UOLAS I I--

SECURITY CLA¶SIFICATION OF ThI. ,I ,.r (r4-i@. .7, Fntetd)

REPORT DOCL. rATION PAGE iTI-ON i:.. "rToNs,_________ _______ _____ .... ING I"L)RM

(PORT2 NUBR 1 GOVT ACCES5.04N ~ C'VA -; UM)

4. TITLE (ad Subitle) 5 TYPE " ' P; , & P'ERIOD COVEREDF.in~ ,tport:Study of Photophysical Processes and Molecular 25Sn71 4ep 81Transformations of Excited States 25 Sep 7') - 24 Sep 81

.•RFORMING ORFG. REPORT NUMBER

7. AUTHOR(&) S. CONTRAG" OR GRANT NUMBER(@)

Howard E. Zimmerman DAAG29 78 .G 0204

9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT, I ROJEC', TASKWe AREA & WORK UNIT NUMBERS

University of WisconsinMadison, WI 53706

I1. CONTROLLING OFFICE NAME AND ADDRESS 12. REPORT DATE

• U. S. A.rmry Research 0ffice -Dec 14. 81Post Office Box 12211 13. NUMBER OF PAGESResearch Triangle Park, NC 27709 _ __1_

1'4. MONITORING AGENCY NAME & ADDREWSII dilfegren Irorn Controllng file..) IS. SECURITY CLASS. (o1 this report)

Uncli.assiried154. DECLASSIIFICATION/DOWNGRADING

SCHEDULE

1S. DISTRIBUTION STATEMENT (frtle kti. port)

Approved for public release; distribution unl'imited. /

I-I

17. DISTRIBUTION STATEMENT (of the. abstract ntered in Block 20, It different froml Report)

NA

,1. SUPPLEME4TARY NOTES

The view, opinions, and/or findings contained in this report are those of theauthor(s) and should not be construed as an cfficial Department of the Armyposition, policy, or decision, unless so designated by other documentation.

19. KEY WORDS (ConfIinuq on tevt&*e ide Ii nece••ary and iden liy 0)' VIOCK n, o?)

molecular transformations photochemistryexcitationphotophysical processesorganic chemistry

241. ASSGTNACT (rahtes reverse ofif It rw~m...ry md IderuiIy by blocik rinumber)

A brief description, including bibliography and personnel, is given of 26 yearsof ARO support in the area of photophysical processs and molecular

. transformations of excited states is given..3-

pOl~lw1*"3 EDITION OF NOV IaS IS, OBSILETS DDD JA ri•' UNICLAsSI F IED

FINAL REPORT ON U.S. ARMY SPONSORED RESEARCH

by Professor Howard E. Zimmerman

University of Wisconsin, Madison, Wisconsin

December 14. 1981

To the U. S. ARMY RESEARCH OFFICE

Grant DAA029 78 G 0204

Approved for Public Release

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TABLE OF CONTENTS

ITEM PAGE

1. Support Period 2

2. Grant Numbers 2

3. Titles 2

4. Personnel Supported During Last 3 Year Period 2

S. Last Three Year's Publication List 3

6. Technical Information S

7. Successfulness of Last Three Year Grant S

8. Accomplishments During 26 Year Period of ARO Grants S

9. General Comments About ARO Funding of Basic Research S

10. Examples of the Principal Investigator's Former Students,ARO, Supported and Not, and Their Relationship to ARO 6

11. List of ARO Supported Personnel and Current Position 7

12. Full List of ARO Supported Publications 9

Accessli ~o"DTIC TAo

By-or--Dist•.ibution/..-

A ;CoAV,.il and/or

D515t special

-------------------------- ~ . ... Die

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1Period of Sugport by U. 8. Armly Research Office:

The U. S. Army Research Office suoported ourresearch in a series of grants beginning in September 1956and ending in September of 1981.

The most recent grant covered the period September

25, 1978 through September 24. 1981.

This final report formally covers this lastthree-year period. However, in view of the very extended

support of our research by the U.S. Army Research Office,and the cessation of this support after a 25-year period.it seems appropriate to cover the entire period to some

extent.

This report is slightly delayed due to lack of

secretarial assistance deriving from the precipitous and

unexpected cessation of ARO support. Thus the report has

had to be prepared in its entirety by the PrincipalIn-vstisator himself.

2. Most Recent Grant Number: DAAG29-78-G-0204.Considering the very long period of support, our records

do not maintain the various grant numbers over the entirepoxiod of 25 years.

3. Title of Research.Project: Our most recent title is:

"Study of Photophysical Processes and MolecularTransformations of Excited States."J

The title previous to this one was "A Study of Unstable

Organic Species and Unusual Organic Transformations. m

The first title covers the last six years of researchsupport.4. Personnel Supported Durins the Last 3 Year Period:

Individual and Au22 Present Position

Yeffrey Blood (Res Asst) Completed Ph.D., nowat Eastman Kodak Co.

Richard Bunco (Res Asst) Completed Ph.D., nowPostdoctoral Fellow at Berkeley

Craig Caufield (Res Asst) Still doing graduate study.

Paula Clausen (Secretary) Moved to another position.

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Thomas Gannett (Rea Asst) Compluted Ph.D.,nowat E. 1. DuPont do Nomours and Co.

Timothy Hirzel (Res Asst) Completed Ph.D., nowat Monsanto, St. Louis

Doreen Lynch (Resaroh Asst) Stiil doing graduate study.

John Nuts (Res Asst) Still doing graduate study.

Robert Pasteris (Res Asst) Completed Ph.D., now atE. I. DuPont do Nemours and Co.

Sohn Penn (Roe Assistant) Completed Ph.D., now PostdoctoralFellow at Univ. of Utah

Richard Swafford (Res Asst) Still doing graduate study.

Anthony Tantillo (Res Asst) Still doing graduate study.

S. Pabl1cationasof ARO Su *rtd Resea•r•

a. A complete list of publications describing A.R.O. supportedresearch is attached.

b. Publications during the most recent, three year grant periodas listed in the following. These total 17 in number.

"Stereochemistry in the Di-s-Methano Rearrangement; Aryl Migration.Exploratory and Mechanistic Organic Photochemistry," H. B. Zimmerman,T. P. Gannett and 0. E. leok. . Amer. Chem. Soo., 1973, 10,323-324.

"Unsual Regioselectivity in tha Di-w-Mothane Rearrangement.Reaction Inhibition and Control by Electron Donating Substituents.Mechanistic and Exploratory Organic Photochemistry.* H. B.Zimmerman and W. T. Gruenbaum, 1. Ora. Chemn, 1978, 4, 1997-2005.

"*Vinylcyclopropene Photochemistry; Photochemistry Applied toOrganic Synthesis. Exploratory and Mechanistic OrganicPhotochemistry," H. E. Zimmerman and S. M. Aasen, Z. Ort. Chem.,1978, 43, 1493-1506.

"*Differing Substituent Effects on Rates and Regioselectivities inthe Di-n-Methane Rearrangement. New Photochemical Theory:Excitation Distribution (the AP Watrix), Reaction Inhibition byVertical Excited State Stabilization, Ground Stite vs. Excited StateControl," H. E. Zimmerman, V. T. Gruenbaun, R. T. Ilun. M. 0.Steinmetz, and T. R. Welter. 7.C.S. Chemical Comunnioations, 1979,228-230.

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"*Control of Regioseleotivity and Excited State Singlet ReactionRates by Substitution in the Di-w-Mothano Rearrangement. Mechanisticand Exploratory Organic Photochemistry,* f. R. Zimmerman and T. R.Welter, 7. Amoer. Chem. Soo,. 1978. 100, 4131-4145.

"The Aryl-Vinyl Methane Version of the Di-w-Methane Rearrangement.Mechanistic and Exploratory Organic Photochemistry,. R. B. Zimmerman,M. G. Steinmetz and C. L. treil, Y __AiEL_.•Jo., 1978, 004146-4162.

"The Di-w-Methane Rearrangement of Systems With Simple VinylMoieties. Mechanistic and Exploratory Organic Photochemistry.*H. n . Zimmerman and R. T. lun, T•etra.4..edo, 1978, ,1775-1803.

"Molecular Control of Excited State Cross-Conjugated Trionis

Rearrangements. Exploratory and Mechanistic Organic Photoohemistry,.1. E. Zimmerman and D. R. Diehl, Y. Al_ý CrSo__j,_ ., 1979, 101,1841-1857.

"Stereochenistry of the Aryl-Vinyl Version of the Di-n-MethaneRearrangement." f. E. Zimmerman, T. P. Gannett and G. R. I6ck,$. Or.. Cheu,. 1979, 44, 1982-1989.

"Uznsual Organic Photochemistry Effected by Cyano and MothozySubstitution. Exploratory and Mechanistic Organic Photoohemistry.*H. 1. Ztmmerman, D. Armesto, M. 0. Amezua. T. P. Gannett, and R. P.

oknason, Y. Amer. ghem. §21, 1979, 101, 6367-6383.

"The INcycle Rearrangement: Relationship to the D-,s-MethaneRearrangement and Control by Bifunnel Distortion. Mechanistic

and Exploratory Organic Photochemistry." R. E. Zimmerman and R. E.Factor, 3.eCbem.,_§oc.. 1980, 102, 3538-3548.

"Rod-like Organic Molecules; Energy Transfer Studies Using SinglePhoton Counting," H. K. Zimmerman, T. D. Goldman, T. K. Hirzel andS. P. Schmidt, L. Orj. CA.Ia.... 1980, 4,. 3933-3951.

"Regioselectivity in Cyclohexadienone Photoohemistry; the Roleof Zwitterions in Type A Photochemical and Dark Rearrangements.Mechanistic and Exploratory Organic Photochemistzy.0 H. B.Zimmerman and R. 3. Pasteris. _.r_._Ce_., 1980.45, 4864-4875.--r.

hIL190

"Type A Zvitterions and Cyclohozadienone Photochemical Rearrange-ments. Meohanistio and Exploratory Organic Photochemistry." B. S.Zimmerman and R. Y. Pasterins. QXz. °hIK,. 1980. •o4876-4801.

"Di-n-Methane Hypersurfaces and Reactý"Yity; Multiplicityand Regioselectivity; Relationship Between the Di-w-Methaneand Bicycle Rearrangements," R. L. Zimmerman and R. B. Factor.Tetrahedron. 1981. 11. Supplement 1, 125-141.

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"Nvew Reactions and Theory in Organic Photoohemistryl The 1,3-

Vinyl Migration and its Relevance to Exchange Integral Control,*R. . Zimmerman, Y. B. Penn and M. R. Yohnson. Pgoo.u NauL..AuL.

Sol. USA. 1981, 18. 2021-2021.

"Evaluation of Single Photon Counting Measurements of Ezoited State

Lifetimes," R. E. Zimmerman, S. R. Penn and C. V. Carpenter, Prog.

Natl I-- -- scheduled for Ianuary or February.

6. Technical Details of Research During thse Throe Yea~jr Pggd.

A comprehensive report of accomplishments was made in our recentrenewal application. namely the renewal which was turned down.Additionally, detailed semiannual technical reports have beenturned in.

7. AcajAhetsD~th The *LPerjodA.Our research has been especially successf.u in adding to basic

research knowledge of the photophysical and photochemicalprocesses available to and utilized by excited state molecules.

8. Ac os~li.hpents Made Possibl seoarh

Our ARO grant support began in 1956 when the PrincipalInvestigator, Howard K. Zimmerman, was a young Assistant Professor.The impact of A!n support has been three-fold. On one hand it hascontributed a number of basic and important scientific findingsand chemical concepts to the field. Secondly, it has contributedto the development of the scientific recognition of the PrincipalInvestigator. Finally, it has supported the graduate and postdoctoralstudies of a large number of very highly skilled and creativestudents. Many of these have gone on into independent careers andare now known professionally. Thus 66 former students of BowardK. Zimmerman's former students have become professors, and anapprociably large fraction of these were supnorted by AROC Thishas created considerable good will for ARO a-d its objectives.

The Principal Investigator received the 1976 James Flack

Norris Award of the American Chemical Society. the 1979 lalpernAward for Photochemistry of the New York Academy of Science, andwas elected in 1980 to the National Academy of Sciences. It was,indeed, ARO support which helped make this recognition possible.

Scientifically, ARO has had major impact.

Thus, even thi first paper describing ARO sponsoredresearch, Reference 10 in the complete bibliography below isnow quoted as laying the groundwork for the stereochemistryof aldolization. This paper provided evidence for a six-memberedtransition state in aldolization, Reformatsky and relatedreactions.

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The photochemical papers provided basie theory which Iallowed and catalyzed the rapid growth of photochemical research.

The Principal Investigator's research group was one of the two

original groups in the U.S. which initiated detailed photochemicalstudies. Most photochemicsl research now follows in thesefootsteps. Note the photochemical references in the completebibliography below.

Reference in the complete bibliograpby describesthe M~biue-BIokel Concept which has become an integral partof modern chemistry. It is to be found now in most sophomoreorganic chemistry textbooks.

The above are some salient examples of the results

of the 26 years of ARO research.

•. aj n etjie ft A _ nuA jaW_. .keAx

It is obvious that the Principal Investigator appreciatesthe 26 years of support of his research by ARO. This supporthas generated very warn feelings towards ARO also by studentssupported in their Ph.D. and Postdoctoral endeavors. Beyondthis, foellow students supported by other means clearlydeveloped positive feelings about ARO in the process. Manyof these people now are men of international stature inresearch.

However, ARO's precipitous withdrawal of support from thePrincipal Investigator was at a time when 1 s research hasbeen most successful and when ARO's confidezae in hisefforts should have been most clearly Justified. Thiswithdrawal at a time when research faning is mostdifficult, caused severe hardship. While the PrincipalInvestigator recognized the ever increased demand forrelevancy, he was assured by Army researchers that relevancewas not lacking in his work. Also he is a bit baffled bysupport of younger people of lesser statu7e in the saneperiod as ARO's withdrawal. That some of *;his support is forphotochemical research pioneered by the PrincipalInvestigator is not too understandable.

Nevertheless, in ligh8 of the 26 years of ARO loyal support.this present comment reflects primarily bafflement. ARO's

past help, encouragement, understanding and loyalty won'tbe forgotten.

10. Izamples of the Princival InvgeetizatoS.'s FVrmer Students.,ARO Suuuorted and Not. Benefittina From ARO Susaportz

Professor Albert Padra - Ruory University. Presently a leadingOrganic Chemist.

Professor Harry R. Morrison - Purdue University. A leadingphotooheeist.

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Professor David I. Schuster - New York University. Also aleading photoohenist.

Professor Yaques Nasieleki - Read of the Cheu. Dept.. Univ.of Brussels and an internationally known chemist.

Professor Yohn S. Swenton - Ohio State Univ. A leadingorganic chemist.

Professor himn Iwamura - Institute for Molecular Science,Japan. One of the most influential younger Yapanesephotochemists.

Professor Gary Keek - University of Utah. Said to be themost promising and brilliant young organic ohemist.

Professor Patrick S. Mariano - University of Maryland. Anotherof the country's most energetic and productive organic chemists.

Professor 7ohn Y. McCullough - McMaster University. One of

Canada's most outstanding few organic photooheinsts.

Professor lames Pincook - Dalhousie University. A particularlyenergetic and brilliant young Canadian photochoeist.

Professor Albert C. Pratt - Dublin. The most eminent Irish

orgasic photoohetist.

Professor Laren Tolbert - University of Kentucky. Anotherwell known young organic photokeheist.

11. List of AR0 &gj.te fPrsonnel sad Current Position

BAICKSTROM. Peter Department of Organic ChemistryAssistant Professor The Royal Institute of Technology

3-100 44 t

3tockholm 70, SWEDEN

BAKER. Joseph T. Roche Research Institute ofMarine Pharmacology4-10 Inman Road, Dee WhyP.O. Box 2$5. pee why. 2099N.W.W.. AUSTRALIA

CRUNRINE. David Department of ChemistryAssociate Professor Loyola University of Chicago

Chicago. Illinois 60626

16 - - .

IBIRBACNI Volflaug Chemisohes Laboratorinm det UniverstittProfessor (CI) Albortstr. 21

7800 PreiburgWEST GRIMANY

PLBCHTNIR. Thomas Department of ChemistryAssociate Professor Cleveland State University

Cleveland. Ohio 44115

t ORNBACK, loseph Department of ChemistryAssociate Professor University of Denver

Denver, Colorado 80210

IWAMURA. Eiias Division of Applied Molecule ScienceProfessor Institute of Molecular Scienoe

Myodaiji. Okazaki 444YAPAN

KICK. Gary Department of Chemistry

Associate Professor University of UtahSalt Lake City. Utah 94112

KURTZ, David Department of ChemistryAssociate Professor Ohio Northern University

Ada. Ohio 45810

MARIANO, Patrick S. Department of ChemistryProfessor University of Maryland

Collee Park, Maryland 20742

MC CULLOUG3, Tohn 3. Department of ChemistryProfessor MeMaster University

Iamiltin, Ontario CANADA

MC KELVEY. Ronald Department of ChemistryAcademic Staff University of Wisconisin-LsCrossLaCrosse, Wisconsin 54601

MORRISON, Harry Department of ChemistryProfessor Purdue University

West Lafayette, Indiana 47907

NASIELSIK. Yacques Service Do Cheist OzganiqueProfessor Universite Libre do Bruxelles

50, Avenue P. D. RooseveltBruzelles S. BELGIUM

NASIELSII, Raymonde Service Do Chemie OrganiqueAssistant Professor Univorsite Libra do Bruzelles

50. Avenue P. D. RooseveltBruxelles S. BELGIUM

PADVA, Albert Department of ChemistryProfessor Emory University

Atlanta. Georgia 30322

• , • -:. .. .:-~ _ ...... .. - - ... -... ,• • • • . k i * . . _. . _ _ _ _: . • .• • •• a.•"" ' • ;- • .

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PAGNI. Riehard Depattuent of ChemistryProfessor University of Tonoesoo

Kaoxville. Tennessee 97914

PAVIA. Donald Department of ChemistryAssistant Professor western Washington State College

Bellingham. Washington 93815

PENN, Yohn Department of ChemistryPostdoctoral Follow University of Utah

Salt Lake City, Utah

PINCOCK, Samos Department of ChemistryAssociate Professor Dalboesti University

Halifax, Nova Scotia. CANADA

PRATT, Albert School of Chemical ScienoesProfessor National Institute for Hisher Eduoation

Dublin, IRELAND

TOLBERT. Laren Department of ChemistryAssociate Professor University of Kentucky

Lexington# Kentucky

YIRIOT, Maris-Laase INPL (Basic)Assistant frofessor Laboratoire De Reoherches De

Chenie Goner-ls1. Rue GrandvilleF-54042-Nanoy Cedex, FRANCE

12. Full List of Publications by k. .~ Ztmemn tlz

10. "The Stereochemistry of the Ivanov and Reformatsky Reactions. I."I. R. Zimmerman and N. D. Trgxler. Y. Amer, Chem. ioc.. 1057.

22. 1920-1923.

16. "Overlap Control of Carbanionoid Reactions. . Stereoseleoctivityin Alkaline Epoxidation." R. E. Zimmerman, L. Singer and B. 8.Thyagarajan, 1. Amer. Chem. Sos., 1959, , 108-116.

17. "Overlap Control of Carbtnionoid Reactions. II. Stereaocheistry ofthe Perkir. and Related Condensation Reactions"* 1. E. Zimmerman andL. Akramjiana Z. AnAa. Clano8o, So 1959. 2j. 2086-2091.

23. "Overlap Control of Organi° Roeations. III. The Stereochemistry ofthe Dazzens Reaction." 1. E. Zimmerman and L. Ahramjian. 1. Aa.,

. §g"., 1960. 3,. 54S9-5466.

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23. *Overlap Control of Organic Reactions. II!. The Sterochlemistry ofthe Darsoes Ioactiou. H. N. Zimmerman and L. Ahramjiana,. Au.ChemL J.1l. 1060, 11, 5459-5466.

36. "A General- Theory of Photochemical Reactions. VII. Mechanisms ofEpoxy Istone Reactions, H. R. Zimmerman. 3. R. Cowley. C-1. Tegng.and 3. W. Wilson. Y. A£195..AfA.o. 1964, 8t, 947-948.

39. "A Study of Hindered Divalent Carbon Species and Ditto Compounds."N. 3. Zisierman and D. N. Paskovioh. I.9. mj...hi.--jjU..., 1964,U.° 2149-2160.

40. "Photoohemical Reactions of 2.3-Rpoxy-2-mathyl-3-phenylindmaone."I. E. Zimmerman and R. D. Sinkin. T. £ssd .jkLQj!t.L, 1964,1847-1851.

41. "The Photoohemical Reaction of Benzoquinone With Tolan." 1. 3.Zimmerman and L. Craft. T_.9• dj.tiajLj.., 1964. 2131-2136.

59. "Chronology in Photochemical Meohanisms. The Reaction of 6-Phenyl-6-p-Cyanophonylbicyolo[S.l.0]hoe-3-en-2-one. Mechanistic OrganicPhotochemistry. XXV." H. E. Zimmerman and 3. 0. Grunevald, T. Auer.ChemL, Sag. 1967. 89, 3354-33S6.

60. "Mechanistic Organic Photoohemistry. XXIV. The Mechanism of theConversion of Barrelene to Senibullyalene. A General PhotoohemicalProcess." H. B. Zimmerman. R. W. Binkley, R. S. Givens, and K. A.Sherwin, 3.. Amer.__ R._j~q, 1967, 12, 3932-3933.

61. "Patbv%7s Leading From Excited-State Reactant to Ground-StatePsodncts in Dienone Photochemistry. Mechanistic and ExploratoryOrganic Photoohemistry. XXVI." R. B. Zimmerman and 1. 0. Grunevald.Y. Aaeg. Chen. Soo-, 1967, 81, 5163-5172.

63. w-w* Rearrangements. The Photochemistry of 1-Methyleno-4.4-Diphonyl-2.,-cyclohezadiene as a Dienone Analog. Mechanistic andExploratory Organic Photochemistry. XXIX." H. R. Zimmerman, P.Hackett, D. F. Iuers, and B. Sohrtder. L Aui..LSJhL.So.,&L, 1967

59 S73-S974.

71. "The Stereochemistry and Mechanism of the Photochemical Iater-conversion of cis- and trans-5,6-Diphenylbicyclo[S.l.O]hexan-2-ones.Mechanistic Organic Photoohemistry. XXXII." N. 3. Zimmerman# K. G.Hancock. and G. Licks, I. Amer. Chem. So. 1963.8. 90, 4892-4911.

78. "Relative Rates of lryl Migrations in Excited State Transformations.Mechanistic and Exploratory Organic Photochemistry. XXXIX." H. R.Zimmerman and N. Levin& T. Auer. Chen. Sec., 1969, IL, 879-886.

79. "Energy Barriers in Photochemical Molecular RearrangeuentsoMechanistic and Exploratory Organic Photochemistry. XL. H. 3.Zimmerman and W. R. Elser, 3. Amer, Chemr. Soc., 1969.887-896.

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80. "The Di-n-Methane Rearrangement. Interaction of ElectronicallyExcited Vinyl Chromophoras. Mechanistic and Exploratory OrganicPhotochemistry. XLI," H. E. Zimmerman and P. S. Mariano, Y. Ame..

hi, 1969, I,. 1718-1727.

81. "Synthesis and Physical Properties of Barrelene, a Unique M6bius-like Molecule," H. E. Zimmerman, R. M. Paufler, and M. A. Sherwin,YT• "mer•_Chemn.So, 1969, 91, 2330-2338.

82. "The Barrelene to Semibullvalene Transformation. Correlation ofExcited State Potential Energy Surfaces With Reactivity. Mechanisticand Exploratory Organic Photochemistry. YLIV," H. E. Zimmerman, R.V. Binkley, R. S. Givens, 0. L.Grunewald, and M. A. Sherwin,Ym Amer, Chem,_S.e_•, 1969, 91, 3316-3323.

85. "C 8.K Interconversion8. An Unusual Rearrangement Providing aNeow loute to Semibullvalene," H. E. Zimmerman, Y. D. Robbins and3. Schantl, Y. Amer. Chem. Soc., 1969, 91, 5878-5879.

87. "Organic Photochemistry. LIII. Directionality of the SingletDi-r-Methane Rearrangement and Alkyl Migration in a UniqueVinylc•z1opropane Transformation," H. E. Zimmerman and A. C.Pratt, L. Amer, Che_..Soc., 1970, 92, 1407-1409.

88. "Organic Photochemistry. LIV. Concertedness, Stereochemistry,and Energy Disaipation in the Di-n-Methane Rearrangement.Source of Singlet-Triplet Reactivity Differences," H. E.Zimmerman and A. C. Pratt, Y. Amer, Chem.Soc., 1970, 92,1409-1411.

91. "Thermal and Photochemical Interconversions of Cyclooctatetraenesand Semibullvalenes. Exploratory Organic Photochemistry. LII,"H. E. Zimmerman and H. Iwamura,, Y. Amer. Chem, Soc., 1970,92, 2015-2022.

96. "Unsymmetrical Substition and the Direction of the Di-ff-MethaneRearrangement; Mechanistic and Exploratory Organic Photochemistry.LVI," H. E. Zimmerman and A. C. Pratt, Y. Amer, Chem, So., 1970,

2, 6259-6267.

97. "Stereochemical Aspects pf the Di-a-Methane Rearrangement;Mechanistic and Exploratory Organic Photochemistry. LVII," H. E.Zimmerman and A. C. Pratt, T. Amer, Chem. Soc., 1970, 92,6267-6271.

98. "Electron Delocalization in Molecules Containing FormallyOrthogonal n-systens, The Synthesis of 2,4,6-2,',4,,6'-Hexa-t-butyldiphenylamotylene and a Study of Its Radical Anion andDianion," H. E. Zimmerman .d Y. R. Dodd, Y. Amer. Chem. So.o_.,1970, 9 6507-6515.

99. "Singlet-Triplet Differentiation. Mechanistic and Exploratory

Organic Photochemistry. LIX," H. E. Zimmerman and V. T. Hull, I3. Amer. Chem. Soc., 1970, 92, 6515-6520.

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100. "Excited State Three Ring bond Opening in Cyclopropyl Ketones.Mechanistic Organic Photochemistry. LX," H. E. Zimmerman andT. W. Flechtner, Y. Amer. Chem,_S.g., 1970. 91, 6931-6935.

101. "Vinylcyclopropane Photochemistry. Mechanistic and ExploratoryOrganic Photochemistry. LXI," H. E. Zimmerman and T. W. Flechtner,Y. Amer .Ck.Sem. E.1L 1970, 92, 7178-7183.

102. "Electron and Energy Transfer Between Bicyclo[3.1.0]ooctaneBridgehead Moieties," H. E. Zimmerman and R. D. McKelvey,, Y.Am_..,_,r_ghe_._.m.,__So__,, 1971, 93, 3638-3654 .

104. "Competitive Photochemical Pathways in the Di-fT-MethaneRearrangement. Exploratory and Mechanistic Organic Photochemistry.LXIII," H. E. Zimmerman, P. Hackett, D. F. Yuers, Y. M. McCall,and B. Schrlder, Y. Amer. h 1971, 93, 3653-3662.

105. "Slither Motion of Divalent Carbon on n-Systems in PhotochemicalRearrangements. Exploratory and Mechanistic Organic Photochemistry.LXIII," H. E. Zimmerman, Y. M. McCall, and B. SchrOder,, Y. Ager.Chem, Soo., 1971, 93, 3662-3674.

106. "The MNbius-Hlokel Concept im Organic Chemistry. Application toOrganic Molecules and Resitions," H. E. Zimmerman, Accounts ofChem, Res., 1971, 4, 272-280.

108. "Cycloheptatrienyldiazomethane. Its Synthesis and Behavior.C 8a Chemistry. X. Correlation Diagrams and Nodal Properties,"H. 1. Zimmerman and L. R. Sousa, Y, Amer._Chemn_,So, 1972, 94,834-842.

109. "Duality of Mechanisms in Photoracemization of Optically ActiveBiphenyls. Mechanistic and Exploratory Organic Photochemistry.LXV, " H. E. Zimmerman and D. S. Crumrine, Y. Amet Chem, Soc,

1972, 94. 498-506.

113. "The Stereochemistry of the Di-a-Methane Rearrangement;Mechanistic and Exploratory Organic Photochemistry. LXIX," H. E.Zimmerman, P. Baeckstrom, T. Yohnson, and D. W. Kurtz, _Y AmyeChem. Soc., 1972, 94, 5504-5505.

119. "MO Following. The Molecular Orbital Counterpart of ElectronPushing." H. E. Zimmerman, Accounts of Chema.-Res., 1972, 5,393-401.

120. "Competitive Naphtho vs. Benzo Bridging in the Di-a-MethaneRearrangement of Benzo-2,3-naphthobarrelene. Exploratory andMechanistic Organic Photochemistry. LXXIV," H. E. Zimmerman andM-L Viriot-Villaume, Y. Amer. Chem. Soc., 1973, 95, 1274-1280.

125. "A Walk Rearrangement of Diazonorcaradiene. Mechanistic andExploratory Organic Photochemistry. LXXVIII," H. 2. Zimmerman andW. Eberbach, 7. Amer. Chem. Soc., 1973, 95, 3970-3976.

128. "Superfast Singlet Excited Stato Di-n-Methane Rearrangement

and Decay Rates; Picosecond Range Measurements by Single PhotonCounting and Use of Magic Multipliers. Mechanistic OrganicPhotochemistry. LXXXI," H. B. Zimmerman, D. P. Werthemann, andK. S. Kama, Y. Amer, Chem•._••2, 1973, 9 S, 5904-5095.

0

130. "A Photochemical 1,3-Sigmatropic Vinyl Migration. Mechanisticand Exploratory Organic Photochemistry. LXXXII," H. E. Zimmerman,D. W. Kurtz, and L. X. Tolbert, Y. Amer. Chem, So~o., 1973, 95,8210-8212.

131. "Single Photon Counting and Magic Multipliers in Direct Measurementof Singlet Excited State Di-m-Methane Rearrangement Rates in thePicosecond Range. Mechanistic Organic Photochemistry. LXXXIII," H.E. Zimmerman, D. P. Werthemann, and K. S. Kamm, Y._Amer. Chan•Soo., 1974, 96, 439-449.

132. "C-1 Stereochemistry of the Ci-n-Methane Rearrangement.Mechauistic and Exploratory Organic Photochemistry. LXXXIV,"H. E. Zimmerman, P. Baeckstrom, T. Yohnson, and D. W. Kurtz,

Y. Amer Chem. S2i., 1974, 96, 1459-1465.

133. "Stereochemistry of the Di-ff-Methane Rearrangement at the MethaneCarbon. Mechanistic and Exploratory Organic Photochemistry," H. E.Zimmerman, 3. D. Rohbins, R. D. McKelvey, C. Y. Samuel, and L. R.Sousa, Y. Amer. Chem. Soc, 1974, 96, 1974-1976.

134. "Stereochemistry as a Probe for Photochemical Reaction Mechanisms,"H. E. Zimmerman, TetrahedX.ol, Van't Hoff - Le Bel Memorial Issue,1974, 30, 1617-1628.

136. "Stereochemistry at the Methane Carbon in the Di-n-MethaneRearrangement. Mechanistic and Exploratory Organic Photochemistry,"H. E. Zimmerman, 7. D. Robbins, R. D. McKelvey, C. Y. Samuel, andL. R. Sousa, Y. Amer. Che• SOc,. 1974, 96, 4630-4643.

141. "A Photochemical Rearrangement Without Light. Dioxetane EffectedPhothchemistry by Direct Intramoleoular Excitation," H. E. Zimmermanand G. E. Keck, 1. Aner.__Chem. So~c, 1975, 97, 3527-3528.

146. "Conformation and Di-%-Methano Reactivity. Mechanistic andExploratory Organic Photochemistry," H. E. Zimmerman and L. M.

Tolbert, Y. Amer. Chem. Soo , 1975, 97, 5497-5507.

147. "Generation of Photochemical Species on Ground, Excited Singlet, andTriplet Hypersurfaces in Barrelene Photochemistry," H. E. Zimmerman,R. Y. Boettcher, N. E. Buehler, and G. E. look, Y. Amer. CghepSojo.,1975. 97, 5635-5637.

152. "Molecular Rearrangements of Excited States Generated by Intra-molecular Dioxetane Scission. Photochemistry Without Light.Mechanistic and Exploratory Organic Photochemistry," H. E. Zimmerman,G. E. leek, and Y. L. Pflederer, Y. Amer. _e._ 1976, 98,5574-5581.

117 7 7.i

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155. *The Photochemistry of Vinyloyclopropenes; a Now and General Cyclo-pentadiene Synthesis. Exploratory and Mechanistic OrganicPhotochemistry." H. E. Zimmerman and S. Aasen, Y. Aer em Soj,

1977, 99, 2342-2344.

156. "Recent Mechanistic and Exploratory Organic Photochemistry," H. E.Zimmerman, Pure and_, 1977, 49, 389-398.

162. "Stereochemistry in the Di-w-Methane Rearrangement; Aryl Migration.Exploratory and Mechanistic Organic Photochemistry," H. E. Zimmerman,T. P. Gannett and G. E. Kock, Y. Amer, 1978, 100,323-324.

163. "Unsual Regioselectivity in the Di-n-Methane Rearrangement.Reaction Inhibition and Control by Electron Donating Substituents.Mechanistic and Exploratory Organic Photochemistry," H. E.Zimmerman and W. T. Gruenbaum, L_2.KOt. Ch.e__.L, 1978, 43, 1997-2005.

164. "Vinyloyclopropene Photochemistry; Photochemistry Applied toOrganic Synthesis. Exploratory and Mechanistic OrganicPhotochemistry," H. E. Zimmerman and S. M. Aasen, . Ogx&.k Qcirn,.1978, 43, 1493-1506.

166. "Differing Substituent Effects on Rates and Rehioselectivities inthe Di-w-Methane Rearrangement. New Photochemical Theory:Excitation Distribution (the AP Matrix), Reaction Inhibition byVertical Excited State Stabilization, Ground State vs. Excited StateControl,* B. E. Zimmerman, V. T. Gruenbaum, R. T. [lun, M. 0.Steinmetz, and T. R. Waelter, j.. Chemical Communictons, 1979,228-230.

167. "Control of Regioselectivity and Excited State Singlet ReactionRates by Substitution in the Di-n-Methane Rearrangement. Mechanisticand Exploratory Organic Photochemistry," R. E. Zimmerman and T. R.Welter, Y Ame, S.____.o•_c_, 1973, 100, 4131-4145.

168. "The Aryl-Vinyl Methane Version of the Di-n-Methane Rearrangement.Mechanistic and Exploratory Organic Photochemistry," H. E. Zimmerman,M. G. Steinmetz and C. L. treil, Y._Aer _heSo_•, 1978, 100,4146-4162.

169. "The Di-n-Methane Rearrangement of Systems With Simple VinylMoieties. Mechanistic and Exploratory Organic Photochemistry,"H. E. Zimmerman and R. T. ilun, Tetrahedig•, 1978, 43,1775-1803.

172. "Molecular Control of Excited State Cross-Conjugated TrieneRearrangements. Exploratory and Mechanistic Organic Photochemistry,"H. 9. Zimmerman and D. R. Diehl, L__AmeXLghe&L_§oq, 1979, 101.1841-1857.

173. "Stereochemistry of the Aryl-Vinyl Version uf the Di-n-MethaneRearrangement," R. E. Zimmerman, T. P. Gannett and 0. E. Keck,L.._21£- Ch1U, 1979, 44, 1982-1989.

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175. "Unusual Organio Photoohemistry Effected by Cyano and MethoxySubstitution. Exploratory and Mechanistic Organic Photochemistry,"H. R. Zimmerman, D. Armesto, K. 0. Anesua, T. P. Gannett, and 1. P.Yohnson, Y. Amer. Chou, Aosls, 1i7079 L, 6367-6383.

177. "The Bicycle Rearrangement: Relationship to the Di-x-MethaneRearrangement and Control by Bifunnel Distortion. Mechanisticand Exploratory Organic Photochemistry, H. E. Zimmerman and R. E.Factor, Y. A•. . _ 1980, 102, 3538-3S48.

180. "Rod-like Organic Molecules; Energy Transfer Studies Using SinglePhoton Counting," H. 3. Zimmerman, T. D. Goldman, T. I. Hirzel andS. P. Schmidt, Y.. Ora. Q.1&,, 1980, 1, 3933-3951.

181. "Regioselectivity in Cyalohexadienone Photochemistry; the Roleof Zwitterions in Type A Photochemical and Dark Rearrangements.Mechanistic and Exploratory Organic Photochemistry," R. E.Zimmerman and R. 3. Pasteris, Ore, €•en•, 1980,45, 4864-4875

182. "Type A Zwitterions and Cyclohexadienone Photochemical Rearrange-

ments. Mechanistic and Exploratory Organic Photoohemistry," H. E. IZimmerman and R. 3. Pasteris, T. O;[z._S.• L, 1980, 45,4876-4891,

183. "Di-w-Methane Zvpersurfaces and Reactivity; Multiplicityand Regioselectivity; Relationship Between the Di-w-Methaneand Bicycle Rearrangements," 9. B. Zimnerman and R. E. Factor,Tetrahedron, 1981. 7, Supplement 1, 125-141.

185. "New Reactions and Theory An Organic Photochemistry: The 1,3-Vinyl Migratton and its Relevance to Exchange Integral Control,"H. E. Zimmerman, 3. H. Penn and M. R. Johnson, Proc. Lp tjo.ge4LSci. USA, 1981, 78, 2021-2025.

190. "Evaluation of Single Photon Counting Measurements of Excited StateLifetimes," B. E. Zimmerman, 3. H. Penn and C. V. Carpenter, Proo.Natl. Acad. Sci. USA, scheduled for January or February..

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