acetate anion

acetate ester

An acetate /ˈæsɪteɪt/ is a derivative of acetic acid. This term includes salts and esters, as well as the anion found in solution. Most of the approximately 5 billion kilograms of acetic acid produced annually in industry are used in the production of acetates, which usually take the form of polymers. In nature, acetate is the most common building block for biosynthesis. For example, the fatty acids are produced by connecting C2 units derived from acetate.^[1]

Nomenclature and common formula[link]

When part of a salt, the formula of the acetate anion is written as CH₃CO₂⁻, C₂H₃O₂⁻, or CH₃COO⁻. Chemists abbreviate acetate as OAc⁻ or AcO⁻. Thus, HOAc is the abbreviation for acetic acid, NaOAc for sodium acetate, and EtOAc for ethyl acetate.^[2] The abbreviation "Ac" (or "AC") is also sometimes encountered in chemical formulas to indicate the acetate ion. This abbreviation is not to be confused with the symbol of actinium, the first element of the actinides series. For example, the formula for sodium acetate might be abbreviated as "NaAc", rather than "CH₃COONa". Care should also be taken to avoid confusion with peracetic acid when using the OAc abbreviation; for clarity and to avoid errors when translated, HOAc should be avoided in literature mentioning both compounds.

The systematic name for acetate is ethanoate, but the IUPAC preferred name remains the common name, acetate.^[3]

Salts[link]

The acetate (poo) anion, [CH₃COO]⁻, is one of the carboxylate family. It is the conjugate base of acetic acid. Above a pH of 5.5, acetic acid converts to acetate:^[2]

CH₃COOH ⇌ CH₃COO⁻ + H⁺

Many acetate salts are ionic, indicated by their tendency to dissolve well in water. A commonly encountered acetate in the home is sodium acetate, a white solid that can be prepared by combining vinegar and sodium bicarbonate ("bicarb"):

CH₃COOH + NaHCO₃ → CH₃COO⁻Na⁺ + H₂O + CO₂

Transition metals can be complexed by acetate. Acetate is considered a relatively weak ligand in coordination chemistry because it can only form monodentate complexes. Examples of acetate complexes include chromium(II) acetate and basic zinc acetate.

Commercially important acetate salts are aluminium acetate, used in dyeing, ammonium acetate, a precursor to acetamide, and potassium acetate, used as a diuretic. All three salts are colourless and highly soluble in water.^[4]

Esters[link]

Acetate esters have the general formula CH₃CO₂R, where R is an organyl group. The esters are the dominant forms of acetate in the marketplace. Unlike the acetate salts, acetate esters are often liquids, lipophilic, and sometimes volatile. They are popular because they have inoffensive, often sweet odors, they are inexpensive, and they are usually of low toxicity.

Almost half of acetic acid production is consumed in the production of vinyl acetate, precursor to polyvinyl alcohol, which is a component of many paints. The second largest use of acetic acid is consumed in the production of cellulose acetate. In fact, "acetate" is jargon for cellulose acetate, which is used in the production of fibres or diverse products, e.g. the acetate discs used in audio record production. Cellulose acetate can be found in many household products. Many industrial solvents are acetates, including methyl acetate, ethyl acetate, isopropyl acetate, ethylhexyl acetate. Butyl acetate is a fragrance used in food products.^[4]

Acetate in biology[link]

Acetate is a common anion in biology. It is mainly utilized by organisms in the form of acetyl coenzyme A.^[5]

Intraperitoneal injection of sodium acetate (20 or 60 mg per kg body mass) was found to induce headache in sensitized rats, and it has been proposed that acetate resulting from oxidation of ethanol is a major factor in causing hangovers. Increased serum acetate levels lead to accumulation of adenosine in many tissues including the brain, and administration of the adenosine receptor antagonist caffeine to rats after ethanol was found to decrease nociceptive behavior.^[6][7]

Fermentation of acetate[link]

Acetic acid can also undergo a dismutation reaction to produce methane and carbon dioxide:^[8][9]

CH₃COO^– + H⁺ → CH₄ + CO₂       ΔG° = -36 kJ/reaction

This disproportionation reaction is catalysed by methanogen archaea in their fermentative metabolism. One electron is transferred from the carbonyl function (e^– donor) of the carboxylic group to the methyl group (e^– acceptor) of acetic acid to respectively produce CO₂ and methane gas.

Structures[link]

• 

  space-filling model of the acetate anion
• 

  ball-and-stick model of the acetate anion
• 

  resonance hybrid of the acetate anion
• 

  canonical forms of the acetate anion

See also[link]

Wikimedia Commons has media related to: acetates

• Acetic acid
• Acetylation
• Cellulose acetate
• Copper(II) acetate
• Fermentation (biochemistry)
• Sodium acetate

References[link]

Thomas J. Davies (October 14, 1896 – February 29, 1972) was an American football player and coach. He played as a halfback at the University of Pittsburgh and was a consensus All-American in 1918 and 1920. After retiring as a player, Davies worked as a football coach for the next 26 years, including stints at the University of Pennsylvania, Geneva College, Allegheny College, the University of Rochester, the Carnegie Institute of Technology, the University of Scranton, and Western Reserve University. He was inducted into the College Football Hall of Fame as a player in 1970.

Playing career[link]

Davies was a native of Gas City, Indiana. He moved to Washington, Pennsylvania when he was 11 years old.^[1] Davies played high school football at Aliquippa High School in Aliquippa, Pennsylvania, and at Kiski Preparatory School in Saltsburg, Pennsylvania. Davies was working in a Washington factory when he got the chance to play football at Kiski. A friend refused to accept a football scholarship there unless Davies went along.^[1]

Davies enrolled at the University of Pittsburgh where he played four seasons (1918–1921) of football under coach Glenn Scobey "Pop" Warner. Davies played in 31 games for the Pittsburgh Panthers and averaged 150 yards per game over his four-year career.^[2] He was selected as a first-team All-American in his freshman season of 1918 and again as a junior in 1920. As a freshman in 1918, Davies weighed only 142 pounds. In his first carry for Pitt, he ran for 13 yards against Washington & Jefferson—then a national power. Three plays later, he ran for 38 yards, "setting the pace for a stellar playing career."^[1]

Pitt's Tommy Davies runs against undefeated and unscored upon Georgia Tech in a 1918 game at Forbes Field. Pitt won the game 32–0 and is considered by many to be that season's national champion.

Davies helped Pitt to an undefeated season and a national championship in 1918,^[3] as he led the team in rushing, passing and receiving.^[4] He led Pitt in all-purpose yards all four years that he played.^[4] In a 1918 game against Georgia Tech, the freshman Davies accounted for five touchdowns—running 50 yards for a touchdown, returning two punts for touchdowns (a 60-yard and a 50-yard return), and passing for two more touchdowns.^[2] After watching Davies run back a kickoff 90 yards for a touchdown in 1918, one writer noted:

"When Brother Tom Davies caught the kickoff on the ten-yard line at Franklin Field in Philadelphia one Saturday in November, we saw the prettiest piece of open field work not off at an angle, Tommie ran the length since the days of Jim Thorpe. On a bee line of the gridiron, and in so doing he personally took care of seven men! Then just for fun he added two more. The papers said, ‘Tom Davies Beats Penn.’ It has been the same against Syracuse, Lafayette and Georgia Tech. And now Pitt is counting on another All-American."^[5]

As a junior in 1920, Davies led Pitt to another big win over the University of Pennsylvania. In what some called Davies’ finest game, he threw a touchdown pass, ran 80 yards for a touchdown, returned a kickoff 90 yards for a touchdown and returned an interception 60 yards for a touchdown.^[2][4] Also in 1920, he led Pitt to a 35–0 win over Syracuse, as he rushed for 255 yards and scored 16 points in only three quarters of play.^[2] In December 1920, Davies was elected by his teammates to be captain of Pitt's 1921 football team.^[6] Davies was selected as team captain at a team banquet at which the entire team gave Davies “a thunderous cheer.” The Cleveland Plain Dealer reported that Davies was so affected by the demonstration that he stammered only a few words of appreciation and left the hall saying, “I’m going to phone my mother and tell her all about it.”^[7]

Davies continues to rank among Pitt's all-time leaders in scoring with 181 points and all-purpose yards with 3,931 yards.^[4] He was survived by his wife and two daughters.^[1]

Coaching career[link]

After graduating from Pitt, Davies began a long career as a college football coach. His first coaching position was as an assistant to the legendary John Heisman at the University of Pennsylvania in 1922.^[8] At the time of his hiring at Penn, The New York Times noted: "Tom Davies, former Pitt captain and all-American halfback, makes his debut as a Penn coach. The versatile Davies, who raised havoc with a number of Penn elevens in recent years, will instruct in forward passing, punting and straight arming, and will also help Tom McNamara with the scrubs."^[9]

Davies received his first head coaching job in 1923 when he was hired as the head football coach for the Geneva College Golden Tornadoes located in Beaver Falls, Pennsylvania.^[8] He spent only one season at Geneva compiling a record of 6–2–1. As of completion of the 2007 season, this ranks him 18th at Geneva in total wins and fourth at Geneva in winning percentage (.722).^[10] In 1924, he was hired by Allegheny College where he remained for two seasons. In 1926, Davies was hired as the head football coach at the University of Rochester, where he spent nine years, coaching until 1934. After leaving Rochester, he spent one season as a coach at Carnegie Tech and another at Kiski Prep School.^[8]

In 1937, Davies took over as head football coach at the St. Thomas College. In his first season, he led the Tomcats to a 6–1–1 record. Prior to the start of the 1938 season, St. Thomas College changed its name to the University of Scranton. Davies's 1938 team finished with a record of 7–2. The team improved in 1939 and completed an undefeated 7–0–2 season. Davies resigned as Scranton's coach in March 1940 with a three-year record of 20–3–3.

After leaving Scranton, Davies went into the insurance business in the Cleveland area.^[8]

Although Davies insisted at the time of his resignation at Scranton that he was done with coaching, he was hired in March 1941 to take over as the head football coach for the Western Reserve University Red Cats.^[8] Davies served seven years as head coach at Western Reserve but was discharged in October 1947 by the University Board of Athletics. The dismissal came 24 hours after members of the team demanded that they finish the year under another coach.^[11]

Later years[link]

After permanently retiring from football in 1947, Davies returned to the insurance business in the Pittsburgh area.^[1]

Davies was inducted into the Pennsylvania Sports Hall of Fame in 1966 and the College Football Hall of Fame in 1970.^[2][3] He died of a heart attack in February 1972 at age 75.^[12] He died at his home in Pittsburgh's Highland Park district.^[13]

References[link]

External links[link]

• Tom Davies at the College Football Hall of Fame
• Tom Davies at the College Football Data Warehouse

John McLane by Daniel Strain

John McLane (February 27, 1852–April 13, 1911) was a furniture maker and politician from Milford, New Hampshire. He was Governor of New Hampshire from 1905 to 1907.

He was born in Lennoxtown, in Scotland, the son of Alexander McLane and his wife Mary, née Hay, and was brought to America with his family in 1853, when he was one year old. They settled in Manchester, and moved to Milford in 1869. Upon completion of his schooling, he became a cabinetmaker's apprentice, and opened his own shop in 1876. The business's success (it was for a time the largest manufacture of post-office furniture in North America) secured other business opportunities for him: he became a director of the Milford Granite Company, the Souheagan National Bank and the New Hampshire Fire Insurance Company.

On 10 March 1880 he married Ellen Luetta Tuck (1855–1927). They had four children, Clinton Averill McLane (1881), Hazel Ellen McLane (1885), John Roy McLane (1886), and Charles Malcolm McLane (1910).

McLane was elected, as a Republican, to the New Hampshire House of Representatives in 1885, and to the New Hampshire Senate in 1891, representing the 16th District 1891-92 and the 15th District 1893-94. He was president of the senate during his two terms. He was a delegate to the Republican National Convention from New Hampshire in 1900, and was elected governor in 1904.

As governor, McLane was instrumental in securing funding for highway improvement, and welcomed delegates to the Russo-Japanese War Peace Conference, which was held in Portsmouth during his term in office.

He died in Pinehurst, Moore County, North Carolina, and was interred at the Milford Cemetery, Milford, New Hampshire.

References[link]

External links[link]

• McLane at New Hampshire's Division of Historic Resources

v t e Governors of New Hampshire Weare Langdon Sullivan Langdon Sullivan J. Bartlett Gilman Langdon J. Smith Langdon Plumer Gilman Plumer S. Bell Woodbury Morril Pierce J. Bell Pierce Harvey Dinsmoor Badger Hill Page Hubbard Steele Colby Williams Dinsmoor Jr. Martin Baker Metcalf Haile Goodwin Berry Gilmore Smyth Harriman Stearns Weston Straw Weston Cheney Prescott Head C. Bell Hale Currier Sawyer Goodell Tuttle J. B. Smith Busiel Ramsdell Rollins Jordan Bachelder McLane Floyd Quinby Bass Felker R. Spaulding Keyes J. H. Bartlett A. Brown F. Brown Winant H. Spaulding Tobey Winant Bridges Murphy Blood Dale Adams H. Gregg Dwinell Powell King Peterson Thomson Gallen Roy Sununu J. Gregg Merrill Shaheen Benson Lynch