Veba Oil—are all either producers or users of propylene. The partners say they will need at least three months to develop EPDC and write a business plan, and then everything must be approved by their shareholders. Only then can construction begin on the grid, which will run from Rotterdam to Antwerp, on to Cologne, and from there to a number of end points within the heavily industrialized Ruhr Valley, northeast of Cologne. Rotterdam and Antwerp are among the major ports of Northwest Europe and the sites of massive chemical development, in part because of their ability to offer companies a competitive advantage from close access to low-cost feedstocks. Inland sites, by comparison, are at a disadvantage. The pipeline grid, however, will open up the inland areas to coastal prices, giving them a competitive advantage similar to the one Dow Chemical has gained from its ethylene pipeline that runs from Rostock, on the Baltic, to Dow's Bohlen site near Leipzig, Germany (C&EN, Aug. 28, page 13). None of the parties is under any illusion that putting together thefinalpackage will be easy. There are 13 different companies, three different countries (Belgium, the Netherlands, and Germany), and four different governments (the three national governments and the European Union) involved. "All these have to get on board," points out a representative of one of the partner firms. Patricia Short
nuclear weapons program with the intent of passing it to a foreign country (see page 29). Last fall, Congress passed a law blocking lab visits by scientists who are citizens of China, Russia, India, and other sensitive countries until 45 days after certification is made. Nearly 2,000 scientists from sensitive countries visit the labs annually (C&EN, Dec. 6, 1999, page 27). Although foreign scientists already employed at the lab were exempt and a very small number of scientists obtained waivers, the moratorium has had a profound effect on scientific exchanges, says James Danneskiold, a Los Alamos spokesman. "We will be very happy to see this end," he notes. Because of the moratorium, Danneskiold says, collaboration between the labs and U.S. universities in some scientific areas has "vanished" because of the large number of foreign scientists, many from sensitive countries, studying at U.S. schools. For example,
one university computer science graduate program that had close ties to Los Alamos had no students who were U.S. citizens. The ban also ended collaboration with key scientists who are world leaders in areas critical to the labs. And it has also led to U.S. scientists leaving Los Alamos, Danneskiold says. Since May, 14 of 34 core computer scientists in Los Alamos' advanced computing lab have left, he says, citing the need for unfettered exchanges with university scientists. "This has been a real blow," Danneskiold says. "Computer science is where we have our strongest needs and do our most active recruiting." Rebuilding may be difficult because the restrictions have damaged personal relationships upon which scientific exchanges are often based. "In some cultures, if scientists trust you, you can get a lot done," Danneskiold says. "If they don't, forget about it." Jeff'Johnson
Benzene Coordinates To Six Mercury Atoms
Ban On Foreign Scientists' Visits To Weapon Labs Lifted Once again, foreign scientists from "sensitive" countries may be able to work with U.S. scientists at Department of Energy nuclear weapons laboratories. Last week, the heads of DOE, the Federal Bureau of Investigation, and the Central Intelligence Agency certified to Congress that DOE now has policies in place needed to safeguard research at Sandia, Lawrence Livermore, and Los Alamos National Laboratories. The certification responds to fears of foreign espionage raised last year in Congress and allegations that a Chinese-born, American nuclear scientist working at Los Alamos had illegally downloaded secret data on the nation's
Benzene has been sandwiched between two identical planar trimetallic molecules in such a way that each of the six metal atoms coordinates to a different C-C bond of the benzene [J. Am. Chem. Soc, 122, 8 3 3 5 (2000)]. The interaction represents a new bonding mode for benzene, according to assistant professor of chemistry François P. Gabbaï and visiting scholar Mitsukimi Tsunoda at Texas A&M University. Tsunoda prepared the "supramolecule" by dissolving in boiling benzene a known Lewis acid—trimeric (tetrafluoro-o-phenylene)mercury (shown in both red and blue, above left). The crystals that formed upon cooling were found by X-ray crystallography to consist of extended stacks of organomercury molecules, with each molecular pair sandwiching a single benzene molecule, as shown here in two views. The side view (right) shows a portion of a stack, with carbon depicted in gray; fluorine, greenish-yellow; and mercury, purple. Hydrogen atoms are not shown. In the view from above (left), the organomercury molecules are seen to be arranged in a staggered conformation, making hexacoordination to mercury possible. Because of the stacked structure, each mercury atom coordinates to a C-C bond of two different benzene molecules. Gabbaï's group is investigating whether this new bonding motif could be used to orient a trio of alkyne molecules for cyclization. Ron Dagani SEPTEMBER 4,2000 C&EN
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