7WWW.CEN-ONLINE.ORG AUGUST 25, 2008

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Adiponitrile

CHEMICAL AND FIBER MAKER Invista is once again suing its rivals. It is taking Rhodia and Du-Pont to court over what it calls a conspiracy to

steal its trade secrets for manufacturing the nylon 6,6 intermediate adiponitrile.

Adiponitrile is used to make hexamethylenediamine, a raw material for nylon 6,6. Invista says it is the world’s largest producer of the chemical. Dupont purchases its adiponitrile from Invista for its nylon 6,6 engineering polymers business.

Both Invista and Rhodia are planning adiponitrile plants in Asia. Invista is building one in Shanghai as part of an integrated nylon 6,6 complex. Rhodia has been studying the feasibility of a plant in Asia and is building a downstream hexamethylenediamine plant in China.

Invista states in the suit filed in New York City that Rhodia plans to use Invista’s Gen 1 technology for mak-ing adiponitrile from butadiene at the plant it is plan-ning. The technology was part of Koch Industries’ 2004 purchase of Invista from DuPont for $4.2 billion.

Invista says Rhodia pilfered the technology via their Butachimie joint venture in France. Invista argues that Rhodia must be planning on using its technology il-licitly because it is not a licensee of another butadiene-based adiponitrile technology, nor has it had the time to develop its own.

Invista says DuPont intends to invest in Rhodia’s adiponitrile plant and is “generally advising Rhodia in its effort to design, construct, and operate” the adi-ponitrile plant using its technology.

Invista is seeking to prevent Rhodia and DuPont from using the technology, as well as unspecified damages.

Rhodia says Invista’s case is without merit. In a statement, the company said the suit “forms part of Invista’s attempts to prevent Rhodia from chal-lenging Invista’s dominant market position in poly-amides.” The company notes that Invista withdrew a suit against it concerning the technology in Texas.

Invista has sued its former owner before. It has an $800 million suit against DuPont to recover costs it is incurring to fix environmental and safety problems at the former DuPont plants that it purchased.

DuPont says that the new suit has no factual basis and that the company respects the intellectual prop-erty rights of others. However, DuPont doesn’t deny that it is considering an investment in the Rhodia plant. “DuPont continues to evaluate a variety of options,” spokesman Daniel A. Turner tells C&EN.—ALEX TULLO

This probe consists of fluorescein (green), a metal-chelating agent (purple), and polyethylene glycol (red) on a peptide scaffold attached to a gold nanoparticle.

INVISTA SUES RHODIA, DUPONT

BAD BLOOD: Firms are trying to steal adiponitrile technology, Invista claims

MOST METHODS for generating imaging probes and other molecular constructions with multiple functions, such as target recognition

and fluorescence, require the different portions of the system to be added sequentially. This sequential process makes it difficult to create reproducible materials with well-characterized stoichiometry, a desirable feature when it comes to medical applications. To address this limitation, researchers at Massachusetts General Hospi-tal have developed a more readily controllable synthesis of multifunctional imaging probes and nanomaterials.

The investigators’ approach is to attach multiple functional moieties to a peptide scaffold that has a single reactive site (Chem. Commun., DOI: 10.1039/b809537j). They then use that site to attach the entire construct to a substrate, such as a gold nanoparticle, in one step. This approach yields a final product with a well-defined stoichiometry, according to Elisabeth Garanger, who presented the work at the American Chemical Society national meeting in Philadelphia at a

symposium sponsored by the Divi-sion of Analytical Chemistry. She is a postdoctoral associate working with Lee Josephson at the hospital’s Center for Molecular Imaging Research.

Garanger described two types of “multifunctional single-attachment point” (MSAP) reagents. Bifunctional scaffolds consist of a dipeptide of lysine and cysteine; trifunctional scaffolds are made of tetrapeptides with two lysines, β-alanine, and cysteine. The functional moieties are attached to the primary amines of the lysines. The cysteine’s thi-ol is modified by a maleimide-containing cross-linking agent to display the desired reactive group.

Garanger reported two probes made by the simpli-fied process. In one, an MSAP reagent bearing poly-ethylene glycol for stabilization and fluorescein and diethylenetriaminepentaacetic acid (a metal-chelating agent) to add a detection function were attached to gold nanoparticles. Usually, multifunctional gold nano-particles are difficult to make reproducibly by sequen-tial synthesis, Garanger said. In the other type of probe, she and her colleagues attached a scaffold containing a metal-chelating agent and a fluorophore to a tumor-targeting cyclic peptide.

“The ability to control the stoichiometry of different groups using the peptide scaffold is very elegant,” says Mansoor M. Amiji, professor of pharmaceutical sci-ences at Northeastern University.—CELIA ARNAUD

SIMPLIFIED PROBE SYNTHESIS

ACS MEETING NEWS: Method yields reproducible multifunctional

probes for cellular imaging