Barry Carpenter—Pioneering physical organic chemist, teacher, mentor, and friend

This special issue of the Journal Physical Organic Chemistry is dedicated to an outstanding physical organic chemist, mentor, and friend, Barry Carpenter, on occasion his official retirement. Knowing that great minds like never fully retire, we thought a fitting tribute would be compilation recent research by people who have been lucky enough crossed paths—trajectories—with him. Here, you will find selection contributions from Barry's science family. We hope diversity these encourage readers broaden their views reactivity delve deeper into its origins—as many contributions, in papers, talks, personal discussions, done. To Barry, say thank for having opened doors our minds, leading us beyond well-trodden minimum energy path new adventures chemistry. Below, include (1) autobiographical sketch provided himself, (2) testimonials colleagues friends speaking both professional personal, (3) comprehensive list publications. I was born Hastings, SE England, lived there until 1967, when left go college. As child, had become interested chemistry biochemistry after discussions with my older brother, first family pursue higher education, studied biochemistry. My interest further piqued being given set as gift. It contained substances, such sodium dichromate, permitted sold children today. Even more remarkably, it perfectly acceptable 12-year-old local pharmacy glass-stoppered bottle filled concentrated hydrochloric or even nitric acid! am probably not killed myself garden-shed laboratory. On other hand, sure whether tepid items pass sets days stimulated me career. education began at University Warwick, which only 2 years before arrival. real pioneering spirit, although also clearly still work progress. Rather than hallowed, ivy-covered buildings centuries' duration, consisted blocks white-tiled structures, causing some wits liken giant public toilet! The principal hazard student time avoiding tiles fall off regularity. In line general Zeitgeist late 1960s, wish try directions Warwick. Germaine Greer lecturer English department time, example. sciences, similar explore ideas. So degree course actually Molecular Sciences, rather Instead teaching conventional fashion what one might call traditional, vertical divisions organic, inorganic, chemistry, effort take topic, stereochemistry, meaning importance across traditional disciplines. Thus, field divided horizontally vertically. believe exposure this way thinking influenced own generalist tendencies later life. originally follow brother's biochemistry, but Warwick inspired particular lecturer, John M. Brown, showed delightful logic decided really wanted do, so pursued doctorate topic Prof. H. R. Hoffmann College London. worked “oxyallyl” cations (the class reactive intermediate formally formed breaking 2,3 C–C bond cyclopropanone). dabbled bit organometallic exploring question newly developed Woodward-Hoffmann rules applied well reactions. Following receipt Ph.D. 1973, headed USA postdoctoral studies. several big-name American chemists accepted them—Jerome Berson Yale University. turned out, very fortunate outcome, because received best possible Berson's lab. felt today, learned 18 months 6 point. mentor. He prescriptive about should study, absolutely rigorous how study it. His intellect combined, must say, qualities just thoroughly decent human being, strong impact me. With hindsight, no surprise all students postdocs went independent researchers—sometimes fields far removed computational during PhD grew Berson. However, doing computer calculations any kind different then carry heavy boxes punched cards street computing center (and heaven forbid slip icy wintertime drop box!). were after, typically, couple could pick them up again, along output massive, folded sheets paper. exercise did much exploratory calculation! drew close, arose do next. hoped return position UK, mid 1970s, UK economy recession essentially positions available. consequently looked places US land Assistant Professor job Cornell After few Cornell, became clear along. Department welcoming social scientific interactions among faculty members. subsequently discovered norm academic departments, so, done happened lab, fallen something bed roses nothing blind luck. fact spent 31 says everything necessary place. When finally 2006, certainly antipathy there. Cardiff University, back created Centre, looking director. They offered position, That where finished career, Wales live. Over blessed large number highly talented graduate postdocs. taught least them, opportunity express sincere gratitude ways they enriched may understand why postdoc inorganic chemist synthetic experience. Nevertheless, always appreciated altered chemical thinking—arrow pushing are rarity all! experience humility gained working labmates over Ithaca made huge approached problems mentoring. grateful guidance, patience, generosity. Happy retirement, Barry! taking courses, see he undergraduate course. One day, privilege witnessing him lecture largely 2nd year undergraduates. During lecture, asked auditorium full question. sat wondering; imagine unfold. Seared memory waiting, patiently waiting quite respond. Of responded, story sheer magnitude gentle patience students. persistent witnessed every single Carpenter group meeting; modeled students, undergraduates, persistence key learning. From beginning school, considered papers essential reference material (reference reads poetry). hyperbolic vast majority understanding kinetic rate theories non-statistical dynamic effects came directly papers. Considering applicability own, completely natural group. Though moving country (US → UK) big life decision, Mathematics Phase Space (CHAMPS) program starting right planning apply positions, considering knew mentoring pretty easy choice make. Working paper together needed know writing papers: push past uncertainty get words page, prioritize rigor clarity above else, precious keeping figures lot time. last lesson obstacle overcome, helped realize others yourself, thus, listen if reader has critiques information coming across. unceremonious departure September 2020, due COVID-19 pandemic, got chance goodbye person. thankful contribute training, teaching, advancing community whole – feels sprawling retirement throughout early then-student Cindy Burrows effect cyano substituents (at five positions!) Claisen rearrangement immensely (C. J. B. K. Am. Chem. Soc. 1981, 103, 6983, 6984). These synthesis, kinetics, theory—the essence modern career Cornell. Nine later, Wes Borden, Keiji Morokuma, Cope, Burrows-Carpenter work. occasions meet meetings, learn him, 1984 book, Determination Reactions Mechanisms, used too. enjoy urbane manner wit. admired relished brave entry world chemistry—computational molecular dynamics. pioneered rich insights mechanisms possible, us—Dan Singleton, Chuck Doubleday, I, name few—followed field. Now host joined time-resolved reactions occur. move fifteen ago loss U.S. science, continues enrich profound goes without saying can described elegant, esthetically pleasing, obviously true fooled believing arrived same penetrating conclusion problem hard long enough. You have, While it's penetrating, skill communicator teacher makes accessible. group, observing approach skills educator. What impressed most wasn't pedagogy, well-crafted meticulous were, respect process communication itself, engaged communication. recognizes common humanity each person sincerely seeking knowledge understanding. talking student, advisees, colleague. repeatedly saw answer recognized “dumb” outward show Nobel laureate. It's those questions. Now, educator, day treat respect. solving problems, able share solutions I've elegant ideas Thanks, Barry. pleasure relay experiences Carpenter. met took famous 665. (This followed next semester 666, think challenging diabolical number!) area. remember lecture—Barry trotted out Schrödinger equation complex derivation does expect But plan lead-in orbital theory. exam mean 20%. None mattered us, however, exceptional teacher. come alive passion; importantly, amazing ability clarify difficult concepts. inspiring love mechanistic choose entire path—and ever that. There coda story. Many recommended (since undergraduate). Quite frankly, 665 legendary. Usually complain course, pushed rise challenge despite course's difficulty, sang praises (Blair Wood) husband, suppose well! 1975 member following January. Whether laboratory classroom, paramount helps grow scientists individuals. readily willing questions had, matter intelligent trivial. For project, while discussing experiments mechanism perform told rather, ask, reaction done? general, suggestions guide intellectually process. If direction discussed, inquire results discuss tried pattern behavior successful, result Therefore, growth scientist part 1978. Everyone called Coming India addressed Professors “Sir” “Professor” mostly elegant. Woodward “supreme patterner chaos.” freedom gave amazing. experimental methods Jim Burlitch second semester. Although cut agreed. easygoing request partly Roald. ran computations himself. guided fronts wanted. Halfway through semester, handle attending two meetings. liked ditched Roald (he remained lifelong friend) fully. weekly problem-solving sessions high point week. literally treated everyone kindness. hardly reports. classes logically arranged. lectures mesmerized. doubts “chalk work” blackboard neat structures drawn good draw ChemDraw! realized hours assignments hand-outs hand-written photocopied. counselor comforter. found seated floor listening Guru! heartbroken trying solve published. Not moved on. Frankly, expected “successful thesis.” put let end 4 years. things life! attended meetings addition advisor, Hoffmann. make lasting memories hearing talk reactivity. use correct here, concept then. Much understood important, decades ago. ahead time; nowadays, including modeling becoming commonplace. led Fe-templated ring-opening methylenecyclopropanes, wherewithal grasped then! Since interacting various conferences getting bit. appreciate opinions politics latter well). amazed fatal flaws approaches projects reveal practitioners helpful hurtful ways. submit referee tell okay. support community, indirectly. quiet inspiration. group's collaboration memorable beginning. photolysis aqueous pyruvic acid. chatting visiting mentioned particularly noticeable smell produced photochemistry. lab “sniffed out” producing acetoin. “That moment walked proclaimed was, favorite your group” (Elizabeth). start wonderful, educational, fun chemists. Meetings around table Anne Monod NMR wizardry Rich Shoemaker studies appreciation mechanisms. wonderfully supportive encouraging attempts development, naïve wrong. Through collaborations, chemically. wonderful fun, is. BARRY'S PUBLICATIONS TO DATE “Synthesis 3(2H) Furanones,” B.K.; Clemens, K.E.; Schmidt, E.A.; Hoffmann, H.M.R. 1972, 94, 6213. “An INDO Orbital Study 1,3 [π] Interactions 2-Substituted Allyl Cations,” B.K. Perkin II, 1974, 1. “Synchronous Double Rotation Stereomutation Optically Active 1-Phenylcyclopropane-2-d1,” Pedersen, L.D.; Berson, J.A.; B.K.J. 1975, 97, 240. (4) “Octamethyl-1,4-cyclohexanedione,” Rawson, D.I.; Ind. (London) 886. (5) “Thermal Cyclopropanes,” 1976, 98, 122. (6) “The Influence Substituents Energies Ground Electronic States Substituted Trimethylenemethanes,” Little, R.D.; J.A. 5723. (7) “2,3-Diazabicyclo[2.2.0]hex-2-ene,” Wildi, Tetrahedron Lett. 1978, 2,469. (8) “Frontier Control Regiospecificity Singlet Cycloadditions 2-Methylenecyclopenta-1,3-diyls,” Siemionko, R.; Shaw, A.; O'Connell, G.; Shen, L.; 3529. (9) “A Simple Model Predicting Effect Rates Thermal Pericyclic Reactions,” 34, 1877. (10) Theoretical Effects Benzannelation Bismethylenation Four-Membered Ring Opening Wilcox, C.F., Jr.; Dolbier, W.R., Jr. Tetrahedron, 1979, 35, 707. (11) “Loss Cation Configuration Electron Conjugated Dienes,” 101, 1786. (12) “Quantitative Prediction Structure-Reactivity Relationships Unsaturated Hydrocarbons. Development Semiempirical Model,” 3879. (13) Stereochemistry Organometallic Electrocyclic Pinhas, A.R.; Commun. 1980, 15. (14) “On Mechanism Iron Carbonyl Promoted 2-Phenylmethylenecyclopropane,” 17. (15) “Experimental Evidence Non-Square Cyclobutadiene Chemically Significant Intermediate Solution,” Whitman, D.W.; 102, 4272. (16) “Conformational Nucleophililic Electrophilic Attack (Arene)Chromium Tricarbonyl Complexes,” Albright, T.A.; Inorg. 19, 3092. (17) 2,3-Diazabicyclo[2.2.0]hex-2-ene. First Example Disrotatory Diazacyclobutene Opening,” Van Engen, D.; 7994. (18) Symmetry Methylenecyclopropane Samuelson, A.G.; Risemberg, Arnold, E.V.; Clardy, J.; 1668. (19) Induced Kinetic Isotope Tool Mechanistic Discrimination,” 354. (20) “Substituent Aliphatic Rearrangement. Synthesis Rearrangement Cyano-Substituted Vinyl Ethers,” Burrows, C.J.; 6983. (21) 2. Analysis,” 6984. (22) “Stereochemistry Alkoxide-Accelerated [1,3] Migration,” Zoeckler, M.T.; 7661. (23) “Limits Activation Parameters Automerization Cyclobutadiene-1,2-d2,” 1982, 104, 6473. (24) “Nucleophilic Addition (η6-Alkylbenzene)Cr (CO)3 Complexes. Dependence Regio-selectivity Size Alkyl Group Reactivity Nucleophile,” Semmelhack, M.F.; Garcia, J.L.; Cortes, Farina, Hong, Organometallics 1983, 2, 467. (25) “Heavy Atom Tunneling Dominant Pathway Solution Reaction? Bond Shift Antiaromatic Annulenes,” 105, 1700. (26) “Dynamics O (1D) Bifunctional Substrates: HCN,” Goldstein, N.; Kam, Wiesenfeld, J.R. Phys. 1984, 81, 1785. (27) Polar Transition State [1,5] Sigmatropic Cyclopentadienes.” Replogle, K.S.; 106, 5751. (28) “Temperature Stereoselectivity Criterion Mechanism. Bicyclo[2.1.1]hexene-5-d Two Phenyl Derivatives,” Newman-Evans, R.H.; (29) “Highly Stereoselective Bicyclo[2.1.1]hexenes-5-d Transmetallation Tetra-alkyl Tin,” 1985, 26, 1141. (30) “Trajectories Fourfold Branchpoint. Implications Stereo-chemistry Biradical 107, 5730. (31) (Bicyclo[6.1.0]nonatriene)tricarbonyl Molybdenum,” Liotta, F.J.; B.K., 6426. (32) Chorismic Acid Related Compounds,” Gajewski, J.J.; Jurayj, Kimbrough, D.R.; Gande, M.E.; Ganem, B.; 1987, 109, 1170. (33) “Structures Mechanisms Bicyclo[6.1.0]nona-2,4,6-triene Complexes Chromium, Molybdenum, Tungsten,” F.J., Duyne, G., 6, 1010. (34) Cyclic C4H4 Radical Ray, J.C., Danis, P.O.; McLafferty, F.W.; 4408. (35) “Identification Quantification Kynurenic Human Brain,” Turski, W.A.; Nakamura, M.; Todd, W.P.; Whetsell, W.O.; Schwarcz, Brain Res. 1988, 454, 164. (36) “Synthesis, Photochemistry, Biological Activity Caged Photolabile Acetylcholine Receptor Ligand,” Milburn, T.; Matsubara, Billington, Udgaonkar, J.B.; Walker, J.W.; Webb, W.W.; Marque, Denk, W.; McCray, Hess, G.P. Biochemistry 1989, 28, 49. (37) “Preparation 4-Halo-3-hydroxyanthranilates Demonstration Inhibition 3-Hyroxyanthranilate Oxygenase Rat Tissue,” Prep. Biochem. 155. (38) “ESR Stereospecific Formation Chair Cyclohexane-1,4-diyl Both Bicyclo[2.2.0]hexane 1,5-Hexadiene,” Williams, F.; Guo, Q.-X.; Bebout, D.C.; 111, 4133. (39) “Catalytic Stoichiometric Cyclooctatetraenes Soluble Nickel Lawrie, Gable, K.G.; 8, 2274. (40) “Characterization Four Molecules Cations Neutralization-Reionization Mass Spectrometry,” Zhang, M.-Y.; Wesdemiotis, C.; Marchetti, F.W. 8341. (41) Intramolecular Dynamics Branching Ratios Rearrangements,” Simon, R.J.; Org. 1990, 55, 695. (42) Amino-acid Neurotransmitters,” Viola, R.W.; Johnson, K.W.; A.P.; Guzikowski, 1585. (43) “Facile Cleavage C-C Dinuclear Complex,” Dankosh, H.; Organomet. Chem.1991, 411, C7. (44) “4-Halo-3-hydroxyanthranilic Acids Potent Competitive Inhibitors 3-Hydroxyanthrani