Rules reaction rule

MarkownikofT s rule The rule states that in the addition of hydrogen halides to an ethyl-enic double bond, the halogen attaches itself to the carbon atom united to the smaller number of hydrogen atoms. The rule may generally be relied on to predict the major product of such an addition and may be easily understood by considering the relative stabilities of the alternative carbenium ions produced by protonation of the alkene in some cases some of the alternative compound is formed. The rule usually breaks down for hydrogen bromide addition reactions if traces of peroxides are present (anti-MarkownikofT addition). 

After the definition of a reaction type, a scheme for the evaluation of the given reaction type can follow in the reaction rule. An entire hierarchy of evaluations can be implemented, from no evaluation at all to a full-fledged estimation of reaction kinetics [12 ... 

All chemical reactions, whether in the laboratory or in living organisms, follow the same "rules." Reactions in living organisms often look more complex than laboratory reactions because of the size of the biomolecules and the involvement of biological catalysis called enzymes, but the principles governing all reactions are the same. 

Inspection of Table 6.1 shows the following rule for electrophobic reactions Rule Gl A reaction exhibits purely electrophobic behaviour ((dr/dO)PA 0) when the kinetics are positive order in the electron donor (D) reactant and negative or zero order in the electron acceptor (A) reactant. 

Here va and va are the stoichiometric coefficients for the reaction. The formulation is easily extended to treat a set of coupled chemical reactions. Reactive MPC dynamics again consists of free streaming and collisions, which take place at discrete times x. We partition the system into cells in order to carry out the reactive multiparticle collisions. The partition of the multicomponent system into collision cells is shown schematically in Fig. 7. In each cell, independently of the other cells, reactive and nonreactive collisions occur at times x. The nonreactive collisions can be carried out as described earlier for multi-component systems. The reactive collisions occur by birth-death stochastic rules. Such rules can be constructed to conserve mass, momentum, and energy. This is especially useful for coupling reactions to fluid flow. The reactive collision model can also be applied to far-from-equilibrium situations, where certain species are held fixed by constraints. In this case conservation laws... 

Eastman, R. H., 158, 166 Eaton, P. F., 460 Eigen, M., 80 Eisenberg, W., 125 Electrocyclic addition, 46 Electrocyclic reaction rules, 339 Electrocyclic reactions, 402,408 4n-examples, 408 (4n + 2)-examples, 410 Electron impact spectroscopy, triplet energy, 220-223 Electronic energy transfer, 267 Electronic integral, 21 Electronic transitions /-a ,16 n -Mr, 16... 

In this model, run on a square grid, each unit can adopt one of N states, 0, 1, 2, 3,..., (N - 1) states other than 0 are "excited states." The neighbors are those cells that share an edge with the target cell (a von Neumann neighborhood). The transition rules can be divided into two types first we have reaction rules ... 

Unless contraindicated for economic reasons, it is recommended to use 10 Eq. each of amine and NaBH3CN for the on-resin reductive amination step. In some cases, as little as 1-2 Eq. of amine will give efficient incorporation. NaBH(OAc)3 can be used instead of NaBH3CN. As a rule, reactions should be performed at 25°C. 

Our goal in this chapter is to help you learn about reactions in aqueous solutions, including titrations. We will present a set of solubility rules you can use to predict whether or not precipitation will take place when two solutions are mixed. You may want to talk to your instructor and/or check your text for other solubility rules. These rules will be useful as you learn to write net ionic equations. If you are unsure about mass/mole relationships, you may want to review Chapter 3. And remember—Practice, Practice, Practice. 

Markovnikov s rule the rule stating that, in an addition reaction of two asymmetrical reactants, the halogen atom or -OH group is usually added to the more substituted carbon atom (the carbon atom that is bonded to the largest number of other carbon atoms) the hydrogen atom is added to the carbon atom that is bonded to the largest number of hydrogen atoms (2.2)... 

SYNLMA performs a retrosynthetic analysis using a special purpose theorem prover built from LMA components. The compound to be synthesized becomes a theorem to be proved. The reaction rules and starting materials become axioms. The choice of a knowledge representation has been one of our greatest problems. 

Our present reaction rule database is made up of approximately one hundred rules adapted from a microfiche generously sent to us by Gelernter (4). For a given reaction, a rule specifies the reactants (subgoal) and the product(s) (goal), in connection table format and any constraints on their composition (Figure 2a). The rules are identified by chapter and schema numbers. The connection tables are organized as follows ... 

Each goal or subgoal clause is terminated with the predicate Rxnrule whose first argument is a reaction rule identification number. After this number, the predicate uses the function LL (for linked list) to list all the atoms in the connection table. 

Figure 2b. Clause representation of the goal and subgoal in reaction rule Chapter 20, Schema 2.

The success of SYNLMA shows that it is possible to base an expert system on a theorem prover. The advantage of using a theorem prover as deductive component is that it allows us to experiment with a number of different representations for chemical information. The same flexibility makes it easy to add new starting materials and reaction rules from large commercial online databases. 

Gibbs phase rule phys chem A relationship used to determine the number of state variables F, usually chosen from among temperature, pressure, and species composition in each phase, which must be specified to fix the thermodynamic state of a system in equilibrium F = C - P - M+2, where C is the number of chemical species presented at equilibrium, P is the number of phases, and M is the number of independent chemical reactions. Also known as Gibbs rule phase rule. gibz faz, rijl I... 

---