Luminescent Polymer Consisting of 9,12‐Linked o‐Carborane

Abstract

The synthesis of novel luminescent polymer containing p-phenylene-ethynylene and 9,12-linked o-carborane units alternately in the main chain is reported. The obtained polymer exhibits intense blue photoluminescence, providing the first insights into the optical properties of a 9,12-disubstituted o-carborane dye. π-Conjugated substituent at 9 and/or 12-positions in o-carborane is electrically independent, and both the HOMO and the LUMO levels slightly increase, whereas LUMO of the π-conjugated substituent at 1 and/or 2-positions in o-carborane decrease. Thus, it is deduced that polymers consisting of the 9,12-linked o-carborane unit are able to be applied as light-emitting materials.

Ethylene‐bridged Periodic Mesoporous Organosilicas with Large Spherical Pores Templated by PEO‐PPO‐PEO Surfactant Micelles Swollen by Ethylbenzene

“…Scheme outlines the synthetic route to 1,9,12‐trifunctional o ‐carborane derivatives 7 a and 7 b . Compound 2 , which was prepared as previously reported,10 was treated with n ‐butyllithium, and the successive Ullmann‐type coupling with 9‐iodophenanthrene ( 3 ) afforded compound 4 in 27 % yield 12. The trimethylsilyl (TMS) groups of 4 were removed by treatment with K 2 CO 3 to obtain diethynyl compound 5 in 93 % yield.…”

“…In solution, the intramolecular charge transfer (ICT) processes from the π‐conjugated moieties to the C1C2 bond of o ‐carborane quenched the emission, whereas the aggregates emitted because of a “freezing” of the C1C2 bond vibration 9. In addition, we recently synthesized a conjugated polymer that was composed of 9,12‐disubstituted o ‐carborane units in the main chain,10 which, in the solution, exhibited intense emission from the locally excited (LE) state of the 9,12‐disubstituted conjugated units. These results indicate that o ‐carborane has completely different emission profiles, which depend on the conjugated moieties at the 1,2‐carbon positions (AIE) and 9,12‐boron positions (LE).…”

Icosahedral boron clusters: a perfect tool for the enhancement of polymer features

“…13 The ratio of monomers incorporated into the PPy backbone of the material was evaluated by UV/vis spectroscopy and turned out to be roughly 1 : 1, indicating that the rate of polymerization of both monomers is practically the same. These synthons (see Chart 5) are as follows: (i) neutral mono-substituted (19), 14 (20), 14 (21), 15 (22); 15 (ii) neutral di-substituted (23), 16 (24) 15 and (iii) anionic mono-substituted compounds (25), 14 (26). This value represents the best performance ever obtained in a heterogeneous phase using a chemical oxidant.…”

“…14 The first conducting polymer functionalized with covalently linked carborane units was obtained by anodic oxidation of the substituted (19) pyrrole monomer in 10 À1 M [NBu 4 ][PF 6 ] anhydrous CH 3 CN. The disubstituted 3,5-pyrrole (24) and its corresponding PPy24(PF 6 ) polymer were oxidized at a more positive potential than the substituted 3-pyrrole (21) and its conforming PPy21(PF 6 ) membrane due to the presence of two sterically hindered carborane clusters at the 3,5-vertices of the pyrrole ring (Table 1). Monomer (20) that presents an ethyl group spacer was more efficiently electropolymerized than (19) with a methylene group.…”

Direct synthesis of carboranylpolystyrene and their applications for oxidation resistance of graphene oxides and catalyst support

“…Polymers incorporating carborane units exhibit unique properties due to inherent chemical inertness, high hydrophobicity, electron deficient, thermal and radiation stability of carborane cages [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. For example, silicone polymers with closo-carborane, C 2 B 10 H 12 , incorporated in its backbone show promising oxidative stability at high temperatures [1][2][3].…”