Chemistry, Electricity and the Environment

During the election cycle, there was much discussion about our energy future.  I imagine that it clear to most that we can not continue to live on Middle Eastern oil forever, but what are the options?  Clean coal technology? Wind? Solar? Nuclear?  Natural Gas?  The choices are numerous and complex.  Further, and maybe more importantly, we must consider the impact on the environment. 

For those of you living in the great state of Texas, you have options.  One of them is Texas Electricity.  You have the choice to save on commercial electric, business electric and residential electric by switching to deregulated electric supply at Texas Electric Company. 

What impresses me is the ability to save the environment, with numerous “green” electric options.  Clean, renewable energy options will keep greenhouse gases like CO2 from being placed in our atmosphere and lead to a measurable decrease in global warming over the coming year.  You can do your part to help with that by visiting Texas Electricity. 

Pollution free electricity is clean, affordable and reliable power.  you can learn more about this and other options for your residential and business power needs by visiting Texas Electricity.  Remeber, this is our chance to leave the Earth better for our children than we found it.

Know your strong nucleophiles

This is important throughout organic chemistry, but will be especially important when trying to determine the products of elimination and substitution (E1, E2, SN1, SN2)reactions.  There are generally three trends to remember when discussing how nucleophilic a reactant is:

1)      Size - Generally, the more linear and/or smaller the nucleophile, the more nucleophilic it will be.  This is because it can react at more sites and will not be sterically hindered if it is smaller or linear.

2)       Electronegativity- The more electronegative an atom is, the less nucleophilic it will be.   This is because more electronegative atoms will hold electron density closer, and therefore will be less likely to let that electron density participate in a reaction.  We see this in calculations and experiments that show nucleophilicity decreases as you get closer to fluorine on the periodic table (C > N > O > F)

3)      Polarizability- The more polarizable an atom is, the more nucleophilic it will be.   Polarizability is defined as the ability to distort the electron cloud of an atom, which allows it interact with a reaction site more easily.  Generally, polarizability increases as you travel down a column of the periodic table (I > Br > Cl > F)

 Below is a table of relative nucleophilic strength.  This is relative because nucleophilic strength is also dependant on other factors in the reaction, such as solvent. 

VERY Good nucleophiles	HS-, I-, RS-
Good nucleophiles	Br-, HO-, RO-, CN-, N3-
Fair nucleophiles	NH3, Cl-, F-, RCO2-
Weak nucleophiles	H2O, ROH
VERY weak nucleophiles	RCO2H

 

As shown above, as a general rule, the anion of a reactant will be a better nucleophile than the neutral form.  (i.e. RCO₂^- is a better nucleophile than RCO₂H)

For more information on this and other topics of organic chemistry interest, please visit organic chemistry