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Equilibria, Kinetics and Mechanism for Rapid Substitution Reactions trans to Triphenyl Silyl in Platinum(II) Complexes

Fast substitution of chloride for bromide and iodide trans to triphenylsilyl in trans-PtCl(SiPh3)(PMe2Ph)2 has been studied by stopped-flow spectrophotometry in acetonitrile solution. Substitution is reversible with an observable solvent path via the solvento complex trans-[Pt(SiPh3)(MeCN)(PMe2Ph)2]+, which has also been synthesized and characterized in solution. Rate constants for the forward and

Acetonitrile and Propionitrile Exchange at Palladium(II) and Platinum(II)

Ligand exchange at square-planar [Pd(MeCN)4]2+ and [Pd(EtCN)4]2+ has been studied by 1H NMR line broadening and at [Pt(MeCN)4]2+ and [Pt(EtCN)4]2+ by isotopic labelling using 1H NMR spectroscopy in deuteriated nitromethane. Exchange takes place via two-term rate laws Rex/4 = (k1 + k2[RCN])cM with well defined k1 paths. Rate constants per co-ordination site k1298/s–1, k2298/kg mol–1 s–1 are 6.9 ± 1Ligand exchange at square-planar [Pd(MeCN)4]2+ and [Pd(EtCN)4]2+ has been studied by 1H NMR line broadening and at [Pt(MeCN)4]2+ and [Pt(EtCN)4]2+ by isotopic labelling using 1H NMR spectroscopy in deuteriated nitromethane. Exchange takes place via two-term rate laws Rex/4 = (k1 + k2[RCN])cM with well defined k1 paths. Rate constants per co-ordination site k1298/s–1, k2298/kg mol–1 s–1 are 6.9 ± 1

Trans effect and trans influence of triphenyl stibine and -phosphine in platinum(II) complexes. A comparative mechanistic and structural study

The kinetics and mechanism of the reactions between trans-[PtI3(PPh3)]– and trans-[PtI3(SbPh3)]– with pyridine, 2- and 4-methylpyridine in acetonitrile solvent have been studied by stopped-flow spectrophotometry. The crystal and molecular structures of the tetrabutylammonium salts of the two anions have been determined. Substitution of iodide trans to stibine is reversible and takes place via paraThe kinetics and mechanism of the reactions between trans-[PtI3(PPh3)]– and trans-[PtI3(SbPh3)]– with pyridine, 2- and 4-methylpyridine in acetonitrile solvent have been studied by stopped-flow spectrophotometry. The crystal and molecular structures of the tetrabutylammonium salts of the two anions have been determined. Substitution of iodide trans to stibine is reversible and takes place via para

Protonolysis of Dialkyl and Alkylaryl Platinum(II) Complexes and Geometrical Isomerization of the Derived Monoorgano-Solvento Complexes: Clear-Cut Examples of Associative and Dissociative Pathways in Platinum Chemistry

SynopsisProtonolysis of the title compounds involves rate-determining proton transfer to the substrate. Subsequent isomerization is dissociative. Activation volumes for the two processes have opposite signs. A new kinetic β-hydrogen accelerating effect for isomerization favoring the fluxionality of a T-shaped 14-electron intermediate is reported.AbstractAbstract ImageProtonolysis of the complexes SynopsisProtonolysis of the title compounds involves rate-determining proton transfer to the substrate. Subsequent isomerization is dissociative. Activation volumes for the two processes have opposite signs. A new kinetic β-hydrogen accelerating effect for isomerization favoring the fluxionality of a T-shaped 14-electron intermediate is reported.AbstractProtonolysis of the complexes cis-[PtR2(PEt3

The costs and finances of World War I according to Eli F. Heckscher

Heckscher published in 1915 a book on the economics of World War I in Swedish. He analyzed the costs and the finances of war along similar lines as his contemporary Pigou (1916). Heckscher reached farther by making a distinction between the short and the long-run costs of war. He also provided a comprehensive theoretical and empirical analysis of the sources of funds for war finance, including a pHeckscher published in 1915 a book on the economics of World War I in Swedish. He analyzed the costs and the finances of war along similar lines as his contemporary Pigou (1916). Heckscher reached farther by making a distinction between the short and the long-run costs of war. He also provided a comprehensive theoretical and empirical analysis of the sources of funds for war finance, including a p

To keep the alcoholic in out-patient treatment. : A differentiated approach through treatment contracts

Eighty-two alcoholics were offered a 2-year out-patient programme characterized by stressing the patients' own decisions both in joining the programme and in the choice of objectives and methods, by repeated feedbacks through treatment evaluations, and by relapse prevention. The 58 patients who accepted were more often married than the others. All but eight completed the programme. The most import

Fructose-induced carbonyl/oxidative stress in S. Cerevisiae : Involvement of TOR

The TOR (target of rapamycin) signaling pathway first described in the budding yeast Saccharomyces cerevisiae is highly conserved in eukaryotes effector of cell growth, longevity, and stress response. TOR activation by nitrogen sources, in particular amino acids, is well studied; however its interplay with carbohydrates and carbonyl stress is poorly investigated. Fructose is a more potent glycoxid

Explosive ice multiplication by mechanical break-up in ice-ice collisions : A dynamical system-based study

Mechanical break-up in ice-ice collisions observed in the laboratory can lead to explosive ice multiplication. The possibility is examined in detail by constructing an idealized analytical single-point (zero-dimension) model assuming spatial homogeneity within a cloud. The rate of generation of primary ice is fixed at a constant value over time, corresponding to a situation in which the relative h

A generalized Sibuya distribution

The Sibuya distribution arises as the distribution of the waiting time for the first success in Bernoulli trials, where the probabilities of success are inversely proportional to the number of a trial. We study a generalization that is obtained as the distribution of the excess random variable N − k given N > k, where N has the Sibuya distribution. We summarize basic facts regarding this distribut

The health-schooling relationship: Evidence from Swedish twins

Health and education are known to be highly correlated, but the mechanisms behind the relationship are not well understood. In particular, there is sparse evidence on whether adolescent health may influence educational attainment. Using a large registry dataset of twins, including comprehensive information on health status at the age of 18 and later educational attainment, we investigate whether h

Acute-phase proteins and incidence of diabetes : a population-based cohort study

Aims: To examine the relationship between plasma levels of the acute-phase proteins ceruloplasmin, alpha-1-antitrypsin, orosomucoid, haptoglobin and C-reactive protein (CRP), and incidence of diabetes in the population-based Malmö Diet and Cancer Study—Cardiovascular Cohort (MDCS-CC). Methods: The study population consists of 4246 participants (aged 46–67 years, 60.8 % women) with no previous hist

What socioeconomic factors are associated with different levels of antenatal care visits in Bangladesh? A behavioral model

We identify the socioeconomic determinants of three levels of antenatal care (ANC) visits (no, intermediate [1–3], and recommended [≥4]) in Bangladesh using a behavior model framework for health care utilization. Using multinomial logistic regression, we found that different levels of visits had different determinants; for example, media exposure increased the likelihood of intermediate compared w

The linkage between patterns of daily occupations and occupational balance : Applications within occupational science and occupational therapy practice

Patterns of daily occupations (PDO) and occupational balance (OB) are recurring phenomena in the literature. Both are related with health and well-being, which makes them central in occupational therapy practice and occupational science. The aim was to review how PDO and OB are described in the literature, to propose a view of how the two constructs may be linked, and elaborate on how such a view