bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cycloadditions of Diarylgermylenes to a Diazabutadiene [1]
Authors: Arndt Annika , Schäfer Helmut , Saak Wolfgang , Weidenbruch Manfred 
Published: May 2005

AbstractThe reaction of tetrakis(2‐tert‐butyl‐4,5,6‐trimethylphenyl)digermene, which dissociates into the germylene molecules 2 in solution, with 1,4‐diisopropyl‐1,4‐diazabuta‐1,3‐diene (3) furnishes the [4+1] cycloaddition product of 2 to the nitrogen atoms of 3. Under drastic conditions tetrakis(2,4,6‐triisopropylphenyl)digermene also forms the germylene molecules 6 which react with 3 in a similar fashion to afford the corresponding [4+1] cycloadduct.
Thiosilicate der Selten‐Erd‐Elemente: III. KLa[SiS4] und RbLa[SiS4] – Ein struktureller Vergleich
Authors: Hartenbach Ingo , Schleid Thomas 
Published: May 2005

AbstractThiosilicates of the Rare‐Earth Elements: III. KLa[SiS4] and RbLa[SiS4] – A Structural ComparisonPale yellow, platelet shaped, air‐ and water resistant single crystals of KLa[SiS4] derived from the reaction of lanthanum (La) and sulfur (S) with silicon disulfide (SiS2) in a molar ratio of 2 : 3 : 1 with an excess of potassium chloride (KCl) as flux and source of potassium ions in evacuated silica ampoules at 850 °C within seven days. The analogous reaction utilizing a melt of rubidium chloride (RbCl) instead also leads to yellow comparable single crystals of RbLa[SiS4]. The potassium lanthanum thiosilicate crystallizes monoclinically with the space group P21/m (a = 653.34(6), b = 657.23(6), c = 867.02(8) pm, β = 107.496(9)°) and two formula units per unit cell, while the rubidium lanthanum thiosilicate has to be assigned orthorhombically with the space group Pnma (a = 1728.4(2), b = 667.23(6), c = 652.89(6) pm) and four formula units in its unit cell. In both compounds the La3+ cations are surrounded by 8+1 sulfide anions in the shape of tricapped trigonal prisms. The Rb+ cations in RbLa[SiS4] show a coordination number of 9+2 relative to the S2− anions, which form pentacapped trigonal prisms about Rb+. This coordination number, however, is apparently too high for the K+ cations in KLa[SiS4], so that they only exhibit a bicapped trigonal prismatic environment built up by eight S2− anions. The isolated thiosilicate tetrahedra [SiS4]4− of the rubidium compound are surrounded by La3+ both edge‐ and face‐capping, but terminal as well as edge‐ and face‐spanning by Rb+. In the potassium compound there is no change for the La3+ environment about the [SiS4]4− tetrahedra, but the K+ cations are only able to attach terminal and via edges. The whole structure is built up by anionic {La[SiS4]}− layers that are separated by the alkali metal cations. In direct comparison the two thiosilicate structures can be regarded as stacking variants.
Syntheses and Structures of RE4Pt10In21 (RE = La–Nd)
Authors: Zaremba Vasyl I. , Hlukhyy Viktor , Rodewald Ute Ch. , Pöttgen Rainer 
Published: May 2005

AbstractThe isotypic indides RE4Pt10In21 (RE = La, Ce, Pr, Nd) were prepared by melting mixtures of the elements in an arc‐furnace under an argon atmosphere. Single crystals were synthesized in tantalum ampoules using special temperature modes. The four samples were studied by powder and single crystal X‐ray diffraction: Ho4Ni10Ga21 type, C2/m, a = 2305.8(2), b = 451.27(4), c = 1944.9(2) pm, β = 133.18(7)°, wR2 = 0.045, 2817 F2 values, 107 variables for La4Pt10In21, a = 2301.0(2), b = 448.76(4), c = 1941.6(2) pm, β = 133.050(8)°, wR2 = 0.056, 3099 F2 values, 107 variables for Ce4Pt10In21, a = 2297.4(2), b = 447.4(4), c = 1939.7(2) pm, β = 132.95(1)°, wR2 = 0.059, 3107 F2 values, 107 variables for Pr4Pt10In21, and a = 2294.7(4), b = 446.1(1), c = 1938.7(3) pm, β = 132.883(9)°, wR2 = 0.067, 2775 F2 values, 107 variables for Nd4Pt10In21. The 8j In2 positions of all structures have been refined with a split model. The In1 sites of the lanthanum and the cerium compound show small defects, leading to the refined composition La4Pt10In20.966(6) and Ce4Pt10In20.909(6) for the investigated crystals. The same position shows Pt/In mixing in the praseodymium and neodymium compound leading to the refined compositions Pr4Pt10.084(9)In20.916(9) and Nd4Pt10.050(9)In20.950(9). All platinum atoms have a tricapped trigonal prismatic coordination by rare‐earth metal and indium atoms. The shortest interatomic distances occur for Pt–In followed by In–In. Together, the platinum and indium atoms build up three‐dimensional [Pt10In21] networks in which the rare earth atoms fill distorted pentagonal tubes. The crystal chemistry of RE4Pt10In21 is discussed and compared with the RE4Pd10In21 indides and isotypic gallides.
1,4‐Di(isopropyl)‐1,4‐diazabutadien als Abfangreagenz für monomere Bruchstücke des Tetragalliumclusters Ga4[C(SiMe3)3]4 – Bildung eines ungesättigten GaN2C2‐Heterocyclus und eines Oxidationsprodukts mit Ga‐O‐O‐Ga‐Gruppe
Authors: Uhl Werner , Melle Sandra , Prött Malte 
Published: May 2005

Abstract1,4‐Di(isopropyl)‐1,4‐diazabutadiene as a Reagent for the Trapping of Monomeric Fragments of the Tetragalliumcluster Ga4[C(SiMe3)3]4 – Formation of an Unsaturated GaN2C2 Heterocycle and an Oxidation Product Containing a Ga‐O‐O‐Ga GroupThe tetrahedral tetragallium cluster Ga4[C(SiMe3)3]4 (1) dissociates upon dissolution to yield the monomeric fragments Ga‐R [R = C(SiMe3)3]. These monomers could be trapped now by the treatment of their solutions with 1,4‐di(isopropyl)‐1,4‐diazabutadiene. The product of the cycloaddition reaction (2) possesses a five‐membered GaN2C2 heterocycle with a coordinatively unsaturated gallium atom and an endocyclic C=C double bond. 2 is rather sensitive towards oxidation by traces of air. The contact with oxygen yielded a digallium peroxide [(C2N2iPr2)RGa‐O‐O‐GaR(C2N2iPr2)] (3) which was isolated in a very low yield only and which has a gallium atom attached to each oxygen atom of the inner peroxo group. Both chelating ligands of 3 possess an unpaired electron.
N‐Heterocyclic Phosphenium, Arsenium, and Stibenium Ions as Ligands in Transition Metal Complexes: A Comparative Experimental and Computational Study
Authors: Burck Sebastian , Daniels Jörg , Gans‐Eichler Timo , Gudat Dietrich , Nättinen Kalle , Nieger Martin 
Published: May 2005

AbstractReaction of 2‐chloro‐1,3,2‐diazaarsolenes and ‐diazaphospholenes with Tl[Co(CO)4] gives instable complexes of type [Co(ER2)(CO)4] which decarbonylated to yield [Co(ER2)(CO)3]. Spectroscopic and X‐ray diffraction studies revealed that the tetracarbonyl complexes can be formulated as ion pair for E = P and as covalent metalla‐arsine for E = As, and the tricarbonyl complexes as carbene‐like species with a formal E=Co double bond. A similar reactivity towards Tl[Co(CO)4] was also inferred for 1,3,2‐diazastibolenes although the products were not isolable and their constitution remained uncertain. Evaluation of structural and computational data suggests that the weak and polarized Co–As bond in [Co(AsR2)(CO)4] can be characterized as an “inverse” M→L donor‐acceptor bond. The computational studies disclosed further η2(EN)‐coordination of the EN2C2 heterocycle as an alternative to the formation of a carbene‐like structure for [Co(ER2)(CO)3]. The η2‐complex is less stable for E = P but close in energy for E = As and more stable than the carbene‐like complex for E = Sb.
Synthesis of Nanocrystalline Zr3N4 and Hf3N4 Powders from Metal Dialkylamides
Authors: Li Jinwang , Dzivenko Dmytro , Zerr Andreas , Fasel Claudia , Zhou Yanping , Riedel Ralf 
Published: May 2005

AbstractA simple process to synthesize Zr3N4 and nitrogen‐rich Hf3N4 powders via ammonolysis of metal dialkylamides, i.e. Zr(NEt2)4 and Hf(NEt2)4, at temperatures below 700 °C is presented. The obtained nitrides have a rhombohedrally distorted NaCl‐type structure, which has previously been reported only for nitrogen‐rich films of these nitrides. Regardless of the atmosphere (N2 and He), the Zr3N4 starts to decompose above about ∼ 650 °C and achieves the highest decomposition rate at about 900 °C, finally yielding the mononitride ZrN. Both Zr3N4 and Hf3N4 powders are nanocrystalline with the crystal size of about 2 nm.
Organometallic Diaza‐dimetalla‐Norbornanes and ‐Cyclohexanes of Aluminium, Gallium and Indium
Authors: Tian Xin , Fröhlich Roland , Mitzel Norbert W. 
Published: May 2005

AbstractSelective formation of 1,3,3,4,6,6‐hexamethyl‐1,4‐diaza‐3,6‐diinda‐norborane was achieved by the reaction of bis(lithiomethyl‐methylamino)methane with dimethylindium chloride by simultaneous formation of two dative metal‐carbon and two metal‐nitrogen bonds accompanied by two ring closures. The synthesis of heterometallic compounds of this type, namely 1,3,3,4,6,6‐hexamethyl‐3‐alumina‐1,4‐diaza‐6‐galla‐norborane [Me2AlCH2N(Me)]CH2[N(Me)CH2GaMe2], was also attempted by the reaction of bis(lithiomethyl‐methylamino)methane with dimethylaluminium and ‐gallium chloride. This compound is formed, but cannot be separated from the simultaneously formed homometallic compounds [Me2MCH2N(Me)]2CH2(M = Al, Ga). The compounds were identified by elemental analyses, mass spectra, NMR spectroscopy (1H, 13C), and by determination of their crystal structures in which they are present as monomers. The norbornane‐like structure is favoured over potential isomers containing three‐membered rings and over polymeric aggregation in both compounds. In addition, the crystal structure of dimethyl(dimethylaminomethyl)indium was determined by single crystal X‐ray diffraction, which shows an intermolecular aggregation into a six‐membered ring dimer.
Anionic Diversity in Iodobismuthate Chemistry
Authors: Lindsjö Martin , Fischer Andreas , Kloo Lars 
Published: May 2005

AbstractThree salts containing different iodobismuthate anions have been synthesized. [(CH3)2NH2]3[BiI6] was prepared by oxidation of bismuth by iodine in N,N‐dimethylformamide. [(CH3)2NH2]3[BiI6] crystallizes in the space group ${\rm R}{\bar 3}$ with a = 30.760(3) Å and c = 8.8039(5) Å and contains monomeric [BiI6]3− anions. The hydrate Na4[Bi2I10] · 14H2O was prepared by the oxidation of bismuth using iodine in acetonitrile in the presence of NaI. Na4[Bi2I10] · 14H2O crystallizes in the space group C2/m with a = 12.875(2) Å, b = 16.177(2) Å, c = 9.904(2) Å and β = 106.57(6)°. The structure contains dimeric [Bi2I10]4− anions and rows of sodium ions, with bridging water molecules. The hydrate [Na{(CH3)2NCHO}2(H2O)]3[Bi2I9] was prepared by dissolution of Na4[Bi2I10] · 14H2O in N,N‐dimethylformamide and crystallizes in the space group ${\rm P}{\bar 1}$ with a = 13.2309(13) Å, b = 13.3791(14) Å, c = 18.722(2) Å, α = 70.338(9)°, β = 72.651(9)° and γ = 62.183(5). The structure contains dimeric [Bi2I9]3− anions and cationic polymers, [Na{(CH3)2NCHO}2(H2O)]+.
Halbantiperowskite: Zur Struktur der Shandite M3/2AS (M = Co, Ni; A = In, Sn) und ihren Typ‐Antitypbeziehungen
Authors: Weihrich Richard , Anusca Irina , Zabel Manfred 
Published: May 2005

AbstractHalf‐Antiperovskites: Structure and Type‐Antitype Relations of Shandites M3/2AS (M = Co, Ni; A = In, Sn)The crystallographic and electronic structures of the ternary shandite type sulfides M3A2S2 (M = Co, Ni; A = In, Sn) were investigated by X‐ray diffraction, as well as density functional theory (DFT) band structure calculations with respect to superstructure and type‐antitype relations. The crystal structure of Ni3In2S2 (space group $R{\bar 3}{\rm m}$, a = 5.371Å, c = 13.563Å) was determined from a single crystal. The shandites show type‐antitype relations to oxostannates(II) M2Sn2O3 (M = K, Rb) analogously to perovskite and antiperovskite. With a perovskite superstructure a group‐subgroup relation is given to antiperowskites like Ni3MgC. Because of the ordered occupation of half of the M‐positions the title compounds are described as half‐antiperowskites M3/2AS. The occupation scheme causes the formation of Kagomé‐nets. From bond distances covalent Ni–S bonds (< 2.20Å), ionic Sn–S and In–S‐interactions, as well as metallic In–Ni and Sn–Ni are concluded. The electronic band structures of the shandites show metallic characteristics similar to Ni3MgC. A band filling scheme explains the stability and properties from Co3In2S2 to Ni3Sn2S2. The highest partly occupied bands are formed by a strong mixing of Co(Ni)‐3d, In(Sn)‐5p and S‐3p states. A bonding description [M3S2]n−[A2]n+ accounts for the structural and electronic properties. Band gaps for Ni3In2S2 and Co3Sn2S2 indicate metal– insulator and magnetic phase transitions.
Crystal Structure of the Mixed‐Valent Basic Mercury Nitrate HgI2(NO3)2·HgII(OH)(NO3)·HgII(NO3)2·4HgIIO [= Hg8O4(OH)(NO3)5]
Authors: Weil Matthias 
Published: May 2005

AbstractLight‐yellow single crystals of the mixed‐valent mercury‐rich basic nitrate Hg8O4(OH)(NO3)5 were obtained as a by‐product at 85 °C from a melt consisting of stoichiometric amounts of (HgI2)(NO3)2·2H2O and HgII(OH)(NO3). The title compound, represented by the more detailed formula HgI2(NO3)2·HgII(OH)(NO3)·HgII(NO3)2·4HgIIO, exhibits a new structure type (monoclinic, C2/c, Z = 4, a = 6.7708(7), b = 11.6692(11), c = 24.492(2) Å, β = 96.851(2)°, 2920 structure factors, 178 parameters, R1[F2 > 2σ(F2)] = 0.0316) and is made up of almost linear [O‐HgII‐O] and [O‐HgI‐HgI‐O] building blocks with typical HgII‐O distances around 2.06Å and a HgI‐O distance of 2.13Å. The Hg22+ dumbbell exhibits a characteristic Hg‐Hg distance of 2.5079(7) Å. The different types of mercury‐oxygen units form a complex three‐dimensional network exhibiting large cavities which are occupied by the nitrate groups. The NO3− anions show only weak interactions between the nitrate oxygen atoms and the mercury atoms which are at distances > 2.6Å from one another. One of the three crystallographically independent nitrate groups is disordered.
Transition Metal Promoted Addition of Methanol to Cyanoguanidine. Molecular Structure and Properties of the Generated Copper(II) and Nickel(II) Complexes
Authors: Williams Patricia A. M. , Ferrer Evelina G. , Baeza Natalia , Piro Oscar E. , Castellano Eduardo E. , Baran Enrique J. 
Published: May 2005

AbstractThe reaction of the CuII and NiII complexes of saccharin with dicyandiamide (cyanoguanidine, cnge) in methanol produces the addition of methanol to the nitrile moiety of this molecule. Furthermore, the product of the reaction coordinates the metal centers generating two new complexes containing saccharinate as the counter anion. The crystal structures of [Cu(cnge‐OCH3)2](sac)2 and of [Ni(cnge‐OCH3)2](sac)2·2H2O (cnge‐OCH3 = 1‐amidino‐O‐methylurea) were solved by single crystal X‐ray diffractometry. Both complexes crystallize in the triclinic space group ${\rm P}{\bar 1}$ and the metallic cations present a quite similar centrosymmetric planar conformation. The complexes were characterized by means of electronic and infrared spectroscopy and also their magnetic and thermal behavior was investigated.
Zur Elektronenstruktur hochsymmetrischer Verbindungen der f‐Elemente. 38 [1] Kristall‐, Molekül‐ und Elektronenstruktur von Tris(hydrotris(1‐pyrazolyl)borato)‐samarium(III)
Authors: Reddmann Hauke , Apostolidis Christos , Walter Olaf , Rebizant Jean , Amberger Hanns‐Dieter 
Published: May 2005

AbstractElectronic Structures of Highly Symmetrical Compounds of f Elements. 38 [1] Crystal, Molecular and Electronic Structure of Tris(hydrotris(1‐pyrazolyl)borato)samarium(III)Tris(hydrotris(1‐pyrazolyl)borato)samarium(III) (SmTp3) crystallizes in the space group P63/m (No. 176) with two molecules in the unit cell. The Sm3+ central ion is coordinated by nine N atoms in the shape of a tricapped trigonal prism, leading to an effective crystal field (CF) of D3h symmetry. The underlying CF splitting pattern was extracted from the absorption and luminescence spectra run at room and low temperatures, and simulated by fitting the free parameters of a phenomenological Hamiltonian achieving an r.m.s. deviation of 9.4 cm−1 for 58 assignments. The parameters used allow the estimation of the global ligand field strength experienced by the Sm3+ central ion, the insertion of SmTp3 into empirical nephelauxetic and relativistic nephelauxetic series, and the set‐up of experimentally based nonrelativistic and relativistic molecular orbital schemes in the f range.
Synthesis of a Stable Biphenyl‐Bis(carbene) and ‐Bis(silylene) [M{(NCH2But)2C6H3‐3,4}]2 (M = C or Si)
Authors: Gehrhus Barbara , Hitchcock Peter B. , Lappert Michael F. 
Published: May 2005

AbstractTreatment of the biphenyl derivative [S=C{(NCH2But)2C6H3‐3,4}]2 or [Cl2Si{(NCH2But)2C6H3‐3,4}]2 with C8K afforded the new bis(carbene) 1 or the first bis(silylene) 2, respectively. The X‐ray structure of 2 is presented.
Synthesis, Crystal Structure Determination from X‐Ray Powder Diffractometry and Vibrational Spectroscopic Properties of Mg[N(CN)2]2 · 4 H2O
Authors: Irran Elisabeth , Jürgens Barbara , Schmid Sabine , Schnick Wolfgang 
Published: May 2005

AbstractMagnesium dicyanamide tetrahydrate Mg[N(CN)2]2 · 4 H2O was synthesized by aqueous ion exchange starting from Na[N(CN)2] and Mg(NO3)2 · 6 H2O. The crystal structure was solved and refined on the basis of powder X‐ray diffraction data (P21/c, Z = 2, a = 737.50(2), b = 732.17(1), c = 971.67(2) pm, β = 98.074(1)°, wRp = 0.059, Rp = 0.046, RF = 0.075). In the crystal there are neutral complexes [Mg[N(CN)2]2(H2O)4] which are only connected via hydrogen bonds. Above 40 °C the tetrahydrate decomposes into anhydrous Mg[N(CN)2]2.
Trichloropalladate(II) Complexes with Pyridine Ligands – Molecular Structure and Conformational Analysis of [K(18C6)][PdCl3(py)]
Authors: Konkol Marcin , Wagner Christoph , Schwieger Sebastian , Lindner Ronald , Steinborn Dirk 
Published: May 2005

Abstract[K(18C6)]2[Pd2Cl6] (1) (18C6 = 18‐crown‐6) was found to react with pyridines in a strictly stoichiometric ratio 1 : 2 in methylene chloride or nitromethane to yield trichloropalladate(II) complexes [K(18C6)][PdCl3(py*)] (py* = py, 2a; 4‐Bnpy, 2b; 4‐tBupy, 2c; Bn = benzyl; tBu = tert‐butyl). The reaction of 1 with pyrimidine (pyrm) in a 1 : 1 ratio led to the formation of the pyrimidine‐bridged bis(trichloropalladate) complex [K(18C6)]2[(PdCl3)2(μ‐pyrm)] (3). The identities of the complexes were confirmed by means of NMR spectroscopy (1H, 13C) and microanalysis. The X‐ray structure analysis of 2a reveals square‐planar coordination of the Pd atom in the [PdCl3(py)]− anion. The pyridine plane forms with the complex plane an angle of 55.8(2)°. In the [K(18C6)]+ cation the K+ lies outside the mean plane of the crown ether (defined by the 6 O atoms) by 0.816(1) Å. There are tight K···Cl contacts between the cation and the anion (K···Cl1 3.340(2) Å, K···Cl2 3.166(2) Å). To gain an insight into the conformation of the [PdCl3(py)]− anion, DFT calculations were performed showing that the equilibrium structure (6eq) has an angle between the pyridine ligand and the complex plane of 35.3°. Rotation of the pyridine ligand around the Pd–N vector exhibited two transition states where the pyridine ligand lies either in the complex plane (6TSpla, 0.87 kcal/mol above 6eq) or is perpendicular to it (6TSper, 3.76 kcal/mol above 6eq). Based on an energy decomposition analysis the conformation of the anion is discussed in terms of repulsive steric interactions and of stabilizing σ and π orbital interactions between the PdCl3− moiety and the pyridine ligand.
Dinuclear and Mononuclear Platinum(II) and Palladium(II) Complexes with Modified 2,2′‐Dipyridylamine Ligands Featuring a Cisplatin Analogous Structure Motif
Authors: Fakih Sarah , Tung Wing Chau , Eierhoff Dirk , Mock Christian , Krebs Bernt 
Published: May 2005

AbstractIn modern cancer therapy the clinical application of platinum‐based drugs is more and more limited by the occurrence of intrinsic or acquired resistances. In this context the potential use of dinuclear platinum complexes in chemotherapy is increasingly relevant. The novel complexes Pd(Bzdpa)Cl2, Pd2(C4H8(dpa)2)Cl4, and Pt2(C4H8(dpa)2)Cl4 allow a direct comparison of mono‐ and dinuclear palladium and platinum complexes respectively deriving from a 2,2′‐dipyridylamine (Hdpa) ligand system. They were characterized by single crystal X‐ray analysis as well as infrared spectroscopy and elemental analysis. The cisplatin analogous mononuclear palladium complex Pd(Bzdpa)Cl2 (1) (Bzdpa: (2,2′‐dipyridylbenzyl)amine) belongs to a range of 2,2′‐dipyridylamine‐based compounds which were extensively studied in our laboratories. 1 crystallizes in the orthorhombic space group Pna21 with a = 13.722(3), b = 13.457(3), c = 9.483(2), V = 1751.1(6) Å3, and Z = 4. The metal binding motif of 1 was expanded by a flexible butyl‐linker to form the tetradentate C4H8(dpa)2 ligand. The resulting isotypic dinuclear complexes Pd2(C4H8(dpa)2)Cl4·2CH3CN (2) and Pt2(C4H8(dpa)2)Cl4·2CH3CN (3) crystallize in the triclinic space group $P{\bar 1}$ with a = 7.8427(2), b = 8.7940(2), c = 11.7645 (3), α = 79.219(2)°, β = 84.033(2)°, γ = 87.744(2)°, V = 792.58(3) Å3 (2) and a = 7.831(5), b = 8.814(5), c = 11.817(5), α = 79.271(5)°, β = 83.571(5)°, γ = 88.063(5)°, V = 796.3(8) Å3 (3), both with one centrosymmetrical molecule in the unit cell.
Plasmachemistry. Formation of Chlorosilazanes, Chlorogermazanes and Related Compounds
Authors: Schiefenhövel Nils , Himmel Hans‐Jörg , Binnewies Michael 
Published: May 2005

AbstractThe plasmachemically activated reaction between N2 and SiCl4 leads via nitrogen atoms to numerous chlorosilazanes: NSi3Cl9, N2Si4Cl10, NSi4Cl11, N2Si4Cl12, N2Si5Cl14, N3Si6Cl15 (3 isomers), N2Si6Cl16 and some related compounds (NOSi4Cl11, N2O2Si6Cl14, N2OSi5Cl12). GeCl4 shows an similar behaviour. This could be shown by GC/MS‐investigations. The structures of
N2Si5Cl14, N2Si6Cl16 and N3Si6Cl15 have been determined by quantum chemical methods. The angle sums around the N atoms are close to 360°.
Ein ungewöhnliches biphenylsubstituiertes Lithiumchlorotriarylsamarat
Authors: Niemeyer Mark 
Published: May 2005

AbstractAn Unusual Biphenylsubstituted LithiumchlorotriarylsamarateThe reaction of the lithium biphenyl LiPmph (Pmph = 2′,3′,4′,5′,6′‐pentamethylbiphenyl) with samarium trichloride in a molar ratio of 3 to 1 affords under elimination of only 2 equivalents lithium chloride the lithium samarate [(thf)3Li][ClSm(Pmph)3(thf)] in a yield of 45°. In the obtained contact ion pair the samarium atom shows an only slightly distorted trigonal bipyramid coordination. Equatorial and axial positions are occupied by three propeller like arranged biphenyl substituents, the Cl{···Li(thf)3} ligand, and a THF molecule, respectively. A rather unusual folding of the aryl ligands leads to comparably short distances of the Sm atom to the ortho‐C–H‐bonds and therefore to the formation of strong agostic interactions.
Steering of Configuration by (2‐Phosphanyl)phenolato Ligands in Trimethylphosphane Iron Complexes
Authors: Klein Hans‐Friedrich , Frey Markus , Mao Shizhen 
Published: May 2005

Abstract(Diphenylphosphanyl)phenols C6H3(1‐OH)(2‐PPh2)(4‐R1)(6‐R2), abbreviated as (P∧OH), oxidatively add to Fe(PMe3)4 affording hydridoiron(II) compounds fac‐FeH(P∧O)(PMe3)3 (1: R1=R2=H; 2: R1=Me, R2=H; 3: R1=OMe, R2=H; 4: R1=Me, R2=CMe3; 5: R1=R2=CMe3) with high stereoselectivity. (2‐diphenylphosphanyl)thiophenol (P∧SH) reacts accordingly forming fac‐FeH(P∧S)(PMe3)3 (9). Complete assignment of 1H, 13C, and 31P signals is achieved by 2D heteronuclear shift correlations. 4,6‐Di‐tert‐butyl‐(2‐diphenylphosphanyl)phenol reacts with FeI(Me)(PMe3)4 to form FeI(P∧O)(PMe3)2 (6). 4, 5 and 9 under 1 bar of CO are converted to monocarbonyl derivatives FeH(P∧X)(CO)(PMe3)2 (7, 8: X = O; 10: X = S) which in solution form mixtures of two isomers A and B. 4 and 5 react with their parent phosphanylphenols, respectively, to give diamagnetic complexes Fe(P∧O)2(PMe3) (11, 12) which dissociate trimethylphosphane to give paramagnetic compounds Fe(P∧O)2. The same phosphanylphenols react with FeCl3 to afford racemic mixtures of complexes Fe(P∧O)3 (13, 14). Structural data were also obtained from single crystals of compounds 1, 5, and 11.