Synthesis and characterization of silver(I), gold(I), and gold(III) complexes bearing a bis-dialkylamino functionalized N-heterocyclic carbene

Bis-1,3-[2-(diisopropylamino)ethyl]-imidazolium chloride, 1, has been prepared and used as a precursor for the synthesis of the corresponding silver(I) chloride complex 2. The single crystal structure analysis reveals that the complex dimerizes in the solid state. Transmetalation of 2 with (tht)AuBr (tht = tetrahydrothiophene) yields the (NHC)Au(I)Br complex 3. By treatment with bromine it is oxidized to (NHC)AuBr₃, 4, which is obtained as a yellow, microcrystalline powder. The UV-vis spectra of 4 are dependent on the pH-value and suggest a square-pyramidal structure in solution.     

Set-valued processes induced by parameterised stochastic differential equations with an application to Tuned Mass Dampers

In this paper ordinary stochastic differential equations whose coefficients depend on uncertain parameters are considered. An approach is presented how to combine both types of uncertainty (stochastic excitation and parameter uncertainty) leading to set-valued stochastic processes. The latter serve as a robust representation of solutions of the underlying stochastic differential equations. The mathematical concept is applied to a problem from earthquake engineering, where it is shown how the efficiency of Tuned Mass Dampers can be realistically assessed in the presence of uncertainty. (© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Neutrale Bis‐Aziridin‐Komplexe des Typs [M(CO)3XAz2] (M = Mn,Re; X = Cl,Br; Az = N(H)C2H2Me2)

The pentacarbonylhalogene complexes [XM(CO)₅] (M = Mn, Re; X = Cl, Br) ( 1a – 2b ) react with 2,2‐dimethylaziridine by thermally induced substitution reaction to give the neutral bis‐aziridine complexes [M(X)(CO)₃Az₂] (Az = N(H)C₂H₂Me₂) ( 3a – 4b ). As a result of the X‐ray structure analyses, the metal atoms are octahedrally configurated in the facial arrangement; the intact three‐membered rings coordinate through their distorted tetrahedrally configurated N atoms. All compounds 3a – 4b are stable with respect to the directed thermal alkene elimination to give the corresponding nitrene complexes (CO)₄(X)M=NH; their IR, ¹H and ¹³C{¹H} NMR, and MS spectra are reported and discussed.     

Effect of donor-acceptor substitution on the nonlinear optical properties of oligo(1,4-phenyleneethynylene)s studied by third harmonic generation spectroscopy

Third-harmonic generation (THG) spectroscopy was performed for oligo(1,4-phenyleneethynylene)s (OPEs) with terminal donor-acceptor (DA) substitution and compared to the results of merely donor substituted OPEs and regular OPE chains with 2,5-dipropoxy benzene rings. Both, extension of the conjugation and push-pull effect enhance the molecular hyperpolarizability gamma, even for the DAOPEs, which exhibit a hypsochromic shift of the long-wavelength absorption for increasing length L of the conjugated chain.     

Enantio‐ and Diastereoselective Synthesis of Chiral Allenes by Palladium‐Catalyzed Asymmetric [3+2] Cycloaddition Reactions

A protocol for the asymmetric synthesis of highly substituted chiral allenes with control of point and axial chirality has been developed. A palladium‐catalyzed [3+2] cycloaddition using readily available racemic allenes gives access to densely functionalized chiral allenes with excellent yields and functional group tolerance. The catalytic asymmetric protocol utilizes a broad range of allenyl TMM (trimethylenemethane) donors to form cyclopentanes, pyrrolidines, and spirocycles with very good control of regio‐, enantio‐, and diastereoselectivity. The chiral allene moiety is shown to be a valuable functional group for rapid elaboration towards complex targets.     

Synthesis and structure of a ferrocenylboron dication

Treatment of the borane Br 2BFc (Fc = ferrocenyl) with the Lewis base 4-methylpyridine and Na[BAr (f) 4] [Ar (f) = 3,5-(CF 3) 2C 6H 3] afforded the boron dication [FcB(NC 5H 4-4-Me) 3][BAr (f) 4] 2. This compound is a rare example of a structurally characterized boron dication.     

Nucleoside und Nucleotide. Teil 10. Synthese von Thymidylyl-(3′-5′) -thymidylyl-(3′-5′)-1-(2′-desoxy-β-D-ribofuranosyl)-2(1 H)-pyridon

Nucleosides and Nucleotides. Part 10. Synthesis of Thymidylyl-(3′-5′)-thymidylyl-(3′-5′)-1-(2′-deoxy-β-D - ribofuranosyl)-2(1 H)-pyridone The synthesis of 5′-O-monomethoxytritylthymidylyl-(3′-5′)-thymidylyl-(3′-5′)-1-(2′-deoxy-β-D -ribofuranosyl)-2(1H)-pyridone ((MeOTr)T_dpT_dp∏_d, 5 ) and of thymidylyl-(3′-5′)-thymidylyl-(3′-5′)-1-(2′-deoxy-β-D -ribofuranosyl)-2(1 H)-pyridone (T_dpT_dp∏_d, 11 ) by condensing (MeOTr) T_dpT_d ( 3 ) and p∏_d(Ac) ( 4 ) in the presence of DCC in abs. pyridine is described. Condensation of (MeOTr) T_dpT_dp ( 6 ) with Π_d(Ac) ( 7 ) did not yield the desired product 5 because compound 6 formed the 3′-pyrophosphate. The removal of the acetyl- and p-methoxytrityl protecting group was effected by treatment with conc. ammonia solution at room temperature, and acetic acid/pyridine 7 : 3 at 100°, respectively. Enzymatic degradation of the trinucleoside diphosphate 11 with phosphodiesterase I and II yielded T_d, pT_d and p∏_d, T_dp and Π_d, respectively, in correct ratios.     

Nonstandard conditions for the global Markov property for lattice fields

The global Markov property (GMP) has been shown in various cases under various conditions by quite different methods. Here we investigate the problem of the GMP (for lattice spin systems) from the nonstandard point of view. By embedding the given system into a hyperfinite system we are able to approximate the conditional expectations that are involved in the formulation of the GMP by internal conditional expectations. This leads to a nonstandard equivalent to the GMP as well as to sufficient nonstandard conditions that are easy to formulate. Finally, we then determine the interrelations between these conditions and some of the standard criteria, thus making their relative position somewhat clearer.     

Theoretical Studies of Inorganic Compounds. 19 1) Quantum Chemical Investigations of the Phosphane Complexes X3B‐PY3 and X3Al‐PY3 (X = H,F, Cl; Y = F,Cl, Me,CN)

We report about quantum chemical ab initio calculations at the MP2/6‐311+G(2d)//MP2/6‐31G(d) level and DFT calculations at BP86/TZP of the geometries and bond dissociation energies of the borane‐phosphane complexes X₃B‐PY₃ and the alane‐phosphane complexes X₃Al‐PY₃ (X = H, F, Cl; Y = F, Cl, Me, CN). The nature of the B‐P and Al‐P bonds is analyzed with a bond energy partitioning method. The calculated bond dissociation energies D_e of the borane adducts X₃B‐PY₃ show for the phosphane ligands the trend PMe₃ > PCl₃ ∼ PF₃ > P(CN)₃. A similar trend PMe₃ > PCl₃ > PF₃ > P(CN)₃ is predicted for the alane complexes X₃Al‐PY₃. The order of the Lewis acid strength of the boranes depends on the phosphane Lewis base. The boranes show with PMe₃ and PCl₃ the trend BH₃ > BCl₃ > BF₃ but with PF₃ and P(CN)₃ the order is BH₃ > BF₃ > BCl₃. The bond energies of the alane complexes show always the trend AlCl₃ ≥ AlF₃ > AlH₃. The bonding analysis shows that it is generally not possible to correlate the trend of the bond energies with one single factor which determines the bond strength. The preparation energy which is necessary to deform the Lewis acid and Lewis base from the equilibrium form to the geometry in the complex may have a strong influence on the bond energies. The intrinsic interaction energies may have a different order than the bond dissociation energies. The trend of the interaction energies are sometimes determined by a single factor (Pauli repulsion, electrostatic attraction or covalent bonding) but sometimes all components are important. The higher Lewis acid strength of BCl₃ compared with BF₃ in strongly bonded complexes is not caused by the deformation energy of the fragments but it is rather caused by the intrinsic interaction energy. P(CN)₃ is a weaker Lewis base than PF₃, PCl₃ and PMe₃ mainly because of its weaker electrostatic attraction. The complex H₃B‐P(CN)₃ is predicted to have a bond dissociation energy D_o = 14.8 kcal/mol which should be sufficient to synthesize the compound as the first adduct with the ligand P(CN)₃. The calculated bond energies at the BP86 level are in most cases very similar to the MP2 results. In a few cases significantly different absolute values have been found which are caused by the method and not by the quality of the basis set.     

Comparison of Proteins in Whole Blood and Dried Blood Spot Samples by LC/MS/MS

Dried blood spot (DBS) sampling methods are desirable for population-wide biomarker screening programs because of their ease of collection, transportation, and storage. Immunoassays are traditionally used to quantify endogenous proteins in these samples but require a separate assay for each protein. Recently, targeted mass spectrometry (MS) has been proposed for generating highly-multiplexed assays for biomarker proteins in DBS samples. In this work, we report the first comparison of proteins in whole blood and DBS samples using an untargeted MS approach. The average number of proteins identified in undepleted whole blood and DBS samples by liquid chromatography (LC)/MS/MS was 223 and 253, respectively. Protein identification repeatability was between 77 %–92 % within replicates and the majority of these repeated proteins (70 %) were observed in both sample formats. Proteins exclusively identified in the liquid or dried fluid spot format were unbiased based on their molecular weight, isoelectric point, aliphatic index, and grand average hydrophobicity. In addition, we extended this comparison to include proteins in matching plasma and serum samples with their dried fluid spot equivalents, dried plasma spot (DPS), and dried serum spot (DSS). This work begins to define the accessibility of endogenous proteins in dried fluid spot samples for analysis by MS and is useful in evaluating the scope of this new approach.