TIMOTHY P. LODGE
`Department of Chemistry, University of Minnesota
`207 Pleasant Street SE, Minneapolis, Minnesota 55455-0431
`(612) 625-3080; Fax (612) 626-2232; E-mail macro@chem.umn.edu
`
`ASSOCIATE EDITORS
`
`John T. Bendler
`South Dakota School of Mines and Technology
`Rapid City, South Dakota 57701-3995
`(605) 394-1238; Fax (605) 394-6914
`E-mail bendler@indigo2.che.sdsmt.edu
`Alan D. English
`DuPont Central Research and Development
`Experimental Station
`Wilmington, Delaware 19880-0356
`(302) 654-4713; Fax (302) 654-4872
`E-mail michele.k.hutchinson@usa.dupont.com
`Andrew J. Lovinger
`1920 North Ohio Street
`Arlington, Virginia 22205
`(703) 534-6772; Fax (703) 534-0680
`E-mail ajl@physics.bell-labs.com
`WayneL. Mattice
`University of Akron
`Akron, Ohio 44325
`(330) 972-5128; Fax (330) 972-5396
`E-mail wlm@polymer.uakron.edu
`James A. Moore
`Rensselaer Polytechnic Institute
`Troy, New York 12180-3590
`(518) 276-2086; Fax (518) 276-2489
`E-mail macro2@rpi.edu
`Herbert Morawetz
`Polytechnic University
`Brooklyn, New York 11201
`(718) 260-3374; Fax (718) 260-3125
`E-mail morawetz@poly.edu
`
`é
`Bruce M. Novak
`North Carolina State University
`Raleigh, North Carolina 27695-8204
`(919) 513-2826; Fax (919) 513-2828
`E-mail macro@ncsu.edu
`
`Christopher K. Ober
`Cornell University
`Ithaca, New York 14853-1501
`(607) 277-0330; Fax (607) 277-1668
`E-mail macromol@ccmr.cornell.edu
`
`Coleen Pugh
`University of Akron
`Akron, Ohio 44325-3909
`(330) 972-7539; Fax (330) 972-8864
`E-mail macro@polymer.uakron.edu
`John F. Rabolt
`Materials Science Program
`University of Delaware
`Newark, Delaware 19716
`(302) 831-8810; Fax (302) 831-8982
`E-mail acs-macro@udel.edu
`ThomasP. Russell
`University of Massachusetts
`Amherst, Massachusetts 01003-9263
`(418) 545-0407; Fax (413) 545-0421
`E-mail macro@mail.pse.umass.edu
`Jerold M. Schultz
`Department of Chemical Engineering
`335 Colburn Laboratory
`University of Delaware
`Newark, Delaware 19716-3110
`(302) 831-1361; Fax (302) 831-1365
`E-mail macromol@udel.edu
`
`Ann-Christine Albertsson_
`Royal Institute of Technology
`
`Nitash Balsara
`University of California
`
`Joseph M. DeSimone
`University of North Carolina
`
`Takeshi Endo
`Tokyo Institute of Technology
`Andrew E.Feiring
`DuPont
`
`Mary E. Galvin
`University of Delaware
`;
`:
`~ Emmanuel P. Giannelis
`Cornell University
`
`EDITORIAL ADVISORY BOARD
`
`Mark M. Green
`Polytechnic University
`ee:
`Loa.
`Zbigniew Jedlinski
`Polish Academy of Sciences
`
`Shiro Kobayashi
`Kyoto University
`
`Ronald Larson
`University of Michigan
`Bernard Lotz
`Institut Charles Sadron
`
`Peter M. Macdonald
`University of Toronto
`Anne M. Mayes
`Massachusetts Institute of
`Technology
`
`Jimmy Mays
`University of Alabama
`at Birmingham
`
`Thomas J. McCarthy
`University of Massachusetts
`
`E. W.“Bert” Meijer
`Eindhoven University of
`Technology
`
`Giorgio Montaudo _
`Universita di Catania
`
`Karen-Winey
`University of Pennsylvania
`
`Karen Wooley
`Washington University
`
`TFS1041
`
`1
`
`TFS1041
`
`

`

`DC 20036. Periodicals postage paid at
`Washington, DC, and additional mailing
`offices. POSTMASTER: Send address
`changes to Macromolecules, Member & Sub-
`scriber Services, P.O. Box 3337, Columbus,
`OH 438210.
`
`Instructions for Authors and Copyright Status Form:See thefirst issue of each volume
`or visit the Publications Division Web site (http://pubs.acs.org). Please conform to these
`instructions when submitting manuscripts.
`
`Manuscript Submission: Send manuscripts to the Editor, Timothy P. Lodge, Department of
`Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455-
`0431.
`
`American Chemical Society
`1155 16th St., N.W.
`Washington, DC 20036
`(202) 872-4614
`TDD (202) 872-6076
`Fax (202) 776-8264
`
`Publishing Operations
`American Chemical Society
`2540 Olentangy River Road
`P.O. Box 3330, Columbus, OH 43210
`(614) 447-3665
`Fax (614) 447-3745; Telex 6842086
`E-mail acsproof@acs.org
`
`Member & Subscriber Services
`American Chemical Society
`P.O. Box 3337, Columbus, OH 43210
`(614) 447-3776; (800) 333-9511
`Fax (614) 447-3671
`E-mail service@acs.org
`
`Advertising Office
`Centcom, Ltd.
`676 East Swedesford Road
`
`Suite 202, Wayne, PA 19087-1612
`(610) 964-8061
`
`Publications Division
`Robert D. Bovenschulte, Director
`
`Publishing Operations
`Mary E. Scanlan, Director
`
`Journal Publications
`AnneC. O’Melia, Manager; Kathleen
`E. Duffy, Journals Editing Manager;
`Curt S. Steger and Kenneth B.
`Gilbert, Associate Editors; Marcia S.
`Ross, Production Associate
`
`Sales & Marketing
`Justin R. Spence, Director
`Dean J. Smith, Institutional Sales
`Matthew J. Price, Product Marketing
`
`Accepted Papers and Proofs: Direct correspondence to Publishing Operations, Columbus,
`OH. Tel: (614) 447-3665. Fax: (614) 447-3745. E-mail: acsproof@acs.org.
`
`Journal Policies: The American Chemical Society and its Editors assume no responsibility
`for the statements and opinions advancedby contributors. Views expressedin the editorials are
`those of the author and do not necessarily representtheofficial position of the Society. Regis-
`tered names and trademarks, etc., used in this publication, even without specific indication
`thereof, are not to be considered unprotected by law.
`
`Document Number: At the end of each document is a 9-character code that serves as a link
`between the printed and electronic products andfacilitates retrieval of the documentin elec-
`tronic form.
`
`Digital Object Identifier (DOI): The DOIidentification system for digital media has been
`designed to provide persistent and reliable identification of digital objects. Information on the
`DOI and its governing body, the International DOI Foundation, can be found at http://
`www.doi.org. In the Web editions of ACS journals, the DOI appears at the top of the HTML
`version of an article and at the bottom ofthe first page in its PDF version; in the printeditions,
`the DOI appearsin the samelocation as in the PDFversion.
`
`2001 Subscription and Ordering Information
`
`North
`America
`
`
`Outside
`North America*
`
`Printed Edition
`
`$ 185
`Members
`$ 139
`Student Members
`$ 352
`Nonmembers
`Institutional
`$1894
`
`Members
`$
`75
`Web Edition*
`Members
`$ 260
`Print/Web Combination*
`* Air service included. * For Institutional rates, call Member & Subscriber Services.
`
`$ 361
`$ 315
`$ 528
`$2070
`$
`75
`$ 436
`
`Web Edition: This journal is available to subscribers via the Internet. Contact Member &
`Subscriber Services [Tel: (614) 447-3776 or (800) 333-9511. Fax: (614) 447-3671. E-mail:
`service@acs.org] or visit the Publications Division Website (http://pubs.acs.org) for additional
`details.
`
`New and Renewal Subscriptions: Send with payment to American Chemical Society,
`P.O. Box 182426, Columbus, OH 43218-2426.
`Institutional subscribers in Japan must enter
`subscription orders with Maruzen Company Ltd., 3-10 Nihonbashi 2-chome, Chuo-ku, Tokyo
`103, Japan. Tel:
`(03) 272-7211.
`
`Subscription Donations: Members may donate/share their personal subscriptions to/with
`libraries but only after 5 years from publication.
`
`Change of Address: Notify Member & Subscriber Services, ACS, Columbus, OH.Tel: (614)
`447-3776 or (800) 333-9511. Fax: (614) 447-3671. E-mail: address@acs.org. Include both old and
`newaddresses and a mailing label from a recentissue.
`
`Microfilm, Microfiche, Back Issue, and Printed Edition Single Issue Orders: Send
`requests to Publications Support Services, ACS, Washington, DC. Tel: (202) 872-4376. Fax:
`(202) 872-6325. E-mail: pss@acs.org. Printed edition not available prior to 1997.
`
`Bulk Reprint Orders: For quotes and information, contact CJS Reprint Services. Tel: (888)
`257-2134 or (410) 819-3991. Fax: (410) 820-9765.
`
`Claimsfor Issues Not Received: Claimswill be honored only if submitted within 90 days of
`the issue date (subscribers in North America) or within 180 days of the issue date (all other
`subscribers). Send requests to Member & Subscriber Services, ACS, Columbus, OH.Tel: (614)
`447-3776 or (800) 333-9511. Fax: (614) 447-3671. E-mail: service@acs.org.
`
`Supporting Information (SI): SI from 1995 to present is available free of charge via the
`Internet (http://pubs.acs.org) from the journal’s home page. For information on electronic
`access, send E-mail to si-help@acs.org. SI prior to 1995 is available, for a fee, from Publications
`Support Services. Tel: (202) 872-4376. Fax: (202) 872-6325. E-mail: pss@acs.org.
`
`Canadian GST Reg. No. 127571347
`Printed in the USA
`
`© Copyright 2001 fopenican Chemical Society
`
`2
`
`

`

`
` i
`
`+
`
`m
`7.8
`
`1
`7.6
`
`1
`
`1
`74
`
`oo
`7.2
`
`7.0
`
`
`
`the Solid-State Emission of Alkyne-Bridged
`Polymers by Interchain Energy Transfer
`
`Neil G. Pschirer, Ken Byrd, and Uwe H.F. Bunz*
`
`Department of Chemistry and Biochemistry, The University
`of South Carolina, Columbia, South Carolina 29208
`
`Received July 26, 2001
`Revised Manuscript Received September 11, 2001
`Wereport the synthesis of novel poly(p-phenylene-
`ethynylene) (PPE, 1) and poly(fluorenyleneethynylene)
`
`(PFE, 2) derivatives, 3 and 4, that contain fluorenone
`
`units as active lumophores. The solution andsolid-state
`absorption and emission properties of these materials
`are reported. Acyclic diyne metathesis (ADIMET)is a
`powerful method to prepare alkyne-bridged polymers
`such as PPE and PFE.! While the PPEs show exciting
`optical properties,!f they are only weakly greenish-
`yellow fluorescent in the solid state, a testimony to
`aggregate formation and concomitant Davydovsplit of
`the excited state,? while the PFEs are strongly blue
`solid-state emitting. Their ease of synthesis, high
`molecular weight, stability, and purity makes both PPEs
`and PFEsattractive as materials in organic semicon-
`ductor-type applications such as PLEDs.!It would be
`of fundamental and practical importance to tunetheir
`emission over the whole spectral range. In inorganic
`semiconductors,this color tuning is achieved by doping
`the matrix with p- or n-type materials,‘ creating elec-
`tronic states that reduce the band gap. In organic
`polymers, this type of covalent “doping” has been less
`popular, despite the important work done in the groups
`of Miillen®~’ and Miller.’ They covalently introduced
`emitter molecules (anthracene, perylene, pyrene) into
`the backbonesof several different conjugated polymers,
`including dialkylpolyfluorene and dialkoxy—PPE.° In
`these systems, solid-state emission arises from exciton
`migration to local minima from which emission occurs.
`
`* Corresponding author. E-mail: Bunz@mail.chem.sc.edu.
`
`Figure 1. Comparison of the ‘H NMRspectraof 3b (5%); 2,7-
`bis(phenylethynyl)fluorene, and 6. The stars in the spectrum
`of 3b represent the °C satellites of CDCls; the band at 7.20
`ppm (7) is a spinning sideband of CHCls. The band at 7.08
`ppm is attributed to an end group signal.
`
`ADIMET of 5a,b in the presence of 2—10% 61°
`furnishes the copolymers 3a,b!"in yields ranging from
`75 to 93% as bright orangish-yellow,well-soluble,film-
`forming powders. In the same way, 10% of 6 and 90%
`of monomer7 gave the copolymer 4.!? Fortuitiously, 6
`is incorporated into the polymerchains of PPE and PFE,
`and the catalytic system is not disturbed by the keto
`groupsin 6. The incorporation of the fluorenoneresidues
`into the polymers is evidenced by IR (v = 1723 cm~})
`and fluorescence spectroscopies (vide infra). For copoly-
`mers 8 with a content of >2% fluorenone(see ref 13)
`1H NMRspectroscopy displays low-field shifted signals
`(6 7.83, 7.69, 7.55) that must be attributed to the
`fluorenone core. The signals appearat lower field than
`those of 61° and even than those of 2,7-bis(phenylethy-
`nyl)fluorenone (Figure 1). These experiments exclude
`the isolated materials to be physical mixtures of 6 and
`1 or of 6 and 2.
`interesting optical
`Copolymer 4 shows the most
`properties. In solution the absorption and emission
`spectra are identical to those of 2 (Table 1) and in the
`solid state, the absorption spectra of 2 and 4 in thin
`films are very similar. However, their solid-state emis-
`sion spectra are very different (Figure 2). In thin films
`of 2, blue emission is observed,!* while in films of 4 only
`an orange emission centered at 533 nm is recorded. All
`
`10.1021/ma011330m CCC: $20.00
`© 2001 American ChemicalSociety
`Published on Web 11/03/2001
`
`3
`
`

`

`150 °C
`= 2-butyne
`
`3aR= dodeyl
`b R =2-ethylhexyl
`
`R
`
`5a R = dodeyl
`b R =2-ethylhexyl
`
`RR
`
`7 R= dodeyl
`
`Mo(CO)g
`
`4-chlorophenol
`150 °C
`- 2-butyne
`
`Table 1. Yields, GPC Data, and Optical Characterization of Polymers 3 and 4
`
`GPC
`absorption
`emission
`
`polymer; % 6
`substituent R
`_yield (%)
`Pat
`M,/M,y
`solution
`thin film
`solution
`thin film (annealed)
`
`3a; 2%
`3a; 5%
`3a; 10%
`3b; 5%
`4a; 10%
`la?
`1b?
`2¢
`
`dodecyl
`dodecyl
`dodecyl
`ethylhexyl
`dodecyl
`dodecyl
`ethylhexyl
`dodecyl
`
`81
`83
`75
`93
`90
`
`195
`49
`148
`202
`48
`89
`119
`98
`
`4.2
`2.3
`8.8
`11.0
`3.5
`4.7
`312
`4.4
`
`398
`386
`392
`388
`388, 406
`384
`384
`388, 407
`
`437
`436
`439
`430
`416
`413, 440
`400, 438
`392, 418
`
`426, 450
`425, 447
`429, 450
`425, 450
`428, 447
`426, 445
`431, 451
`428,454
`
`539 (533)
`534 (531)
`544 (537)
`522 (523)
`531 (533)
`534 (452, 487, 502, 528 (sh))
`441, 466, 487 (442, 468, 488)
`429, 454 (—)
`
`« P, are repeat units based upon polystyrene standard. ’ According to Bunz, U. H. F. Chem. Rev. 2000, 100, 1605. ¢ Pschirer, N. G.;
`Bunz, U. H. F. Macromolecules 2000, 33, 3961.
`
`
`
`
`
`
`
`——— 4a (10%) film em
`—— 4a (10%) film abs
`
`——PFEfilm abs
`
`1.6
`
`= nD
`
`
`
`intensity(a.u.) o eo
`
`ob
`
` —— PFEfilm em
`
`and the PFE parts, while the lamellar orderplaces the
`fluorenone lumophores into close spatial contact to
`several polymerchains. Intra- and intermolecular (For-
`ster) energy transfer are effective to funnel the excita-
`tion energy into the LUMO offluorenone from which
`efficient orangish-yellow emission takes place (see
`Figure 2). Physical mixtures of PFE with dipropy-
`nylfluorenone 6 do not show this behavior.
`In that regard, copolymers8 are similar to 4. PPEs 1
`show blue-shifted solid-state emission upon annealing
`in thesolid state. In pristine samplesof the copolymers
`3, the emission of the fluorenone-containing lumophore
`is detected, resulting in emission which is both red-
`shifted and strongly intensified with respect to the
`greenish solid-state emission of didodecyl-PPE. Upon
`annealing resulting in increased ordering of
`samples,! the thin film emission spectra do not change,
`suggesting an effective inter/intramolecular energy
`transfer from the PPE-backbone to the fluorenone
`similar as to discussed in the PFE-hybrids 4. The
`absence of observable excimer emission seems to be a
`result of the reduced amount of active lumophores,®
`which are unaffected by polymeralignment. This effect
`is observed in PPEsat fluorenone contents > 2% weight
`of monomerfeed.
`
`In conclusion, we have demonstrated that covalent
`doping of PPE and PFE with fluorenoneutilizing alkyne
`metathesis is feasible. While doping levels of 2—10%
`show noeffect on solution emission, they are sufficient
`to ensure complete energy transfer into the dopantsites
`andleadto efficient orange solid-state emission of these
`interesting conjugated polymers. Intra- and inter-chain
`energy transferis the cause of such behavior. In future,
`we will report upon the introduction of other highly
`fluorescent dopants into PPE-types. An added-on ap-
`pealing feature of the ketone-containing polymers 3 and
`4 is their principal usefulness in postfunctionalization
`
`300
`
`350
`
`400
`
`550
`
`600
`
`650
`
`500
`450
`wavelength (nm)
`Figure 2. Thin film absorption and emission (Aex. = 390 nm)
`spectra of 2 and 4 (10% fluorenone content). In 2 the Stokes
`shift is very small, while thin filmsof 4 only show fluorenone-
`centered, bright emission with a very large stokes shift. The
`main emission of 4 is at Amax of 540 nm,i.e., 110 nm red-shifted
`from the emission of2.
`
`emission from the PFE skeleton is suppressed.Efficient
`energy transfer from the PFE-part to the fluorenone
`takes place in the solid state but not in solution, where
`exciton migration along the polymer backboneis not
`very efficient. Rotational decoupling or coiling of the
`polymer chain may bethe explanation.It is interesting
`to note that Miller’s copolymers show both emission
`from the polyfluorene and from the perylenein solution.
`This may be a combined result of perylene’s highly
`emissive nature and the higher doping concentration
`in their copolymers (15%). We observe only blue emis-
`sion from the PFE or PPE backbonein solution (some
`fluorenone emission is observed for copolymers with
`> 25% fluorenonecontent), while only orangish-yellow,
`fluorenone-centered emission is observedin thin films.
`In the solid state planarization of the polymer backbone
`almost certainly enhancesconjugation of the fluorenone
`
`4
`
`

`

`search Funds for generous funding. U.H.F.B. is Camille
`Drefus Teacher-Scholar (2000—2004). N.G.P. thanks the
`College of Science and Mathematics of the University
`of South Carolina for a Graduate School Dissertation
`Fellowship, and K.B. is an NSF REU participant.
`
`References and Notes
`
`(11)
`
`(1) (a) Bunz, U. H. F. Chem. Rev. 2000, 100, 1605. (b) Klop-
`penburg, L.; Song, D.; Bunz, U. H. F. J. Am. Chem.Soc.
`1998, 120, 7973. (c) Kloppenburg,L.; Jones, D.; Bunz, U.
`H. F. Macromolecules 1999, 32, 4194 (d). Kloppenburg,L.;
`Jones, D.; Claridge, J. B.; zur Loye, H. C.; Bunz, U. H. F.
`Macromolecules 1999, 32, 4460. (e) Pschirer, N. G.; Bunz,
`U. H. F. Macromolecules 2000, 33, 3961. (f) Halkyard, C.
`E.; Rampey, M. E.; Kloppenburg, L.; Studer-Martinez, S.
`L.; Bunz U. H. F. Macromolecules 1998, 31, 8655. (g) Steffen,
`W.; Bunz, U. H. F. Macromolecules 2000, 33, 9518. (h)
`Brizius, G.; Pschirer, N.; Steffen, W.; Stitzer, K.; zur Loye,
`H. C.; Bunz, U. H. F. J. Am. Chem. Soc. 2000, 122, 12435.
`(i) Pschirer, N. G.; Vaughn, M. E.; Dong, Y. B.; zur Loye, H.
`C. Chem. Commun. 2000, 85. (j) Pschirer, N. G.; Miteva,
`T.; Evans, U.; Roberts, R. S.; Marshall, A. R. Neher, D.;
`Myrick, M. L.; Bunz, U. H. F. Chem. Mater. 2001, 13, 2691.
`(2) Koren, A. B.; Curtis, M. D.; Kampf, J. W. Chem. Mater. 2000,
`12, 1519.
`(3) Weder, C.; Wrighton, M. S. Macromolecules 1996, 29, 5157.
`Weder, C.; Sarwa, C.; Montali, A.; Bastiaansen, G.; Smith,
`P. Science 1998, 279, 835. Palmans, A. R. A.; Smith, P.;
`Weder, C. Macromolecules 1999, 32, 4677. Schmitz, C.;
`Posch, P.; Thelakkat, M.; Schmidt, H. W.; Montali, A.;
`Feldman, K.; Smith, P.; Weder, C. Adv. Funct. Mater. 2001,
`11, 41. Montali, A.; Smith, P.; Weder, C. Synth. Met. 1998,
`97, 123.
`(4) Ball, P. Made to Measure, New Materials for the 21 Century;
`Princeton University Press: Princeton, 1997.
`(5) List, E. J. W.; Creely, C.; Leising, G.; Schulte, N.; Schliiter,
`A. D.; Scherf, U.; Millen, K.; Graupner, W. Chem. Phys. Lett.
`2000, 323, 132 (b) List, E. J. W.; Creely, C.; Leising, G.;
`Schulte, N.; Schliiter, A. D.; Scherf, U.; Millen, K.; Graup-
`ner, W. Synth. Met. 2001, 119, 659.
`(6) Tasch, S.; List, E. J. W.; Hochfilzer, C.; Leising, G.; Schlich-
`ting, P.; Rohr, U.; Geerts, Y.; Scherf, U.; Mullen, K. Phys.
`Rev. B 1997, 56, 4479.
`(7) Wohlgenannt, M.; Graupner, W.; Wenzl, F. P.; Tasch, S.;
`List, E. J. W.; Leising, G.; Graupner, M.; Hermetter, A.;
`Rohr, U.; Schlichting, P.; Geerts, Y.; Scherf, U.; Millen, K.
`Chem. Phys. 1998, 227, 99. For the synthesis of polyfluo-
`renone, see: Uckert, F.; Setayesh, S.; Mullen, K. Macro-
`molecules 1999, 32, 4519.
`(8) Klarner, G.; Lee, J.-I.; Davey, M. H.; Miller, R. D. Adv.
`Mater. 1999, 11, 115. Lee, J. I.; Zyung, T.; Miller, R. D.; Kim,
`Y. H.; Jeoung, S. C.; Kim, D. J. Mater. Chem. 2000, 10, 1547.
`(9) (a) Levitsky, I. A.; Kim, J. S.; Swager, T. M. J. Am. Chem.
`Soc. 1999, 121, 1466. (b) Swager, T. M.; Gil, C. J.; Wrighton,
`M.S. J. Phys. Chem. 1995, 99, 4886.
`(10) Synthesisof 6. CrO3 24.0 g (240 mmol) and diiodofluorene
`(41.8 g, 100 mmol) in acetic anhydride (600 mL) werestirred
`at room temperature for 12 h. The reaction mixture was
`
`(12)
`
`(13)
`
`(14)
`
`propynegas, and shakenfor 16 h. Filtration over Celite (2:1
`hexanes/CHeClz) and crystallization from EtOH furnishes
`6 (3.94 g, 73%). Mp: 127-129. 1H NMR (CDCls): 6 7.60 (d,
`J = 0.8, 2H), 7.46 (dd, J = 7.0, 1.7 Hz, 2H), 7.37 (dd, J =
`7.7,0.8 Hz, 2H), 2.04 (s, 6H). 8C NMR (CDCls): 6 141.9,
`132.5, 122.8, 98.1, 34.2, 32.0, 30.8, 29.8, 29.7, 29.4, 22.7,
`14.1. IR (neat): v (em~+) 2954, 2920, 2850, 1723, 1503, 1467,
`1098, 885, 720.
`Synthesis of 3. Dipropynyls 5a,b or 7 and 6, Mo(CO)g (5
`mol %), and 4-chlorophenol (1 equiv with respect to 5 or 7)
`are dissolved in 1,2-dichlorobenzene (10—15 mL for 1—2 g
`of monomer) and heated to 150 °C for 24 h under a steady
`stream of No. To the resulting solution was added 50 mL of
`CHCl3. The organic portion was washed with 10% NaOH,
`10% HCl, and H20 and then poured into 400 mL MeOHfor
`precipitation. 3a (2%). 1H NMR (CDCls): 6 7.81 (s), 7.67—
`7.63 (m), 7.59—7.52 (m), 7.36 (bs), 7.29 (s), 7.12—7.11 (m),
`7.07—7.05 (m), 6.98 (s), 2.81 (bs), 2.05 (s), 1.70 (bs), 1.52
`(s), 1.51—-1.23 (m), 0.85 (t, J = 7.1). 8C NMR (CDCls): 6
`141.9, 182.5, 122.8, 93.1, 34.2, 32.0, 30.8, 29.8, 29.7, 29.4,
`22.7, 14.1. IR (neat): v (em~!) 2954, 2920, 2850, 1723, 1508,
`1467, 1093, 885, 720. 8a (5%). 1H NMR (CDCls): 6 7.81 (bs),
`7.67—7.63 (m), 7.54—7.52 (m), 7.36 (bs), 7.35 (s), 7.34 (s),
`7.29 (s), 7.22 (s), 2.82 (bm), 2.70 (ra), 2.10 (s), 1.70 (m), 1.61
`(s), 1.53—1.23 (m), 0.85 (t).&'C NMR (CDCls):6 141.9, 141.7,
`134.5, 132.4, 123.4, 122.8, 121.9, 93.1, 92.5, 91.3, 90.3, 77.2,
`34.2, 33.9, 32.0, 30.8, 30.5, 29.8, 29.7, 29.5, 29.4, 22.7, 14.2,
`4.6. IR (neat): v (em) 2955, 2920, 2850, 1723, 1502, 1466,
`892, 720. 8a (10%). 1H NMR (CDCls): 6 7.80 (s), 7.65—7.60
`(m), 7.59—7.56 (m), 7.36 (bs), 6.98 (s), 2.81 (bm), 2.10 (s),
`1.70 (bm), 1.52 (bs), 1.51—1.23 (m), 0.85 (bs). 8C NMR
`(CDCl3): 6 141.9, 182.4, 122.8, 93.1, 34.2, 31.9, 39.8, 29.8,
`29.7, 29.4, 22.7, 14.1. IR (neat): v (em7!) 2920, 2850, 17238,
`1503, 1466, 856. 3b (5%). 1H NMR (CDCls): 6 7.83 (s), 7.69
`(bd), 7.55 (bd), 7.36 (s), 7.85—7.34 (m), 7.29 (s), 7.22 (s), 2.82
`(bm), 2.70 (m), 2.10 (s), 1.70 (m), 1.61 (s), 1.53—1.23 (m),
`0.85(t). 83C NMR (CDCls): 6 141.0, 133.4, 123.1, 93.3, 77.4,
`40.3, 38.5, 32.5, 28.8, 25.6, 23.1, 14.1, 10.8. IR (neat):
`(em~1) 2955, 2920, 2850, 1738, 1461, 1376, 1238, 1019, 904.
`4 (10%). 1H NMR (CDCls): 6 7.86 (d, J = 13.6 Hz), 7.71-
`7.66 (m), 7.65 (s), 7.64—7.50 (m), 7.46, (d, J = 7.7 Hz), 7.47—
`7.34 (m), 2.09 (s), 2.07 9s), 1.99 (bm), 1.19—1.04 (bm), 0.85—
`0.81 (m), 0.59 (bm). 18C NMR (CDCls):. 6 151.1, 151.0, 140.7,
`140.0, 130.8, 130.5, 125.9, 122.7, 122.0, 121.7, 120.0, 119.9,
`90.8, 90.7, 86.1, 80.6, 55.3, 40.5, 31.9, 30.1, 29.6, 29.4, 29.3,
`23.8, 22.7, 14.1, 4.5. IR (neat): v (em!) 2954, 2916, 2852,
`1726, 1464, 1126, 885, 823.
`Integration of the 'H NMRaromatic signals suggests a lower
`incorporation of fluorenone units by a factor of 0.5 when
`compared to monomeraddition (6), i.e., 3a 5% contains
`roughly 2.5% fluorenone.
`Thin films were heated past their isotropic point as deter-
`mined by DSC, cooled to their LC phase, andleft at this
`teperature for 2 h, then slowly cooled to ambient tempera-
`ture. An increase in chain ordering was evidenced by powder
`XRD.
`
`MA011330M
`
`5
`
`