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Synthesis and physical properties of π‐conjugated metallacycle polymers of cobalt and ruthenium
Author(s) -
Kurashina Masashi,
Murata Masaki,
Nishihara Hiroshi
Publication year - 2004
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.200450510
Subject(s) - arylene , conjugated system , polymer , selectivity , ruthenium , materials science , cobalt , regioselectivity , polymer chemistry , metal , electrochemistry , chemistry , photochemistry , organic chemistry , catalysis , electrode , aryl , alkyl
Recent studies on two types of π‐conjugated metallacylce polymers are reviewed. Reaction of CpCo(PPh 3 ) 2 with conjugated diacetylenes afford poly(arylene cobaltacyclopentadienylene) and that of CpRuBr(cod) does poly(arylene ruthenacyclopentrienylene)s in ambient conditions. Regioselectivity of the former metallacycling reacion is not perfect (at most 80% of the 2,5‐diaryl selectivity) but that of the latter is satisfactory (∼100% of the 2,5‐diaryl selectivity) for the formation of π‐conjugated structure. Electrochemical oxidation of the cobaltacyclopentadiene polymer and reduction of the ruthenacycle polymer occur facilely and quasi‐reversibly by the contribution of metal d ‐orbitals. Physical properties in undoped (neutral) and doped (charged) sates show the behavior of electronic band structure derived from the organic π‐conjugated main chain strongly coupled with the metal d ‐orbitals. This affords, for example, photoconductivity in the neutral form of the cobaltacylopentadiene polymer and ferromagnetic interaction in the reduced form of the ruthenacyclopentatriene polymer.