Molecular structure of methyl 1-isopropenyl-5a,5b,8,8,14a-pentamethyl-1,2,3,3a,4,5,5a,5b,6,7,7a,8,9,14,14a,14b,15,16,16a,16b-icosahydrocyclopenta[7,8] phenanthro[2,1-b]carbazole-3a-carboxylate

The molecular and crystal structure of methyl 1-isopropenyl-5a,5b,8,8,14a-pentamethyl-1,2,3,3a,4,5,5a,5b, 6,7,7a,8,9,14,14a,14b,15,16,16a,16b-icosahydrocyclopenta[7,8]phenenthro[2,1-b]carbazole-3a-carboxylate is determined. Compound C₃₇H₅₁NO₂ II crystallizes in the C2 chiral space group: a = 27.0380(5) ?, b = 7.9817(15) ?, c = 18.1980(3) ?, β = 123.580(3)°.     

Binuclear CpV,Cp*V,and Cp*Ta Complexes containing Organochalcogenolato Bridges, μ‐ER (E = Sulfur,Selenium, Tellurium; R = Methyl,Phenyl, and Ferrocenyl)

Photolysis of the halfsandwich tetracarbonylmetal complexes CpV(CO)₄, Cp*V(CO)₄ and Cp*Ta(CO)₄ in solution in the presence of di(organyl)dichalcogenides E₂R₂ (E = S, Se, Te; R = Me, Ph, Fc) leads to diamagnetic doubly organochalcogenolato‐bridged compounds, [Cp⁽⁾M(CO)₂(μ‐ER)]₂. According to the X‐ray structure determinations carried out for [CpV(CO)₂(μ‐TeMe)]₂, [Cp*V(CO)₂(μ‐TePh)]₂ and [Cp*Ta(CO)₂(μ‐SPh)]₂, the molecular framework consists of a folded M₂(μ‐ER)₂ ring with the cyclopentadienyl ligands in cis‐configuration and the organyl substituents R in a syn‐equatorial arrangement, thus forming a bowl‐shaped molecule with the four terminal CO ligands protruding into the inner sphere. The M…M distances (in the range between 305 and 330 pm) are not considered to indicate direct bonding interactions. The vanadium complexes [Cp⁽⁾V(CO)₂(μ‐ER)]₂ are completely decarbonylated in the presence of an excess of E₂R₂ in boiling toluene, and in many cases the paramagnetic quadruply‐bridged products, [CpV(μ‐ER)₂]₂, can be isolated.     

Einkristallstrukturuntersuchungen an hexagonalen Fluorperowskiten AMIIF3 (MII = Mg,Mn, Fe,Co, Ni)

Single Crystal Structural Studies at Hexagonal Fluoride Perovskites AM^IIF₃ (M^II = Mg, Mn, Fe, Co, Ni) At single crystals of nine fluoride phases AMF₃ the hexagonal perovskite structures were refined by X‐ray methods, of RbNiF₃ below T_C £ 145 K, too. The hexagonal 6 L type (P6₃/mmc, Z = 6) is found at: RbMgF₃ (a = 585.7(1); c = 1426.0(1) pm), CsMnF₃ (624.4(1); 1515.4(4) pm), CsFeF₃ (616.8(1); 1488.4(6) pm), Rb_0.63Cs_0.37CoF₃ (599.1(1); 1460.3(4) pm), RbNiF₃ (128 K: 582.6(1); 1426.4(6) pm), Cs₂BaLiNi₂F₉ (593.1(1); 1447.1(4) pm). Of the hexagonal‐rhombohedral 9 L type (R 3 m, Z = 9) are CsCoF₃ (620.1(1); 2264.0(7) pm) and yellow CsNiF₃ (614.7(1); 2235.3(6) pm), prepared at lower temperatures resp. under high pressure, whereas light green CsNiF₃ (625.5(1); 524.2(1) pm) belongs to the 2 L type (P6₃/mmc, Z = 2). The occurence of these structures and the interatomic distances observed, comparing also normal and high pressure phases, are discussed in connection with the tolerance factor.     

Synthese,Struktur und Eigenschaften von [nacnac]MX3‐Verbindungen (M = Ge,Sn; X = Cl,Br, I)

Synthesis, Structure, and Properties of [nacnac]MX₃ Compounds (M = Ge, Sn; X = Cl, Br, I) Reactions of [nacnac]Li [(2,6‐ⁱPr₂C₆H₃)NC(Me)C(H)C(Me)N(2,6‐ⁱPr₂C₆H₃)]Li ( 1 ) with SnX₄ (X = Cl, Br, I) and GeCl₄ in Et₂O resulted in metallacyclic compounds with different structural moieties. In the [nacnac]SnX₃ compounds (X = Cl 2 , Br 3 , I 4 ) the tin atom is five coordinated and part of a six‐membered ring. The Sn–N‐bond length of 3 is 2.163(4) Å and 2.176(5) Å of 4 . The five coordinated germanium of the [nacnac]GeCl₃ compound 5 shows in addition to the three chlorine atoms further bonds to a carbon and to a nitrogen atom. In contrast to the known compounds with the [nacnac] ligand the afore mentioned reaction creates a carbon–metal‐bond (1.971(3) Å) forming a four‐membered ring. The Ge–N bond length (2.419(2) Å) indicates the formation of a weakly coordinating bond.     

Synthesis,characterization, and reactivity of a novel ruthenium carbonyl cluster containing tri-O-benzyl-d-glucal as a chiral carbohydrate ligand

A chiral carbohydrate ligand 3,4,6-tri-O-benzyl-d-glucal (L) reacts with the cluster triruthenium dodecacarbonyl Ru₃(CO)₁₂ giving a novel chiral cluster Ru₃(μ-H)₂(CO)₉(L-2H) (I) that shows fluxional behavior at room temperature. The reaction of Ru₃(μ-H)₂(CO)₉(L-2H) (I) with triphenylphosphine and diphenylphosphinoethane (dppe) gives two new clusters Ru₃(μ-H)₂(CO)₇(L-2H)(PPh₃)₂ (II) and Ru₃(μ-H)₂(CO)₇(L-2H)(dppe) (III). The new compounds I, II and III have been characterized by a combination of elemental analysis, mass spectrometry, infrared and variable temperature NMR spectroscopy.     

Synthesis,characterization, luminescence,antibacterial, and catalytic activities of a palladium(II) complex involving a Schiff base

A new Pd(II) complex of fluorine-containing Schiff base ligand, [Pd₂(L)₂Cl₂] (1) [L?=?N-(4-fluorobenzylidene)-2,6-diethylbenzenamine], has been synthesized using solvothermal method and characterized by elemental analysis, IR-spectroscopy, thermogravimetric analysis, powder X-ray diffraction, UV–vis absorption spectra, and single-crystal X-ray diffraction. Complex 1 is a μ-chloro-bridged dinuclear cyclometallated Pd(II) complex. Thermal analysis indicates that 1 is quite stable to heat. 1 exhibits quadruple emissions in the solid state (λ _max?=?766?nm) and possesses fluorescence lifetimes (τ ₁?=?87.20?ns, τ ₂?=?190.45?ns, and τ ₃?=?1805.10?ns at 616?nm); broad structureless bands at 690–800?nm are tentatively assigned to an excimeric ³IL transition. The Schiff base (L) and its palladium(II) compound (1) have been screened for their antibacterial activity against several bacteria, and the results are compared with the activity of penicillin. Moreover, 1 has been shown to be highly effective in the Heck reaction of 4-bromotoluene with acrylic acid.     

Relative rate constants for reactions of HFC 152a, 143, 143a, 134a,and HCFC 124 with F or Cl atoms and for CF2CH3, CF2HCH2, and CF3CFH radicals with F2, Cl2, and O2

Relative rate experiments using UV photolysis of F₂ or Cl₂ have been used to determine rate constant ratios for several hydrofluorocarbon (HFC) reactions with Cl or F atoms and for HFC alkyl radicals with molecular halogens. For mixtures with F₂ present, dark reactions are, also, observed which are attributed to thermal dissociation of the F₂ to form F atoms. At 296 K, the rate of reaction (1a) [CF₂HCH₃ + F → CF₂CH₃ + HF] relative to (1b) [CF₂HCH₃ + F → CF₂HCH₂ + HF] is k_1a/k_1b = 0.73 (±0.13) and is independent of T (= 262–348 K). At 296 K, the ratio of reaction (2a) [CF₂HCH₂F + F → products] to that of (k_1a + k_1b) is (k_1a + k_1b)/k_2a = 2.7 (±0.4), and for reaction (2b) [CF₃CH₃ + F → products] (k_1a + k_1b)/k_2b = 22 ± 12. The temperature dependence (263–365 K) of the rate constant of reaction (3) [CF₃CFH₂ + Cl → products] relative to reaction (4) [CF₃CFClH + Cl → products] is k₃/k₄(±10%) = 1.55 exp(?300 K/T). For the alkyl radicals formed from HFC 152a (CF₂HCH₂ and CF₂CH₃) and from HFC 134a (CF₃CFH), rate constants for the reactions with F₂ and Cl₂ were measured relative to their reactions with O₂. The rate constant of reaction (5cl) [CF₂CH₃ + Cl₂ → CF₂ClCH₃ + Cl] relative to (5o) [CF₂CH₃ + O₂ → CF₂(O₂)CH₃] is k_5cl/k_5o(±15%) = 0.3 exp(200 K/T). For reaction (5f) [CF₂CH₃ + F₂ → CF₃CH₃ + F], k_5f/k_5o(±35%) = 0.23. The ratio for reaction (6f) [CF₂HCH₂ + F₂ → CF₂HCH₂F + F] relative to (6o) [CF₂HCH₂ + O₂ → CF₂HCH₂O₂] is k_6f/k_6o(±40%) = 1.23 exp(?730 K/T). The rate constant ratio for reaction (8cl) [CF₃CFH + Cl₂ → CF₃CFClH + Cl] relative to reaction (8o) [CF₃CFH + O₂ → CF₃CFHO₂] is k_8cl/k_8o(±18%) = 0.16 exp(?940 K/T). For reaction (8f) [CF₃CFH + F₂ → CF₃CF₂H + F], k_8f/k_8o(±35%) = 0.6 exp(?860 K/T). © 1993 John Wiley & Sons, Inc.     

M(SCN)2 (M = Eu,Sr, Ba): Kristallstruktur,thermisches Verhalten,Schwingungsspektroskopie

M(SCN)₂ (M = Eu, Sr, Ba): Crystal Structure, Thermal Behaviour, Vibrational Spectroscopy Single crystals of M(SCN)₂ (M = Eu, Sr, Ba) have been obtained via metathesis of NaSCN and MCl₂ (M = Eu, Sr, Ba) at 340 °C. The isotypic crystal structures of the thiocyanates M(SCN)₂ (C2/c, Z = 4, Eu: a = 979.3(2), b = 660.8(1), c = 815.7(2) pm, β = 91.58(3)°, R_all = 0.0245, Sr: a = 985.5(2), b = 662.9(2), c = 819.6(2) pm, β = 91.29(3)°, R_all = 0.0435, Ba: a = 1018.8(2), b = 687.2(1), c = 852.2(1) pm, β = 92.43(2)°, R_all = 0.0392) contain alternating layers of M²⁺ and SCN^–. According to M(SCN)_4/4(NCS)_4/4 M²⁺ is eight‐coordinated by four sulfur and four nitrogen atoms forming a square antiprism. Thermal investigations show that the compounds melt without decomposition. Vibrational spectroscopic investigations are presented and discussed.     

Synthesis,Structure, Chemical Bonding,and Properties of CaTIn2 (T = Pd,Pt, Au)

The new compounds CaPdIn₂, CaPtIn₂, and CaAuIn₂ were prepared from the elements by reaction in glassy carbon crucibles under flowing argon. They crystallize with the MgCuAl₂ structure type (space group Cmcm), a ternary ordered version of the Re₃B type. The three crystal structures were refined from single‐crystal four‐circle diffractometer data: a = 444.35(7), b = 1038.0(1), c = 781.32(9), wR2 = 0.1352, 455 F² values for CaPdIn₂, a = 439.65(7), b = 1043.8(1), c = 781.22(8) pm, wR2 = 0.0368, 462 F² values for CaPtIn₂, and a = 456.35(5), b = 1074.8(1), c = 759.69(8) pm, wR2 = 0.0640, 763 F² values for CaAuIn₂, with Z = 4 and 16 parameters for each refinement. Structural elements of these compounds are transition metal (T) centered trigonal prisms formed by the calcium and indium atoms. The transition metal and indium atoms form three‐dimensionally infinite [TIn₂] polyanions in which the calcium atoms occupy pentagonal channels. First principles calculations of the electronic structures of these materials strongly suggest the idea of an In–In bonded three‐dimensional network. Theoretical charge density as well as COHP analyses reveal that the calcium atom in CaAuIn₂ (isotypic with NaAuIn₂) has not completely lost its two valence electrons. Magnetic susceptibility measurements of compact polycrystalline samples of CaPdIn₂, CaPtIn₂, and CaAuIn₂ indicate weak Pauli paramagnetism. The compounds are metallic conductors with room temperature values for the specific resistivities of 35 ± 10, 20 ± 10, and 25 ± 10 μ Ωcm for CaPdIn₂, CaPtIn₂, and CaAuIn₂, respectively.     

Synthesis,Structure, and Fluorescence of a Novel Samarium Compound

A novel samarium compound, [Sm(Phen)₂(H₂O)₅]₂(Phen)₂(Bipy)Cl₆ · 7H₂O (I) (Phen = 1,10-phenanthroline and Bipy = 2,2'-bipyridine), was prepared by a solvothermal reaction. The crystal structure of I was characterized by X-ray single-crystal diffraction method (CIF file CCDC no. 1025736). Compound I is an isolated structure with the samarium ions possessing a nine-coordinated distorted monocapped square antiprism geometry. There are abundant hydrogen bonding and π–π stacking interactions which connect the molecules together to yield a three-dimensional (3D) supramolecular structure. The fluorescence spectra data reveals that I can display the characteristic emission ⁴G_5/2 → ⁶H _J transitions (J = 5/2, 7/2, 9/2 and 11/2, respectively) of Sm³⁺ ions.     

Kristallstrukturbestimmungen an Cs2NaCr(CN)6 und weiteren Verbindungen A2BM(CN)6 (A = Rb,Cs; B = Na,K, Rb,NH4; M = Cr,Mn, Fe,Co): Oktaederkippung und Toleranzfaktor von Cyanokryolithen

Crystal Structure Determinations of Cs₂NaCr(CN)₆ and further Compounds A₂BM(CN)₆ (A = Rb, Cs; B = Na, K, Rb, NH₄; M = Cr, Mn, Fe, Co): Tilting of Octahedra and Tolerance Factor of Cyano Cryolites The crystal structures of Cs₂NaCr(CN)₆ (space group P2₁/n, Z = 2; a = 763.2(1), b = 789.8(1), c = 1102.4(1) pm, β = 90.09(1)°) and of 9 isostructural cyano cryolites A₂BM(CN)₆ of the elements M = Cr, Mn, Fe, Co were determined by X‐rays at single crystals. The results, including data from the literature, were studied with respect to the interdependence of radii resp. bond lengths and cyano bridge angles M–CN–B resp. tilting of [M(CN)₆] and [BN₆] octahedra: The average tilt angles κ of the latter are within the range 13° ≤ κ ≤ 23° and increase linearly if the modified tolerance factor t (of range 0,87 ≥ t ≥ 0,78) decreases.     

Darstellung,Kristallstruktur und Eigenschaften von Ln3AuO6 (Ln = Sm,Eu, Gd)

Syntheses, Crystal Structures, and Properties of Ln₃AuO₆ (Ln = Sm, Eu, Gd) The title compounds have been prepared from amorphous Au₂O₃ · x H₂O (x = 1–3) and Ln₂O₃ (Ln = Nd, Sm, Eu) via solid state reaction under elevated oxygen pressure adding KOH as mineralizing agent. They crystallize in a new structure type (triclinic, P1, Z = 1, Sm₃AuO₆: a = 3.7272(2) Å, b = 5.6311(2) Å, c = 7.0734(3) Å, α = 90.32(2)°, β = 103.983(3)°, γ = 90.822(2)°, 125 powder intensities, R_p = 2.57%, Eu₃AuO₆: a = 3.7012(2) Å, b = 5.6134(2) Å, c = 7.0652(4) Å, α = 90.838(3)°, β = 102.956(3)°, γ = 90.909(2)°, 122 powder intensities, R_p = 3.16%, Gd₃AuO₆: a = 3.6720(2) Å, b = 5.5977(2) Å, c = 7.0636(2) Å, α = 90.509(2)°, β = 102.889(3)°, γ = 91.068(2)°, 3424 reflections, R₁ = 12.90%). The crystal structure was solved and refined from single crystal data of Gd₃AuO₆. The structures of Sm₃AuO₆ and Eu₃AuO₆ were refined from powder diffraction data. The isolated square planar AuO₄ units are stacked along the a‐axis and are linked by LnO₆‐ and LnO₆₊₁‐polyhedra. One of the oxygen atoms is exclusively coordinated by trivalent lanthanides, in tetrahedral geometry. The lanthanoid aurates decompose between 700 and 900 °C into Ln₂O₃, Au and O₂. The magnetic moments μ_eff(Gd₃AuO₆) = 7.9 μ_B and, at 20 °C respectively, μ_eff(Sm₃AuO₆) = 1.55 μ_B as well as μ_eff(Eu₃AuO₆) = 3.5 μ_B confirm that the lanthanides are trivalent. The UV/VIS absorption spectra can be interpreted at assuming free ions.     

Synthesis, structure, and reactivity of a pyridine-stabilized germanone

The first isolable pyridine‐stabilized germanone has been prepared and its reactivity toward trimethylaluminum has been investigated. The germanone adduct results from a stepwise conversion that starts from 4‐dimethylaminopyridine (DMAP) and the ylide‐like N‐heterocyclic germylene LGe: (L=CH{(C?CH₂)(CMe)[N(aryl)]₂}, aryl=2,6‐iPr₂C₆H₃) ( 1 ) at room temperature, and gives the corresponding germylene–pyridine adduct L(DMAP)Ge: ( 2 ) in 91 % yield. The latter reacts with N₂O at room temperature to form the desired germanone complex L(DMAP)Ge?O ( 3 ) in 73 % yield. The Ge? O distance of 1.646(2) Å in 3 is the shortest hitherto reported for a Ge?O species. The reaction of 3 with trimethylaluminum leads solely to the addition product LGe(Me)O[Al(DMAP)Me₂] ( 4 ). The latter results from insertion of the Ge?O subunit into an Al? Me bond of AlMe₃ and concomitant migration of the DMAP ligand from germanium to the aluminum atom. Compounds 2 – 4 have been fully characterized by analytical and spectroscopic methods. Their molecular structures have been established by single‐crystal X‐ray crystallographic analysis.     

Synthesis,X-ray structure,DFT studies,and catalytic activity of a vanadium(V) complex containing a tridentate Schiff base

Reactions of a solution of NH₄VO₃ in H₂O₂ and water and salicylidene benzoyl hydrazine as a tridentate Schiff base (ONO) afford a six-coordinate V(V) complex [VO(ONO)(OCH₃)(CH₃OH)] with a distorted octahedral configuration. The complexes [VO(ONO)(OCH₃)(CH₃OH)] were isolated as air-stable crystalline solids and fully characterized, including by single-crystal X-ray structure analysis. DFT calculations have been performed to understand the electronic structure of the complex. Vibrational frequencies and maximum absorption wavelengths of the complex theoretically calculated are in good agreement with experimental values. [VO(ONO)(OCH₃)(CH₃OH)] shows efficient oxidation of sulfides to their corresponding sulfoxides using urea hydrogen peroxide as the oxidant at room temperature under air.     

Syntheses and Crystal Structures of Ln(phen)2(NO3)3 with Ln = Pr,Nd, Sm,Eu, Dy,and phen = 1,10‐phenanthroline

Five new complex compounds of the formula Ln(phen)₂(NO₃)₃ were prepared. The X‐ray structural analyses indicate that they crystallize isostructurally in the monoclinic space group C2/c (no. 15) with cell dimensions for example for Pr(phen)₂(NO₃)₃: a = 11.194(1) Å, b = 18.095(2) Å, c = 13.101(2) Å, β = 100.52(1)°, V = 2609.1(6) ų, Z = 4. The crystal structures consist of [Ln(phen)₂(NO₃)₃] complex molecules. The rare earth atoms are coordinated by four N atoms of two phen ligands and six O atoms of three nitrato groups to complete a distorted bicapped dodecahedron. The [Ln(phen)₂(NO₃)₃] complex molecules are assembled via π‐π stacking interactions between the neighboring phen ligands to form 1D columnar chains, which are then arranged in the crystal structures according to pseudo 1D close‐packed patterns.     

Synthesis,structure, and photochemistry of a rhenium(I) enolate complex

The rhenium(I) enolate complex fac-(CO)₃(P(CH₃)₃)₂Re(OC(CH₃)C₅H₄) (4 was prepared from the reaction of (η⁵-C₅H₄C(O)CH₃)Re(CO)₃ (3) with P(CH₃)₃. Compound 4 was characterized structurally in the solid state by X-ray crystallography and in solution by IR and ¹H, ¹³C, and ³¹P NMR spectroscopy. Photolysis of 4 at 337 nm in CH₂Cl₂ solution cleaves the ReO bond: smooth conversionto fac-(CO)₃(P(CH₃)₃)₂ReCl (5) is observed with a quantum yield of 0.04.     

An efficient catalytic method for the synthesis of 2,7-dialkyl-2,3a,5a,7,8a,10a-hexaazaperhydropyrenes

An efficient method for the synthesis of 2,7-dialkyl-2,3a,5a,7,8a,10a-hexaazaperhydropyrenes in high yields (up to 95%) via the intermolecular cyclization of 1,4,5,8-tetraazadecalin with N,N-bis(methoxymethyl)-N-alkylamines in the presence of SmCl₃·6H₂O as the catalyst has been developed.     

Synthesis,Crystal Structure,and Luminescence of a Three-Dimensional Supramolecular Compound Based on a Dinuclear Tin Cluster

A three-dimensional (3D) supramolecular compound, [(phen)LSnS]₂·(H₂O)₂ (phen = 1,10-phenanthroline, L = mercaptoacetic acid), has been synthesized and the crystal structure was determined by a single crystal X-ray diffraction study. 1 is triclinic, space group P-1 with a = 6.695(1) Å, b = 10.929(2) Å, c = 12.117(2) Å, α = 114.55(3)°, β = 93.53(2)°, γ = 104.06(3)°, and Z = 1. The dinuclear cluster of [(phen)LSnS]₂ and H₂O are linked into a 3D supramolecular framework by a combination of O[sbnd]H…O, C[sbnd]H…O hydrogen bonds and π–π stacking interactions. Its luminescence property is discussed.     

Synthesis,structure, and properties of a pentanuclear cobalt(III) coordination cluster

The synthesis, X-ray structure and properties of a pentanuclear cobalt(III) coordination cluster [{L(O₂CCH₃)Co₂O(OCH₃)₂}₂Co](ClO₄)₃ (1) (L^? = 2,6-bis((3-aminopropylimino)methyl)-4-methylphenolate) are described. The dinucleating L^? is coordinated with two cobalt(III) centers to form the {L(O₂CCH₃)Co₂O(OCH₃)₂} unit, where each metal center is in a distorted octahedral N₂O₄ environment. The oxo and the methoxo ligands of these two dinuclear units assemble a distorted octahedral O₆ coordination sphere around the central cobalt(III). Elemental analysis and spectroscopic (IR, NMR, UV–vis, and HRMS) features are consistent with the pentanuclear structure of the complex. The diamagnetic complex is a 1?:?3 electrolyte in solution. It is redox-active and displays a metal-centered reduction at E_1/2 = ?0.04 V (vs. Ag/AgCl).