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J. Phys. Chem. B 1998, 102, 9746-9749
Allen J. Bard
Courtesy of Allen J. Bard
Biography This issue of The Journal of Physical Chemistry is dedicated to Allen J. Bard on the occasion of his 65th birthday anniversary. The articles collected here have been contributed by former students, postdoctoral associates, collaborators, and friends in recognition of his scientific achievements and professional contributions to the field of chemistry over the past four decades. It is in sincere appreciation of Allen’s friendship, generosity, and legendary enthusiasm for science that this issue has been organized and dedicated. Allen was born in New York City on December 18, 1933, the son of John and Dora Bard. His father was an accountant (CPA) and his mother was a housewife. Allen grew up and attended public schools in the Bronx. As a youth he was always interested in science, largely due to the influence of his older brother, Selden, and older sister, Shirley. He spent a lot of time at the Museum of Natural History, the Bronx Zoo, and the Bronx Botanical Gardens, and in doing as many science experiments as reasonable in an apartment in New York City. This interest in science was strengthened during his attendance at the Bronx High School of Science (1948-51). He entered The City College of New York (CCNY) in January 1951 and majored in chemistry. Allen was also active in student politics, and was Vice-President of the Student Council and President of the Senior Class of 1955. He worked at a number of jobs while in college, including a stint as student aide trainee at the New York
Naval Shipyard (1954). Aircraft carriers were being overhauled at the shipyard, and it was Allen’s job to analyze for the oxygen content in the hydraulic fluid used in deck elevators. Allen also worked as a flunky at the Women’s International News Service, and, during holidays and the summer, as a busboy, waiter, or camp counselor. Upon graduation in January 1955, he took a job with The General Chemical Company (a branch of Allied Chemical Company) in Morristown, NJ, commuting from the Bronx. At the time, General Chemical was developing an instant pancake batter using a propellant, Genetrons (Allied Chemical’s fluorocarbon equivalent to DuPont’s Freons), to help fluff the batter; one of Allen’s duties was to analyze for fluoride content in the pancake batter. He soon decided to try graduate school. Allen entered Harvard University in September 1955, beginning his graduate studies with Geoffrey Wilkinson (Nobel Prize in Chemistry, 1973) in the then new area of metallocene chemistry. Wilkinson was denied tenure at Harvard and left in January 1956, a rather fortunate turn of events for the analytical and physical chemistry communities, as Allen then began research in the spring of 1956 with James J. Lingane, a former student of I. M. Kolthoff. Work with Lingane at Harvard mainly centered on electroanalytical methods. Allen’s dissertation was entitled “Studies in the Electrochemistry of Tin.” He graduated from Harvard with a Ph.D. in June 1958.
10.1021/jp984042+ CCC: $15.00 © 1998 American Chemical Society Published on Web 12/03/1998
J. Phys. Chem. B, Vol. 102, No. 49, 1998 9747 Allen joined the faculty at The University of Texas at Austin (UT) in 1958. He was hired by the chemistry department chairman, Norman Hackerman, at the rank of Instructor for a nine-month salary of $5200 and with start-up funds of $5000 (which the chemistry department hoped he would not spend completely). The department was unwilling to provide an interview trip to Austin (then something of a cow town) and was content to hire him sight unseen. He came to Austin in August 1958 to find that the office and labs were not airconditioned and the culture was very different from that of New York and Boston. The course load for his first semester consisted of two sections of sophomore analytical chemistry and one section of a freshman chemistry-calculations class. The graduate students at this time were scarce and largely netted by the senior faculty. In fact, junior faculty could only codirect dissertations with senior faculty. In spite of this abusive situation, he stayed and eventually some graduate students joined his group helping to enable him to earn promotion to Assistant Professor. Essentially all of Allen’s research has been carried out at UTAustin, where he has held the Hackerman-Welch Regents Chair in Chemistry since 1985. The vast majority of his research has been done in collaboration with the numerous graduate students and postdoctoral associates that have had the privilege to work in his laboratories during his 40 years at UT. However, Allen has often collaborated with faculty colleagues in the UT chemistry department and elsewhere. He spent a sabbatical in the CNRS lab of Jean-Michel Save´ant in Paris in 1973, where he obtained a deeper understanding of the use of cyclic voltammetry for elucidating reaction mechanisms. It was in Paris that he also started work on semiconductor photoelectrochemistry, a research area that his group has contributed to for the past 25 years. Allen also spent a semester in 1977 at the California Institute of Technology, where he was a Sherman Fairchild Scholar, working with Fred Anson on the electrochemistry of polymers. Beginning with his graduate work on coulometric and voltammetric methods with Lingane at Harvard, Allen gained an interest in the development of electrochemical methods that has remained with him throughout his career. He has made contributions to the development of controlled potential coulometry, rotating ring-disk electrode voltammetry, chronopotentiometry, ultramicroelectrode electrochemistry, and many other techniques. While a graduate student, Allen also worked with David Geske (at the time an Instructor at Harvard) on some of the earliest attempts at employing electrochemical methods to elucidate electrode reaction mechanisms. Geske also introduced Allen to electrochemistry in nonaqueous solvents. Allen has continued work in this area and throughout his career has studied the application of electrochemistry to the generation of interesting chemical species. A brief list of electrode reactions investigated in his laboratory include the elucidation of the mechanism of hydrodimerization of activated olefins, electrontransfer-induced isomerizations, studies of novel organometallic species, and the first electrochemical studies of films of fullerenes. In studying the mechanisms of organic electrode reactions in aprotic solvents, Allen became interested in the generation and study of radical ions by electrochemical methods, and, following the work of Geske and Maki, began work on the electron spin resonance (ESR) of electrogenerated species. Along with other electrochemists of the time, Allen and coworkers helped establish the importance of radical ions in the mechanisms of most organic redox reactions and the dominance of one-electron pathways in both oxidation and reduction
reactions (e.g., aromatic hydrocarbon oxidation, with K. S. V. Santhanam and J. Phelps, 1967; azo compound reduction, with J. L. Sadler, 1968). He also developed (with I. Goldberg, 1971) the simultaneous electrochemistry electron spin resonance (SEESR) technique for studies of short-lived electrogenerated radical ions. During studies of the electrochemistry of radical ions in aprotic solvents, he (with K. S. V. Santhanam, 1965) discovered the generation of excited states at electrode surfaces by highly energetic electron-transfer reactions, i.e., electrogenerated chemiluminescence, ECL. ECL was also found at essentially the same time by David Hercules’ group at MIT and E. A. Chandross at Bell Labs. Allen’s group remains very active in developing new ECL systems and has been largely responsible for the development of this field of research during the past 30 years. In the course of this work, the electrochemistry and ECL of Ru(bpy)32+ was elucidated with the first descriptions of the oxidative and reductive electrochemistry of this species in aprotic media (with N. E. T. Takvoryan, 1972). He also first described (with L. R. Faulkner, 1969) magnetic field effects in ECL and on triplettriplet reactions in fluid solution, the generation of exciplexes in polar media via electron-transfer reactions (with S.-M. Park), and ECL based on the oxalate (with T. Saji, 1977) and peroxydisulfate (with H. S. White, 1982) systems. Discovery of the latter reactions made possible the generation of ECL at a single electrode by a simple oxidation or reduction reaction. This led to the first successful observation of ECL in aqueous solutions and made possible analytical applications of this technique. Recent work in this area has focused on the application of ECL for highly sensitive and selective analysis (e.g., immunoassay) based on ECL labels, ECL of organized monolayers, and the use of ECL to probe metal-chelate/DNA interactions (with M. T. Carter 1989). The latter approach is currently being used by several companies for immunoassays and quantitative DNA analysis (based on a patent with G. M. Whitesides, 1988). Allen’s group has also investigated inverse photoemission spectroscopy at metal electrodes (with J. Ouyang, 1985). The most recent work in this area has been concerned with the design of a sensor based on ECL for the detection of specific single-strand DNA (with X. Xu, 1994) Allen’s interest in electrogeneration of radical species for ECL led to benchmark investigations of the rates of very rapid electron-transfer reactions of aromatic species (with H. Kojima, 1975) and a comparison of those results to self-exchange measurements by ESR (with L. S. Marcoux and B. A. Kowert, 1972). Later work in this area led to the first demonstrations of the effect of solvent viscosity on heterogeneous electron transfer (with J. Leddy and X. Zhang, 1985) and electron-transfer and ion-transfer reactions at the liquid/liquid interface (with M. Mirkin, C. Wei, M. Tsionsky, and T. Solomon 1995). Beginning in 1974, Allen’s interest in the interaction of light and electrochemical systems led to studies of photoelectrochemistry at semiconductor electrodes, with possible applications of these systems to solar energy conversion. Among the contributions of the Bard group in this area were the first description of the use of cyclic voltammetry and nonaqueous solvents in mapping semiconductor electrode energetics (with S. N. Frank, 1975), the first use of Fe2O3 and other oxide electrodes (with K. L. Hardee, 1976), the establishment of thermodynamic criteria for semiconductor electrode stability (with M. S. Wrighton, 1977), the discovery of the photo-Kolbe reaction (with B. Kraeutler, 1978), the trapping and confirmation of hydroxyl radical as a reaction intermediate on TiO2 (with C. D. Jaeger, 1979), the proposal of Fermi level pinning at the
9748 J. Phys. Chem. B, Vol. 102, No. 49, 1998 semiconductor/liquid interface (with Wrighton and F.-R. F. Fan, 1980), the stabilization of Si electrodes with metal films and conductive polymers (with F.-R. F. Fan, 1982), and the development of methods including photoacoustic spectroscopy, photothermal spectroscopy, and impedance spectroscopy for studies of semiconductor materials (with A. Fujishima and G. Brilmyer, 1980). In the course of investigating photoelectrochemistry, the concepts of heterogeneous photocatalysis and photosynthesis at particulate semiconductors were introduced and developed in Allen’s laboratory. The first studies on particulate TiO2 for photooxidation of cyanide and sulfite appeared in 1977 (with S. N. Frank). This work suggested the use of TiO2 for treatment of waste streams and oxidation of organics, a field that has developed extensively in recent years and is being commercialized. Later papers in this area introduced the ideas of metallization of particles with catalysts (with B. Kraeutler, 1978), photodecarboxylation reactions, the photodeposition of metals, and the photosynthesis of amino acids (with W. W. Dunn, H. Reiche, 1978, 1981). The incorporation of semiconductor particles into polymer and other matrices and the concept of integrated chemical systems was introduced in 1983 in collaboration with colleagues at the University of Texas (with M. Krishnan, J. R.White, and M. A. Fox). Such systems have been investigated intensively in the construction of systems for solar energy conversion (with A. Campion, M. A. Fox, T. E. Mallouk, S. E. Webber, J. M. White, and others, 1984-89). Recent work has focused on the behavior of very small semiconductor (Q-) particles and the effect of excess charge on particle energetics (with C.-Y. Liu, 1989) and photoelectrochemical cells designed around liquid-crystal porphyrins (with B. A. Gregg and M. A. Fox, 1989). Films of porphyrins (and other materials) have been found to be useful as charge-trapping materials and are being investigated as possible fast, high density, storage media (with C-.Y. Liu, M. A. Fox, and H. Pan, 1993). Allen’s interest in electrode reactions at extreme potentials and under extreme conditions led to investigations of many different solvent systems over the years. These included studies of organic electrode reactions in liquid ammonia (with A. Demortier, 1973) and liquid SO2 (with L. A. Tinker, 1979). The ammonia studies led to the discovery of auride (Au-) ion (with T. H. Teherani and J. J. Lagowski, 1978) and the electrochemical characterization and photoemission studies of solvated electrons (with Teherani and K. Itaya, 1978). Studies in liquid SO2 led to the first observation of new, highly oxidized, forms (e.g., Ru(bpy)34+,5+, FeCp22+) (J. G. Gaudiello and P. R. Sharp, 1982) and the direct oxidation of aliphatic hydrocarbons and quaternary ammonium compounds (E. Garcia, 1989). The first electrochemical studies in near-critical and supercritical fluids (H2O, SO2, NH3, acetonitrile) were also first reported by Allen’s group (R. M. Crooks and W. M. Flarsheim, 1984). Allen’s interest in the nature of electron-transfer reactions led him to investigations of redox molecules with multiple redox centers. The question of simultaneous multiple-electron transfers to the same molecule was extended to studies of dissolved polymers in solution (with S. E. Webber, T. Saji, F. C. Anson, and J. B. Flanagan, 1978), a topic investigated with Fred Anson at Cal Tech. This study naturally led to the concept of electrodes coated with polymer films, such as poly(vinylferrocene) (with A. Merz, 1978). Many other polymer films, such as Nafion (with I. Rubinstein, 1981), have been investigated since then. Related studies from Allen’s laboratory included the invention of a polymer reference electrode (with P. J. Peerce, 1980), early studies of the electronically conductive polypyrrole (with R.
A. Bull, F.-R. F. Fan, 1982), studies of electrodes of onedimensional conductors, e.g., TTF-TCNQ (with C. D. Jaeger, 1979), biconductive polymer films (with T. P. Henning, H. S. White, 1981), incorporation of catalysts into conductive polymers (with R. A. Bull, F.-R. F. Fan,1984), and clay-modified electrodes (with P. Ghosh, 1983). Over the years, Allen has also maintained an interest in the electrochemistry of biopolymers. An early voltammetric study in his laboratory focused on the interaction of proteins with mercury electrode surfaces and the mechanism of their redox processes (with M. T. Stankovich, 1977). More recent work at UT has been concerned with the application of electrochemical methods to studies of bioconjugation, e.g., the interaction of metal chelates with DNA and the determination of binding constants and for the cleavage of DNA (with M. T. Carter and M. Rodgriguez, 1989). Studies of the ECL of metal chelates with adsorbed DNA monolayers have led to the development of sensitive DNA probes (with X. Xu, 1994). In recent years, the new area of high-spatial-resolution electrochemistry has been a focus of work in Allen’s investigations, often in collaboration with his long-time associate, Dr. Fu-Ren Frank Fan. Allen’s work in this area includes the first description of the application of the scanning tunneling microscope (STM) to examine surfaces under liquids (with H. Y. Liu, C. Lin, and Fan, 1986). The scanning electrochemical microscope (SECM) was invented in 1987 and used for very highresolution fabrication, i.e., metal deposition and etching, and semiconductor etching. The application of the SECM to the characterization of the surfaces of conductors and insulators and the theory of its operation was reported in 1988 (with J. Kwak, Fan, and O. Lev). Later work illustrated the use of the SECM in studying surface reactions on polymers, minerals, and metals and probing fast heterogeneous kinetics and homogeneous reactions. Recent work has dealt with the trapping and detection of single electroactive molecules by SECM (with Fan, 1995), with the observation of coulomb staircase effects (single electron-transfer events) at nanometer-size electrodes in electrochemical cells (with Fan, 1997), and in studies of electron transfer at the liquid/liquid interface (with M. Mirkin, C. Wei, and M. Tsionsky, 1995-97). On the basis of his contributions to electrochemistry and, in particular, for the development of the SECM, Al was honored this past year by the National Academy of Sciences as one of 12 scientists to receive awards for their research achievements. Thus far, Allen’s bibliography includes more than 700 original research articles and book chapters. He has authored three books, Chemical Equilibrium (1966), Electrochemical Methodss Fundamentals and Applications (1980, with L. R. Faulkner), and Integrated Chemical Systems: A Chemical Approach to Nanotechnology (1994). Electrochemical Methods is the most significant, modern monograph dedicated to the theory and practice of electrochemistry and has been used to teach graduate courses to thousands of students during the past two decades; a second edition is planned for publication in 1999. Allen has also edited several widely read books and series, including the highly successful series, Electroanalytical Chemistry, which he founded in 1964 and which has thrived for nearly 25 years under his editorship. Two others, the Encyclopedia of the Electrochemistry of Elements (Vols. I-XIII, 1973-89) and Standard Reduction Potentials in Aqueous Solutions (with Roger Parsons and Joseph Jordan), are important sources of information regarding reaction mechanisms and thermodynamic data. In addition to his many research accomplishments, Allen has contributed extensively to the profession of chemistry. He has
J. Phys. Chem. B, Vol. 102, No. 49, 1998 9749 served as Editor-in-Chief of the Journal of the American Chemical Society since 1982. (Allen’s 16-year stint is second only to Arthur Lamb, 1918-50; Allen also served as associate editor for two years, 1980-82). Under Allen’s guidance, J. Am. Chem. Soc. remains the premier publication medium for chemists and has significantly grown, not only in terms of the number of papers published but also in its breadth of coverage to include new frontiers representing the cutting edge of chemistry. Anyone who submits articles to J. Am. Chem. Soc. has been disappointed, at least once, in having their article “returned” by Allen or one of his associate editors. However, Allen is regarded as being extraordinarily fair and cool in his editorial decisions, and always considerate of authors’ views. Allen has also served in many roles on the National Research Council and in the International Union of Pure and Applied Chemistry. He served as President of IUPAC from 1991 to 1993, catalyzing major changes in the organization and function of that organization. He also played a major role in the Pimentel report, helping define the discipline and challenges of chemistry in the 1990s. Allen has received numerous well-deserved honors and awards, including election to the National Academy of Sciences in 1982. A small sample of awards include the Carl Wagner Memorial Award (The Electrochemical Society), the Fisher Award in Analytical Chemistry (American Chemical Society), the first Charles N. Reilley Award (Society of Electroanalytical Chemistry), Docteur Honoris Causa (Universite de Paris-VII), the New York Academy of Sciences Award in Mathematics and Physical Sciences, the Willard Gibbs Award (American Chemical Society, Chicago Section), the Olin-Palladium Medal (Electrochemical Society), the Analytical Chemistry Award in Electrochemistry (American Chemical Society), the Luigi Galvani Medal (Societa´ Chimica Italiana), and National Academy of Sciences Award in Chemical Sciences. He was named the Woodward Professor at Harvard University (1988) and the Sherman Mills Fairchild Scholar at California Institute of Technology (1977). He has given over 80 named lectureships at universities and colleges throughout the United States and overseas. Allen would be the first to point out that no one achieves the magnitude of significant accomplishments enumerated in this short essay without many dedicated co-workers. At the time of this writing, he has worked as mentor and collaborator at the University of Texas with 69 Ph.D. students, 14 M.S. students, 117 postdoctoral associates, and numerous visiting scientists. He has always helped his junior colleagues, a large number of whom have gone on to develop independent research careers, to attain their maximum level of achievement both in his laboratories and afterwards. He has an innate sense for picking the right project for each individual, rarely shooting too high or too low, and following up with just the right amount of mentoring. Allen encourages students to seek answers and solutions on their own, allowing them to delve as deeply as possible into a research problem. However, students never feel as if they are on their own, as Allen’s enthusiasm for science is infectious and nonstopshe always finds positive results in any student’s effort. Certainly his students leave the group with a true sense of accomplishment and self-confidence. Allen taught undergraduate and graduate analytical chemistry courses during his career. During the past two decades he taught mainly graduate-level electrochemistry and electronics for scientists. The word among graduate students, postdoctoral associates, and visiting scientists was that going to UT-Austin
and not taking electrochemistry from Bard was like going to Rome and not seeing the Pope. None will forget the decadesold, tattered notes that he brought to class each day (but rarely looked at) or the colored chalk with which he so effectively elucidated the mysteries of electrochemistry. His wry wit and ability to stimulate good questions from his students are his stock and trade in the classroom. Of course he commands respect in the classroom, but perhaps even more importantly he reciprocates with the same level of regard for his students. Besides science, Allen teaches fairness, patience, tolerance, loyalty, and the importance of intellect and hard work, and it is these qualities, which he himself best embodies, that his students remember most fondly. Colleagues worldwide also know that Allen has a unique ability to start intellectually stimulating conversations about science while hiking or over a beer (always just “one light beer,” for which he even asked in a Seattle microbrewery a few years back). Although his sense of humor can be a bit obtuse, we recall his comment shortly after a mild heart attack in 1989: “The bright side of this is that it demonstrates that the editor of JACS is not a heartless old S.O.B!” Indeed, he is not. The respect and sense of fair play displayed by Allen toward students and colleagues extends outside the laboratory. He has been active with the Committee of Concerned Scientists, a group working toward rights for scientists and engineers worldwide. Particular emphasis was placed on protesting job terminations of scientists and engineers who requested exit visas from oppressive governments. A significant achievement of electrochemists in this group was the successful nomination of the eminent Russian scientist Benjamin Levich for the Electrochemical Society (ECS) Olin-Palladium Medal. Levich could not obtain a visa to visit the U.S. to collect award, a requirement that was waived by the ECS. This same group was eventually able to help Dr. Levich emigrate to the U.S. Allen also circulated a petition in the early 1960s to allow African American graduate students at UT hold teaching assistantships (only one of his colleagues in the Chemistry Department at UT would ultimately sign this petition). Allen married Frances Joan Segal 41 years ago while he was a graduate student at Harvard. Frances recently retired from a teaching career with the Austin public school system, but not from dealing patiently with Allen’s travel schedule, students and colleagues, and hectic work schedule. Allen and Frances have two children, Edward David, who works for a computer software firm in Portland, OR, and Sara Lynn (a CPA in Austin), and two grandchildren (Alex, almost 5 years old, and Marlee, eight months old). Allen is developing a reputation as a doting grandfather. On his frequent travels, he often arranges for a change of planes in Oregon so that he can visit with his grandson. It had been an honor to assist in the recognition of Allen J. Bard’s many contributions to science on his 65th birthday anniversary. Those who have experienced first hand Al’s love for science will appreciate that this anniversary Festschrift issue simply marks a passing milestone in a scientific career that remains as active as it was when he first started 40 years ago. Perhaps this continuing enthusiasm for science is his most visible and lasting legacy. We look forward to many more years of research achievements, teaching, and friendship from this remarkable scientist, colleague, and friend. Henry S. White Richard M. Crooks Guest Editors
