[CME/Answers: Self-Determined Dying: The Challenge of Medical End-of-Life Decisions].

CME/Answers: Self-Determined Dying: The Challenge of Medical End-of-Life Decisions Modern medical interventions make it possible today to postpone dying. Thus the process of dying confronts with numerous end-of-life decisions. The authority to make such decisions does not lie with the doctors.

[CME: Self-Determined Dying: The Challenge of Medical End-of-Life Decisions].

CME: Self-Determined Dying: The Challenge of Medical End-of-Life Decisions Modern medical interventions make it possible today to postpone dying. Thus the process of dying confronts with numerous end-of-life decisions. The authority to make such decisions does not lie with the doctors.

Peroxynitrous acid: controversy and consensus surrounding an enigmatic oxidant.

The isomerisation of ONOOH to NO(3)(-) and H(+), some oxidations and all hydroxylations and nitrations of aromatic compounds are first-order in ONOOH and zero-order in the compounds that are modified. These reactions are widely believed to proceed via homolysis of ONOOH into HO˙ and NO(2)˙ to an extent of ca. 30%.

Novel type of bicellar disks from a mixture of DMPC and DMPE-DTPA with complexed lanthanides.

We report on the formation of bicelles from a mixture of dimyristoylphosphatidylcholine (DMPC) and the chelator-lipid dimyristoylphosphatidylethanolamine-diethylenetriaminepentaacetate (DMPE-DTPA) with complexed lanthanides, either thulium (Tm(3+)) or lanthanum (La(3+)). The two phospholipids used have the same acyl-chain length but differ in headgroup size and chemical structure. The total lipid concentration was 15 mM, and the molar ratio of DMPC to DMPE-DTPA was 4:1.

Magnetic field alignable domains in phospholipid vesicle membranes containing lanthanides.

Magnetic fields were applied as a structuring force on phospholipid-based vesicular systems, using paramagnetic lanthanide ions as magnetic handles anchored to the vesicle membrane. Different vesicle formulations were investigated using small angle neutron scattering (SANS) in a magnetic field of up to 8 T, cryo-transmission electron microscopy (cryo-TEM), (31)P NMR spectroscopy, dynamic light scattering (DLS), and permeability measurements with a fluorescent water-soluble marker (calcein). The investigated vesicle formulations consisted usually of 80 mol % of the phospholipid 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and 20 mol % of a chelator lipid (DMPE-DTPA; 1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine-diethylenetriaminepentaacetate) with complexed lanthanide ions (Tm(3+), Dy(3+), or La(3+)), and the total lipid concentration was 15 mM.

Secondary interactions or ligand scrambling? Subtle steric effects govern the iridium(I) coordination chemistry of phosphoramidite ligands.

The like and unlike isomers of phosphoramidite (P*) ligands are found to react differently with iridium(I), which is a key to explaining the apparently inconsistent results obtained by us and other research groups in a variety of catalytic reactions. Thus, the unlike diastereoisomer (aR,S,S)-[IrCl(cod)(1 a)] (2 a; cod=1,5-cyclooctadiene, 1 a=(aR,S,S)-(1,1'-binaphthalene)-2,2'-diyl bis(1-phenylethyl)phosphoramidite) forms, upon chloride abstraction, the monosubstituted complex (aR,S,S)-[Ir(cod)(1,2-eta-1 a,kappaP)](+) (3 a), which contains a chelating P* ligand that features an eta(2) interaction between a dangling phenyl group and iridium. Under analogous conditions, the like analogue (aR,R,R)-1 a' gives the disubstituted species (aR,R,R)-[Ir(cod)(1 a',kappaP)(2)](+) (4 a') with monodentate P* ligands.

Silver-ethene complexes [Ag(eta(2)-C2H4)n][Al(OR(F))4] with n = 1, 2, 3 (R(F) = fluorine-substituted group).

Compounds including the free or coordinated gas-phase cations [Ag(eta(2)-C(2)H(4))(n)](+) (n = 1-3) were stabilized with very weakly coordinating anions [A](-) (A = Al{OC(CH(3))(CF(3))(2)}(4), n = 1 (1); Al{OC(H)(CF(3))(2)}(4), n = 2 (3); Al{OC(CF(3))(3)}(4), n = 3 (5); {(F(3)C)(3)CO}(3)Al-F-Al{OC(CF(3))(3)}(3), n = 3 (6)). They were prepared by reaction of the respective silver(I) salts with stoichiometric amounts of ethene in CH(2)Cl(2) solution. As a reference we also prepared the isobutene complex [(Me(2)C=CH(2))Ag(Al{OC(CH(3))(CF(3))(2)}(4))] (2).

Vesicles as soft templates for the enzymatic polymerization of aniline.

The feasibility of using surfactant vesicles as soft templates for the peroxidase-triggered polymerization of aniline was investigated. It was found that mixed anionic vesicles (diameter approximately 80 nm) composed of sodium dodecylbenzenesulfonate (SDBS) and decanoic acid (1:1, molar ratio) are promising templates. In the presence of the vesicles and horseradish peroxidase/hydrogen peroxide (H2O2) as initiator system, aniline polymerizes under optimized conditions at pH=4.

Neutral and cationic main group element cages of germanium(II) with pyrazolyl ligands: solid state structures, DFT calculations and advanced solution NMR investigations.

Two equivalents of 3,5-bis(trifluoromethyl)pyrazole or 5-methyl-3-(trifluoromethyl)pyrazole react with [Ge{N(SiMe(3))(2)}(2)] to give dimeric homoleptic germanium(ii) compounds [{Ge(3,5-RR'pz)(2)}(2)] (R = R' = CF(3) (1); R = Me, R' = CF(3) (2)), which provide cationic triply pz-bridged cages of the general formula [Ge(mu(2)-3,5-RR'pz)(3)Ge](+)[OTf](-) (R = R' = CF(3) (3); R = Me, R' = CF(3) (4)) upon treatment with one equivalent of triflic acid (HOTf, HSO(3)CF(3)). The compounds were studied using the pulsed field gradient spin-echo (PGSE) NMR technique and (19)F,(1)H-HOESY NMR methods. Single crystal X-ray structure determinations of all compounds are reported.

Conformational behavior of cinchonidine revisited: a combined theoretical and experimental study.

Conformational space of cinchonidine has been explored by means of ab initio potential and free energy surfaces, and the temperature-induced changes of conformational populations were studied by a combined NOESY-DFT analysis. The DFT-derived potential energy surface investigation identified four new conformers. Among them, Closed(7) is substantially relevant to fully understand the conformational behavior.

Hydrogen-bonding interactions in cinchonidine-2-methyl-2-hexenoic acid complexes: a combined spectroscopic and theoretical study.

Molecular interactions between cinchonidine (CD) and 2-methyl-2-hexenoic acid (MHA) have been studied by means of NMR, ATR-IR MES, DFT, and ab initio molecular dynamics. These interactions are of particular interest due to their pivotal role in the chiral induction occurring in the heterogeneous catalytic asymmetric hydrogenation of alpha,beta-unsaturated acids. The population density of the Open(3) conformer of CD, the most populated one at room temperature in apolar solvents, considerably increased to a maximum by addition of MHA to CD in toluene.

Syntheses, reactivity and DFT studies of group 2 and group 12 metal complexes of tris(pyrazolyl)methanides featuring "free" pyramidal carbanions.

Reactions of HC(Me2pz)3 with Grignard reagents, dialkyl magnesium compounds and dimethylzinc are reported, together with a DFT study on some of the aspects of this chemistry. Reactions of HC(Me2pz)3 with MeMgX (X=Cl or Br) gave the half-sandwich zwitterionic compounds [Mg((Me)Tpmd)X] (X=Cl (2) or Br (3); (Me)Tpmd(-)=[C(Me2pz)3](-)). Addition of HCl to 2 gave the structurally characterised half-sandwich compound [Mg{HC(Me2pz)3}Cl2(thf)] (4).

Structure, stability and guest affinity of tris(3-ureidobenzyl)amine capsules in solution.

In non-competitive solvents, the tris(3-ureidobenzyl)amines 1 a-c form dimeric assemblies in which guests such as CH(3)CN, CH(3)NO(2), CH(2)Cl(2), CH(3)I, CH(2)BrCl, CH(2)Br(2), CHCl(3) and C(6)H(6) can be encapsulated. Variable temperature (1)H and (1)H,(1)H-ROESY NMR spectroscopy, as well as pulsed-gradient spin-echo (PGSE) diffusion measurements were used to investigate the encapsulation within 1 a1 a (1 a: tris{3-[N'-(4-butylphenyl)ureido]benzyl}amine). Kinetic parameters for the encapsulation of CH(3)NO(2), CH(2)Cl(2) and CH(3)I, both in CDCl(3) and in [D(8)]toluene have been obtained by using magnetisation transfer methods.

Synthesis and characterization of novel fluorinated poly(oxomolybdates).

Two novel poly(oxofluoromolybdate) clusters, [Mo6O18F6]6- and [Mo7O22F3]5-, have emerged from systematic field studies on the hydrothermal fluorination of poly(oxometalates). They are accessible via the hydrothermal treatment of Mo(VI)-based precursors in the presence of MF additives (M = Li, Na, Cs, NMe4). The new fluorinated polyanions are stabilized by specific alkali-cation combinations, and their packing motifs can be tuned through the careful choice of cations and synthetic parameters.

Ketosteroids and hydroxyketosteroids, minor metabolites of sugarcane wax.

Besides beta-sitosterol and stigmasterol, the major steroids of sugarcane, the following minor steroids have been isolated and identified from sugarcane wax: 3,6-diketosteroids, Delta(4)-3-keto steroids, and Delta(4)-6-hydroxy-3-keto steroids. Their structures were established by spectroscopic techniques and chemical correlations.

Chiral phosphane alkenes (PALs): simple synthesis, applications in catalysis, and functional hemilability.

A simple synthesis of a chiral phosphane alkene (PAL) involves: 1) palladium-catalyzed Suzuki coupling of 10-bromo-5H-dibenzo[a,d]cyclohepten-5-ol (1) with phenylboronic acid to give quantitatively 10-phenyl-5H-dibenzo[a,d]cyclohepten-5-ol (2); 2) reaction of 2 with Ph(2)PCl under acidic conditions to give a racemic mixture of the phosphane oxide (10-phenyl-5H-dibenzo[a,d]cyclohepten-5-yl)diphenylphosphane oxide ((Ph)troppo(Ph), 3), which is separated into enantiomers by using high-pressure liquid chromatography (HPLC) on a chiral column; 3) reduction with trichlorosilane to give the enantiomerically pure phosphanes (R)- and (S)-(10-phenyl-5H-dibenzo[a,d]cyclohepten-5-yl)diphenylphosphane ((Ph)tropp(Ph), 4). This highly rigid, concave-shaped ligand serves as a bidentate ligand in Rh(I) and Ir(I) complexes. Catalysts prepared from [Rh(2)(mu(2)-Cl)(2)(C(2)H(4))(4)] and (S)-4 have allowed the efficient enantioselective 1,4-addition of arylboronic acids to alpha,beta-unsaturated carbonyls (Hayashi-Miyaura reaction) (5-0.

Coinage metal complexes of tris(pyrazolyl)methanide [C(3,5-Me2pz)3]-: kappa3-coordination vs. backbone functionalisation.

Tris(pyrazolyl)methanides, [C(3,5-R2pz)3]-, contain an unassociated tetrahedral carbanionic centre in the bridgehead position. In addition to nitrogen donor centres for transition metal coordination, an accessible reactive site for further manipulations is available in the backbone of the ligand. The coordination variability of the ambidental C-/N ligand [C(3,5-Me2pz)3]- was elucidated by investigating its coinage metal complexes.

Sodium compounds of the benzophenone dianion (diphenyloxidomethanide).

The benzophenone dianion [diphenyloxidomethanide, (Ph(2)CO)(2-)], which occurs in the well known deeply violet sodium/benzophenone tetrahydrofuran solutions, was crystallised with sodium cations in form of the two polymeric chain compounds [Na(2)(Ph(2)CO)(tetraglyme)](infinity) and [Na(2)(Ph(2)CO)(thf)(2)](infinity). It was found to aggregate with its conjugated acid, the alcoholate (Ph(2)CHO)(-), around a central unit of sodium hydroxide, resulting in the mixed cage compound [Na(13)(Ph(2)CO)(4)(Ph(2)CHO)(4)(OH)(mtbe)(4)].mtbe.