Herman Pines — He revolutionized the general understanding of catalysis

Her­man Pines

Her­man Pines

Her­man Pines was born in Lodz, Poland, in 1902. After earn­ing his degree at the École Supérieure de Chimie in Lyon, France, he came to the U.S. in 1928. He was the clos­est asso­ciate of Vladimir Niko­layevitch Ipati­eff from the day they met in 1930, until Ipatieff’s death in 1952. Ipati­eff, who was 35 years older than Pines, then held two jobs: he was an employee of Uni­ver­sal Oil Prod­ucts (UOP) in Des Plaines and a research pro­fes­sor at North­west­ern Uni­ver­sity. As a con­se­quence of the close inter­ac­tion of these two devoted sci­en­tists, Her­man Pines, an employee at UOP, became involved in Ipatieff’s research at North­west­ern. What started spon­ta­neously and unof­fi­cially, was for­mal­ized in 1941, when Her­man was appointed Research Assis­tant Pro­fes­sor at North­west­ern, with the stip­u­la­tion that he should spend his Wednes­days work­ing here. This appoint­ment coin­cided with the relo­ca­tion of Ipatieff’s lab from the base­ment of Uni­ver­sity Hall to the newly erected Tech­no­log­i­cal Institute.

One of the first actions of this new pro­fes­sor was to write, with Ipati­eff, a mem­o­ran­dum to the Chem­istry Depart­ment propos­ing the cre­ation of a Catal­y­sis Teach­ing and High Pres­sure Lab­o­ra­tory. This doc­u­ment was dated Sep­tem­ber 29, 1941, but it was not until 1947 that the Catal­y­sis Lab offi­cially opened in the Tech­no­log­i­cal Insti­tute. A spe­cial High Pres­sure Lab­o­ra­tory was built in 1952 and offi­cially ded­i­cated August 14, 1953, in the pres­ence of the Pres­i­dents of North­west­ern Uni­ver­sity and of UOP. Pro­fes­sor Sir Hugh Tay­lor of Prince­ton Uni­ver­sity gave a lec­ture on catal­y­sis for the occa­sion. Shortly there­after, a bronze plaque hon­or­ing Vladimir N. Ipati­eff was mounted over the entrance of the High Pres­sure Lab; it is now located in the recep­tion area of the Catal­y­sis Center.

Mean­while, Her­man Pines had been pro­moted, in 1951, to the rank of Asso­ciate Research Pro­fes­sor; after Ipatieff’s death, in 1952, he became the first V.N. Ipati­eff Pro­fes­sor of Organic Chem­istry. On Jan­u­ary 1, 1953, he left UOP and began offi­cially as a full-time pro­fes­sor at Northwestern.

Only a few of the out­stand­ing sci­en­tific achieve­ments of Her­man Pines can be men­tioned here; it is not an over­state­ment to say that his work rev­o­lu­tion­ized the gen­eral under­stand­ing of chem­istry, in par­tic­u­lar the chem­istry of hydro­car­bons inter­act­ing with strong acids.

An unchal­lenged dogma of the chem­istry of the 1930’s was that paraf­fins would not react with any­thing at low tem­per­a­ture; even the name of this class of com­pounds, “parum affi­nis,” was based on this assumed lack of reac­tiv­ity. It must have been quite a shock to the sci­en­tists of those days, when Pines and Ipati­eff showed, in 1932, that in the pres­ence of a strong acid the paraf­fin iso-butane would react, even at –35 ºC, with olefins. This was the basis of the alky­la­tion process, patented in 1938 and indus­tri­ally devel­oped soon after. Its most spec­tac­u­lar appli­ca­tion is the syn­the­sis of iso-octane from n-butene and iso-butane. Iso-octane improves the qual­ity of gaso­line and air­plane fuel; it played a deci­sive role in the vic­tory of the Royal Air Force dur­ing the Bat­tle of Britain in 1941. The catal­y­sis of con­vert­ing paraf­fins to isoparaf­fins is, of course, one of the cor­ner­stone of the petro­leum industry.

The alky­la­tion process was not dis­cov­ered by acci­dent. It was the pin­na­cle of research that started with an obser­va­tion that puz­zled Her­man Pines in 1930. At that time he was work­ing in the ana­lyt­i­cal lab of UOP; his task was to vig­or­ously shake petro­leum frac­tions with con­cen­trated sul­fu­ric acid in a cal­i­brated glass cylin­der and to deter­mine how much of the oil dis­solved in the aque­ous acid phase. It was known that only unsat­u­rated hydro­car­bons would be dis­solved in the acid; this exper­i­ment of shak­ing the petro­leum and read­ing the menis­cus was the stan­dard pro­ce­dure to deter­mine how many unsat­u­rated prod­ucts were present in a petro­leum frac­tion. Her­man observed, how­ever, that after a few hours the phase bound­ary between oil and acid had shifted again: more oil was formed-oil that would not dis­solve in the aque­ous phase. Appar­ently paraf­fins had been formed from olefins; Her­man con­cluded that this process required the simul­ta­ne­ous for­ma­tion of a highly unsat­u­rated coprod­uct which remained dis­solved in the aque­ous phase. They called this process “con­junct poly­mer­iza­tion,” and years later ana­lyt­i­cal meth­ods were found which per­mit­ted iden­ti­fi­ca­tion of this unsat­u­rated coprod­uct as a mix­ture of sub­sti­tuted cyclopen­ta­di­enes. The step which led from this early obser­va­tion to the alky­la­tion process was later described by Herman:

On a hunch we thought that paraf­fins might even react with olefins in the pres­ence of acids; we there­fore intro­duced a stream of eth­yl­ene and hydro­gen chlo­ride to a stirred mix­ture of the pen­tanes and AlCl3. We observed that the eth­yl­ene was absorbed and that the hydro­car­bons recov­ered from the reac­tion con­sisted of sat­u­rated hydro­car­bons only, an indi­ca­tion that eth­yl­ene must have reacted with the pentanes.”

On this basis, Her­man Pines and Vladimir Ipati­eff devel­oped the new chem­istry of acid cat­alyzed reac­tions; it formed the cor­ner­stone of their sci­en­tific work and was brought to its present beauty by Her­man in his years at North­west­ern. Major dis­cov­er­ies led to new processes for the iso­mer­iza­tion of paraf­fins and the alky­la­tion of aro­matic com­pounds, but also to base cat­alyzed organic reac­tions. Two hun­dred and fifty pub­li­ca­tions in the sci­en­tific lit­er­a­ture, one hun­dred and forty-five U.S. patents and the book “The Chem­istry of Cat­alytic Hydro­car­bon Con­ver­sions” demon­strate the wealth of Herman’s sci­en­tific legacy. The forty-one grad­u­ate stu­dents and thirty-three post­doc­toral fel­lows who per­formed research in his lab helped carry his sci­en­tific mes­sage to the world. As U.S. edi­tor of Advances in Catal­y­sis, he keenly looked for and crit­i­cally eval­u­ated new con­cepts of catal­y­sis, and assured that their orig­i­na­tors described them care­fully to the sci­en­tific com­mu­nity. In 1957 he was chair­man of the Chicago Catal­y­sis Soci­ety, in 1960 chair­man of the Gor­don Con­fer­ence of Catal­y­sis. He received three awards from the ACS, an hon­orary degree from the Uni­ver­sity of Lyon and invi­ta­tions to lec­ture and advise in Israel, Brazil, Venezuela, Argentina, Poland, Czecho­slo­va­kia and Spain.

The Catal­y­sis Cen­ter remained his sci­en­tific home. He rarely missed a sem­i­nar and often asked crit­i­cal ques­tions. He could be quite sharp when speak­ers used catal­y­sis only as a buzz­word for the intro­duc­tion of their lec­tures and spoke about work of rather ques­tion­able rel­e­vance to “real” catal­y­sis. Although he could be crit­i­cal, he was never insen­si­tive; his gen­tle and friendly nature made it quite impos­si­ble for him to do any harm to any­one. While there is a unan­i­mous con­sen­sus that he was one of the tow­er­ing sci­en­tists of this cen­tury, he always remained very mod­est; when his trend­set­ting dis­cov­er­ies of the 1930’s were men­tioned, he always referred them to Ipati­eff. He worked assid­u­ously his entire life, bring­ing his last book to com­ple­tion at the age of ninety. Future gen­er­a­tions can learn from his exam­ple how rev­o­lu­tion­ary dis­cov­er­ies arise from sharp obser­va­tions by an inves­ti­gat­ing mind. Her­man Pines passed away on April 10, 1996.
Con­tributed by Wolf­gang Sachtler