(Cyclopentadienyl)neodymium borohydrides with auxiliary N3-heterocyclic ligands

Mononuclear [CpNd(BH₄)₂L] borohydrides comprising L = 1,3,5-trimethyl-1,3,5-triazacyclohexane (Me₃tach) and L = 1,4,7-trimethyl-1,4,7-triazacyclononane (Me₃tacn) were obtained and structurally characterized. Their catalytic activity in coordination–insertion ring-opening poly-merization of ε-caprolactone was studied.     

Syntheses of [BpBut,Me]AlMe2 and [BpBut,Me]GaMe2: structural comparison of a pair of bis(pyrazolyl)hydroborato aluminum and gallium methyl complexes

The aluminum and gallium dimethyl complexes, [Bp^But,Me]AlMe₂ and [Bp^But,Me]GaMe₂, are readily obtained by the reactions of [Bp^But,Me]Tl with Me₃Al and Me₃Ga, respectively. [Bp^But,Me]AlMe₂ and [Bp^But,Me]GaMe₂ have been structurally characterized by X-ray diffraction, which indicates that the most noticeable difference in these otherwise very similar structures is the C–M–C bond angle, which increases from 118.9(3)° for [Bp^But,Me]AlMe₂ to 124.0(2)° for [Bp^But,Me]GaMe₂.     

Synthese und Kristallstruktur von [(Me3Si)2BiCu(PMe3)3], dem ersten Komplex mit einer Bismut—Kupfer‐Bindung

Synthesis and Crystal Structure of [(Me₃Si)₂BiCu(PMe₃)₃] — the First Complex with a Bismuth—Copper Bond The reaction of CuO^t Bu with PMe₃ and Bi(SiMe₃)₃ in hexane yields the phosphine‐stabilized complex [(Me₃Si)₂Bi‐Cu( PMe₃)₃]. This synthesis gave rise to the first binuclear Bi—Cu compound to be structurally characterized by X‐ray crystallography.     

Synthesis and unexpected electrochemical behavior of the triphenylamine‐based aramids with ortho‐ and para‐trimethyl‐protective substituents

Two series of new organosoluble polyamides with methyl‐substituted triphenylamine (MeTPA) units showing anodically electrochromic characteristic were prepared from the phosphorylation polyamidation reaction of two diamine monomers, 4,4′‐diamino‐2″,4″,6″‐trimethyltriphenylamine (Me₃TPA‐diamine; 2 ) and 4,4′‐diamino‐4″‐methyltriphenylamine (MeTPA‐diamine; 2 ′), with various dicarboxylic acids, respectively. These polymers were readily soluble in many polar solvents and showed useful levels of thermal stability associated with relatively high glass‐transition temperatures (T_g) (314–329 °C) and high char yields (higher than 62% at 800 °C in nitrogen). In addition, the polymer films showed reversible electrochemical oxidation, high coloration efficiency (CE), low switching time, and anodic green electrochromic behavior. The unexpected electrochemical behavior of higher oxidation potential and lower electrochemical stability of Me₃TPA‐polyamides I than MeTPA corresponding polymers could be attributed to the higher steric hindrance of ortho‐substituents in Me₃TPA moieties, thus made the resonance stabilization of cation radical much more difficult for the Me₃‐substituted phenyl ring. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

十甲基五元瓜环与几种金属离子配合物的晶体结构

合成了3个十甲基五元瓜环(Me₁₀Q[5])分别与铷离子、铈离子水合物相互作用形成的配合物以及四氯锌根离子存在下形成的单晶体,并测定了其单晶结构。3个配合物均形成以Me₁₀Q[5]为“胶囊体”,水分子为“胶囊”芯材,金属离子或水分子为“胶囊盖”的“分子胶囊”结构,并通过配键或氢键组装形成一维超分子链结构实体。     

Zwitterionic λ5Si‐Silicates with SiO2S2C Skeletons: Syntheses and Structural Characterization in the Solid State

The zwitterionic λ⁵Si‐silicates [(dimethylammonio)methyl]bis[methanecarboxylatothiolato(2–)‐O,S]silicate ( 9 ) and bis[benzene‐1‐carboxylato‐2‐thiolato(2–)‐O,S][(dimethylammonio)methyl]silicate ( 10 ) were synthesized by treatment of the zwitterionic λ⁵Si‐tetrafluorosilicate F₄SiCH₂NMe₂H with two molar equivalents of Me₃SiSCH₂C(O)OSiMe₃ and 1,2‐Me₃SiS–C₆H₄–C(O)OSiMe₃, respectively (formation of four molar equivalents of Me₃SiF). Compounds 9 and 10 were characterized by elemental analyses (C, H, N, S) and solid‐state NMR studies (¹³C, ²⁹Si). In addition, compound 10 was structurally characterized by single‐crystal X‐ray diffraction.     

[Tc(NBCl2Ph)Cl2(Me2PhP)3] und [Tc(NBH3)Cl2(Me2PhP)3] – die ersten Technetium‐Komplexe mit Nitridobrücken zwischen Technetium und Bor

[Tc(NBCl₂Ph)Cl₂(Me₂PhP)₃] and [Tc(NBH₃)Cl₂(Me₂PhP)₃] – the First Technetium Complexes with Nitrido Bridges between Technetium and Boron [TcNCl₂(Me₂PhP)₃] reacts with BCl₂Ph or BH₃ · THF at low temperatures under formation of complexes containing a nitrido bridge between technetium and boron. The compounds are instable and decompose at room temperature under cleavage of the N–B bonds. The pale‐purple [Tc(NBCl₂Ph)Cl₂(Me₂PhP)₃] crystallizes in the orthorhombic space group Fdd2. The Tc≡N bond is only slightly lengthened by the formation of the N–B bond of 1.564(4) Å. However, a considerable lengthening of the Tc–Cl bond in trans position to the nitrido ligand is observed which can be attributed to an decreasing of the structural trans influence of the nitrido moiety. A similar structural feature can be found in [Tc(NBH₃)Cl₂(Me₂PhP)₃] which is the first structurally characterized transition metal complex containing a nitrido bridge to unsubstituted borane.     

Synthesis and characterization of [(Me3SiCH2)2GaP(SiMe3)2]2, an example of a gallium-phosphorus dimer obtainable only through an indirect reaction pathway

The dimeric gallium-phosphorus compound [(Me₃Si-CH₂)₂GaP(SiMe₃)₂]₂ ( 1 ) was prepared from the 1:1 mole ratio lithium-halide elimination reaction of (Me₃SiCH₂)₂GaP(SiMe₃)₂Ga(CH₂SiMe₃)₂Cl with LiP-(SiMe₃)₂ in benzene solution and has been characterized through multinuclear solution NMR, partial elemental analysis, and single-crystal X-ray analysis. Compound 1 could not be obtained from the direct reactions of (Me₃SiCH₂)₂GaCl with P(SiMe₃)₃ or LiP(SiMe₃)₂. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9:147–150, 1998     

Organotin(IV) esters of (E)‐3‐furanyl‐2‐phenyl‐2‐propenoic acid: Synthesis,investigation of the coordination modes by IR,multinuclear NMR (1H, 13C, 119Sn) and In Vitro biological studies

Complexes [Me₂SnL₂ ( I ), Me₃SnL ( II ), Et₂SnL₂ ( III ), n‐Bu₂SnL₂ ( IV ), n‐Bu₃SnL ( V ), n‐Oct₂SnL₂ ( VI )], where L is (E)‐3‐furanyl‐2‐phenyl‐2‐propenoate, have been synthesized and structurally characterized by vibrational and NMR (¹H, ¹³C and ¹¹⁹Sn) spectroscopic techniques in combination with mass spectrometric and elemental analyses. The IR data indicate that in both the di‐ and triorganotin(IV) carboxylates the ligand moiety COO acts as a bidentate group in the solid state. The ¹¹⁹Sn NMR spectroscopic data, ¹J[¹¹⁹Sn,¹³C] and ²J[¹¹⁹Sn, ¹H], coupling constants show a four‐coordinated environment around the tin atom in triorganotin(IV) and five‐coordinated in diorganotin(IV) carboxylates in noncoordinating solvents. The complexes have been screened against bacteria, fungi, and brine‐shrimp larvae to assess their biological activity. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:612–620, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20488     

Formation and structural study of a mixed ene/enyl ligand on reaction of [Ru(C5Me5)Cl2]2 with 1,3-cyclononadiene

The reaction of [Ru(C₅Me₅)Cl₂]₂ with an excess of 1,3-cyclononadiene in the presence of metallic zinc leads to Ru(C₅Me₅)(1,2,3,6,7-η⁵-C₉H₁₃), in which the nine-membered ring provides both allyl and olefin coordinations, linked together on each side by C₂H₄ bridges. The complex has been characterized analytically, spectroscopically, and structurally.     

Formation and Reactivity of a Molecular Magnesium Hydride with a Terminal MgH Bond

A complex featuring a terminal magnesium hydride bond supported by an NNNN macrocyclic ligand, [Mg{Me₃TACD ? Al(iBu)₃}H] ( 3 ), was formed from its labile Al(iBu)₃ adduct. Use of Al(iBu)₃ to block the amido nitrogen of the NNNN macrocyclic ligand was essential to prevent aggregation. The structurally characterized compound 3 reacted with BH₃ to give the BH₄ derivative, whereas Me₃SiC?CH and PhSiH₃ led to the corresponding acetylide and silyl derivative under H₂ elimination. Pyridine is inserted into the Mg?H bond to give selectively the 1,4‐dihydropyridinate.     

A Novel Divalent Ytterbium Complex Supported by a Bridged Diamide Ligand: Synthesis and Structure of [{Me2Si(NPh)2Yb(THF)2}(μ3‐Cl)(μ4‐Cl){Li(THF)}2]2·2THF

The reaction of anhydrous YbCl₃ with 1 equiv. of Li₂Me₂Si(NPh)₂ in THF, after workup, yielded a ytterbium(III) chloride [{Me₂Si(NPh)₂Yb}(μ₂‐Cl)(TMEDA)]₂·3PhMe ( 1 ) (TMEDA=tetramethylethanediamine). The same reaction followed by treatment with Na‐K alloy afforded a new ytterbium(II) complex supported by a bridged diamide with four coordinated LiCl molecules, [{Me₂Si(NPh)₂Yb(THF)₂}(μ₃‐Cl)(μ₄‐Cl){Li(THF)}₂]₂·2THF ( 2 ) in high yield. Both complexes were structurally characterized by X‐ray analysis to be dimers. Complex 1 was a chlorine‐bridged dimer with ytterbium in a distorted octahedral geometry. In complex 2 two [Me₂Si(NPh)₂Yb(THF)₂]‐(μ₃‐Cl)[Li(THF)]₂ moieties were connected with each other by two μ₄‐Cl bridges to form a "chair‐form" framework.     

Synthesis and structures of the chelating diamido zirconium and hafnium compounds

The chelating diamide lithium complex [Me₂Si{NLiCH(Me)Ph}₂]₂ (1) was synthesized. The X‐ray structure of complex 1 reveals that in the solid state it is a dimer; every lithium atom is three coordinated. The [{Me₂Si{NCH(CH₃)Ph}₂}ZrCl₂LiCl(OEt₂)₂]₂ (2) and [{Me₂Si{NCH(CH₃)Ph}₂}HfCl₂LiCl(OEt₂)₂]₂ (3) complexes were formed by treatment of complex 1 with ZrCl₄ and HfCl₄ respectively in diethyl ether at ambient temperature. Complexes (2) and (3) were also characterized by X‐ray single‐crystal diffraction. Copyright © 2005 John Wiley & Sons, Ltd.     

Unexpected isolation and structural characterization of a redox-active Fe(II) piano-stool complex with an η-dppe ligand

A new cationic complex [(η²-bipy)(η⁵-C₅Me₅)Fe(η¹-dppe)][BPh₄] featuring a pendant free diphenylphosphine arm has been isolated in good yield after reaction of 2,2′-bipyridine with the known chloro precursor complex (η²-dppe)(η⁵-C₅Me₅)FeCl in presence of NaBPh₄. This complex which can be envisioned as a new redox-active building-block has been structurally characterized.     

Gemischtligand-Komplexe des Rheniums. IV. Die Reaktion von [ReNCl2(Me2PhP)3] mit Dithiocarbamaten. Kristallstrukturen von trans-Chloro-dimethyldithiocarbamato-bis(dimethylphenylphosphan) nitridorhenium(V), [ReN(Cl)(Me2PhP)2(Me2dtc)], und Bis(diethyldithiocarbamato)(dimethylphenylphosphan)nitridorhenium(V), [ReN(Me2PhP)(Et2dtc)2]

Mixed-Ligand Complexes of Rhenium IV. The Reaction of [ReNCl₂(Me₂PhP)₃] with Dithiocarbamates. X-Ray Crystal Structures of trans-Chloro-dimethyldithiocarbamato-bis(dimethylphenylphosphine) nitridorhenium(V), [ReN(Cl)(Me₂PhP)₂(Me₂dtc)], and Bis(diethyldithiocarbamato)(dimethylphenylphosphine)nitridorhenium(V), [ReN(Cl)(Me₂PhP)(Et₂dtc)₂] [ReNCl₂(Me₂PhP)₃] reacts with dialkyldithiocarbamates, R₂dtc^?, under a stepwise ligand exchange. Final products of these reactions are the well-known [ReN(R₂dtc)₂] bischelates. Intermediatelly, however, complexes of the general formulae [ReN(Cl)(Me₂PhP)₂(R₂dtc)] and [ReN(Me₂PhP)(R₂dtc)₂] can be isolated. Representatives have been structurally characterized. [ReN(Cl)(Me₂PhP)₂(Me₂dtc)] crystallizes monoclinic in the space group P2₁/c, Z = 4. The dimensions of the unit cell are a = 13.071(3); b = 11.622(1); c = 15.667(3) Å; β = 97.09(1)°. The rhenium atom has a distorted octahedral environment; the Re≡N bond length is 1.71(1) Å. The Re? Cl bond distance is markedly lengthened (2.665(2) Å) as a consequence of the strong trans labilizing influence of the coordinated nitrido ligand. [ReN(Me₂PhP)(Et₂dtc)₂] crystallizes monoclinic in the space group P2₁/c, Z = 4, a = 17.262(3); b = 14.915(2); c = 9.888(2); β = 76.35(8)°. The equatorial coordination sphere is occupied by one phosphorus atom and three sulphur atoms. One of the dithiocarbamate ligands is coordinated bidentately; the second one with two distinct Re? S bond lengths. The Re? S(4) distance is 2.7983(2) Å which can be discussed as a weak interaction with the metal.     

A Structurally Characterized Fluoroalkyne

The facile synthesis of a stable and isolable compound with a fluoroalkynyl group, M−C≡CF, is reported. Reaction of [Ru(C≡CH)(η⁵‐C₅Me₅)(dppe)] with an electrophilic fluorinating agent (NFSI) results in the formation of the fluorovinylidene complex [Ru(=C=CHF)(η⁵‐C₅Me₅)(dppe)][N(SO₂Ph)₂]. Subsequent deprotonation with LiN(SiMe₃)₂ affords the fluoroalkynyl complex [Ru(C≡CF)(η⁵‐C₅Me₅)(dppe)]. In marked contrast to the rare and highly reactive examples of fluoroalkynes that have been reported previously, this compound can be readily isolated and structurally characterized. This has allowed the structure and bonding in the CCF motif to be explored. Further electrophilic fluorination of this species yields the difluorovinylidene complex [Ru(C=CF₂)(η⁵‐C₅Me₅)(dppe)][N(SO₂Ph)₂].     

Ring Contraction by NHC‐Induced Pnictogen Abstraction

The reaction of [Cp′′′Co(η⁴‐P₄)] ( 1 ) (Cp′′′=1,2,4‐tBu₃C₅H₂) with ^MeNHC (^MeNHC=1,3,4,5‐tetramethylimidazol‐2‐ylidene) leads through NHC‐induced phosphorus cation abstraction to the ring contraction product [(^MeNHC)₂P][Cp′′′Co(η³‐P₃)] ( 2 ), which represents the first example of an anionic CoP₃ complex. Such NHC‐induced ring contraction reactions are also applicable for triple‐decker sandwich complexes. The complexes [(Cp*Mo)₂(μ,η^6:6‐E₆)] ( 3 a , 3 b ) (Cp*=C₅Me₅; E=P, As) can be transformed to the complexes [(^MeNHC)₂E][(Cp*M)₂(μ,η^3:3‐E₃)(μ,η^2:2‐E₂)] ( 4 a , 4 b ), with 4 b representing the first structurally characterized example of an NHC‐substituted As^I cation. Further, the reaction of the vanadium complex [(Cp*V)₂(μ,η^6:6‐P₆)] ( 5 ) with ^MeNHC results in the formation of the unprecedented complexes [(^MeNHC)₂P][(Cp*V)₂(μ,η^6:6‐P₆)] ( 6 ), [(^MeNHC)₂P][(Cp*V)₂(μ,η^5:5‐P₅)] ( 7 ) and [(Cp*V)₂(μ,η^3:3‐P₃)(μ,η^1:1‐P{^MeNHC})] ( 8 ).     

A trinuclear Mo-Fe-Mo cluster compound [Et_4N] { [Me_2dtcMo-O(μ-S)_2]_2Fe} containing dialkyldithiocarbamate ligand

A trinuclear linear Mo-Fe-Mo dialkyldithiocarbamate complex [Et4N] { [ Me2dtcMoO (μ-S)2 ]2Fe} has been obtained and structurally characterized, which contains two Me2dtcMoO-(μ-S)2 units coordinated to a central tetrahedral Fe atom. A comparison of the structural parameters indicates the metal oxidation states of 2Mo(v) Fe(III). The 1H NMR shows chemical shifts of Me2dtc ligands at 5 10.14 and 8 9.40 with the intensity ratio of 1:1. The cyclic voltammogram displays a reversible couple at - 1.41 V/ - 1.36 V responsible for 1-/2-anions of the complex and an irreversible oxidation at 0.5 V, which seems to show the apparent lack of stability for its neutral species (Me2dtcMoOS2)2Fe.     

Syntheses and structures of Me3Sb+CH2COO−·H2O,the monohydrate of the antimony analogue of betaine,and related compounds

The syntheses of the antimony analogue of betaine, Me₃Sb⁺CH₂COO^? (1), of the precursor [Me₃SbCH₂COOH][Br] (2) and of [Me₃SbCH₂COOCH₂CH₃][Br] (3) are reported. A new method for the synthesis of solvent‐free Me₃Sb is described. The structures of 1·H₂O and 3 were determined by single crystal X‐ray diffractometry. Copyright © 2002 John Wiley & Sons, Ltd.     

Tetrahedral Coordination in the First Structurally Characterized Dichlorooxovanadium(V) Alkoxide

Reaction of VOCl₃ with 2‐phenoxyethanol in n‐hexane in a 1:1 fashion gives dichlorooxo(2‐phenoxyethanolato)vanadium(V). HCl elimination yields the orange vanadium(V) complex, which is the first structurally characterized dichlorooxovanadium(V) alkoxide. The structure analysis reveals an unexpected tetrahedral coordination around the vanadium atom in the monomeric compound. Alcoholysis and hydrolysis reactions of [VOCl₂(OCH₂CH₂OPh)] are monitored by ⁵¹V NMR spectroscopy. Activated with Me₃SiCH₂MgCl or ⁿBu₂Mg the complex catalyses the polymerisation of styrene.