Conjugated systems are the main things that make up chromophores. Chromophores are light-absorbing parts of a molecule that can cause a compound to have a visible color. Chromophores are often present in various organic compounds and sometimes present in polymers that are colored or glow in the dark. Chromophores often consist of a series of conjugated bonds and/or ring systems, which can include C-C, C=C, C=O, or N=N bonds. Many times, chromophores have aromatic rings.
Prince Fielder
Prince Semien Fielder (born May 9, 1984 in Ontario, California) is an American Major League Baseball player. He currently plays for the Texas Rangers. He debuted in the MLB for the Milwaukee Brewers on June 13, 2005 when he was called up from the minor league Nashville Sounds. He was sent back down but was called up again on August 17, 2005 where he finished the season with the Brewers and was used as a pinch-hitter. Fielder is a 3-time All Star and is also one of 26 players in the 50 home run club.
Kurt Alder
Kurt Alder (July 10, 1902 – June 20, 1958) was a German chemist and Nobel laureate.
Alder was born in the industrial area of Königshütte, Silesia (modern day Chorzów, Upper Silesia, Poland). He received his early schooling there. Alder left the area for political reasons when Königshütte became part of Poland in 1922. He studied chemistry at the University of Berlin from 1922, and later at the University of Kiel where his earned a PhD in 1926 for work supervised by Diels.
In 1930 Alder was appointed reader for chemistry at Kiel, and promoted to lecturer in 1934. In 1936 he left Kiel to join I G Farben Industrie at Leverkusen, where he worked on synthetic rubber. In 1940, he was appointed Professor of Experimental Chemistry and Chemical Technology at the University of Cologne and Director of the Institute of Chemistry there. Throughout this time and despite the many obstacles to original research in Europe at the time, he continued a systematic program of investigations of his particular interests in the synthesis of organic compounds. In all he published more than 151 papers in this field.
Alder received several honorary degrees and other awards, most famously the 1950 Nobel Prize in Chemistry which he shared with his teacher Diels for their work on what is now known as the Diels–Alder reaction. The lunar crater Alder is named in his honour. The insecticide aldrin, created through a Diels–Alder reaction, is also named for him.
Kenichi Fukui
Kenichi Fukui (October 4, 1918–January 9, 1998) was a Japanese chemist. He won the 1981 Nobel Prize in Chemistry.
Fukui was the oldest of three sons of Ryokichi Fukui, who was a merchant. He was born in Nara, Japan.
He graduated from Kyoto Imperial University in 1941.
Fukui worked at the Army Fuel Laboratory of Japan during World War II.{
In 1943, he was appointed a lecturer in fuel chemistry at Kyoto Imperial University.
He was professor of physical chemistry at Kyoto University from 1951 to 1982.
He was president of the Kyoto Institute of Technology between 1982 and 1988.
Fukui shared the 1981 Nobel Prize with Roald Hoffmann. Fukui and Hoffmann worked separately on the mechanisms of chemical reactions. Fukui explained in his Nobel lecture that,
Woodward's rules
Woodward's rules are a set of rules about how organic chemical compounds absorb ultraviolet light.
They give information about the wavelength of the absorption maximum (symbol λ ) in an ultraviolet-visible (UV) spectrum of a compound. The rules are named after Robert Burns Woodward. He was a Harvard University professor who won the 1965 Nobel Prize in chemistry. The rules are sometimes called the Woodward-Fieser rules, to also honor Louis Fieser.
The rules build the prediction on the type of chromophores present, the substituents on the chromophores, and changes due to the solvent. Examples are conjugated carbonyl compounds, conjugated dienes, and polyenes.
One set of Woodward-Fieser rules for dienes is shown in table one. A diene is either homoannular with both double bonds contained in one ring or heteroannular with two double bonds distributed between two rings.
These rules predict the UV absorption maximum of compounds. Here are two examples:
In the compound on the left the base value is 214 nm (a heteroannular diene). This diene group has 4 alkyl substituents (labeled 1,2,3,4) and the double bond in one ring is exocyclic to the other (adding 5 nm for an exocyclic double bond). In the compound on the right, the diene is homoannular with 4 alkyl substituents. Both double bonds in the central B ring are exocyclic with respect to rings A and C.
Lemon shark
The Lemon shark is a shark that gets its name from its deep yellow back. Its belly is off-white. Lemon sharks are usually eight to ten feet long. They have long, sharp teeth for catching slippery fish. Lemon sharks are common on the southeast coast of the United States of America.
The Lemon shark gets its name from the fact that it is yellow in colour. The underside is usually white or a lighter yellowish colour. Besides yellow, the Lemon shark is also brown and olive grey in colour. The Lemon shark is stocky, blunt-nosed, and has two dorsal fins of similar size and shape. The first dorsal fin is low and positioned at the back of the pectoral fins, and the second dorsal is of similar shape and size and positioned at the front of the anal fin. The pelvic fin weakly concave (curving inwards) rear margins, and the pectoral fin's outer margin is slightly convex (curving outwards), and both fins are weakly falcate. The snout is round and shorter than the width of the mouth. There is no mid-dorsal ridge present on this species.
The upper teeth are narrow and broad with triangular smooth-edged cusps and finely serrated bases. These teeth get more oblique as they get closer to the corner of the mouth. The lower teeth are narrow and triangular with smooth-edged cusps.
Lemon shark scales are large and overlapping with 3 to 5 ridges. The middle ridge is high, sharp and separated by deep furrows, and the back margins are opposite the primary ridges. The basal plates and pedicels are broad.
Lemon sharks usually range between the lengths of , and have a growth rate of 0.21 inches per year (0.54 cm per year). The maximum length that can be reached by this species is between . Pups are between 24-26 inches (60-65 cm) at birth.
The Lemon shark is viviparous, meaning that they give live birth. After a gestation period of 10 to 12 months, pregnant females enter shallow nursery areas in spring and summer to give birth to litters of 4 to 17 pups. The pups have a very slow growth rate and remain within nursery grounds for quite a long time, where they are in less danger from predators. The mangroves that the young mainly inhabit are highly productive waters, creating an excellent area for feeding, but also an area of very low oxygen content. However, the Lemon shark has many adaptations that increase oxygen uptake, such as blood with an unusually high affinity for oxygen. As they grow, their range increases dramatically, from up to around . Maturity is reached at about 6 and a half years of age, and it is believed that the Lemon shark lives for up to 27 years.
When it comes to hunting, the Lemon shark is known to be very patient. They are able to use their yellow coloring to help them successfully hide in their natural habitat. They are often found swimming along the sand of the bottom of the water so they blend in easily. This makes it easy to hide from predators and also to be able to find prey.
It is believed that this shark has a special set up with the retina. This enables them to be able to see very clearly even in the murky depths under the water. The Lemon Shark can be aggressive to humans, and is known to have a powerful bite. Most of the attacks that have been noted were provoked, but not all. Since Lemon sharks can blend into their surroundings so well, it is easy for someone to accidentally disrupt the shark.