INORGANIC ANTIAROMATICITY
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"Despite the major challenges that Schering- Plough faces to- day, we can turn this situation around and build a strongfuture!' —Fred Hassan, CEO BUSINESS 2.49 A ANTITRADITION Wang (left) and Boldyrev teamed up to make the anti- aromatic Al/~ anion, which is stabilized by three lithium cations (Li = red, Al = blue). HASSAN TO LEAD SCHERING-PLOUGH Fixer of broken companies is hired to return drugmaker to success S CHERING-PLOUGH, AFTER suffering through two years of stagnating sales growth and declining earnings, has elect- ed Fred Hassan, 57, as its new chairman, president, and CEO. He succeeds Richard Jay Kogan, who relinquished the title of chairman in November 2002 and the title of CEO on April 20. Hassan became free to join Schering-Plough two weeks ago after declining the vice chairman's job at Pfizer, which just acquired Pharmacia, the company he for- merly headed. Hassan had joined what was then Pharmacia & Up- john in 1997, and within a few years, he had improved its prof- itability purchased Monsanto for its Searle drug unit, spun off Monsanto's agribusiness opera- tions, and struck a $58 billion merger deal with Pfizer. Schering-Plough's sharehold- ers and board of directors hope Hassan will now work his magic on improving his new company In the past year, the company saw sales drop after its $3 biUion-per- year antihistamine Claritin be- came a cheaper over-the-counter product. The firm also had to re- solve FDA compliance issues through a $500 million consent decree and faced a Securities & Exchange Commission probe and civil action related to inappropri- ate information disclosures. Last week at Schering-Plough's annual meeting, Hassan laid out a five-phase agenda he expects will take five to six years to complete. It includes stabilizing the busi- ness, then repairing and turning it around through an improved corporate culture, reduced costs, and better product flow Eventu- ally Hassan foresees growth based on a foundation of several key products, including the anticho- lesterol drug Zetia, launched in late 2002 with Merck. Standard & Poor's calls Has- san's appointment a positive de- velopment but says the change does not affect its outlook on the company For now, the credit-rat- ing agency says it will monitor Schering-Plough's progress in re- vitalizing its core pharmaceutical business.-ANΝ THAYER CHEMICAL BONDING INORGANIC ANTIAROMATICITY Al 4 4_ is first reported all-metal system with An τι electrons MAGE AND PHOTO COURTESY OF A. BOLDYREV, L-S. WANG A ROMATIC COMPOUNDS — stabilized by An + 2 ττ elec- trons —were once thought to be purely the domain of organic chemistry. But in the past few years, chemists have discovered several aromatic all-metal cluster systems. Now, the concept of anti- aromaticity—desta- bilization observed in cyclic systems with An ττ electrons —is following suit. Chemistry pro- fessor Alexander I. Boldyrev of Utah State University and physics professor Lai-Sheng Wang of Washington State University'sTri-Cities cam- pus and Pacific Northwest Na- tional Lab and their coworkers have made Li 3 Al 4 " in which the AI4 4 " anion has four ττ electrons {Science, 300,622 (2003)}. The work is an extension of re- search that Boldyrev and Wang have carried out on all-metal aro- matics, such as NaAl 4 ~ in which the Al 4 2 " anion contains two ττ electrons (C&EN, Sept. 24,2001, page 39). They reasoned that if the Al 4 4 ~ anion with two addi- tional ττ electrons could be made, it would be antiaromatic. Li 3 Al 4 ~ was prepared by laser vaporization of a LiAl alloy and separated from other Li x Al y ~spe- cies using time-of-flight mass spectrometry It was character- ized by photoelectron spectros- copy and ab initio calculations to determine the optimized struc- ture and molecular orbital pic- tures, verifying the presence of the four ττ electrons. The bonding patterns and the rectangular shape of the A^ 4- unit are analogous to cyclobutadiene, which is the quin- tessential antiaromatic organic compound, the researchers note. Further advancement of aro- maticity and antiaromaticity in- to metal territory will be valuable for understanding the properties ofmetal clusters, bulk metals, and alloys, the researchers believe. Making A^ 4- on a large scale is an interesting idea but might not be possible, Wang adds, although heavier group 13 analogs could be easier to make. Bimetallic com- pounds exhibiting antiaromatic structural units may already ex- ist, he says.-STEVE RITTER 8 C&EN / APRIL 28, 2003 HTTP://WWW.CEN-ONLINE.ORG ο ο χ Q- - < < Χ NEWS OF THE WEEK
Transcript of INORGANIC ANTIAROMATICITY
"Despite the major challenges that Schering-Plough faces today, we can turn this situation around and build a strong future!' —Fred Hassan, CEO
B U S I N E S S
2.49 A
ANTITRADITION Wang (left) and Boldyrev teamed up to make the anti-aromatic Al/~ anion, which is stabilized by three lithium cations (Li = red, Al = blue).
HASSAN TO LEAD SCHERING-PLOUGH Fixer of broken companies is hired to return drugmaker to success
S CHERING-PLOUGH, AFTER suffering through two years of stagnating sales growth
and declining earnings, has elected Fred Hassan, 57, as its new chairman, president, and CEO. He succeeds Richard Jay Kogan, who relinquished the title of chairman in November 2002 and the title of CEO on April 20.
Hassan became free to join Schering-Plough two weeks ago after declining the vice chairman's job at Pfizer, which just acquired Pharmacia, the company he formerly headed. Hassan had joined what was then Pharmacia & Up
john in 1997, and within a few years, he had improved its profitability purchased Monsanto for its Searle drug unit, spun off Monsanto's agribusiness operations, and struck a $58 billion merger deal with Pfizer.
Schering-Plough's shareholders and board of directors hope Hassan will now work his magic on improving his new company In the past year, the company saw sales drop after its $3 biUion-per-year antihistamine Claritin became a cheaper over-the-counter product. The firm also had to resolve FDA compliance issues
through a $500 million consent decree and faced a Securities & Exchange Commission probe and civil action related to inappropriate information disclosures.
Last week at Schering-Plough's annual meeting, Hassan laid out a five-phase agenda he expects will take five to six years to complete. It includes stabilizing the business, then repairing and turning it around through an improved corporate culture, reduced costs, and better product flow Eventually Hassan foresees growth based on a foundation of several key products, including the anticho-lesterol drug Zetia, launched in late 2002 with Merck.
Standard & Poor's calls Hassan's appointment a positive development but says the change does not affect its outlook on the company For now, the credit-rating agency says it will monitor Schering-Plough's progress in revitalizing its core pharmaceutical business.-ANΝ THAYER
C H E M I C A L B O N D I N G
INORGANIC ANTIAROMATICITY Al4
4_ is first reported all-metal system with An τι electrons
MAGE AND PHOTO COURTESY OF A. BOLDYREV, L-S. WANG
AROMATIC COMPOUNDS — stabilized by An + 2 ττ electrons —were once thought
to be purely the domain of organic chemistry. But in the past few years, chemists have discovered several aromatic all-metal cluster systems. Now, the concept of anti-
aromaticity—desta-bilization observed in cyclic systems with An ττ electrons —is following suit.
Chemistry professor Alexander I. Boldyrev of Utah State University and physics professor
Lai-Sheng Wang of Washington State University'sTri-Cities campus and Pacific Northwest National Lab and their coworkers have made Li3 Al4" in which the AI44" anion has four ττ electrons {Science, 300 ,622 (2003)}.
The work is an extension of research that Boldyrev and Wang have carried out on all-metal aro-matics, such as NaAl4~ in which the Al4
2" anion contains two ττ electrons (C&EN, Sept. 24,2001, page 39). They reasoned that if the Al4
4~ anion with two additional ττ electrons could be made, it would be antiaromatic.
Li3Al4~ was prepared by laser
vaporization of a LiAl alloy and separated from other LixAly~spe-cies using time-of-flight mass spectrometry It was characterized by photoelectron spectroscopy and ab initio calculations to determine the optimized structure and molecular orbital pictures, verifying the presence of the four ττ electrons. The bonding patterns and the rectangular shape of the A^ 4 - unit are analogous to cyclobutadiene, which is the quintessential antiaromatic organic compound, the researchers note.
Further advancement of aro-maticity and antiaromaticity into metal territory will be valuable for understanding the properties of metal clusters, bulk metals, and alloys, the researchers believe. Making A^ 4 - on a large scale is an interesting idea but might not be possible, Wang adds, although heavier group 13 analogs could be easier to make. Bimetallic compounds exhibiting antiaromatic structural units may already exist, he says.-STEVE RITTER
8 C & E N / A P R I L 2 8 , 2 0 0 3 H T T P : / / W W W . C E N - O N L I N E . O R G
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