Nonisothermal Kinetics of Sub‐Solidus Phase Transitions in C10Zn,C16Zn and Their Binary System

Nonisothermal kinetics of the solid‐solid phase transition in (n‐C₁₀H₂₁NH₃)₂ZnCl₄(C₁₀Zn), (n‐C₁₆H₃₃NH₃)₂ZnCl₄(C₁₆Zn) and their binary system were determined by Kissinger and Ozawa methods from DSC measurements. The activation energy E_a of the binary system shows a waving dependence on W_C10Zn%, which is caused by not only an intermediate (C₁₀H₂₁NH₃)(n‐C₁₆H₃₃NH₃)ZnCl₄ but also three solid solution ranges (α, β, γ) in the phase diagram of C₁₀Zn‐C₁₆Zn. The variations of the layer d‐spacing are also convenient for the above result.     

Subsolidus Binary Phase Diagrams of C10ZnCl‐C16ZnCl and C12ZnCl‐C16ZnCl

Decylammonium tetrachlorozincate (n‐C₁₀H₂₁NH₃)₂ZnCl₄(C₁₀ZnCl), dodecylammonium tetrachlorozincate (n‐C₁₂H₂₅NH₃)₂ZnCl₄(C₁₂ZnCl) and hexadecylammonium tetrachlorozincate (n‐C₁₆H₃₃NH₃)₂ZnCl₄‐(C₁₆ZnCl) were synthesized and a series of their mixtures C₁₀ZnCl‐C₁₆ZnCl and C₁₂ZnCl‐C₁₆ZnCl were prepared. The experimental binary phase diagrams of C₁₀ZnCl‐C₁₆ZnCl and C₁₂ZnCl‐C₁₆ZnCl were established by means of differential scanning calorimetry (DSC), IR and X‐ray diffraction. In the phase diagram a stable solid compound and two eutectoid invariants were observed. It is noticeable that the phase diagram contains solid solution ranges.     

Synthesis and characterization of some bis(cyclopentadienyl)titanium(IV) complexes with internally functionalized oximes(LH): sol–gel transformations of Cp2TiCl2, Cp2TiClL and Cp2TiL2 to nano‐sized anatase titania

Some bis(cyclopentadienyl)titanium(IV) complexes of the type [Cp₂TiCl_2?n{L}_n] {where, n = 1 or 2; L = ONC(R)Ar; R = H or CH₃ and Ar = C₅H₄N‐2, C₄H₃O‐2 or C₄H₃S‐2} have been synthesized by the metathetical reactions of Cp₂TiCl₂ with the sodium salt of internally functionalized oximes in 1:1 and 1:2 stoichiometry in anhydrous THF. All these red to brown colored solid derivatives have been characterized by elemental analyses, FT‐IR and NMR (¹H and ¹³C{¹H}) spectral studies. The FAB mass spectra of some representative derivatives indicate their monomeric nature. Oximato ligands in all the complexes appear to bind the titanium via N and O in a dihapto ( ‐N, O) manner in the solid state. Thermogravimetric curves of [Cp₂TiCl{ONC(CH₃)C₅H₄N‐2}] and [Cp₂Ti{ONC(CH₃)C₅H₄N‐2}₂] suggest the formation of hybrid materials CpTiO(Cl) and Cp₂TiO, respectively, as the final products at 900 °C under nitrogen atmosphere. Sol–gel transformations of Cp₂TiCl₂, [Cp₂TiCl{ONC(CH₃)C₅H₄N‐2}] and [Cp₂Ti{ONC(CH₃)C₅H₄N‐2}₂] yielded titania a–c, respectively, at low sintering temperature (600 °C). The powder XRD patterns, IR as well as Raman spectra of all these oxides indicate the formation of nano‐sized anatase phase. The SEM images of titania a–c indicate agglomers like surface morphologies. The absorption spectra of a–c exhibit an energy band gap in the range of 3.47–3.71 eV. Copyright © 2011 John Wiley & Sons, Ltd.     

Subsolidus binary phase diagram of (n-CnH2n+1NH3)2ZnCl4 (n?=?14, 16, 18)

The thermotropic phase solid–solid transitions compound (n-C _n H_2n+1NH₃)₂ZnCl₄ (n = 14, 16, 18) were studied, and a series of their mixtures were prepared. These laminar materials contain bilayers sandwiched between metal halide layers. The low temperature crystal structures of the pure salts are characteristic of the piling of sandwiches in which a two-dimensional macro-anion ZnCl₄ ²⁻ is sandwiched between two alkylammonium layers. These layers become conformationally disordered in the high temperature phases. The subsolidus binary phase diagrams of (n-C₁₄H₂₉NH₃)₂ZnCl₄-(n-C₁₈H₃₇NH₃)₂ZnCl₄ and (n-C₁₆H₃₃NH₃)₂ZnCl₄-(n-C₁₈H₃₇NH₃)₂ZnCl₄ were established by differential thermal analysis and X-ray diffraction. In each phase diagram, an intermediate compound and two eutectoid invariants were observed. There are three noticeable solid solution ranges (α, β, γ) at the left boundary, right boundary, and middle of the phase diagram.     

2,5‐Bis[4‐methyl‐3‐(pyridin‐3‐yl)phenyl]‐1,3,4‐oxadiazole and its one‐dimensional polymeric complex with ZnCl2

2,5‐Bis[4‐methyl‐3‐(pyridin‐3‐yl)phenyl]‐1,3,4‐oxadiazole (L), C₂₆H₂₀N₄O, forms one‐dimensional chains via two types of intermolecular π–π interactions. In catena‐poly[[dichloridozinc(II)]‐μ‐2,5‐bis[4‐methyl‐3‐(pyridin‐3‐yl)phenyl]‐1,3,4‐oxadiazole], [ZnCl₂(C₂₆H₂₀N₄O)]_n, synthesized by the combination of L with ZnCl₂, the Zn^II centres are coordinated by two Cl atoms and two N atoms from two L ligands. [ZnCl₂L]_n forms one‐dimensional P (plus) and M (minus) helical chains, where the L ligand has different directions of twist. The helical chains stack together via interchain π–π and C—H...π interactions.     

Calcium-mediated dearomatization, C-H bond activation, and allylation of alkylated and benzannulated pyridine derivatives

A facile and general synthetic pathway for the production of dearomatized, allylated, and C? H bond activated pyridine derivatives is presented. Reaction of the corresponding derivative with the previously reported reagent bis(allyl)calcium, [Ca(C₃H₅)₂] ( 1 ), cleanly affords the product in high yield. The range of N‐heterocyclic compounds studied comprised 2‐picoline ( 2 ), 4‐picoline ( 3 ), 2,6‐lutidine ( 4 ), 4‐tert‐butylpyridine ( 5 ), 2,2′‐bipyridine ( 6 ), acridine ( 7 ), quinoline ( 8 ), and isoquinoline ( 9 ). Depending on the substitution pattern of the pyridine derivative, either carbometalation or C? H bond activation products are obtained. In the absence of methyl groups ortho or para to the nitrogen atom, carbometalation leads to dearomatized products. C(sp³)? H bond activation occurs at ortho and para situated methyl groups. Steric shielding of the 4‐position in pyridine yields the ring‐metalated product through C(sp²)? H bond activation instead. The isolated compounds [Ca(2‐CH₂‐C₅H₄N)₂(THF)] ( 2 b ?(THF)), [Ca(4‐CH₂‐C₅H₄N)₂(THF)₂] ( 3 b ?(THF)₂), [Ca(2‐CH₂‐C₅H₃N‐6‐CH₃)₂(THF)_n] ( 4 b ?(THF)_n; n=0, 0.75), [Ca{2‐C₅H₃N‐4‐C(CH₃)₃}₂(THF)₂] ( 5 c ?(THF)₂), [Ca{4,4′‐(C₃H₅)₂‐(C₁₀H₈N₂)}(THF)] ( 6 a ?(THF)), [Ca(NC₁₃H₉‐9‐C₃H₅)₂(THF)] ( 7 a ?(THF)), [Ca(4‐C₃H₅‐C₉H₇N)₂(THF)] ( 8 b ?(THF)), and [Ca(1‐C₃H₅‐C₉H₇N)₂(THF)₃] ( 9 a ?(THF)₃) have been characterized by NMR spectroscopy and metal analysis. 9 a ?(THF)₄ and 4 b ?(THF)₃ were additionally characterized in the solid state by X‐ray diffraction experiments. 4 b ?(THF)₃ shows an aza‐allyl coordination mode in the solid state. Based on the results, mechanistic aspects are discussed in the context of previous findings.     

Isobutene polymerization initiated by [CP*TiMe2]+ in the presence of a series of novel,weakly coordinating counteranions

The highly electrophilic borane B(C₆F₅)₃ reacts with n‐octadecanol (n‐C₁₈H₃₇OH) and n‐octadecanethiol (n‐C₁₈H₃₇SH) to form the 1:1 adducts (n‐C₁₈H₃₇EH)B(C₆F₅)₃ (E = O or S). The latter are acidic and react with Cp*TiMe₃ in methylene chloride and toluene to give methane and the complexes [Cp*TiMe₂][(n‐C₁₈H₃₇E)B(C₆F₅)₃], which are very good initiators for the carbocationic polymerization of isobutene (IB) from ?40 to ?20 °C. High conversions to high molecular weight polyisobutene (PIB) in methylene chloride and moderate conversions to high molecular weight PIB in toluene are observed and are consistent with the anions [(n‐C₁₈H₃₇E)B(C₆F₅)₃]^? being very weakly coordinating. Although polymerization in methylene chloride is too rapid for the temperature to be controlled, polymerization in toluene is slower, and the temperatures can be controlled so that Arrhenius‐type plots of the logarithm of the number‐average molecular weight versus T^?1 = 1/T may be obtained. Activation energies for the degree of polymerization in these polymerization reactions and similar polymerizations carried out with n‐C₁₈H₃₇EH:borane ratios of 1:2 and with the activators [Ph₃C][B(C₆F₅)₄] and Al(C₆F₅)₃ range from ?11 to ?27 kJ mol^?1, values comparable to those for most conventional IB polymerization initiators. However, the values of the weight‐average and number‐average molecular weights are unusually high for the temperatures used, and this is consistent with current theories of the role of weakly coordinating anions. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3302–3311, 2002     

Syntheses and structures of three macrocyclic supramolecular complexes and one ZnII‐containing coordination polymer generated from a semi‐rigid multidentate N‐containing ligand

Semirigid organic ligands can adopt different conformations to construct coordination polymers with more diverse structures when compared to those constructed from rigid ligands. A new asymmetric semirigid organic ligand, 4‐{2‐[(pyridin‐3‐yl)methyl]‐2H‐tetrazol‐5‐yl}pyridine ( L ), has been prepared and used to synthesize three bimetallic macrocyclic complexes and one coordination polymer, namely, bis(μ‐4‐{2‐[(pyridin‐3‐yl)methyl]‐2H‐tetrazol‐5‐yl}pyridine)bis[dichloridozinc(II)] dichloromethane disolvate, [Zn₂Cl₄(C₁₂H₁₀N₆)₂]·2CH₂Cl₂, ( I ), the analogous chloroform monosolvate, [Zn₂Cl₄(C₁₂H₁₀N₆)₂]·CHCl₃, ( II ), bis(μ‐4‐{2‐[(pyridin‐3‐yl)methyl]‐2H‐tetrazol‐5‐yl}pyridine)bis[diiodidozinc(II)] dichloromethane disolvate, [Zn₂I₄(C₁₂H₁₀N₆)₂]·2CH₂Cl₂, ( III ), and catena‐poly[[[diiodidozinc(II)]‐μ‐4‐{2‐[(pyridin‐3‐yl)methyl]‐2H‐tetrazol‐5‐yl}pyridine] chloroform monosolvate], {[ZnI₂(C₁₂H₁₀N₆)]·CHCl₃}_n, ( IV ), by solution reaction with ZnX₂ (X = Cl and I) in a CH₂Cl₂/CH₃OH or CHCl₃/CH₃OH mixed solvent system at room temperature. Complex ( I ) is isomorphic with complex ( III ) and has a bimetallic ring possessing similar coordination environments for both of the Zn^II cations. Although complex ( II ) also contains a bimetallic ring, the two Zn^II cations have different coordination environments. Under the influence of the I^? anion and guest CHCl₃ molecule, complex ( IV ) displays a significantly different structure with respect to complexes ( I )–( III ). C—H…Cl and C—H…N hydrogen bonds, and π–π stacking or C—Cl…π interactions exist in complexes ( I )–( IV ), and these weak interactions play an important role in the three‐dimensional structures of ( I )–( IV ) in the solid state. In addition, the fluorescence properties of L and complexes ( I )–( IV ) were investigated.     

Nuclear magnetic resonance study of the ferroelastic phase transition of order-disorder type in [N(C2H5)4]2CdCl4

This study uses nuclear magnetic resonance (NMR) techniques to examine the detailed changes in [N(C₂H₅)₄]₂CdCl₄ around its phase transition at the temperature T_C = 284 K. The chemical shifts and spin-lattice relaxation times in the rotating frame (T_1ρ) were determined from ¹H magic angle spinning (MAS) NMR and ¹³C cross-polarization (CP)/MAS NMR spectra. The two sets of inequivalent ¹H and ¹³C nuclei in CH₃ and CH₂ were distinguished. A ferroelastic phase transition was observed at T_C, without structural symmetry change. The phase transition is mainly attributed to the orientational ordering of the [N(C₂H₅)₄]⁺ cations, and the spectral splitting at low temperature is associated with different ferroelastic domains.     

Assembly of a Highly Stable Luminescent Zn5 Cluster and Application to Bio‐Imaging

The assembly sequence of the coordination cluster [Zn₅(H₂Lⁿ)₆](NO₃)₄]⋅8 H₂O⋅2 CH₃OH ( Zn₅ , H₃Lⁿ=(1,2‐bis(benzo[d]imidazol‐2‐yl)‐ethenol) involves in situ dehydration of 1,2‐bis(benzo[d]imidazol‐2‐yl)‐1,2‐ethanediol (H₄L) through the formation of the [Zn(H₃L)₂]⁺ monomer, dimerization to [Zn₂(H₃L)₂]⁺, dehydration of the ligand to [Zn₂(H₂Lⁿ)₂]⁺, and the final formation of the pentanuclear cluster. The cluster has the following special characteristics: 1) high stability in both refluxing 37 % HCl and 27 % NH₃, 2) low cytotoxicity, and 3) pH‐sensitive fluorescence in the visible‐to‐near‐infrared (Vis/NIR) region in the solid state and in solution. We have applied it as a fluorescent probe both in vivo and in vitro. Its H‐bonding ability is the key to its affinity and selectivity for imaging lysosomes in HeLa cells and tumors in male BALB/C mice. It provides a new type of sensitive and biocompatible fluorescent probe for detecting small tumors (13.5 mm³).     

Ein neues cis‐[Bi3I12]3−‐Anion in Tri(n‐butyl)methylammonium Dodecaiodotribismutat

The Novel cis‐[Bi₃I₁₂]^3?‐Anion in Tri(n‐butyl)methylammoniumdodecaiodo‐tribismutate By reaction of equivalent amounts of BiI₃, KI and I₂ in [N(CH₃) (n‐C₄H₉)₃][N(SO₂CF₃)₂] as Ionic Liquid, transparent reddish crystals with the composition [N(CH₃)(n‐C₄H₉)₃]₃[Bi₃I₁₂] are formed. Concerning to X‐ray diffraction investigations based on single crystals as well as powders, [N(CH₃)(n‐C₄H₉)₃]₃[Bi₃I₁₂] crystallizes monoclinic (P2₁/c; a = 2383.0(5); b = 1241.0(3); c = 2493.0(5) pm; β = 97.50(3)°; Z = 4). The anion consists of distorted (BiI₆)‐octahedra, which are face‐shared via cis‐oriented octahedral faces. With the cis‐[Bi₃I₁₂]^3?‐anion such a connectivity is firstly described.     

The infinite double‐stranded chain polymer catena‐poly­[[bis­(dicyan­amido)­zinc(II)]‐di‐μ‐1,2‐bis(1,2,4‐triazol‐1‐yl)­ethane‐κ4N4:N4′]

The coordination geometry of the Zn^II atom in the title complex, [Zn(C₂N₃)₂(C₆H₈N₆)₂]_n or [Zn(dca)₂(bte)₂]_n, where bte is μ‐1,2‐bis(1,2,4‐triazol‐1‐yl)­ethane and dca is dicyan­amide, is distorted compressed octahedral, in which the Zn^II atom lies on an inversion center and coordinates four N atoms from the triazole rings of four symmetry‐related bte ligands and two N atoms from two symmetry‐related monodentate dca ligands. The structure is polymeric, with 18‐membered spiro‐fused rings extending in the b direction and each 18‐membered ring involving two inversion‐related bte mol­ecules.     

Chemical modification of zeolite beta surface and its effect on gas permeation of mixed matrix membrane

Chemical modification of zeolite beta (BEA) with a series of organosilane compounds [R(CH₃)_nSiX_(3‐n), where X is a chloro or alkoxy group with n = 0 and 2, and R is an alkyl chain varying from CH₃ to C₁₈H₃₇] was investigated. The results of FT‐IR and ²⁹Si CP/MAS NMR indicated that the alkylsilyl species were covalently anchored onto the BEA surface. Grafting density of the alkylsilyl species was determined by CHN elemental analysis and thermogravimetric analysis (TGA). Evidently, it can be adjusted by varying the reaction time and organosilane concentration. The reaction kinetics was found to resemble the kinetics of the well‐known monolayer formation, i.e. SAMs. The kinetic plot illustrated two distinct regions, a rapid attachment followed by a gradual increase of grafting density. The degradation temperature at maximum rate (T_max) of the surface‐grafted BEA was observed in the range of 440–460°C. The modified BEA showed surface hydrophobic characteristic by having a strong affinity to the non‐polar n‐heptane. Good particle distribution and strong interfacial adhesion were observed in the mixed matrix membranes of the BEA grafted with C₃H₇ to C₁₈H₃₇. The grafted chain length was found to have an effect on gas permeability. Carbon dioxide, oxygen, and ethylene permeabilities of the membranes containing the unmodified BEA were comparable to those of the CH₃Si‐grafted BEA. Interestingly, the membranes containing the BEA grafted with C₃H₇ to C₁₈H₃₇ species showed enhancement of the carbon dioxide permeability. Affinity of the long alkyl chain to carbon dioxide probably caused the increase of carbon dioxide permeability. Copyright © 2008 John Wiley & Sons, Ltd.     

Crystal and Molecular Structure of [2,6‐(Me2NCH2)2C6H3]2SnF2, an Intramolecularly Coordinated Diorganotin Difluoride

Single‐crystal X‐ray diffraction analysis of [2,6‐(Me₂NCH₂)₂C₆H₃]₂SnF₂ reveals that only one of the two dimethylaminomethyl groups of each pincer‐type ligands [2,6‐(CH₂NMe₂)₂C₆H₃]^? is coordinated to the tin atom at Sn‐N distances of 2.576(2) and 2.470(2) Å, inducing chirality of the latter. The tin atom exhibits a distorted octahedral trans(C,C)cis(N,N)cis(F,F) configuration. Extensive intra‐ and intermolecular C‐H···F hydrogen bonding is observed with the latter giving rise to formation of polymeric chains.     

Structure‐Directing Forces in Intercluster Compounds of Cationic [Ag14(CCtBu)12Cl]+ Building Blocks and Polyoxometalates: Long‐Range versus Short‐Range Bonding Interactions

Crystallization of [Ag₁₄(C?CtBu)₁₂Cl][BF₄] and different polyoxometalates in organic solvents yields a series of new intercluster compounds: [Ag₁₄(C?CtBu)₁₂Cl(CH₃CN)]₂[W₆O₁₉] ( 1 ), (nBu₄N)[Ag₁₄(C?CtBu)₁₂Cl(CH₃CN)]₂[PW₁₂O₄₀] ( 2 ), and [Ag₁₄(C?CtBu)₁₂Cl]₂[Ag₁₄(C?CtBu)₁₂Cl(CH₃CN)]₂[SiMo₁₂O₄₀] ( 3 ). Applying the same technique to a system starting from polymeric {[Ag₃(C?CtBu)₂][BF₄]?0.6 H₂O}_n and the polyoxometalate (nBu₄N)₂[W₆O₁₉] results in the formation of [Ag₁₄(C?CtBu)₁₂(CH₃CN)₂][W₆O₁₉] ( 4 ). Here, the Ag₁₄ cluster is generated from polymeric {[Ag₃(C?CtBu)₂][BF₄]?0.6 H₂O}_n during crystallization. In a similar way, [Ag₁₅(C?CtBu)₁₂(CH₃CN)₅][PW₁₂O₄₀] ( 5 ) has been obtained from {[Ag₃(C?CtBu)₂][BF₄]?0.6 H₂O}_n and (nBu₄N)₃[PW₁₂O₄₀]. The use of charged building blocks was intentional, because at these conditions the contribution of long‐range Coulomb interactions would benefit most from full periodicity of the intercluster compound, thus favoring formation of well‐crystalline materials. The latter has been achieved, indeed. However, as a most conspicuous feature, equally charged species aggregate, which demonstrates that the short‐range interactions between the “surfaces” of the clusters represent the more powerful structure direction forces than the long‐range Coulomb bonding. This observation is of significant importance for understanding the mechanisms underlying self‐organization of monodisperse and structurally well‐defined particles of nanometer size.     

Luminescent Amphiphilic 2,6‐Bis(1,2,3‐triazol‐4‐yl)pyridine?Platinum(II) Complexes: Synthesis,Characterization, Electrochemical,Photophysical, and Langmuir–Blodgett Film‐Formation Studies

A new series of platinum(II) complexes with tridentate ligands 2,6‐bis(1‐alkyl‐1,2,3‐triazol‐4‐yl)pyridine and 2,6‐bis(1‐aryl‐1,2,3‐triazol‐4‐yl)pyridine (N7R), [Pt(N7R)Cl]X ( 1 – 7 ) and [Pt(N7R)(C?CR′)]X ( 8 – 17 ; R=n‐C₄H₉, n‐C₈H₁₇, n‐C₁₂H₂₅, n‐C₁₄H₂₉, n‐C₁₈H₃₇, C₆H₅, and CH₂‐C₆H₅; R′=C₆H₅, C₆H₄‐CH₃‐p_, C₆H₄‐CF₃‐p, C₆H₄‐N(CH₃)₂‐p, and cholesteryl 2‐propyn‐1‐yl carbonate; X=OTf^?, PF₆^?, and Cl^?), has been synthesized and characterized. Their electrochemical and photophysical properties have also been studied. Two amphiphilic platinum(II)? 2,6‐bis(1‐dodecyl‐1,2,3‐triazol‐4‐yl)pyridine complexes ( 3‐Cl and 8 ) were found to form stable and reproducible Langmuir–Blodgett (LB) films at the air/water interface. These LB films were characterized by the study of their surface‐pressure–molecular‐area (π–A) isotherms, XRD, and IR and polarized‐IR spectroscopy.     

(C5H14N2)[Zn3(HPO4)4], a New 3D Open‐framework Zincophosphate Synthesized by Hydrothermal Reversible Transformation of (C5H14N2)[Zn2(HPO4)3]·H2O

In the system ZnO/H₃PO₄/H₂O/1,4‐diazacycloheptane (C₅H₁₂N₂), a new zincophosphate (ZnPO), (C₅H₁₄N₂)[Zn₃(HPO₄)₄] ( I ), was prepared by hydrothermal transformation (180 °C) of the known ZnPO hydrate (C₅H₁₄N₂)[Zn₂(HPO₄)₃]·H₂O ( II ). The thermally‐induced transformation is reversible; upon keeping the heterogeneous mixture of I and mother liquor at 80 °C recrystallization of II was observed. Single‐crystal X‐ray crystallography revealed that I possesses a unique three‐dimensional (3D) open‐framework structure built from corner‐linked ZnO₄ and HPO₄ tetrahedra. The (3,4)‐connected framework of I differs considerably from the 3D open‐framework ZnPO structure of II . Crystal data for I : Monoclinic system, space group Cc (No. 9) , Z = 4, a = 9.1389(6), b = 23.627(2), c = 9.3073(6) Å, β = 109.463(7)°, T = 298 K.     

Rare‐Earth‐Metal–Hydrocarbyl Complexes Bearing Linked Cyclopentadienyl or Fluorenyl Ligands: Synthesis,Catalyzed Styrene Polymerization,and Structure–Reactivity Relationship

A series of rare‐earth‐metal–hydrocarbyl complexes bearing N‐type functionalized cyclopentadienyl (Cp) and fluorenyl (Flu) ligands were facilely synthesized. Treatment of [Y(CH₂SiMe₃)₃(thf)₂] with equimolar amount of the electron‐donating aminophenyl‐Cp ligand C₅Me₄H‐C₆H₄‐o‐NMe₂ afforded the corresponding binuclear monoalkyl complex [({C₅Me₄‐C₆H₄‐o‐NMe(μ‐CH₂)}Y{CH₂SiMe₃})₂] ( 1 a ) via alkyl abstraction and C? H activation of the NMe₂ group. The lutetium bis(allyl) complex [(C₅Me₄‐C₆H₄‐o‐NMe₂)Lu(η³‐C₃H₅)₂] ( 2 b ), which contained an electron‐donating aminophenyl‐Cp ligand, was isolated from the sequential metathesis reactions of LuCl₃ with (C₅Me₄‐C₆H₄‐o‐NMe₂)Li (1 equiv) and C₃H₅MgCl (2 equiv). Following a similar procedure, the yttrium‐ and scandium–bis(allyl) complexes, [(C₅Me₄‐C₅H₄N)Ln(η³‐C₃H₅)₂] (Ln=Y ( 3 a ), Sc ( 3 b )), which also contained electron‐withdrawing pyridyl‐Cp ligands, were also obtained selectively. Deprotonation of the bulky pyridyl‐Flu ligand (C₁₃H₉‐C₅H₄N) by [Ln(CH₂SiMe₃)₃(thf)₂] generated the rare‐earth‐metal–dialkyl complexes, [(η³‐C₁₃H₈‐C₅H₄N)Ln(CH₂SiMe₃)₂(thf)] (Ln=Y ( 4 a ), Sc ( 4 b ), Lu ( 4 c )), in which an unusual asymmetric η³‐allyl bonding mode of Flu moiety was observed. Switching to the bidentate yttrium–trisalkyl complex [Y(CH₂C₆H₄‐o‐NMe₂)₃], the same reaction conditions afforded the corresponding yttrium bis(aminobenzyl) complex [(η³‐C₁₃H₈‐C₅H₄N)Y(CH₂C₆H₄‐o‐NMe₂)₂] ( 5 ). Complexes 1 – 5 were fully characterized by ¹H and ¹³C NMR and X‐ray spectroscopy, and by elemental analysis. In the presence of both [Ph₃C][B(C₆F₅)₄] and AliBu₃, the electron‐donating aminophenyl‐Cp‐based complexes 1 and 2 did not show any activity towards styrene polymerization. In striking contrast, upon activation with [Ph₃C][B(C₆F₅)₄] only, the electron‐withdrawing pyridyl‐Cp‐based complexes 3 , in particular scandium complex 3 b , exhibited outstanding activitiy to give perfectly syndiotactic (rrrr >99 %) polystyrene, whereas their bulky pyridyl‐Flu analogues ( 4 and 5 ) in combination with [Ph₃C][B(C₆F₅)₄] and AliBu₃ displayed much‐lower activity to afford syndiotactic‐enriched polystyrene.     

Heterobimetallische Komplexe von Lithium,Aluminium und Gold mit dem N‐[2‐N′,N′‐(Dimethylaminoethyl)‐N‐methyl‐aminoethyl]‐ferrocenyl‐Liganden (η5‐C5H5)Fe{η5‐C5H3[CH(CH3)N(CH3)CH2CH2NMe2]‐2}

Heterobimetallic Complexes of Lithium, Aluminum, and Gold with the N ‐[2‐ N ′, N ′‐(dimethylaminoethyl)‐ N ‐methyl‐aminoethyl]‐ferrocenyl Ligand (η⁵‐C₅H₅)Fe{η⁵‐C₅H₃[CH(CH₃)N(CH₃)CH₂CH₂NMe₂]‐2} N‐[2‐N′,N′‐(dimethylaminoethyl)‐N‐methyl‐aminoethyl]ferrocene FcN,NH ( 1 ) reacts with ⁿBuLi under formation of the lithium organyl (FcN,N)Li ( 2 ). At reactions of 2 with AlBr₃ and AuCl · PPh₃ the heterobimetallic organo derivatives (FcN,N)AlBr₂ ( 3 ), (FcN,N)Au · PPh₃ ( 4 ) are formed. A detailed characterization of 2 – 4 was carried out by single crystal x‐ray analyses as well as by NMR and Mößbauer spectroscopy.     

One‐dimensional coordination polymers generated from a new triazole bridging ligand and HgX2 (X = Cl,Br and I): characterization and luminescent properties

The new 4‐amino‐1,2,4‐triazole asymmetric bridging ligand 4‐amino‐5‐(pyridin‐3‐yl)‐3‐[4‐(pyridin‐4‐yl)phenyl]‐4H‐1,2,4‐triazole (L) has been used to generate three novel isomorphic one‐dimensional coordination polymers, viz. catena‐poly[[tris[dichloridomercury(II)]‐bis{μ₃‐4‐amino‐5‐(pyridin‐3‐yl)‐3‐[4‐(pyridin‐4‐yl)phenyl]‐4H‐1,2,4‐triazole}] acetonitrile monosolvate], {[Hg₃Cl₆(C₁₈H₁₄N₆)₂]·CH₃CN}_n, (I), and the bromido, {[Hg₃Br₆(C₁₈H₁₄N₆)₂]·CH₃CN}_n, (II), and iodido, {[Hg₃I₆(C₁₈H₁₄N₆)₂]·CH₃CN}_n, (III), analogs. The asymmetric ligand acts as a tridentate ligand to coordinate the three different Hg^II centers (two of which are symmetry‐related). Two ligands and two symmetry‐related Hg^II centers form centrosymmetric rectangular units which are linked into one‐dimensional chains via the other unique Hg atoms, which sit on mirror planes. The chains are elaborated into a three‐dimensional structure via interchain hydrogen bonds. The acetonitrile solvent molecules are located in ellipsoidal cavities. The luminescent character of these three coordination complexes was investigated in the solid state.