Dehalogenation Polymerization of 1,1′-Dihaloferrocene with Magnesium as a New Convenient Synthetic Route to Poly(1,1′-ferrocenylene)

Abstract1,1′-Dibromoferrocene and 1,1′-diiodoferrocene are readily converted into poly(1,1′-ferrocenylene) in a 45—77% yield by dehalogenation polymerization with magnesium, n(XC5H4FeC5H4X) + nMg → (\\llap–C5H4FeC5H4) \\llap–n + nMgX2. The polymer obtained was fractionated into four parts by solubilities in organic solvents: Fraction I (soluble in hexane, 23—29 wt%), Fraction II (soluble in C6H6 at room temperature but nonsoluble in hexane, 6—11 wt%), Fraction III (soluble in C6H6 at 80°C but nonsoluble at room temperature, 6—12 wt%), and Fraction IV (insoluble in C6H6 at 80°C, 47—62 wt%). Infrared (IR) and nuclear magnetic resonance (NMR) spectra of Fractions I—IV indicate that they are constituted of regularly recurring 1,1′-ferrocenylene units. The number-average molecular weights of Fractions I and II are about 900 and 1500 respectively as determined by vapor pressure osmometry (VPO), whereas that of Fraction IV was calculated as about 4600 from analytical data, assuming that both polymer ends have halogen. The polymers have high thermal stabilities and the thermal stabilities are enhanced by preparing the polymer in the presence of a nickel compound, NiCl2(2,2′-bipyridine). The X-ray diffraction pattern of the powdery polymer shows fairly sharp peaks, indicating the presence of micro crystals. Doping of Fraction IV with acceptors such as iodine and 7,7,8,8-tetracyano-p-quinodimethane (TCNQ) afforded semi-conducting materials having electric condutivities of 10−2—10−4S cm−1 at room temperature.

[1]  Takakazu Yamamoto,et al.  Preparation of thermostable and electric-conducting poly(2,5-thienylene) , 1980 .

[2]  E. Neuse,et al.  Synthesis of poly-1,1′-ferrocenylenesvia ferrocenylenecuprates(1) , 1979 .

[3]  E. Neuse,et al.  Polyferrocenylenes by oxidative coupling of 1,1′-dilithioferrocene with Cu2+ Ion(1) , 1979 .

[4]  Takakazu Yamamoto,et al.  A novel type of polycondensation utilizing transition metal-catalyzed CC coupling. II. Preparation of polymethylene from α,ω-dibromo-n-alkanes by using copper catalysts , 1979 .

[5]  E. Neuse,et al.  The Organolithium Organohalide Coupling Reaction as a Synthetic Route to Poly(1,1'-ferrocenylenes) , 1979 .

[6]  Takakazu Yamamoto,et al.  A Novel Type of Polycondensation Utilizing Transition Metal-Catalyzed C–C Coupling. I. Preparation of Thermostable Polyphenylene Type Polymers , 1978 .

[7]  M. Rausch,et al.  Formation of 1,2-oligomeric ferrocenes from ullmann reactions of iodoferrocenes , 1977 .

[8]  Takakazu Yamamoto,et al.  A novel type of polycondensation of polyhalogenated organic aromatic compounds producing thermostable polyphenylene type polymers promoted by nickel complexes. , 1977 .

[9]  K. Tamao,et al.  Nickel-Phosphine Complex-Catalyzed Grignard Coupling. I. Cross-Coupling of Alkyl, Aryl, and Alkenyl Grignard Reagents with Aryl and Alkenyl Halides: General Scope and Limitations , 1976 .

[10]  D. Hendrickson,et al.  Electron transfer in oxidized biferrocene, biferrocenylene, and [1.1]ferrocenophane systems , 1975 .

[11]  A. Kasahara,et al.  The Formation of 1,1′-Oligomeric Ferrocenes from Chloromercuriferrocene and Bis(chloromercuri)ferrocene , 1975 .

[12]  D. Cowan,et al.  Oxidation-State and Electron-Transfer Properties of Mixed-Valence 1,1'-Polyferrocene Ions , 1975 .

[13]  D. Cowan,et al.  Organic solid state. VII. Semiconducting polymers. Mixed valence ferrocene-ferricenium polymers , 1972 .

[14]  M. Rausch,et al.  Formation of 1,1'-oligomeric ferrocenes from mixed Ullmann reactions of haloferrocenes , 1972 .

[15]  Takakazu Yamamoto,et al.  Organo (dipyridyl) nickel complexes. I. Stability and activation of the alkyl-nickel bonds of dialkyl (dipyridyl) nickel by coordination with various substituted olefins , 1971 .

[16]  J. Anderson,et al.  Proton Magnetic Resonance Studies of Molecular Interactions in Polymer Solutions , 1970 .

[17]  H. Rosenberg,et al.  Crosslinking polyferrocenylenes by polymethylol compounds , 1969 .

[18]  H. Rosenberg,et al.  Synthesis of 1,1'-biferrocenylene , 1969 .

[19]  J. N. Willis,et al.  An infrared and Raman study of 1,1′-disubstituted ferrocene compounds , 1968 .

[20]  Eberhard W. Neuse,et al.  Metallocene polymers XIX. Polyferrocenylenes , 1967 .

[21]  H. Rosenberg,et al.  Ferrocene-containing polymers. A reinvestigation of the polyrecombination of ferrocene , 1966 .

[22]  I. J. Spilners,et al.  Synthesis of Polyferrocenylene1 , 1965 .

[23]  M. Rausch.  Ferrocene and Related Organometallic π-Complexes. IV. Some Ullmann Reactions of Haloferrocenes1 , 1961 .

[24]  H. Shechter,et al.  Ferrocenyl and 1,1'-Ferrocenylene Grignard Reagents1a , 1961 .

[25]  J. Broomhead,et al.  Corrigenda - Mono Complexes of 2,2'-Bipyridine and 1,10-Phenanthroline with Metal Halides , 1961 .

[26]  M. Kharasch,et al.  Grignard Reactions of Nonmetallic Substances , 1954 .