A new derivative of the strained 3,3,6,6-tetramethylthiacycloheptyne (TMTH) bearing a functional handle is reported. Following an optimized synthesis, the handle was introduced by mild alkylation of the sulphur atom. The resulting functionalized strained 4,5-didehydro-3,3,6,6-tetramethyl-2,3,6,7-tetrahydrothiepinium (TMTI) proved to be stable and underwent extremely fast [3+2] cycloaddition rea...

To predict the branching between energetically allowed product channels, chemists often rely on statistical transition state theories or exact quantum scattering calculations on a single adiabatic potential energy surface. The potential energy surface gives the energetic barriers to each chemical reaction and allows prediction of the reaction rates. Yet, chemical reactions evolve on a single po...

[1] This paper presents the development and illustration of a numerical model of reactionbased geochemical and biochemical processes with mixed equilibrium and kinetic reactions. The objective is to provide a general paradigm for modeling reactive chemicals in batch systems, with expectations that it is applicable to reactive chemical transport problems. The unique aspects of the paradigm are t...

in this study, synthesis of copper nanoparticles and effect of the reaction conditions on the particle size were investigated. the copper nanoparticles were synthesized and stabilized in a narrow temperature range in the presence of polyvinylpyrrolidone under nitrogen atmosphere. reaction temperature and concentration ratio of the reducing agent to the precursor (r/p) as two main conditions i...

nanoparticles of manganese-dioxide synthesized by mechano-chemical reaction were used foras(iii) and as(v) sorption from water environment. the influence of a milling time of manganese-dioxide on sorption was examined with batch procedure. sorption as a function of contact time was investigated. kinetic of sorption, for both as(iii) and as(v), was fast. the equilibrium condition for milled sorb...

Reactions in real chemical systems often take place on vastly different time scales, with "fast" reaction channels firing very much more frequently than "slow" ones. These firings will be interdependent if, as is usually the case, the fast and slow reactions involve some of the same species. An exact stochastic simulation of such a system will necessarily spend most of its time simulating the m...

Many biochemical and industrial applications involve complicated networks of simultaneously occurring chemical reactions. Under the assumption of mass action kinetics, the dynamics of these chemical reaction networks are governed by systems of polynomial ordinary differential equations. The steady states of these mass action systems have been analyzed via a variety of techniques, including stoi...

This section describes the research efforts and progress made for the implementation and performance of the quantum mechanical reactive scattering application (3D-REACT) across CASA heterogeneous computer environments with nodes that can reside at geographically different locations. This is a scientifically and technically important application. The formalism uses a symmetrized hyperspherical c...

We analyze certain chemical reaction networks and show that every solution converges to some steady state. The reaction kinetics are assumed to be monotone but otherwise arbitrary. When diffusion effects are taken into account, the conclusions remain unchanged. The main tools used in our analysis come from the theory of monotone dynamical systems. We review some of the features of this theory a...