RESEARCH
synthesis for mixed trialkylboranes. Previously, these have been very difficult to prepare a n d have required many hours of work b y circuitous methods. T h e discovery that alkyl groups will exchange between a Grignard reagent and a trialkylborane gives a much more direct route. Thus, reaction of ethylmagnesium bromide with tri-w-butylborane gave either n-butyldiethylborane or di-n-butylethylborane depending upon the ratio of the reactants and the mode of addition.
Graphite Crucibles Give Pure Potassium Chloride Platinum impurities in p o t a s sium chloride crystals affect their electrical a n d optical properties Use graphite crucibles t o grow really pure potassium chloride crystals; t h e soPhjirsiwl·* called pure crysInorganic tals made in platChemistry ^ inum crucibles are not as pure as many people think. This advice Allen B. Scott of Oregon State College gave to the Division of Physical a n d Inorganic Chemistry. Much interest has centered on t h e alkali halide crystals for studying electrical and optical properties of ionic crystals. Such studies have a bearing on photography, scintillation counters, crystal counters, radiation dosimetry, infrared detection, and the behavior of insulators, to name a few. The alkali halide crystals a r e particularly important because they have simple structures and can b e obtained in large, single crystals. But the properties of KCl crystals are very sensitive to impurities». F o r this reason, the crystals are usually grown in platinum crucibles. However, molten alkali halides attack platinum at high temperatures in t h e presence of air. • Platinum Contamination. Scott and his coworker, William J. Fredericks, of Stanford Research Institute, examined several commercial and laboratory-grown KCl crystals, made, of ACS NATIONAL MEETING
133
course, in platinum crucibles. They found tfiat the crystals were luminescent —they emitted yellow light under ultraviolet excitation. Scott and Fredricks then intentionally contaminated potassium chloride with platinum and were able to relate the ultraviolet absorption to platinum content. Their conclusion—contamination in KCl crystals may run as high as 2, p.p.m. (as P t C l 6 - -) and could possibly be more at lower valent forms. T o bypass platinum contamination,
the researchers turned to graphite crucibles. They carefully purified the starting material, used a n inert atmosphere (argon), and avoided contaminating the crucible. T h e result was a KCl crystal which was "pure" as judged by ultraviolet absorption spectroscopy. Next step now that they have "pure" crystals: reinvestigate several important electrical and optical properties of alkali halides. National Science Foundation supported their work.
ACS Award—Paul-Lewis Laboratories Award in Enzyme Chemistry
EUGENE P. KENNEDY At the University of Chicago, Eugene P. Kennedy has a reputation as a n "outstandingly good teacher." Other achievem e n t s , however, lie behind his receipt of the PaulL e w i s Laboratories Award i n Enzyme Chemistry. F o r one thing, Kennedy has been able to tie down t h e specific role of cytidine nucleotides in the enzymatic synthesis of lecithin. H e has pinpointed these nucleotides a s t h e carriers of the ni- Eugene P. Kennedy, University of Chicago trogenous bases, choline (right), looks at his Enzyme Chemistry Award and ethanolamine. Ken- with Richard Kurth of Paul-Lewis Laboratories nedy's^ net synthesis of lecithin lias m a d e it available i n readily measurable amounts and prize for his work on the metabolism has m a d e it possible to follow the of glycerol. stoicfiiometry of lecithin biosynthesis Born in Chicago, Kennedy refrom its building blocks. ceived a B.Sc. from DePaul UniverKennedy also pioneered in demonsity in 1943. Then, with t h e biostrating fatty acid oxidation with chemical division of Armour & Co., isolated mitochondria. His experihe contributed greatly to the World m e n t a l techniques have been used War II program on large-scale fract o synthesize sphingomyelin enzytionation of human blood plasma. matically. This work with sphingoKennedy did his graduate work at myelin may make it possible to study the University of Chicago, at the in vitro the biosynthesis of the comsame time continuing his work with plex lipides found in brain and nerve Armour. He received his P h . D . in tissue. In other investigations, Ken1949, and in 1951 joined Ben May nedy was able to explain the rapid Laboratory for Research and the deturnover of phosphorus in certain partment of biochemistry at the Uniphosphorylation reactions. In 1956, versity of Chicago. H e has been the Soap a n d Glycerine Producers professor of biochemistry since 1956. Association awarded him the glycerol
APRIL
2 8,
1958
C&EN
5 7
