TY - JOUR
T1 - Occurrence of radical cation localization in chemically modified poly(methylphenylsilane): Poly(methylphenyl-co-4-dimethylaminophenylmethylsilane)s and poly (methylphenyl-co-4-bromophenylmethylsilane)s
AU - Cleij, TJ
AU - King, JK
AU - Jenneskens, LW
PY - 2000/1
Y1 - 2000/1
N2 - Chemical modification of poly(methylphenylsilane) 1 using triflate chemistry gave two series of random copolymers with different composition ratios, viz., poly(methylphenyl-co-4-dimethylaminophenylmethylsilane)s 3-7 and poly(methylphenyl-co-4-bromophenylmethylsilane)s 8-9. The optical and electronic properties of the copolymers have been studied and are compared with those of the homopolymers 1 and poly(4-dimethylaminophenyl-methylsilane) 2. Electrochemical measurements in THF/LiClO4 give strong evidence that, in marked contrast to the results observed for 1 and 2, the onset of oxidation (V-i) of 3-7 and 8-9, respectively, does not represent the silicon backbone valence band. Instead, in these copolymers, a mixture of decoupled electronic domains exists of which those possessing the lowest V-i govern the electrochemical response. As a consequence, the radical cations become confined, i.e. localization occurs. This interpretation is further supported by fluorescence emission spectroscopy, the presence of a confined exciton is indicated by the appearance of an additional broad band for the copolymers. Remarkably, copolymers with optical and electronic properties comparable to those of 3-7 are also accessible by (reversible) protonation of the 4-dimethylamino substituents of 2.
AB - Chemical modification of poly(methylphenylsilane) 1 using triflate chemistry gave two series of random copolymers with different composition ratios, viz., poly(methylphenyl-co-4-dimethylaminophenylmethylsilane)s 3-7 and poly(methylphenyl-co-4-bromophenylmethylsilane)s 8-9. The optical and electronic properties of the copolymers have been studied and are compared with those of the homopolymers 1 and poly(4-dimethylaminophenyl-methylsilane) 2. Electrochemical measurements in THF/LiClO4 give strong evidence that, in marked contrast to the results observed for 1 and 2, the onset of oxidation (V-i) of 3-7 and 8-9, respectively, does not represent the silicon backbone valence band. Instead, in these copolymers, a mixture of decoupled electronic domains exists of which those possessing the lowest V-i govern the electrochemical response. As a consequence, the radical cations become confined, i.e. localization occurs. This interpretation is further supported by fluorescence emission spectroscopy, the presence of a confined exciton is indicated by the appearance of an additional broad band for the copolymers. Remarkably, copolymers with optical and electronic properties comparable to those of 3-7 are also accessible by (reversible) protonation of the 4-dimethylamino substituents of 2.
U2 - 10.1021/cm9910916
DO - 10.1021/cm9910916
M3 - Article
SN - 0897-4756
VL - 12
SP - 84
EP - 89
JO - Chemistry of Materials
JF - Chemistry of Materials
IS - 1
ER -