R&T Code b41c011dar. Technical Report No. 40. Synthesis, Characterization, and Electropolymerization of Ferrocene Substituted Anilines.

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1 AD-A SE.E T E R SEP "r r OFFICE OF NAVAL RESEARCH Contract No. N K-0732 R&T Code b41c011dar Technical Report No. 40 Synthesis, Characterization, and Electropolymerization of Ferrocene Substituted Anilines Cohn P. Horwitz, Norman Suhu, and Gregory C. Dailey Prepared for Publication in Journal of Electroanalytical and Interfacial Electrochemistry Rensselaer Polytechnic Institute Department of Chemistry Troy, NY May 1991 Reproduction in whole or in part is permitted for any purpose of the United States Government This document has been approved for public release and sale; its distribution is unlimite /l~tllillllllltl~llllltk ll

2 SECUR17' CASS;CA7:ON 0; -,'IS PAGE ia RIE:ORT SEC-URITY C'AS3.;CAT:ON Unclassified REPORT DOCUMENTATION PAGE :o RESTQICtV:E MARKINGS Form -Ioorav.? 2a. SECURITY CLASSIFICATION AUTHORITY 3 DiSTRIBUTON/AVAILABILIT' OF RP(OR7 Approved for public release and sale. 2b. DEC.ASSIFICATION DOWNGRADING 3CHEDULE Di1st r ibut ion unli mi ted )70s-jjo 4. PERFORMING ORGANIZATION REPORT NUMBER(S) 5 MONITORING ORGANIZATiCN REPOR7 NuMBER(S'l ONR Tecmjial Report No. 4o 6a. NAME OF PERFORM NG ORGANIZA71ON 6o OFFICE SYMBOL 7a. NAME OF MONITORING ORGANiZA:C)N Department ot Materials (if appiicaole) Science and Engineering Office of Naval Research 6C. ADDRESS (City, Stare, and ZIP Code) 7b ADDRESS Ciry. State, and ZIP Coce) University of Pennsylvania Dr. Robert Nowak, Chemistry Divis~on 3231Walnt SteetONR, 800 North Quincy Street Philadelphia, PA Arlington, VA a. NAM.E OF FUNDING;5SPONSORING 3ab OFF;CE SYMBOL 9 PROC'UREMENIT INSTRUM1E.N DENT7FICA7 ON4 'IUMBE ORGAIZAION(if apokiable) 8c. ADDRESS (City, State, and ZIP Code) 10~ SOURCE CF :UNDING -NUMBERS Chemistry Division, 0NR PROGRAM IPROJECT -ASK (VORK NiT 800 North Quincy Street EEME N NO No NO ACCE:3scN NO Arlington, VA TITL: (include Security Classification) Synthesis, Characterization, and Electropolymerization of Ferrocene Substituted Ani lines 12. PERSONAL AUTHOR(S) Colin P. Horwitz, Norman Suhu, and Gregory C. Dailey 13a 7v'c Of REDORT 13b TIME QyRED 14 DATE OF REPORT (Year, Monti), Day) i5 PACE :CUN7 Techlnical I ROM,i9 To 5/ , June SLP"LEMENTARY NOTATION Submitted to: Journal of Electroanalytical and Interfacial Electrochemistry I The synthesis and electrochemical properties of anilne and aniline like molecules substituted with ferrocene are described [(C5H5)Fe (C5H4CH2NHR) where R= C6H5, 1, C6H5,-3-NH2,2, C6H5-3-OH, 3, and (CH2)2NHC 6 5,41. All compounds polymerize upon electrochemnical oxidation of the aromatic amidne portion of the complex in a CH3CN solution containing Bu4NC1O 4 as supporting electolyte. The phenol substituted complex shows its best polymerization characteristics when approximately one equivalent of NEt3 is added to the electrolysis solution. The polymer.-, characterized by cyclic voltammetry, show well defined couples for the ferrocene but there is no electrochemical indication that the polymer backbones are electroactive. Spectroelectrochemidcal measurements show changes in the visible absorption spectrum characteristic for formation of the ferricinium cation, Xmax = 620 rim, in all of the polymers upon oxidation. In the case of the polymer fromn 2, an intense absorption at 480 rn also is recorded which suggests that the polymer backbone is in fact electrochemically active. '0 S-Ri9U"'ON A'JAILABIL!7Y OF AEBSTRAC- 2' ABSTRAC- SECURIT" C-ASSP;CA7'O)N.2IC,,ASSIFED:,UNLWI7ED 0 SAME AS RP- l :)- C JSE;ZS Unc lassif i ed.z) :,IE OF ;E5SPONS.8I E NDIVtDU1L 22b 7E-.E?"-NE (Inciuce.1rea Czce. '- : 2iCENKA Gregory C. Farrington DD Form 1473, JUN 86 -rev,ous eairons are oosole le R- NCTC ~~

3 SYNTHESIS, CHARACTERIZATION, AND ELECTROPOLYMERIZATION OF FERROCENE SUBSTITUTED ANILINES Colin P. Horwitz, Norman Suhu, and Gregory C. Dailey Department of Chemistry, Rensselaer Polytechnic Institute, Troy NY, ABSTRACT ' The synthesis and electrochemical properties of aniline and aniline like molecules substituted with ferrocene are described [(C;H;)Fe(C;H 4 CH-NHR) where R = C.H5.. 1, CAHq-3-NH,, 2, C 6 H 5-3-OH, 3, and (CH 2 ) 2 NHC 6 H, -74AtAll compounds polymerize upon electrochemical oxidation of the aromatic amine portion of the complex in a CH 3 CN solution containing Bu 4 NC10 4 as supporting electrolyte. The phenol substituted complex shows its best polymerization characteristics when approximately one equivalent of NEt 3 is added to the electrolysis solution. The polymers, characterized by cyclic voltammetry, show well defined couples for the ferrocence but there is no electrochemical indication that the polymer backbones are electroactive. Spectroelectrochemical measurements show changes in the visible absorption spectrum characteristic for formation of the ferricinium cati.n, Xmax 620 nm,4n all of the polymers upon oxidation In the case of the polymer from 2, an intense absorption at 480 nm also is recorded which suggests that the polymer backbone is in fact electrochemically active.

4 The ferrocene polymers that have been described exhibit a number of desireable properties which may lead to their use in practical devices. These polymers are quite stable to standard electrochemical conditions, show good stability to storage at ambient conditions, and the monomers can be synthesized using simple techniques. Furthermore, the mild positive potentials used in forming the films simplifies device fabrication. All of these aspects offer considerable improvements over existing methodologies for preparing electropolymerized polyferrocene films. The methodology of incorporating a redox active transition metal complex onto a possible electronically conducting organic backbone holds promise for preparing novel materials. As demonstrated for the polyphenylene oxide like polymers, a synergistic effect can occur between the different componelts. In this example, the ferrocene aids in propagating charge through what normally would be an insulating film while the phenol backbone provides a useful means for immobilizing the ferrocene. Studies are ongoing to determine the generality of the present approach to polymer film formation. i.ji e, Io ),..,.,,. ',.. I Dist. Ii

5 RESULTS " All compounds can be electropolymerized * Compound 2 is the best method to form polyphenylene oxide films - a new electronic conductor * Compound 3 may have an electronically conducting polyaniline backbone * Compound 4 has poor film forming properties a) Decrease free volume for ion motion b) Alkyl chain is hydrophobic and rejects ions " Promise of new materials with unique properties is being realized

6 COMPOSITE ELECTRONIC - REDOX HOPPING CONDUCTORS " Organic polymers which are electronically conducting may be used for battery electrodes * Redox hopping conductors prepared from metal complexes allow control of ion concentration " Composite materials should have unique and novel properties

7 Materials synthesized, characterized, and electropolymerized (9CH 2 N (?-CH 2N (Y-CH2 N O Fe Fe Fe 2 3 H Fe 4 1) Polyaniline or polyphenyleneoxide like backbones 2) Metal ion can be oxidized to control anion levels 3) Compound 4 may be viewed as a polyethyleneimine analog