with a hitherto not isolated tetramer [(PdCl₂Cl_2/2)₄]^4– group.     

Solvolysis of palladium(II) and platinum(II) complexes of asymmetric ligands: Synthesis and structural characterization of [Pd(AMP)(dmso)Cl]BF4 and [Pt(AMP)(dmso)Cl]ClO4

Treatment of [M(AMP)Cl₂] (M = Pt^II, Pd^II; AMP = 2-aminomethylpyridine) with 1 mole of AgX (X = ClO₄, BF₄, PF₆) in dmso yields [M(AMP)(dmso)Cl]X. Single crystal X-ray structure determinations of the Pd^II and Pt^II complexes indicate that dmso is S-bondedtrans to the pyridyl ring in both complexes. (2-Aminomethylpyridine)chloro(dimethylsulphoxide-S) palladium(II) tetrafluoroborate.     

Superchiral Pd3L6 Coordination Complex and Its Reversible Structural Conversion into Pd3L3Cl6 Metallocycles

Large, non‐symmetrical, inherently chiral bispyridyl ligand L derived from natural ursodeoxycholic bile acid was used for square–planar coordination of tetravalent Pd^II, yielding the cationic single enantiomer of superchiral coordination complex 1 Pd₃ L ₆ containing 60 well‐defined chiral centers in its flower‐like structure. Complex 1 can readily be transformed by addition of chloride into a smaller enantiomerically pure cyclic trimer 2 Pd₃ L ₃Cl₆ containing 30 chiral centers. This transformation is reversible and can be restored by the addition of silver cations. Furthermore, a mixture of two constitutional isomers of trimer, 2 and 2′ , and dimer, 3 and 3′ , can be obtained directly from L by its coordination to trans‐ or cis‐N‐pyridyl‐coordinating Pd^II. These intriguing, water‐resistant, stable supramolecular assemblies have been thoroughly described by ¹H DOSY NMR, mass spectrometry, circular dichroism, molecular modelling, and drift tube ion‐mobility mass spectrometry.     

The structure of [Pd3(η3-2-methylallyl)2Cl4]

An X-ray crystal structure determination of [Pd₃(2-methylallyl)₂Cl₄] shows it to be centrosymmetric with a rippled near-planar arrangement of PdCl₂PdCl₂Pd, the terminal Pd atoms being η³-bonded to the 2-methylallyl ligand.     

Darstellung von trans-[Mo6Cl8]Cl4Br22−ausgehend von kristallisierten [Mo6Cl8]Cl4(H2O)2 und die Kristallstruktur von [(C6H5)4As]2[Mo6Cl8]Cl4Br2

Preparation of trans-[Mo₆Cl₈]Cl₄Br₂^2? Starting from Crystalline [Mo₆Cl₈]Cl₄(H₂O)₂ and Crystal Structure of [(C₆H₅)₄As]₂[Mo₆Cl₈]Cl₄Br₂ The synthesis of the title compound is successful if the crystallized [(Mo₆Cl₈)Cl₄(H₂O)₂] containing the H₂O molecules in trans-position reacts with HBr + [(C₆H₅)₄As]Br in ethanol in a heterogeneous reaction. The X-ray structure investigation confirms the existence of discrete trans-Br-substituted cluster anions of composition [(Mo₆Cl₈)Cl₄Br₂]^2? in the crystal. The reaction in homogeneous solutions proceeds to Br-enriched compounds. [(C₆H₅)₄As]₂[(Mo₆Cl₈)Cl₄Br₂] crystallizes in the triclinic space group P¯1 with a = 11.071(2), b = 11.418(2), c = 12.813(2) Å, α = 116.10(2), β = 95.27(2) and γ = 94.41(2)° (?133°C). The crystal structure at ?133°C was determined from single crystal X-ray diffraction data (R₁ = 0.026). The [(Mo₆Cl₈)Cl₄Br₂]^2?-anions are not completely ordered but distributed statistically among the three positions which are possible within the limits of the ordered [Mo₆Cl₈]-cores (ratio 11:5:4). The frameworks of the anions consist of Mo₆ cluster units with (slightly distorted) octahedral arrangement of the metal atoms (d(Mo? Mo): 2.600(1) up to 2.614(1) Å), which are coordinated by the halogeno ligands in a square-pyramidal manner. The details of the structure will be discussed and compared with similar [(Mo₆X₈)Y₄] cluster units (X, Y ? Cl, Br).     

CsPdCl3 – eine Verbindung mit [Pd2Cl6]-Baugruppen und anorganischem Kation

CsPdCl₃ – A Compound with Isolated [Pd₂Cl₆] Groups and an Inorganic Cation The crystal structure of CsPdCl₃ has been characterized by X-ray powder diffraction methods. Meanwhile it was possible to isolate single crystals and to confirm the structure by single crystal X-ray investigations. CsPdCl₃ crystallizes orthorhombic in space group Ibam (No. 72) with a = 13.724(1), b = 10.579(1), c = 8.499(1) Å, and Z = 8. CsPdCl₃ is a compound with a dinuclear [Pd₂Cl₆]^2– group and a cesium cation. Formerly such groups are only found in combination with large “organic” cations so far.     

Beiträge zur Chemie der Elemente Niob und Tantal. 81. Niob- und Tantalkomplexe mit der anionischen Gruppe {[Me6X12]X}; X = Cl,Br

The compounds A₄[Nb₆Cl₁₂]Cl₆ (A ? Na, K, Cs), K₄[Nb₆Br₁₂]Br₆ and A₄[Ta₆Cl₁₂]Cl₆ (A ? Na, K, Cs) are prepared. The chemical equations for formation and decomposition are taken into consideration. The complexes [Nb₆Br₁₂]²⁺ and [Ta₆Cl₁₂]²⁺, unstable in the binary systems, are stabilized in the ternary compounds. The compounds are isotypic with the known K₄[Nb₆Cl₁₂]Cl₆. For some of them lattice constants and molecular volumes are communicated.     

Synthese und Struktur der Komplexe [(n‐Bu)4N]2[{(THF)Cl4Re≡N}2PdCl2], [Ph4P]2[(THF)Cl4Re≡N‐PdCl(μ‐Cl)]2 und [(n‐Bu)4N]2[Pd3Cl8]

Synthesis and Crystal Structure of the Complexes [(n‐Bu)₄N]₂[{(THF)Cl₄Re≡N}₂PdCl₂], [Ph₄P]₂[(THF)Cl₄Re≡N‐PdCl(μ‐Cl)]₂ and [(n‐Bu)₄N]₂[Pd₃Cl₈] The threenuclear complex [(n‐Bu)₄N]₂[{(THF)Cl₄Re≡N}₂ PdCl₂] ( 1 ) is obtained in THF by the reaction of PdCl₂(NCC₆H₅)₂ with [(n‐Bu)₄N][ReNCl₄] in the molar ration 1:2. It forms orange crystals with the composition 1· THF crystallizing in the monoclinic space group C2/c with a = 2973.3(2); b = 1486.63(7); c = 1662.67(8)pm; β = 120.036(5)° and Z = 4. If the reaction is carried out with PdCl₂ instead of PdCl₂(NCC₆H₅)₂, orange crystals of hitherto unknown [(n‐Bu)₄N]₂[Pd₃Cl₈] ( 3 ) are obtained besides some crystals of 1· THF. 3 crystallizes with the space group P1¯ and a = 1141.50(8), b = 1401.2(1), c = 1665.9(1)pm, α = 67.529(8)°, β = 81.960(9)°, γ = 66.813(8)° and Z = 2. In the centrosymmetric complex anion [{(THF)Cl₄Re≡N}₂PdCl₂]^2— a linear PdCl₂ moiety is connected in trans arrangement with two complex fragments [(THF)Cl₄Re≡N]^— via asymmetric nitrido bridges Re≡N‐Pd. For Pd(II) thereby results a square‐planar coordination PdCl₂N₂. The linear nitrido bridges are characterized by distances Re‐N = 163.8(7)pm and Pd‐N = 194.1(7)pm. The crystal structure of 3 contains two symmetry independent, planar complexes [Pd₃Cl₈]^2— with the symmetry 1¯, in which the Pd atoms are connected by slightly asymmetric chloro bridges. By the reaction of equimolar amounts of [Ph₄P][ReNCl₄] and PdCl₂(NCC₆H₅)₂ in THF brown crystals of the heterometallic complex, [Ph₄P]₂[(THF)Cl₄Re≡N‐PdCl(μ‐Cl)]₂ ( 2 ) result. 2 crystallizes in the monoclinic space group P2₁/n with a = 979.55(9); b = 2221.5(1); c = 1523.1(2)pm; β = 100.33(1)° and Z = 2. In the central unit ClPd(μ‐Cl)₂PdCl of the centrosymmetric anionic complex [(THF)Cl₄Re≡N‐PdCl(μ‐Cl)]₂^2— the coordination of the Pd atoms is completed by two nitrido bridges Re≡N‐Pd to nitrido complex fragments [(THF)Cl₄Re≡N]^— forming a square‐planar arrangement for Pd(II). The distances in the linear nitrido bridges are Re‐N = 163.8(9)pm and Pd‐N = 191.5(9)pm.     

Drei Wege zur Oxydation von [Ta6Cl12]2+ ([Ta6Br12]2+ und [Nb6Cl12]2+)

Three Oxidation Paths of [Ta₆Cl₁₂]²⁺ ([Ta₆Br₁₂]²⁺ and [Nb₆Cl₁₂]²⁺) [Ta₆Cl₁₂]²⁺ is oxidized autocatalytically to [Ta₆Cl₁₂]⁴⁺ by HNO₃. The titration of [Ta₆Cl₁₂]²⁺ with KBrO₃ (in HBr-containing solutions) or with Ce⁴⁺ or K₂Cr₂O₇ (in HNO₃-containing solutions) leads to a clear [Ta₆Cl₁₂]³⁺ step. The further titration leads beside [Ta₆Cl₁₂]⁴⁺ to the formation of Ta₂O₅(· xH₂O). [Ta₆Cl₁₂]²⁺ behaves with KBrO₃(+ HBr) equally, but the formation of [Ta₂O₅](· xH₂O) is only small. [Nb₆Cl₁₂]²⁺ (22°C) titrated with Ce(ClO₄)₄ in 2n HClO₄ gives the first potential step nearby exact ([Nb₆Cl₁₂]³⁺) and at a very slow titration in a second step a precipitation of Nb₂O₅(· xH₂O) occurs, which adsorbed Ce⁴⁺ additionally. At ?15°C with Ce(ClO₄)₄ the first potential step was exactly at [Nb₆Cl₁₂]^2+→3+, while the second step needs a distinct additional consumption of titer. (Formation of [Nb₆Cl₁₂]⁴⁺ and beside it [Nb₂O₅](· xH₂O)). From the titration curves and sections of its normal progress in all cases we get the normal potentials 2+/3+ and 3+/4+ with an accuracy of ± 0.01 volt. In alkaline solution the complexes are oxidized with air-oxygen to [M₆X₁₂](OH)₆^2?, while the Br-containing complexes suffer hydrolysis afterwards.     

Pr6C2‐Doppeltetraeder in Pr6C2Cl10 und Pr6C2Cl5Br5

Pr₆C₂‐Bitetrahedra in Pr₆C₂Cl₁₀ and Pr₆C₂Cl₅Br₅ The compounds Pr₆C₂Cl₁₀ and Pr₆C₂Cl₅Br₅ are prepared by heating stoichiometric mixtures of Pr, PrCl₃, PrBr₃ and C in sealed Ta capsules at 810 ? 820 °C. They form bulky transparent yellow to green and moisture sensitive crystals which have different structures: space groups C2/c, (a = 13.687(3) Å, b = 8.638(2) Å, c = 15.690(3) Å, β = 97.67(3)° for Pr₆C₂Cl₁₀ and a = 13.689(1) Å, b = 10.383(1) Å, c = 14.089(1) Å, β = 106.49(1)° for Pr₆C₂Cl₅Br₅). Both crystal structures contain C‐centered Pr₆C₂ bitetrahedra, linked via halogen atoms above edges and corners in different ways. The site selective occupation of the halogen positions in Pr₆C₂Cl₅Br₅ is refined in a split model and analysed with the bond length‐bond strength formalism. The compound is further characterized via TEM investigations and magnetic measurements (μ_eff = 3.66 μ_B).     

Structure and Bonding of the Hexameric Platinum(II) Dichloride,Pt6Cl12 (β‐PtCl2)

The crystal structure of Pt₆Cl₁₂ (β‐PtCl₂) was redetermined ( a_h = 13.126Å, c_h = 8.666Å, Z = 3; a_rh = 8.110Å, α = 108.04°; 367 hkl, R = 0.032). As has been shown earlier, the structure is in principle a hierarchical variant of the cubic structure type of tungsten (bcc), which atoms are replaced by the hexameric Pt₆Cl₁₂ molecules. Due to the 60° rotation of the cuboctahedral clusters about one of the trigonal axes, the symmetry is reduced from to ( ). The molecule Pt₆Cl₁₂ shows the (trigonally elongated) structure of the classic M₆X₁₂ cluster compounds with (distorted) square‐planar PtCl₄ fragments, however without metal‐metal bonds. The Pt atoms are shifted outside the Cl₁₂ cuboctahedron by Δ = +0.046Å ( (Pt—Cl) = 2.315Å; (Pt—Pt) = 3.339Å). The scalar relativistic DFT calculations results in the full symmetry for the optimized structure of the isolated molecule with d(Pt—Cl) = 2.381Å, d(Pt—Pt) = 3.468Å and Δ = +0.072Å. The electron distribution of the Pt‐Pt antibonding HOMO exhibits an outwards‐directed asymmetry perpendicular to the PtCl₄ fragments, that plays the decisive role for the cluster packing in the crystal. A comparative study of the Electron Localization Function with the hypothetical trans‐(Nb₂Zr₄)Cl₁₂ molecule shows the distinct differences between Pt₆Cl₁₂ and clusters with metal‐metal bonding. Due to the characteristic electronic structure, the crystal structure of Pt₆Cl₁₂ in space group is an optimal one, which results from comparison with rhombohedral Zr₆I₁₂ and a cubic bcc arrangement.     

Primary reactions in the photochemistry of hexahalide complexes of platinum group metals: A minireview

We review the results obtained for Pt^IVCl₆²⁻, Pt^IVBr₆²⁻, Ir^IVCl₆²⁻, Ir^IVBr₆²⁻, and Os^IVBr₆²⁻ complexes in aqueous and alcoholic solutions using ultrafast pump–probe spectroscopy, laser flash photolysis, ESR, and photoelectron spectroscopy. We discuss the correlations between the photophysics and the photochemistry of these complexes. The key reaction for Pt^IVCl₆²⁻ is the inner-sphere electron transfer, which results in an Adamson radical pair that lives for several picoseconds, and the subsequent photoaquation in aqueous solutions and photoreduction in alcohols. The chlorine atom formed as the primary product escapes the solvent cage in aqueous solutions or oxidizes a solvent alcohol molecule via secondary electron transfer, producing secondary intermediates that react on the microsecond time scale. The photoexcitation of Pt^IVBr₆²⁻ results in the formation of pentacoordinated Pt^IV intermediates, i.e. ³Pt^IVBr₅⁻ and ¹Pt^IVBr₅⁻, with characteristic lifetimes of approximately 1 and 10 ps, respectively. Subsequent reactions of these intermediates result in the complexation of a solvent molecule. Photoreduction is also possible in alcohols. Similar reactions occur with rather low quantum yields for Ir^IVCl₆²⁻, therefore, only the ground-state recovery could be monitored in ultrafast experiments, which occur on the 10-ps time scale. The photochemical behaviours of the Ir^IVBr₆²⁻ and Os^IVBr₆²⁻ complexes are similar to those of Ir^IVCl₆²⁻ and Pt^IVBr₆²⁻, respectively.     

Insertion of acetylenes in the PdPd bond of Pd2 (Ph2 PCH2 PPh2)2 Cl2

Dimethylacetylene dicarboxylate and hexafluoro-2-butyne add to Pd₂(dpm)₂Cl₂ (dpm = Ph₂PCH₂PPh₂) to give crystalline adducts Pd₂(dp)₂(μ-acetylene)Cl₂. An X-ray crystal structure of Pd₂(dpm)₂(μ-C₄F₆)Cl₂ reveals that the acetylene has inserted into the metalmetal bond and has been transformed into a cis-dimetallated olefin. The central CC bond length of the bridging olefin is 1.338(16) Å. The coordination about each of the two similar palladium ions is planar and involves two trans-phosphines (one from each of the bridging dpm ligands), a terminal chloride, and one carbon of the bridging olefin. Both Pd₂(dpm)₂Cl₂ and Pd₂(dpm)₂(μ-C₂{CO₂H₃}₂)Cl₂ catalyze the cyclotrimerization of dimethyl-acetylene dicarboxylate.     

Synthesen,Eigenschaften und Kristallstrukturen der Cluster‐Salze Bi6[PtBi6Cl12] und Bi2/3[PtBi6Cl12]

Syntheses, Properties and Crystal Structures of the Cluster Salts Bi₆[PtBi₆Cl₁₂] and Bi_2/3[PtBi₆Cl₁₂] Melting reactions of Bi with Pt and BiCl₃ yield shiny black, air insensitive crystals of the subchlorides Bi₆[PtBi₆Cl₁₂] and Bi_2/3[PtBi₆Cl₁₂]. Despite the substantial difference in the bismuth content the two compounds have almost the same pseudo‐cubic unit cell and follow the structural principle of a CsCl type cluster salt. Bi₆[PtBi₆Cl₁₂] consists of cuboctahedral [PtBi₆Cl₁₂]^2? clusters and Bi₆²⁺ polycations (a = 9.052(2) Å, α = 89.88(2)°, space group P 1, multiple twins). In the electron precise cluster anion, the Pt atom (18 electron count) centers an octahedron of Bi atoms whose edges are bridged by chlorine atoms. The Bi₆²⁺ cation, a nido cluster with 16 skeletal electrons, has the shape of a distorted octahedron with an opened edge. In Bi_2/3[PtBi₆Cl₁₂] the anion charge is compensated by weakly coordinating Bi³⁺ cations which are distributed statistically over two crystallographic positions (a = 9.048(2) Å, α = 90.44(3)°, space group ). Bi₆[PtBi₆Cl₁₂] is a semiconductor with a band gap of about 0.1 eV. The compound is diamagnetic at room temperature though a small paramagnetic contribution appears towards lower temperature.