What are you reading!?

Discussion in 'The Bookshelf' started by Dryice, Mar 13, 2010.

  1. Hell yes...I've thought about getting one similar to the picture up there...Will you describe them or put up a pic?
     
     
    And Marsbergen-You go through a shitload of books...You must spend a fortune...or if you get them from the library it must be a damn good one...lol
     
  2. GetAttachment.aspx5.jpg
    here is a quick pic...i plan on doing outer space in the background like Saturn or a comet or somethin wild...i also have a tattoo of the crimson king on the back of my leg couldnt get a good pic tho its an image from the comics
    untitled.png
     
  3.  
    Ebay is where I get them. Most are in very good condition and are cheap as fuck.
     
  4. That looks great..may just get one one day...first off is a phoenix for me..

     Good to know ;)
     
  5. Behold a pale horse by William C. Cooper, good book. There are some very serious accusations in this book, all are pretty plausible, if you ask me.
     
  6. [​IMG]FIrst novel, publised in '03.  So far it's really good stuff, with lots of literary significant characters in a cool murder mystery set RIGHT AFTER the Civil War.
     
     
     
  7.  
    Could be but consider the source - Cooper was an HIV/AIDS denier and more or less batshit crazy
     
  8. Currently:
    \t\t\tRegioselectivity and the Markovnikov RuleOnly one product is possible from the addition of these strong acids to symmetrical alkenes such as ethene and cyclohexene. However, if the double bond carbon atoms are not structurally equivalent, as in molecules of 1-butene, 2-methyl-2-butene and 1-methylcyclohexene, the reagent conceivably may add in two different ways. This is shown for 2-methyl-2-butene in the following equation.
    \t 
    \t\t\t\t\t\t(CH[SUB]3[/SUB])[SUB]2[/SUB]C=CHCH[SUB]3[/SUB]   +   H-Cl\t\t\t\t\t\t\t\t\t[​IMG]\t\t\t\t\t\t\t\t\t(CH[SUB]3[/SUB])[SUB]2[/SUB]CH–CHClCH[SUB]3[/SUB]\t\t\t\t\t\t\t\t\tor\t\t\t\t\t\t\t\t\t(CH[SUB]3[/SUB])[SUB]2[/SUB]CCl–CHHCH[SUB]3[/SUB]\t\t\t\t\t\t\t\t2-methyl-2-butene\t\t\t\t\t\t\t\t\t \t\t\t\t\t\t\t\t\t2-chloro-3-methylbutane\t\t\t\t\t\t\t\t\t \t\t\t\t\t\t\t\t\t2-chloro-2-methylbutane\t\t\t 
    When addition reactions to such unsymmetrical alkenes are carried out, we find that one of the two possible constitutionally isomeric products is formed preferentially. Selectivity of this sort is termed regioselectivity. In the above example, 2-chloro-2-methylbutane is nearly the exclusive product. Similarly, 1-butene forms 2-bromobutane as the predominant product on treatment with HBr.
     
    \t\t\t\t\t\t[​IMG]\t\t\t 
    After studying many addition reactions of this kind, the Russian chemist Vladimir Markovnikov noticed a trend in the structure of the favored addition product. He formulated this trend as an empirical rule we now call The Markovnikov Rule:  When a Brønsted acid, HX, adds to an unsymmetrically substituted double bond, the acidic hydrogen of the acid bonds to that carbon of the double bond that has the greater number of hydrogen atoms already attached to it.
    In more homelier vernacular this rule may be restated as, "Them that has gits."
     
     
    \t\t\t\tIt is a helpful exercise to predict the favored product in examples such as those shown below:
    \t\t\t\t\t\t\t\t\t\t \t\t\t\t\t\t[​IMG]\t\t\t\t\t\t\t\t\t 
    Empirical rules like the Markovnikov Rule are useful aids for remembering and predicting experimental results. Indeed, empirical rules are often the first step toward practical mastery of a subject, but they seldom constitute true understanding. The Markovnikov Rule, for example, suggests there are common and important principles at work in these addition reactions, but it does not tell us what they are. The next step in achieving an understanding of this reaction must be to construct a rational mechanistic model that can be tested by experiment.
    [​IMG] All the reagents discussed here are strong Brønsted acids so, as a first step, it seems sensible to find a base with which the acid can react. Since we know that these acids do not react with alkanes, it must be the pi-electrons of the alkene double bond that serve as the base. As shown in the diagram on the right, the pi-orbital extends into the space immediately above and below the plane of the double bond, and the electrons occupying this orbital may be attracted to the proton of a Brønsted acid. The resulting acid-base equilibrium generates a carbocation intermediate (the conjugate acid of the alkene) which then combines rapidly with the anionic conjugate base of the Brønsted acid. This two-step mechanism is illustrated for the reaction of ethene with hydrogen chloride by the following equations.
    <a></a>
     ​
     
    \t\t\t\tFirst Step:       H[SUB]2[/SUB]C=CH[SUB]2[/SUB]   +   HCl\t\t\t\t\t\t\t[​IMG]\t\t\t\t\t\t\tHH[SUB]2[/SUB]C–CH[SUB]2[/SUB]<sup>(+)</sup>   +   Cl<sup>(–)</sup>\t\t\t\t\t\tSecond Step:     HH[SUB]2[/SUB]C–CH[SUB]2[/SUB]<sup>(+)</sup> + Cl<sup>(–)</sup>\t\t\t\t\t\t\t[​IMG]\t\t\t\t\t\t\tHH[SUB]2[/SUB]C–CH[SUB]2[/SUB]Cl\t\t 
    [​IMG] An energy diagram for this two-step addition mechanism is shown to the left. From this diagram we see that the slow or rate-determining step (the first step) is also the product determining step (the anion will necessarily bond to the carbocation site). Electron donating double bond substituents increase the reactivity of an alkene, as evidenced by the increased rate of hydration of 2-methylpropene (two alkyl groups) compared with 1-butene (one alkyl group). Evidently, alkyl substituents act to increase the rate of addition by lowering the activation energy, ΔE<sup>‡</sup>[SUB]1[/SUB] of the rate determining step, and it is here we should look for a rationalization of Markovnikov's rule.
    As expected, electron withdrawing substituents, such as fluorine or chlorine, reduce the reactivity of an alkene to addition by acids (vinyl chloride is less reactive than ethene).
     
     
    \t\t\t\t[​IMG]\t\t\t\t\t\t\t \t\t\t\t\t\t\tEnergy
    \t\t\t\t higher

    begin

    lower
    \t\t\t\t\t 
    George Hammond formulated a useful principle that relates the nature of a transition state to its location on the reaction path. This Hammond Postulate states that a transition state will be structurally and energetically similar to the species (reactant, intermediate or product) nearest to it on the reaction path. In strongly exothermic reactions the transition state will resemble the reactant species. In strongly endothermic conversions, such as that shown to the right, the transition state will resemble the high-energy intermediate or product, and will track the energy of this intermediate if it changes. This change in transition state energy and activation energy as the stability of the intermediate changes may be observed by clicking the higher or lower buttons to the right of the energy diagram. Three examples may be examined, and the reference curve is changed to gray in the diagrams for higher (magenta) and lower (green) energy intermediates.
    The carbocation intermediate formed in the first step of the addition reaction now assumes a key role, in that it directly influences the activation energy for this step. Independent research shows that the stability of carbocations varies with the nature of substituents, in a manner similar to that seen for alkyl radicals. The exceptional stability of allyl and benzyl cations is the result of charge delocalization, and the stabilizing influence of alkyl substituents, although less pronounced, has been interpreted in a similar fashion.
    \t 
    \t\t\t\t\t\t\t\t\t\t\t\t\t\t\tCarbocation
    \t\t\t\t\t\t\t\t\tStability \t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\tCH[SUB]3[/SUB]<sup>(+)</sup>\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\tCH[SUB]3[/SUB]CH[SUB]2[/SUB]<sup>(+)</sup>\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t(CH[SUB]3[/SUB])[SUB]2[/SUB]CH<sup>(+)</sup>\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t≈\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\tCH[SUB]2[/SUB]=CH-CH[SUB]2[/SUB]<sup>(+)</sup>\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\tC[SUB]6[/SUB]H[SUB]5[/SUB]CH[SUB]2[/SUB]<sup>(+)</sup>\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t≈\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t(CH[SUB]3[/SUB])[SUB]3[/SUB]C<sup>(+)</sup>\t\t\t\t\t\t\t\t\t\t 
    From this information, applying the Hammond Postulate, we arrive at a plausible rationalization of Markovnikov's rule. When an unsymmetrically substituted double bond is protonated, we expect the more stable carbocation intermediate to be formed faster than the less stable alternative, because the activation energy of the path to the former is the lower of the two possibilities. This is illustrated by the following equation for the addition of hydrogen chloride to propene. Note that the initial acid-base equilibrium leads to a pi-complex which immediately reorganizes to a sigma-bonded carbocation intermediate. The more stable 2º-carbocation is formed preferentially, and the conjugate base of the Brønsted acid (chloride anion in the example shown below) then rapidly bonds to this electrophilic intermediate to form the final product.
     
  9. #2071 Kermitfrg, Jul 14, 2014
    Last edited by a moderator: Jul 14, 2014
    Just finished this book:

    [​IMG]


    .
     
  10. Finally going to be able to crack open doctor sleep. It's been gathering dust since winter. 
     
  11. More Money than God. History of Hedge Funds and how they will dominate the future of finance. Highly recommended.


    Sent from my iPhone using Grasscity Forum
     
  12. #2074 Deleted member 42976, Jul 22, 2014
    Last edited: Jul 22, 2014
    [​IMG]
    hopefully i make it through this one faster than book one. having a gf sucks sometimes lol especially when you're trying to get through your favorite book series in good time lol
     
  13. Finally got my hands on Burnt Black Suns by Simon Strantzas.
     
  14.  
    Just the title will do lol
     
  15. #2078 LuxSpiritus, Jul 26, 2014
    Last edited by a moderator: Jul 26, 2014
    It's ok, I really don't get it either. Probably will start up my minor(Sorry re-start it, I'm an undergrad in my minor) or go for a long term program at university, hard to learn on my own.
     
  16. House of Leaves by Mark Z. Danielewski - super trippy, definitely interesting.
    In Cold Blood by Truman Capote - i don't know why i waited so long to read this..only halfway through and i'm pretty sure it's one of my favorite books
     

Share This Page