THE INFRASTRUCTURE OF IR SPECTROMETRY:
Reminiscences of Pioneers and Early Foil A. Miller Department of Chemistry University of Pittsburgh Pittsburgh, PA 15260
"Infrastructure: the basic underlying framework of something, especially of a technological kind... " (1).
The Third James L Waters Annual Symposium Recognizing Pioneers in the Development of Analytical Instrumentation was held at the 1992 Pittsburgh Conference and Exposition in New Orleans. This year's symposium honored five pioneers in the field of infrared spectrometry: Paul L. Wilks, Jr., Foil A. Miller, Norman Sheppard, Peter R. Griffiths, and Bryce L. Crawford. In our September issues, we present adaptations of the talks given by four of these innovators. Here Wilks describes the evolution of commercial IR spectrometers and Miller discusses the infrastructure of IR spectrometry. In the Sept. 15 issue, Sheppard discusses the United Kingdom's contributions to IR spectroscopic instrumentation and Griffiths describes the remarkably circular development of commercial FT-IR instruments.
Many things had to be in place to make it feasible to manufacture commercial IR instruments and to catalyze the rapid growth of their use. It had to be known that they would provide useful information. Suitable optical and electronic components had to be available. There h a d to be knowledgeable u s e r s , a need t h a t was filled by special training courses, meetings, and books. There also had to be good sample-handling techniques. I call this ancillary material the infrastructure of infrared spectrometry; it was the support system that underlay the success of the technique. In this REPORT I will review the development of this infrastructure and include reminiscences of some pioneers and early commercial IR instruments. Jones (2) has presented two excellent historical reviews of vibrational spectroscopy. Essential preliminaries By 1940 there was a large body of knowledge concerning IR spectroscopy. The IR region was known to extend from the visible to the Hertzian portion of the spectrum. Rubens and Paschen and their students had explored the far-IR region, and Nichols and Tear (3) had linked it to "electric wave spectra" at 0.4 mm or 25 cm - 1 . Indices of refraction of useful prism materials were known, and gratings had already been employed in IR spectroscopy. There were usable detectors and amplifying systems. The theory of vibrational spectra was understood reasonably well, and it was known that IR spectra were potentially useful to chemists. There was just one problem: In 1940 no IR instruments were commercially available except for a small and unsatisfactory one t h a t Adam Hilger Ltd. first marketed in 1913. In 1938 only about 15 IR instruments were opera-
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tional in the United States (4), and I suspect that every one of them was homemade. Three preliminaries warrant special comment. The first concerns materials for prisms and windows. Initially, natural rock salt was the most widely used substance, but it was not entirely satisfactory because of impurities, imperfections in the crystals, and uncertain supply. Van Zandt Williams once told me an interesting story of how the IR group at American Cyanamid Co. obtained crystals of Russian rock salt. In about 1939 he and one or two others went to the Amtorg Trading Corporation in New York City, which was then the Soviet Union's business agent in the United States, to inquire about buying natural sodium chloride crystals mined in the USSR. The salesman said that they could be provided and asked what size pieces were wanted. After a brief consultation among the Cyanamid people, one of them held out his forefingers to indicate two sizes of blocks t h a t would be appropriate. One size would provide material for windows and cells, and several larger blocks would be used to make prisms. The salesman took out a ruler, measured the spacings carefully, and noted them on the order. Nothing was heard for a very long time. Finally, more than a year later, an urgent message was received. If they wanted their rock salt, they should come immediately to New York City, take a small boat out to a certain ship in the harbor, and pick up their purchase. The reason for the haste was t h a t World War II was about to start in Europe, and the Soviets wanted to get their ships back to home ports as quickly as possible. In fact, this was the last Soviet ship to leave New York. The packages— several wooden boxes of about 1 ft. in each dimension—were lowered over the ship's rail to the recipients in a small boat below. When they were opened back at the laboratory, each box contained a number of neatly wrapped blocks of rock s a l t . E a c h block h a d b e e n cleaved to the exact size t h a t had been indicated in such an impromptu fashion. The buyers realized then 0003 - 2700/92/0364 -824A/$03.00/0 © 1992 American Chemical Society
Commercial IR Instruments that they could have asked for any size within their wildest dreams and would have received it. This supply lasted C y a n a m i d l a b o r a t o r i e s for many years. Robert S. McDonald re members sawing a prism blank from one of the larger pieces with a wet string saw. Fortunately, methods for growing large single crystals were developed in time to make them available when needed. In 1930 John Strong grew the first large alkali halide crystals in this country; they were composed of KBr, KC1, and KI (5). Many people later became involved, and synthetic crystals of the alkali halides, CaF 2 and BaF 2 , as well as other useful ma terials, became commercially avail a b l e — n o t a b l y from t h e H a r s h a w Chemical Company of Cleveland. The second important preliminary was the availability of excellent and inexpensive mirrors. In 1835 Justus von Liebig developed the first method of chemically silvering mir rors. This capability was important because it allowed the superior re flectivity of a metal to be combined with t h e mechanical stability and polishability of glass. His method, however, resulted in back-surfaced m i r r o r s t h a t were useless for IR work because of the absorption of glass. John A. Brashear, a noted op t i c i a n in P i t t s b u r g h , i n v e n t e d a method for m a k i n g front-surfaced m i r r o r s by chemical silvering (6). (Brashear also developed the tech nique for optically finishing rock salt surfaces.) Unfortunately, silver coat ings t a r n i s h and therefore do not have long-term stability. In 1932 S t r o n g developed t h e method of making mirrors by vac uum evaporation of aluminum (6), an important advance. Strong was also a pioneer in preparing antireflective coatings that were the basis for some of the special filters used later for the separation of grating orders. The t h i r d preliminary was t h a t t h r e e U.S. i n d u s t r i a l laboratories had realized the usefulness of IR spectroscopy for chemistry and had research teams who built their own instruments. These labs were Ameri can Cyanamid Co. research laborato ries, led by R. Bowling Barnes, whose team included Van Zandt Williams,
Urner Liddel, Robert C. Gore, Robert S. M c D o n a l d , a n d N o r m a n B . C o l t h u p ; Shell D e v e l o p m e n t Co., whose IR team leaders were Robert R. B r a t t a i n and R. S. Rasmussen; and Dow Chemical Co., led by Nor man Wright. Publications describing the instruments from these laborato ries and their applications were im portant in publicizing the potential of IR spectroscopy. Finally, three programs of great importance during World War II pro vided the impetus to begin the man ufacture of IR instruments: the syn thetic rubber program, largely a U.S. project; the production of aviation fuel, primarily a U.K. project; and the penicillin program, a joint U . S . U.K. e n d e a v o r . T h e s e p r o g r a m s prompted the U.S. government to contract with Beckman Instruments (then called National Technical Lab oratories) and Perkin Elmer to build IR spectrometers during World War II. The first successful commercial IR spectrometers descended from these instruments.
REPORT Beckman shipped its first IR in strument, the IR-1, on Sept. 18, 1942 (7), and Perkin Elmer shipped its first, the Model 12A, in 1944. The growth in the use of IR spectroscopy was explosive. It has been said t h a t four i n d u s t r i a l IR s p e c t r o m e t e r s were in use at the beginning of World War II and approximately 400 at the end (8). Alternatively, Lecomte esti m a t e d t h a t the n u m b e r of opera tional IR spectrometers in the United States increased from 15 in 1938 to more than 500 in 1947. Of these, 400 were being used in analytical labora tories (4). Using an early IR instrument I will digress to describe what it was like to use one of the early commer cial IR i n s t r u m e n t s : t h e P e r k i n E l m e r Model 12B. T h e o r i g i n a l Model 12A employed a galvanometer and made point-by-point measure ments of spectra. In March 1945 I re ceived a quotation of $1900 to add a dc breaker amplifier and an auto
matic recorder. These parts, plus a motor drive, were the main compo nents of the upgrade to the Model 12B. Our 12B was obtained in 1945 by the chemistry department at the University of Illinois. It was a singlebeam instrument that was not linear in anything useful—μπι, c m - 1 , %T, or absorbance. Extensive replotting of the raw data was therefore neces sary to obtain a real spectrum. There was no chopping of the radiation, but the instrument did have a strip chart recorder so that the spectrum could be scanned, which I regarded as a wonderful feature. The usual procedure was to con vert the abscissa scale to wavelength or wavenumber. The Littrow mirror was rotated by a gear mechanism, and pip marks were automatically put on the pen trace at equal incre ments of rotation. These marks had to be calibrated a g a i n s t reference spectra of gases such as NH 3 , HC1, C 0 2 , and water vapor. The ordinate was proportional to the signal reaching the thermocou ple. This signal was essentially the blackbody emission of the source as modified by the transmission of the prism and the windows, with the ab sorption of the atmosphere and the sample superimposed. The procedure was to make a scan with a reference cell to obtain the reference signal (I0), and then to make a scan with the sample to measure the sample signal (/). For both scans, the position of the zero line h a d to be checked fre quently by inserting an opaque shut ter in the beam. Zero moved because the thermocouple responded to any change in temperature, not j u s t to the heat delivered by the radiation beam. A baseline w a s d r a w n between these zero positions, and from it the height of the sample signal (I) and the corresponding height of the refer ence signal (I0) were measured with a ruler a t each pip mark. The ratio I/I0 was the transmission, which was then plotted on a separate sheet of graph paper against the wavenum ber value for that pip mark. It was hoped t h a t conditions were the same for both runs. One had to work hard to run and plot two spectra a day. But it was even worse than this
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REPORT because the thermal drift was horri ble. The early instruments used dc thermocouples, which were ex tremely sensitive and responded to any change in t e m p e r a t u r e . Al though they had a compensating junction that was shielded from the light beam and was supposed to can cel the effect of ambient temperature changes, the compensation was wildly inadequate. If one lit a match and held it n e a r t h e i n s t r u m e n t housing, the pen moved. I had a corner laboratory at Illinois that was heated by steam radiators. When the steam came on, the base line climbed upward and went off the paper if zero was not reset. The spec t r u m was therefore r u n in m a n y short segments so it could be kept on scale. When the steam went off, the room cooled and the process was re versed. Thus it was absolutely es sential to check zero frequently and to draw a sloping baseline for both reference and sample. Initially, Per kin Elmer provided a thick white felt liner for the housing in the hope that this would reduce the effect, but it gave off so much water vapor that I threw it away. These experiences have been de scribed in some detail because I be lieve that today's researchers do not fully appreciate the vast advances made by the instrument manufactur ers. There was one good thing about the early instruments, however, es pecially the single-beam ones: A per son had no compunction about taking off the lid and tinkering with the op tics and the electronics. In fact, most
Robert R. Brattain (known as "Breezy" Brattain) had a policy of ordering serial number 7 of a new instrument. He assumed that six would be manufactured in the initial batch, that problems would be found and rectified, and that he would obtain the first of the second group. This policy greatly irritated Howard Cary, because he knew he had an assured sale of a new instrument if only he could dispose of the first six.
users did so frequently. I have re aligned all t h e optics, u s i n g t h e Foucault knife-edge test to focus the parabola. I have provided a new get ter for the thermocouple and reevacuated it, attached a small vacuum p u m p to t h e t h e r m o c o u p l e a n d pumped on it continuously, or just replaced the thermocouple and refocused on it. The contacts on the breaker amplifier were cleaned fre quently. The instrument was no black box; we knew what was going on inside it. Howard Cary, who designed superb i n s t r u m e n t s for Beckman I n s t r u ments and later for his own firm, Cary Instruments, had the opposite philosophy. His products were built like b a t t l e s h i p s — v e r y solid—and cover plates were held on with hun dreds of screws. He said t h a t he didn't want amateurs getting into his instruments and therefore made it
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Norman B. Colthup in 1950 operating a Perkin Elmer Model 12C spectrometer equipped with a General Motors breaker amplifier and a Leeds and Northrup recorder. 826 A · ANALYTICAL CHEMISTRY, VOL. 64, NO. 17, SEPTEMBER 1, 1992
quite difficult, or at least tedious, to do so.
Advances in instrumentation Once IR instruments became com mercially available in the mid- 1940s, several important follow-ups con tributed to the rapid growth of the field. Vigorous competition among i n s t r u m e n t m a n u f a c t u r e r s led to steady improvement in performance and easier use of the instruments. O t h e r developments included t h e training of u s e r s by special short courses, the appearance of some ex cellent books, the organization of stimulating meetings, and the devel opment of useful sampling methods. Shortly after the end of World War II there were many important ad vances in IR instrumentation. First was the development of the H o r n i g Hargreaves-O'Keefe thermocouple and Max Liston's dc breaker ampli fier. Faster thermocouples became available later that permitted the use of chopped radiation (10-13 s _1 ) and tuned ac amplifiers. This vital step forward solved the problem of ther mal drift. In addition, much-improved elec tronic components, such as quiet ac amplifiers, Helipot precision helical potentiometers, and useful servo mo tors for converting electrical signals to mechanical motion, became avail able. Strip chart recorders were a tre mendously useful advance that has not been a d e q u a t e l y recognized. Originally, point-by-point measure ments were made with a sensitive galvanometer. Some clever refine ments were devised to amplify the signal optically and reduce the noise (9), and photographic recording was used in some laboratories to follow the galvanometer light beam. (Some of these devices were called "beam chasers" and worked quite well.) Ex amples of spectra recorded this way can be seen in the book by Randall and coauthors (10). Strip chart re corders were a vast improvement. I remember best the Leeds and Northrup "Speedomax" and the Brown "Electronik" recorders. The Walsh d o u b l e - p a s s system (11) nearly doubled the resolution of single-beam instruments, although it was not used on double-beam ones. The introduction of double-beam IR spectrophotometers was a tremen dous advance because it made IR spectroscopy a much more practical technique. The first commercial dou ble-beam instrument, based on an instrument built at Dow Chemical Co. by Wright and Herscher (12), was
manufactured by Baird Associates (13). I had the privilege of using Baird's serial number 1 instrument at Mellon Institute in Pittsburgh, where it was acquired in 1947 by A. L. Marston. With it a spectrum could be obtained in about 20 min on preprinted chart paper that was linear in both microns and percent transmission. What a wonderful improvement this was! A steady s t r e a m of visitors came to Mellon Institute to see this marvelous instrument. (Mellon also obtained the first Cary UV-vis instrument [the Model 11] in April 1947 through Marston's initiative.) Linear micrometer and, later, linear c m - 1 drives were also introduced, which was a t r e m e n d o u s help in making instruments practical. They brought t h e convenience of p r e printed chart paper. Prism instruments, such as the Baird and the Perkin Elmer 21, used a cam to give a linear wavelength drive. After gratings came into use, cosecant bars provided linear wavenumber plots. Gratings also replaced prisms. It was fortunate that excellent gratings became available in adequate quantity at reasonable cost. In 1910 Wood (14) invented the echelette grating, which has its grooves ruled at a carefully controlled angle so that most of the radiant intensity is diffracted into a selected order on one side of the central image. This concentration is essential for IR spectroscopy because of the weakness of the signal. Following World War II, David Richardson of Bausch and Lomb, Inc., developed a method for making replicas of gratings. These copies are as good as or better than the originals, and many of them can be produced from one master. This capability was necessary for the widespread
Shortly after World War II, the Chemistry Department at MIT had both Beckman and Perkin Elmer single-beam instruments. Robert S. McDonald, then a graduate student there, found that the Beckman gave distinctly poorer spectra than did the Perkin Elmer. One day Howard Cary visited the laboratory. When he saw the Beckman his eyes lit up and he said, "I designed that instrument. How do you like it?" McDonald said that he had a rather poor opinion of it. "What do you think is wrong?" asked Cary. "Possibly it is the amplifying system," said McDonald. "Oh, I didn't do that. I designed the optics," replied Cary. The Beckman IR instrument was derived from the famous Beckman DU UV-vis instrument with suitable changes of components, and the prism orientation had been reversed to avoid a stray light problem. Someone at Beckman later found that they had forgotten to reverse the slit curvature, and when this was done the performance improved dramatically. use of gratings, because originals could not be ruled quickly or cheaply enough to satisfy the demand. The final thing needed to make gratings practical in the IR region was a means of sorting the orders so that u n w a n t e d r a d i a t i o n would be r e jected. Originally this was done with a fore prism, but later satisfactory filters were developed that greatly simplified the instrumentation. The Golay cell was introduced in
Harald H. Nielsen, Nelson Fuson, Harrison M. Randall, and Norman Wright (l-r) in March 1965 at the Pittsburgh Conference on Analytical Chemistry and Applied Spectroscopy.
1946 as a superior detector in the far-IR region (15) and, finally, computers were applied to dispersive instruments. At about the same time, IR interferometers became practical, and today they have almost completely replaced dispersive i n s t r u ments.
Short courses and meetings When instruments became available, potential u s e r s clamored to know how to use them and how to interpret the results. Information was slow to enter college curricula and, to fill the need for immediate training, a number of short courses were established that had a significant influence on the growth of the field. The first IR short course was held at MIT in 1950 (16). This course, which moved to Bowdoin College in 1972, is still being offered and is thus the longest running of all IR short courses that have been presented. It h a s also been given abroad nine times, and more than 5000 students have taken it. The course was started because Perkin Elmer and Baird Associates were concerned t h a t their i n s t r u ment sales would be limited by a scarcity of users who were knowledgeable in the measurement and interpretation of IR spectra. They went (separately) to Richard Lord at MIT and asked him to establish a short course to fill these needs. The first year, 50 students attended, and tuition was a mere $60. For the first two years the course consisted of two identical one-week sessions of lectures and laboratory experiments taught by Lord and myself. In the third year the course was expanded so that the two weeks had different contents, and guest lecturers were added. Another prominent course over the years has been the one given by the Fisk IR Institute in Nashville. Nelson Fuson started this course in 1950 as a single l e c t u r e by G.B.B.M. S u t h e r l a n d , a n d by 1953 had expanded it to a week-long session. It too is still operating, although there was an interregnum of three years between 1984 and 1986. Other courses have included those given by Herman Symanski at Canisius College in Buffalo (1957-69); Robert P. Bauman at Brooklyn Polytechnic Institute (1955-58); Bryce Crawford, S. W. Fenton, and W. J. Potts at the University of Minnesota (1959-69); and Jacob Fuchs at Arizona State University ( 1 9 6 1 present). Commercial companies— notably Sadtler Research Labora-
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REPORT t o r i e s — h a v e also offered s h o r t courses on IR spectroscopy. Meetings provided another way in which information was distributed quickly and efficiently. Among the many meetings on IR spectroscopy, the most prominent include the Conference on Molecular Structure and Spectroscopy (held annually at Ohio State University since 1946); the European Congress on Molecular Spectroscopy (EUCMOS), which began in 1947 and has been held during most odd-numbered years since then in various European cities (it moved to even-numbered years s t a r t i n g in 1992); the Pittsburgh Conference on Analytical Chemistry and Applied Spectroscopy (Pittcon), which a t tracts many practical users of spectroscopy; and the Gordon Conference on IR Spectroscopy, which has met in even-numbered years since 1954. Books The first "modern" compilation of IR spectra (at least in English) was published in a 1943 paper (17) and a 1944 book (18) by Barnes et al. Both contain the same text and the same 363 spectra, but the book also has an extensive bibliography with 2701 references. The book thus provides an excellent entry into the early literature on IR spectroscopy. A number of other books on the use of IR spectroscopy for chemical purposes appeared in succeeding years. The most influential by far was the one by Bellamy (19). First published in 1954, the book has had several editions and reprintings. More than 40,000 copies have been sold—a remarkable figure for an advancedlevel technical book t h a t is not a textbook. Peter Griffiths found that over a certain time interval, Bellamy was the seventh most-cited author in Citation Index—the Bible was first, and Bellamy was just ahead of Sigmund Freud. Bellamy brushed this off in his characteristically humorous way by saying that one gets cited when one makes mistakes and others correct them. His being ahead of
Left: John D. Strong (courtesy American Institute of Physics Niels Bohr Library); right: Robert S. McDonald.
In the early days of IR spectroscopy at MIT, Bob McDonald and Betty Fax ran spectra for the graduate students in organic chemistry. They did not, however, replot the spectra; that was up to the students. The latter were given the two single-beam traces and the wavenumber calibration table and had to convert these to the actual spectrum. The students complained bitterly about this to Arthur C. Cope, chairman of the department, but Cope said that it was good experience for them. Finally one day Cope said that he would replot a spectrum to show the students that he was willing to do what he asked of them. He took the material home that weekend, and the story is that when he came in on Monday he authorized the purchase of a Baird double-beam instrument.
Freud merely m e a n t t h a t he had made more mistakes than Freud. Among the many other publications on IR spectroscopy, one of the most significant is t h e "Colthup Chart," a compact representation of characteristic IR group frequencies that has been widely used. It was
first published in 1950 (20), and many versions have appeared since then. Colthup was an undergraduate student on a cooperative work/study program when he s t a r t e d this project. He was noted for going around the laboratory at American Cyanamid Co. asking others where they had found IR bands for various samples and jotting down the information. From this and his own work he developed his famous chart. Sample handling One of the great advantages of IR spectroscopy is that it can be applied to almost any sample in any state of matter except metals. Simple cells for gases and liquids were described by Coblentz in his 1905 book (21), and numerous other techniques for handling more difficult samples were developed l a t e r a n d c o n t r i b u t e d greatly to the utility of IR spectroscopy. Mineral oil mulls (usually called "Nujol" mulls in the United States) have been very widely used for powders. It was difficult to find out who originated this technique, but I am pleased to be able to give credit to the inventors. Lecomte, in his 1943 paper "The Method of Powders for Obtaining IR Absorption Spectra" (22), mentions the use of a thin layer or wafer of solid paraffin for supporting powders in an IR beam. (The sample was rubbed on the solid paraffin with
Richard C. Lord and Foil A. Miller posing by a truck that appeared on the MIT campus during the summer IR course in 1966. (The name of the firm was purely fortuitous and was a remarkable coincidence. I asked the driver about the owners of the firm and he replied, "Miller's still active, but Lord has been dead for years. ")
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There was dose collaboration between users and instrument people, with much useful feedback from the former. I remember an early Ohio State Conference when some of the attendees were sitting outside the residence hall on a very hot summer evening. Van Zandt Williams told us that Perkin Elmer was designing a new double-beam instrument (which became the Model 21), and he wanted opinions on what size the chart paper should be. People held out their hands to indicate their preference, and Williams went around with a tape rule, measured the spacings, and jotted them in a notebook. That, in part, accounts for the size of the paper drum on the Model 2 1 .
a finger.) He says nothing, however, about the use of liquid paraffin oil. The Nujol mull technique was un known to Wright when he wrote his 1941 survey paper (23), and he was well informed on such matters. How ever, it was mentioned by Barnes et al. (17) in 1943. Robert S. McDonald recently told me that he believes he made the first Nujol mull as the re sult of a suggestion made by Barnes. McDonald was working in the Amer ican Cyanamid Co. IR laboratory in 1942 when a number of phthalocyanine samples, which were intracta ble, were submitted for examination. A paint laboratory happened to be just around the corner. Workers sus pended pigments in paint vehicles by g r i n d i n g the s l u r r y between two glass disks 6 - 8 in. in d i a m e t e r . Barnes suggested that McDonald try this method for the phthalocyanines b u t u s e Nujol for t h e liquid. It w o r k e d like a c h a r m , a n d t h e y quickly found that they could scale down the procedure. Although they did not describe the method in detail in the literature, the 1943 paper m e n t i o n s it casually. Thus the method seems to have been introduced in 1942 or early 1943. In terestingly, the collection of spectra that Barnes et al. presented (17, 18) does not contain that of Nujol. It is a pleasure to be able to give credit at long last to the people who originated this useful technique; it is long over due. P e r h a l o g e n a t e d oils, developed during and just after World War II, are a useful complement to Nujol. Their use for IR mulls seems to have
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been first described by Crocket and Haendler in 1959 (24). The use of KBr pressed disks was first described in 1952 by Sister Mir iam M. Stimson of Siena Heights College (Adrian, MI) (25). She devel oped the procedure while looking for a technique to obtain both UV and IR spectra on the same sample. It has been widely used in the IR region but scarcely at all in the UV region. Attenuated total reflection (ATR) was developed i n d e p e n d e n t l y by Fahrenfort (26) and Harrick (27) be tween 1959 and 1960. It has been es pecially useful for thick samples, strongly absorbing samples, and sur face studies. Matrix isolation (freezing a sample at about 10 Κ as a very dilute solu tion in an inert medium such as ar gon) was introduced independently in 1954 by Norman and Porter (28) and by Whittle, Dows, and Pimentel (29). Variable long-path gas cells, origi nally devised by White (30); the dia mond high-pressure cell, developed by Weir, Lippincott, Van Valkenburg, and Bunting (31); and diffuse reflec tance, developed by Willey (32) and by Fuller and Griffiths (33) have also been important developments. All of these things constitute what I have called "the infrastructure of IR s p e c t r o m e t r y " : prior k n o w l e d g e ; availability of good optical compo nents; great improvements in instru mentation; training courses, books, and meetings; and an unusually wide range of sample-handling methods. They all contributed to the feasibility and rapid acceptance of commercial IR instruments. I would like to express my warm appreciation to the many friends who provided information for this paper, especially Norman B. Colthup, Fre derick Halverson, Robert W. Hannah, and Rob ert S. McDonald. Preparing this has been a nos talgic experience because it led me to think about some events of long ago, and that brought a flood of pleasant memories. I therefore extend my sincere thanks to the organizing committee of the Waters Symposium for inviting me to participate. References (1) The Random House Dictionary of the En glish Language, 1968. (2) a. Jones, R. N. In Chemical, Biological, and Industrial Applications of IR Spectros copy; Durig, J. R., Ed.; John Wiley and Sons: New York, 1985; Chapter 1, pp. 1-50. b. Jones, R. N. European Spectros copy News 1987, 70, 10-20; 72, 10-20; 74, 20-34. (3) Nichols, E. F.; Tear, J. D. Astrophy. J. 1925, 61, 17-37. (4) Lecomte, J. Le Rayonnement Infrarouge; Gauthier-Villars: Paris, 1949; Vol. 2, p. 395. (5) a. Strong, J. Phys. Rev. 1930,36, 1663-
V. Z. Ind. Eng. Chem., Anal Ed. 1943, 15, 66. b. Strong, J. Phys. Today April 1951, 659-709. p. 14. (6) Strong, J. Procedures in Experimental (18) Barnes, R. B.; Gore, R. C; Liddel, U.; Physics; Prentice-Hall: New York, 1943. Williams, V. Z. Infrared Spectroscopy. In (Brashear's method was also given in dustrial Applications and Bibliography; the CRC Handbook of Chemistry and Physics Reinhold Publishing Corp.: New York, until at least 1963.) 1944. (19) Bellamy, L. J. The Infrared Spectra of (7) Beckman, A. O.; Gallaway, W. S.; Complex Molecules; Methuen and Co.: Kaye, W.; Ulrich, W. F. Anal. Chem. London, and John Wiley and Sons: New 1977, 49, 280 A-300 A. York, 1954. (8) Barnes, R. B.; Perkin, R.; Sanderson, J. Α.; Warga, M. E. Phys. Today June (20) Colthup, N. B.J. Opt. Soc.Amer. 1950, 1966, p. 115. 40, 397-400. (9) Firestone, F. A. Rev. Sci. Instrum. (21) Coblentz, W. W. Investigations ofInfra 1932, 3, 162-88. red Spectra; Publication No. 35, Carnegie Institution of Washington, 1905. Re (10) Randall, H. M.; Fowler, R. G.; Fuson, printed in 1962 by the Coblentz Society N.; Dangl, J. R. Infrared Determination of and Perkin Elmer. Organic Structures; Van Nostrand: New York, 1949. (22) Lecomte, J. Cahiers de Physique 1943, 17, 1-26. (11) a. Walsh, A. D. /. Opt. Soc. Amer. 1952, 42, 94-100, 496-500; b. Walsh, (23) Wright, N. Ind. Eng. Chem., Anal. Ed. A. D. /. Opt. Soc. Amer. 1953, 43, 215, 1941, 13, 1-8. 989—92 (24) Crocket, D. S.; Haendler, H. M. Anal. Chem. 1959, 31, 626-27. (12) Wright, N.; Herscher, L. W. /. Opt. Soc. Amer. 1947, 37, 211-16. (25) Stimson, M. M.; O'Donnell, M. J. / Am. Chem. Soc. 1952, 74, 1805-08. (13) Baird, W. S.; O'Bryan, H. M.; Ogden, G.; Lee, D. /. Opt. Soc. Amer. 1947, 37, (26) Fahrenfort, J. Spectrochim. Acta 1961, 754-61. 17, 698-709. (27) a. Harrick, N. J. Phys. Rev. Lett. 1960, (14) a. Wood, R. W. Phil. Mag. 1910, 20, 4, 224-26. b. Harrick, N. J. /. Phys. 770-78. b. Wood, R. W.; Trowbridge, A. Chem. 1960, 64, 1110-14. Phil. Mag. 1910, 20, 886-98. (15) a. Zahl, Η. Α.; Golay, M.J.E. Rev. Sci. (28) Norman, I.; Porter, G. Nature 1954, Instrum. 1946, 17, 511-15. b. Harrison, 174, 508. G. R.; Lord, R. C; Loofbourow, J. R. (29) Whittle, E.; Dows, D. Α.; Pimentel, Practical Spectroscopy; Prentice-Hall: En- G. C.J. Chem. Phys. 1954, 22, 1943. glewood Cliffs, NJ, 1948; pp. 308-09. (30) White, J. U. /. Opt. Soc. Amer. 1942, 32, 285-88. (16) Lord, R. C. Spectroscopy 1989, 4, 2 8 29. (31) a. Weir, C. E.; Lippincott, E. R.; Van Valkenburg, Α.; Bunting, Ε. Ν. /. Res. (17)'Barnes, R. B.; Liddel, U.; Williams,
Natl. Bur. Stds. 1959, 63A, 55-62. b. Lip pincott, E. R.; Welsh, F. E.; Weir, C. E. Anal. Chem. 1961, 33, 137-43. (32) Willey, R. R. Appl. Spectrosc. 1976, 30, 593-601. (33) Fuller, M. P.; Griffiths, P. R. Anal. Chem. 1978, 50, 1906-10.
Foil A. Miller is professor emeritus at the University of Pittsburgh. He received his B.S. degree in chemistry from Hamline University in 1937 and his Ph.D. from Johns Hopkins University in 1942. After holding various positions at the Univer sity of Minnesota, the University of Illi nois, and the Mellon Institute, he joined the faculty of the University of Pittsburgh in 1967. He obtained his first IR spectrum in 1941 through the courtesy of IR pio neers at American Cyanamid Co. Re search Laboratories and acquired his first IR instrument in 1945.
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