Benzene snapshot captures images of individual rings

The distinctive six-membered-ring shape of benzene is clearly visible in pic­tures of the molecule generated with a scanning tunneling microscope (STM) by IBM scientists. The images look remarkably like the space-filling molecular models of benzene that chemists have used for decades. The technique, invented at IBM's research labs in Zurich in 1981, employso a needlelike probe that scans the sample surface at a distance of about 10 A. A current passes between the probe and sample when a voltage is applied to the probe. The size of the current, which varies with the gap between the two surfaces, is a sensitive indicator of the distance between them. Scientists at IBM's Almaden Research Center in San Jose, Calif., studied an ordered array of benzene and carbon monoxide molecules tightly bonded to a rhodium surface. (The carbon monoxide does not show up in the picture.) The researchers first tried to work with benzene alone, but found the molecules tended to slither across the rhodium surface, blurring the STM image.

Capacity grows for olefins worldwide With growing demand for ethylene and its coproducts and derivatives, announcements of expansions con­tinue in the olefins segment of the chemical industry.

The largest expansion announced this month is by Dow Chemical, which plans a new cracker at its Freeport, Tex., plant site with an ethylene capacity of 1.5 billion lb per year. Coproducts capacity will be 600 million lb per year of pro­pylene, other olefins, and aromatics, including 80 million gal of benzene a year. Dow anticipates startup in early 1992 for the cracker. Feed­stocks will range from ethane to naphtha.

Two new propylene facilities are being planned. Enterprise Products Co. has begun a joint venture with Aristech Chemical, Fina Oil & Chemical, and Quest Energy to build a unit at Mont Belvieu, Tex., capa­ble of making 720 million lb per year of polymer-grade propylene through fractionation and purifica­tion of various propylene-rich feed­stocks. The Enterprise unit can be expanded to more than 1 billion lb, says Charles J. Roth, executive vice president. Enterprise currently runs a 680 million lb-per-year propylene unit at the site.

Intercontinental Terminals will build and operate, at its Houston Ship Channel terminal, a 10,000 met-ric-ton-per-year refrigerated storage facility to be under long-term lease to Himont. The Himont storage unit will be the second that Interconti­nental Terminals will build for use in export and import of propylene, says Intercontinental Terminals president Stephen W. Miles.

Polyolefin expansions include units for both high-density poly­ethylene and polypropylene. Phil­lips 66 Co. will expand its Pasade­na, Tex., HDPE unit by 275 million lb per year to about 1.8 billion lb per year by early 1990. In the U.K., Shell Chemical U.K. will build a new polypropylene unit at Carring-ton with capacity for 287 million lb per year. When completed in 1991, the unit will replace an old 265 mil­lion lb-per-year unit.

Industry executives are aware of the potential for sizable overcapaci­ty (and marginal profits) for basic organic chemicals and their deriva­tives by the early 1990s. Some in­dustry sources have suggested that many of the capacity expansion plans revealed since early this spring could be preemptive announce-

In a major policy decision taken by the British government, work on fast breeder reactor technology in the U.K. is to be cut back during the next five years. One outcome of the move is that the work force of the U.K. Atomic Energy Authority will be reduced drastically.

In making the announcement, Cecil E. Parkinson, U.K. Secretary of State for Energy, notes that his de­cision is based on "the expectation that commercial deployment of fast reactors in the U.K. will not be re­quired for 30 or 40 years." Continu-

ments, aimed at making other pro­ducers re th ink their expansion plans. Large reductions in company market research staffs during recent years, one industry source says, could mean there possibly are er­rors in estimates of future demand for chemicals and polymers.

Bruce Greek

ing the program at the present lev­el doesn't warrant the high costs involved, he reasons.

Ironically, British scientists were among the early proponents of the fast breeder reactor 40 or so years ago. The term takes its name from the high speed of the neutrons in the reactor core, which leads to more efficient use of fuel. Indeed, a fea­ture of such reactors is that plutoni­um, itself a fuel, is bred when the fast neutrons collide with uranium-238 nuclei. So by progressively gen­erating and burning plutonium, a

U.K. slashes breeder reactor program

August 1, 1988 C&EN 5

News of the Week

fast breeder reactor can extract up to 60 times more energy from a giv­en quantity of natural uranium than is possible with conventional nu­clear reactors.

Faced with the likelihood of a decline in uranium supplies and ris­ing costs of hydrocarbon fuels in the 1950s—prospects that since have changed markedly—it seemed pru­dent at the time to proceed with fast breeder reactor development. First to go in at Dounreay, Scotland, was a 15-MW experimental reactor that started up in 1957. By 1977, the U.K/s 250-MW prototype'fast breed­er reactor reached full thermal pow­er and has been supplying electric­ity to the Scottish grid ever since.

The prototype fast breeder reac­tor will remain in operation until 1994, and the fuel reprocessing plant at the site will continue operating for a further three years. Meanwhile, fast breeder reactor R&D spending throughout the UKAEA will be pared to about $17 million annually, less than a fifth of the current rate, a reduction that will affect 1500 jobs.

Dermot O'Sullivan

Nature refutes research it had published earlier Nature, which four weeks ago pub­lished what it considered unbeliev­able research results, refuted them last week, calling them "a delusion" and "not reproducible."

That conclusion emerged after a trio of investigators, led by Nature editor John Maddox, spent five days observing the researchers perform the controversial experiments under carefully controlled conditions. The investigative team's report, published in the journal's July 28 issue, is sharp­ly critical of the researchers working in Jacques Benveniste's lab at the National Institute of Health & Med­ical Research (INSERM) outside Paris.

In a rebuttal in that issue, Benve-niste lashes out at his "lesson-givers," charging that their investigation was "a mockery of scientific inquiry" and that their report "is filled with inaccuracies and distortions."

The controversy made interna­tional headlines on June 30 when Benveniste and a dozen coworkers

in France, Israel, Italy, and Canada published an amazing claim in Nature [333,816 (1988)]. They reported * that an aqueous solution of an anti­body retains its ability to evoke a biological response even when di­luted to the point where no anti­body molecules could be expected to remain (C&EN, July 4, page 5).

The results, according to the jour­nal, suggested that "water can be imprinted with the memory of past solutes." Homeopathic doctors, who claim that vanishingly small doses of certain drugs can effect cures, embraced the French findings as vindication of their beliefs.

But the Nature panel says it could find "no substantial basis" for the claim that antibody diluted by fac­tors as great as 10120 retains its bio­logical activity. Such claims, the panel says, are based largely on ex­periments lacking good statistical controls. The researchers, it adds, made no real effort to exclude sam­pling errors, observer bias, or the possibility of contamination. Many of the data, the report notes, are "artefacts of statistical noise." And experiments that did not support their claim—and there were many— were brushed off without an inves­tigation of the reasons for the fail­ure, according to Nature. No charg­es of fraud or trickery were made.

The Nature investigative team con­sisted of Maddox, a journalist whose background is in theoretical phys­ics, and two men who have worked to expose scientific fraud—Walter W. Stewart of the National Institutes of Health and magician James Randi, who is also a MacArthur Foundation fellow. Besides examining lab note­books, the trio observed and even participated in experimental runs.

The Nature team was not given access to most of the data collected at the other labs involved in the original study. The data from Israel "are far more impressive" than those from the INSERM lab, Maddox tells C&EN. However, he adds, there is evidence that the samples were con­taminated with protein.

Following the investigation, Ben­veniste was allowed one page to reply to the panel's report, with the promise that his words would not be altered. What resulted is an emotional—and at times disjointed—

rebuttal that invokes "Salem witch­hunts." Benveniste charges that the three investigators—none of whom has first-hand experience in his re­search field—failed "to get to grips with our biological system." The panel, he says, created a climate of suspicion and fear in his lab in which attempts to reproduce their data became "an ordeal." "Who, with even the slightest research background, would blot out five years of our work and that of five other laboratories on such grounds?" Benveniste says in his rebuttal.

Daniel E. Koshland Jr., editor of Science, the American analogue of Nature, is puzzled why the British journal chose to publish Benveniste's results before investigating them. "I would want to publish papers that confronted existing theory with totally new ideas," he says. But if a new idea runs counter to well-estab­lished scientific theory, you need much more convincing data, he says. The French data, he believes, are too "flimsy" to support the extraordinary claim of a memory effect in water.

When C&EN asked Maddox why his journal published Benveniste's paper before conducting its inquiry, Maddox cited a number of factors. Publication had been held up for two years while the French group complied with the journal's and the referees' requests for additional ex­periments and controls. In the end, the referees "could see nothing wrong with the experiments as de­scribed [in the paper]," Maddox says. Benveniste was exceedingly insist­ent that Nature was withholding "one of the world's great discov­eries," according to Maddox. The general press in France was already heralding the findings and allud­ing to their suppression by the jour­nals. "We had gotten to the point where we couldn't really see how to make progress without [putting it before the scientific community]," Maddox says. "A mixture of exas­peration and curiosity eventually persuaded us to publish it."

Benveniste remains convinced that he's right and "is not going to throw the towel in," Maddox says. "But in the long run, everything will depend on what his scientific colleagues say."

Ron Dagani

6 August 1, 1988 C&EN