double bondtriennial john m. prausnitz award for applied chemical thermodynamics, and he will...
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The Newsletter of the Western New York Section of the American Chemical Society
Volume 79 September 2007
2007 JACOB F. SCHOELLKOPF MEDAL
The Schoellkopf Committee of the Western New York Section of the American Chemical Society is pleased to announce that Dr. David Kofke from the Department of Chemical and Biological Engineering, University at Buffalo, is the 2007 Schoellkopf award recipient.
Dr. Kofke will be presented with the Schoellkopf Medal in recognition of his significant and lasting contributions to the field of applied thermodynamics, and for his creative insight and advancement of applied thermodynamic theory. Also cited will be his innovative and important pedagogical contributions to the undergraduate chemical engineering curriculum.
Please see Dr. Kofke's biographical sketch on p. 12 and make reservations to attend the ceremony on September 18.
FROM THE EDITOR
Greetings Western New York,
You knew it was coming. The weather cools down and the chemistry season begins to heat up. In trying to top last year's 100th anniversary celebration, the WNYACS section has moved the regular date for the annual presentation of the Schoellkopf medal to September. Please join me in congratulating Dr. Kofke for this recognition of his accomplishments and ongoing contributions to the excellence of chemistry in our region. Also please join your fellow section members at the celebration we will have on September 18 at the Frog Grille.
Hope to see you there,
Timothy Gregg Department of Chemistry and Biochemistry Canisius College
PREPARING FOR LIFE AFTER GRADUATE SCHOOL
The University at Buffalo Department of Chemistry hosted an ACS sponsored career development workshop for graduate students in June. the program, which has the inspiring acronym, PfLAGS, focuses on three areas that traditional graduate programs in chemistry may not emphasize. These areas are: Defining the variety of career options for Ph.D. chemists; Highlighting nontechnical skills that can be vital to surviving in the workplace, such as communication, intellectual property issues and ethics; and lastly, The job market—finding and landing the right job.
Over 25 UB graduate students and postdocs attended the workshop in June over 3 days. The activities included talks, discussions, mock interviews and resume review. The presenters included:
Lisa M. Balbes, Balbes Consultants Timothy Gregg, Canisius College Jeff Jordan, Nanodynamics, Inc. Janet R. Morrow, University at Buffalo Ray O’Donnell, S.U.N.Y., Oswego David Watson, University at Buffalo
The PfLAGS workshop is available to chemistry departments at Ph.D.-granting universities through the ACS Office of Graduate Education and the ACS Department of Career Management and Development.
LOCAL SECTION ELECTIONS
The next issue of The Double Bond will include a
ballot for 2008 WNYACS officer positions as well as brief biographical statements from the candidates.
Please keep your eyes open for the arrival of this important opportunity to be involved in local chemistry activities.
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WNYACS Double Bond 12 Vol. 79, September 2007
The Western New York Section of the American Chemical Society
Invites you to be present at The Seventy-Seventh Presentation of the
Jacob F. Schoellkopf Medal To
Dr. David A. Kofke
Tuesday evening the Eighteenth of September
Two Thousand Seven
Cash Bar with cold and hot hors d’oeuvres at six o'clock Dinner at seven o'clock
Presentation to follow Dinner
Frog Grille (formerly Warren’s) 561 Main Street
Tonawanda, New York
Formal Dress Optional R.S.V.P.
Tickets may be picked up at the door
Dinner Selections: Sliced Filet of Beef with Saltimbocca
Grilled Fresh Salmon with Bourbon Glaze Penne ala Roma with Artichoke and Sundried Tomatoes
(Vegetarian)
Wine served with meal
For reservations call:
Ms. Alice Steltermann Department of Chemistry and Biochemistry
Canisius College 2001 Main Street
Buffalo, New York 14208 (716) 888-2340
Plates at $40.00
Please respond by September 12th Make checks payable to
Western New York Section - American Chemical Society
David Kofke received his B.S. in chemical
engineering in 1983 from Carnegie-Mellon University, and his Ph.D. in 1988 from the University of Pennsylvania, where he worked under the supervision of Eduardo Glandt. Since 1989 he has been on the chemical engineering faculty of the University at Buffalo, SUNY, where he now holds the rank of UB Distinguished Professor and is Department Chair. Prof. Kofke’s expertise is in molecular simulation. His research interests consider the development and understanding of molecular simulation methods, particularly as they pertain to free-energy calculations and configurational integrals in general. He is also active in development of object-oriented molecular simulation software suitable for educational and research applications. Author of nearly 100 refereed publications, Prof. Kofke received a Presidential Young Investigator Award in 1990, the SUNY Chancellor’s Award for Excellence in Teaching in 1994, and the SUNY Chancellor’s Award for Excellence in Research and Creative Activity in 2004; he is the 2004 recipient of the triennial John M. Prausnitz Award for applied chemical thermodynamics, and he will deliver the Area 1a keynote lecture at the Fall 2007 meeting of the American Institute of Chemical Engineers.
WNYACS Double Bond 13 Vol. 79, September 2007
THIS MONTH IN CHEMICAL HISTORY
Harold Goldwhite, California State University, Los Angeles ([email protected])
In the standard general chemistry courses that most of us have taken, or taught, or both, the subject of the role of the electron in the current view of the structure of the atom usually encompasses the contributions of J.J. Thomson and Robert Millikan and then moves to Bohr’s theory of the hydrogen atom. As I was reading C.H. Douglas Clark’s book “The Basis of Modern Atomic Theory” (Methuen, London, 1926) I was reminded that the early history of the electron is much richer than that. In this column and the next I will explore the contributions of many early researchers to our understanding of the electron.
The story begins with Michael Faraday whose experimental work established the laws of electrolysis and who, in collaboration with William Whewell, invented the language of electrochemistry including the terms ion, anion, cation, and electrolyte. (QUIZ: For extra credit I challenge my readers to find the origin of the prefixes an- and cat- for the oppositely charged classes of ions.) Faraday’s laws lead directly to the idea that different ions must carry electrical charges that are integral multiples of some fundamental amount of charge. For example, to use modern terminology, the electrolysis of (molten) lead chloride generates one mole of lead atoms from the lead ions for every two moles of chlorine atoms (appearing as one mole of chlorine molecules) from the chloride ions. Thus the total electric charge on the mole of lead ions must be exactly twice the charge on each mole of chloride ions. Despite this kind of observation many distinguished scientists of the time, including Maxwell, rejected the idea of discontinuous ionic charges.
In 1881 Helmholz, in his Faraday lecture, said the logical inference from Faraday’s laws was that if matter is atomic, then electricity should also be “atomic”. In the same year Johnstone Stoney endorsed the idea that when a valence bond was broken a definite amount of electricity was involved. In 1891 Stoney named this definite quantity an “electron”. Using modern terminology again it is clear that if the total charge on a mole of ions is known from electrolytic experiments and if Avogadro’s number can be determined, then the charge on a single electron can be calculated. Estimates of Avogadro’s number date back to the 19th Century and were based on kinetic theory of gases and early in the 20th Century. Perrin (remember Jean Perrin?) used observations on the sedimentation of colloidal particles to obtain a value of about 7 x 1023 .
In 1897 J. S. Townsend, one of J. J. Thomson’s first graduate students, began work on the charges carried by
ions in gases. Charges carried by gases have a long chemical history, some of the earliest observations being made by Lavoisier and Laplace who noted that when metals dissolve in acids the hydrogen produced is charged. Later Enright in 1890 showed that the charge is positive, and Townsend established that the charge was not due to spray but to the gas itself. He established that gases produced by electrolysis were also charged. Townsend showed that these charged gases provided centers for the condensation of water vapor, thus demonstrating the principle of the cloud chamber, which became of great utility in nuclear research. Townsend then measured the total charge carried in a determined volume of a charged gas using a quadrant electrometer. Determination of the number of charged gas molecules was more challenging. He formed a cloud of charged droplets by passing the charged gas through water and assumed each charged molecule produced one droplet. Then by observing the average rate of fall of the droplets under gravity he estimated their average mass and size. Absorbing the cloud in sulfuric acid gave the total mass of the cloud and hence the number of droplets and ions. These data led Townsend to his estimate of the charge on both positive and negative ions in gases; his value of the charge on the electron was about 75% of the currently accepted value.
Also in 1897 Townsend’s mentor, J. J. Thomson, published his well-known work on the determination of e/m for cathode rays which led him to the assertion that electrons were a constituent of all atoms. Now that e/m was known with some precision there was a powerful incentive for researchers to get a better value for e, the charge on the electron.
From 1897 to 1903 Thomson himself carried out a
number of determinations of e by using ionizing agents including X-rays, ultraviolet light, and radioactive sources to produce ionized gases. He used Townsend’s methods to determine the mass and number of ions –
(continued on p. 14)
WNYACS Double Bond 14 Vol. 79, September 2007
60 YEARS AGO IN THE DOUBLE BOND
The following excerpt from the June, 1947 issue of the Double Bond was written by E.F. Lefson
The April meeting of the Western New York Section
of the American Chemical Society was held Tuesday, April 15, in Norton Hall at the University of Buffalo. The speaker was Dr. Dorothy Wrinch of Smith College. Dr. Wrinch, who was the 1947 Steeglitz lecturer, discussed the present state of our knowledge of the structure of natural proteins.
Despite the impression created by organic chemistry texts, which appear to explain proteins by a review of the structure and properties of the constituent amino acids, the configuration of the protein skeleton remains today a major unsolved problem. How vital a problem it is, may be seen from a consideration of the viruses, enzymes, genes, immune bodies and other biologically important proteins. Their actions would be understood once the structure of a single protein is elucidated. Not only would this serve as powerful impetus to the study of the biological sciences but would very likely shed much light on the nature of growth processes as well.
It was Dr. Wrinch's premise that the protein molecule is essentially a simple skeleton and that the variety observed in natural proteins arises from the number of substituents in exactly the same way that the numerous compounds of the aromatic series are obtained by substitution in the benzene ring. Evidence to support this view has come from recent work in physical chemistry and chemical crystallography. X-ray diffraction study, which has proved so valuable in confirming the structure of the sterols and penicillin, is an especially powerful tool. Crystallographic x-ray diffraction data provides information relating to size and shape and molecular weight and in some cases can also give structure.
The speaker pointed out that crystallography alone will not disclose structure unless a general idea of the approximate structure is at hand. The evidence of organic chemistry and of enzymology is required to first set up hypothetical structures that may be compared with crystallographic data for corroboration or rejection.
In the biosynthesis of protein molecules, the “active patch” theory appears to best explain the observations. It is postulated that a protein molecule maintains its existence by virtue of the association of favorably located substituents. The biologic function resides on one of the crystal faces and there is generated a “crystallizability” at this face resulting in the deposition thereon of its complement. This favorable juxtaposition of amino acid substituents lends not only rigidity to the molecule but also the protein character.
Dr. Wrinch concluded by discussing the recent work on Gramicidin and Thyrocidin and expressed the hope that such knowledge would apply to protein structure. With elucidation of the protein skeleton, the fundamental phenomena of enzymology, immunology, pharmacology and other fields of protein study would be explained and the same factor may throw light on the true nature of the biosynthesis of proteins.
THIS MONTH IN CHEMICAL HISTORY (continued from p. 13)
methods subject to major uncertainties including evaporation of the water drops during the experiments and the validity of applying Stokes’ Law to the rate of settling of the drops. In 1903 H. A. Wilson introduced a new idea in the determination of e. While also using charged water drops he introduced an electrostatic field of some 2000 volts/cm within his equipment and by applying a charge he could influence the rate of settling of the cloud of water drops.
Enter Robert Millikan. In 1908, with Begeman, he initially adopted Wilson’s method but with a field of 4000 volts/cm and by thus reducing the times of observation he reduced evaporation errors and obtained more precise and more accurate values of e. In 1909 he published his first observations on studying individual droplets, still of water. He adjusted the electrostatic field to halt the movement of a single droplet, and occasionally noted that suddenly a droplet would begin to move either up or down, showing that it had suddenly acquired or lost additional charge. By 1911 Millikan had overcome the evaporation problem by switching to observations on involatile oil droplets, and had determined a very good value of e and of Avogadro’s number; values within 1% of those accepted today.
In conclusion a few brief comments on sub-electrons. Some of Millikan’s early results seemed to suggest the existence of charges on drops that were less than e, though he did not include those results in his publications. At the same period Ehrenfest published results derived from experiments on tiny metal particles, similar in principle to those of Millikan, indicating charges of around one-third or two-thirds of e on some drops. Millikan strongly argued against these results. There has been some controversy in the history of science community about whether Millikan “fudged” his data by suppressing those results that did not agree with his views of a single value for the smallest possible electric charge. The current view of those best qualified to interpret Millikan’s data is that the suppressed values were typically for those drops that carried very large numbers of electron charges (30e to 50e or the equivalent in positive charges) which, for a variety of reasons, are most susceptible to experimental errors.
If there is a moral to this long and involved tale of the history of the electron it is a familiar one. Even though fame’s mantle may settle finally on a handful of individuals, generally their work depends on the work of many unsung heroes.
WNYACS Double Bond 15 Vol. 79, September 2007
WNYACS Officers & Staff
Chair Greg Shafer Honeywell (716) 827-6307 (w) [email protected]
Chair Elect
Vice-Chair Sherry Chemler University at Buffalo, SUNY (716) 645-6800 x 2136 (w) [email protected]
Secretary Mary O’Sullivan Canisius College (716) 888-2352 (w) [email protected]
Treasurer Andrew Poss Honeywell (716) 827-6268 (w) [email protected]
Councilor Peter Schaber Canisius College (716) 888-2351 (w) [email protected]
Councilor David Nalewajek Honeywell (716) 827-6303 (w) [email protected]
Newsletter Editor Timothy Gregg Canisius College (716) 888-2259 (w)
Schoellkopf Award Peter Schaber
Canisius College (716) 888-2351 (w)
Education Committee Ronald Spohn
Praxair (716) 879-2251 (w)
Chemistry Olympiad Mariusz Kozik
Canisius College (716) 888-2337 (w) [email protected]
National Chemistry Week David Nalewajek
Honeywell (716) 827-6303 (w)
Senior Chemists Joseph Bieron
Canisius College (716) 888-2357 (w)
Member-at-Large South William Sullivan
Praxair, Inc. (716) 879-7794 (w)
Member-at-Large North Robert Keem
Invitrogen (716) 774-0204 (w)
Newsletter Assistant Editor Alice Steltermann Canisius College
(716) 888-2340 (w) [email protected]
ISSUE COPY DEADLINE: FIRST OF MONTH PRIOR TO PUBLICATION
The Western New York Section of the American Chemical Society (ACS) and its editors assume no responsibility for the statements and opinions advanced by the contributors. Views expressed in the editorials are those of the authors and do not necessarily represent the official position of the Western New York Section of the American Chemical Society. All materials to appear in the next issue of Double Bond must be received by the Editor, in care of the Chemistry Department, Canisius College, 2001 Main Street, Buffalo, New York 14208, by the FIRST day of the month. Notice for change of address should be made through ACS Member and Subscriber Services at (800) 333-9511 or the website, www.chemistry.org/contactus.html.
The NF=B Double Bond (aka Double Bond) is published from September through June by the WNY Section of the ACS. Contact information: email: [email protected]; website: membership.acs.org/W/WNY. Member subscriptions are included in the annual National ACS dues. Permission to reprint is granted for this publication.