J. A M. C H E M. SOC.
NEWS OF THE WEEK STM tip
The researchers precisely position the probe tip of a scanning tunneling microscope over the diacetylene segments of 10,12-nonacosadiynoic ( R´ R acid molecules assembled side by ELECTRONICS: Researchers link ) on a flat graphite surface. An R n polymer nanowires to single molecules side applied voltage initiates polymerization of the diacetylene moieties, forming a “wire” that propagates until it bumps against a nanocluster of SINGLE-MOLECULE electrical circuit, in which phthalocyanine molecules. One of these molecules, deorganic compounds substituting for components posited on top of the long carboxylic acid chains, forms such as wires, transistors, and rectifiers are all a bond to the reactive end of the nanowire about 70% covalently bonded, just took a step closer to reality, acof the time, the researchers find. cording to a new report (J. Am. Chem. Soc., DOI: 10.1021/ With the chemical soldering technique, the researchja111673x). In addition to being exceedingly small—a ma- ers connect two polymer wires to a single phthalojor goal in electronics—such a circuit could have higher cyanine molecule. This circuit, they say, could act as a computing power than current silicon-based devices. molecular-scale resonant tunneling diode, a circuit eleConnecting molecular nanowires in a controlled ment that allows electrons to tunnel through at specific fashion to single molecules that function like circuit energy levels. This work is a “breakthrough” for the elements is “one of the great challenges of field, says Robert Stadler, a physical chemthe field,” says Mark A. Ratner, a materials VIDEO ONLINE ist at the University of Vienna, but “it chemist at Northwestern University. Yuji doesn’t mean that we are now ready to print single-moleOkawa of Japan’s National Institute for Materials Scicule circuits.” Further studies must be done, and Okawa ence and coworkers have now addressed this challenge says that measuring the electronic properties of his new by developing “chemical soldering,” a bond-forming circuit and linking polymer nanowires to molecules method that connects a conductive polymer wire and a other than phthalocyanine are up next.—LAUREN WOLF phthalocyanine molecule to create a circuit.
WIRING A SINGLEMOLECULE CIRCUIT
A
JAPAN’S CHEMICAL PROFITS SURGE ANNUAL RESULTS: Earthquake had
minimal impact on 2010 results
M
AJOR JAPANESE chemical firms reported
much better profits in their most recent fiscal year, which ended on March 31, than in the yearago period. The March 11 earthquake did disrupt production significantly at many companies, but it affected only the last three weeks of a generally strong year. Japan’s largest chemical company, Mitsubishi Chemical, reported a record net profit of more than $1 billion, or six-and-a-half times more than the previous year. For most of the year, Mitsubishi enjoyed favorable conditions in Japan thanks to rising consumer and corporate spending. The firm said conditions became “severe” after the earthquake because it had to stop operations in Kashima, where it operates its largest plants. Sumitomo Chemical, Japan’s second-largest chemical producer, raised its net profit by 66%. It credited strong demand for electronic materials and higher margins for industrial chemicals. Sumitomo noted that the start-up of its Rabigh joint venture in Saudi Arabia in April 2009 boosted its sales of petrochemicals. Crediting buoyant economic conditions in Asia,
R´
N
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N NH
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N
An STM tip initiates polymerization of the diacetylene groups in longchain carboxylic acid molecules on a surface to form a wire (yellow) that then forms a bond to a single phthalocyanine molecule (blue). R = CH3(CH2)15 and R´ = HOOC(CH2)8.
Japan’s most profitable chemical company, Shin-Etsu Chemical, boosted its net profit by almost 20% to $1.2 billion in the latest fiscal year. Shin-Etsu noted that the semiconductor business was quite strong in the first half of the year. The company is still struggling to restart PVC production at a site near Tokyo and silicon wafer output at a plant closer to the earthquake’s epicenter. JSR, a maker of synthetic JAPANESE COMPANY RESULTS rubber and elecFirms post strong profits for fiscal 2010 tronic materials, increased its net SALES earnings by 87%. EARNINGSa PROFIT MARGINb CHANGE Company Presi$ MILLIONS 2010 2009 2010 FROM 2009 2010 2009 dent Nobu KoAsahi Kasei $19,314 11.5% $728 $306 3.8% 1.8% DIC 9,412 2.8 190 31 2.0 0.3 shiba tells C&EN JSR 4,116 9.8 309 165 7.5 4.4 that his firm was Kaneka 5,484 10.0 140 102 2.6 2.0 able to maintain Mitsubishi 38,265 25.9 1,010 155 2.6 0.5 or improve its rubber margins. Mitsui 16,816 15.2 301 -338 1.8 def In the electronShin-Etsu 12,787 15.4 1,210 1,013 9.5 9.1 Sumitomo 23,954 22.3 295 178 1.2 0.9 ics business, he Teijin 9,856 6.5 304 -431 3.1 def notes, the marToray 18,604 13.2 700 -171 3.8 def ket for semiconductor materials NOTE: Fiscal year ended March 31. Monetary figures converted at March 31 exchange rate of $1.00 = 82.76 yen. a After-tax earnings. was generally b After-tax earnings as a percentage of sales. def = deficit. healthy. But demand for liquidcrystal display materials slackened in Japan after the end of a stimulus program.—JEAN-FRANÇOIS TREMBLAY
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