27Dec 2012 by Vincent Summers 1 Comment

Forming Nitrogen Heterocycles from Aliphatic Amino Acids

Chemistry
How are nitrogen heterocycles formed from aromatic amines? Aliphatic hydrocarbons¹ take a number of forms. The simplest is written CH₃(CH₂)nCH₃, where n is a positive integer.²  Replace a hydrogen atom at one end of the chain with a carboxylic acid group (-COOH) and a hydrogen atom at the other end with an amino group (-NH₂), and you have a straight chain amino acid. For instance, choose n = 3. That gives the molecule HOOC-CH₂-CH₂-CH₂-CH₂-NH₂ Its name is 5-aminopentanoic acid or 5-aminovaleric acid. Cyclization Under the right conditions, this species can be cyclized to form an amine salt. The salt is then converted to a cyclic amide, a delta lactam. The lactam is next reduced to the amine piperidine. The overall process is illustrated in Fig. 1. Nitrogen Heterocycles A cyclic…
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26Dec 2012 by Vincent Summers 2 Comments

Organic Chemistry: Pericyclic Reactions

Chemistry
In chemistry, many reactions are simple, intuitive, and straight forward. Others can fool the uninformed. Organic pericyclic reactions are included among the latter. To illustrate this, we consider two reactions. The first is a simple esterification reaction, leading to the obvious product. The second is a pericyclic reaction. The Esterification Reacting an alcohol with a carboxylic acid generally produces a simple ester. So in the presence of a dehydrating agent, one can react ethyl alcohol with acetic acid, to get the ester ethyl acetate plus water. CH₃COOH + HO-C₂H₅ → CH₃COO-C₂H₅ + H₂O Organic Pericyclic Reactions CH₃-CH=CH-CH=CH-CH=CH-CH₃ → two possible ring structures The illustration in Fig. 1 shows a straight chain organic hydrocarbon converting into one of two cyclic structures, depending upon the source of energy. The input energy, whether heat…
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14Dec 2012 by Vincent Summers No Comments

Aromatic Tropylium Ion

Chemistry
[caption id="attachment_20212" align="alignright" width="440"] Aromatic tropylium cation[/caption] Aromatics are separate category of organic compounds. Often aromatic compounds are electrically neutral. However, a few do carry a charge. They are ions.¹ In fact many aromatic ions would not be aromatic if they lost their charge. We will consider the aromatic tropylium cation in this article. Three Carbon Atoms The smallest aromatic ion is the cyclopropenyl cation. The neutral cyclopropene molecule possesses 4 π-electrons. That is not an aromatic number. By making it a cation, it loses 2 of them, meeting the qualification for aromatic compounds.¹ [caption id="attachment_16191" align="alignright" width="240"] Spacefill Model.[/caption] Four Carbon Atoms On the basis of π-electron count alone, one might suppose a cyclobutadienyl di-anion or a cyclobutadienyl di-cation, would display aromaticity. That is not the case. There are…
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03Dec 2012 by Vincent Summers No Comments

Why Balloons Blow Up Round

Physics
[caption id="attachment_13619" align="alignright" width="440"] Balloons.[/caption] When you blow up latex balloons and build up some pressure in them, unless they are especially made to become some other shape, they tends toward roundness—they assume a spherical shape. Balloons blow up round! Why does it do that? Let’s look at the simple math and physics of the thing. Stretching Requires Force Take an ordinary piece of burst balloon and pull on it with your fingers. It takes a definite force to accomplish that, doesn’t it? And the task becomes more difficult the more you stretch it. We call the exertion “force.” It takes force to stretch the rubber. Since the required force becomes greater the more you stretch the skin of balloons, it is clear the more air you blow into them,…
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03Dec 2012 by Vincent Summers No Comments

Why are Some Bananas Sweeter than Others

Food
Some bananas are sweeter than others. How is that? Having purchased the golden fruit many times, I asked myself, why are some bananas sweeter than others? You pick up a bunch of small, curly, bright yellow fruits.¹ You take them home. On the way, you remove the one with the label. You peel it most of the way down. With a few quick bites, you finish it off. You go shopping again. Displayed are large, straight bananas. You note some bananas are sweeter, while others are starchier. Banana Varieties Each variety of banana is grown for a specific end use. Some (plantains) are fried in a skillet. They are starchy. Others are raised for sweetness and aroma. Those are called dessert bananas. The most popular form of dessert banana is…
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16Nov 2012 by Vincent Summers 4 Comments

Where Does Light Go? Why is the Universe Dark?

Astronomy
[caption id="attachment_3236" align="alignright" width="480"] The Andromeda Galaxy (M31)[/caption] Where does light emitted from a flashlight go? On a universal scale, what happens to all the light? If Space is not infinite, goes the line of incorrect reasoning, then all the light that has ever been radiated by stars and galaxies should make the Universe a blindingly bright place. Hence, the universe, based on this reasoning, must be infinite. But, if the Universe is not infinite, the light should bounce back and forth, building up. Most scientists consider the universe to be expanding, yet not infinite. So where does all the light go? First, let's discuss what light actually is. What Is It? Light is a form of energy that radiates outward — radiant energy. Radiant energy can be readily absorbed,…
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14Nov 2012 by Vincent Summers 1 Comment

Navigation: Where Am I?

History
[caption id="attachment_3227" align="alignright" width="380"] Navigation in the 1700's.[/caption] When people started traveling, it was imperative to be able to answer the question: where am I? This is not such a problem with land navigation because there are lots of landmarks to guide the traveler. Early, the Portuguese sailors used sets of directions they called rutters. A rutter might say, “Sail directly west from Sagres until you see a small Island. If you arrive there after October 30, wait until April 1 to proceed north or you will never make it…”. The Portuguese kept their rutters out of foreign hands. The invention of latitude and longitude to map the earth made the rutters obsolete. But how do you know the latitude and longitude of your present position? Latitude is One Thing…
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11Nov 2012 by Vincent Summers 5 Comments

Why Some Boiled Eggs Don’t Peel Right

Food
[caption id="attachment_3204" align="alignright" width="440"] Eggs: Microsoft Clipart[/caption] What's the matter with boiled eggs? It looks like one egg should be as good as another, right? So what makes them different? You put a pot of water on to boil. When it finally reaches a boil, you add some ordinary chicken eggs to make egg custard, deviled eggs, egg salad, or just individual "hen fruits" to munch on with a free sprinkling of sea salt and a little cracked pepper. But... Problem Peeling Boiled Eggs? You experience a problem when you go to peel them. Why don't your boiled eggs peel right? In fact, sometimes they do, and sometimes they don't. Why not every time? Anatomy of an Egg Within the eggshell lies more than just a white and a yolk.…
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09Nov 2012 by Vincent Summers 1 Comment

How Cream Turns to Butter

Food
[caption id="attachment_3195" align="alignright" width="440"] Old-Fashioned Butter Churn[/caption] You've seen it as a youngster. A demonstration in which cream is turned into butter by whipping, perhaps by an electric mixer, perhaps using a hand mixer. How is it possible? Cream is a suspension of fat globules spread throughout a water-based or aqueous solution—a solution that contains water-soluble substances. Preventing the tiny fat globules from joining together—coalescing—is a kind of membrane surrounding each one, called a milk fat globule membrane (MFGM). Butter? MFGM Composition and Structure This membrane is composed of proteins, enzymes, and lipids.¹ Actually, there are two layers that develop around each fat core—a phospholipid layer (developed at the time of formation) encased within a plasma membrane layer (formed at the time of secretion).² The combination is often referred to…
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09Nov 2012 by Vincent Summers 3 Comments

Beginner Level Russian Crossword

Language
[caption id="attachment_3187" align="alignright" width="480"] The Czar's Palace: Kremlin, Moscow, Russia[/caption] Would you care to play a simple beginner's level Russian crossword puzzle? If the solution is also provided? RUSSIA! It's an amazing, multicultural part of this diverse world. Although I cannot afford to visit Russia, I find its people, its history, and its language fascinating. Part of me would like to visit Russia, part of me wouldn't. It doesn't matter. The cost is prohibitive for me. All Things Russian Some time ago, while seeking beginning level Russian video and audio files, I discovered Natalia Worthington and her lovely Spoonful of Russian website. Since I benefited from her efforts, I thought I would contribute to it in some small way. Using Microsoft Word, I generated a beginner's level crossword puzzle. I…
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