Synthesis and Spectral Properties of Novel Poly(disubstituted acetylene)s

Abstract

The synthesis of mostly new acetylenes, R1CCR2, (R1 = 4‐t‐butylphenyl; R2 = 4‐t‐butylphenyl; 4‐[(t‐butyl)(diphenyl)silyloxy]phenyl; 1‐naphthyl; 2‐naphthyl; 9‐anthryl) is reported. Their UV‐vis characteristics are discussed in comparison to the results of TD‐DFT calculations. R1CCR2 (except for R2 = 9‐anthryl) give polyacetylenic polymers—[C(R1) = C(R2)]‐n, insoluble if R1 = R2 and well soluble if R1 ≠ R2 in polymerization with TaCl5/SnBu4. Polymerizability increases with increasing monomer triple bond accessibility for the catalyst. The photoluminescence yield of the soluble polymers rises in the R2 order: 1‐naphthyl < 2‐naphthyl < 4‐[(t‐butyl)(diphenyl)silyloxy]phenyl.

Poly(disubstituted acetylene)s With Pendant Naphthalimide‐Based Fluorophore Groups

“…It proves that neither co‐monomeric composition nor degree of substitution of Cl atoms with N 3 groups influences fluorescence characteristics of the types A and B PDAs. Hence, it is clear that the fluorescence originates from PDA main chains as it was already claimed for others PDAs 33, 41. The observed occurrence of two fluorescence components with different lifetimes might be ascribed to the cis – trans isomerism of PDA main chains.…”

“…PDAs were obtained in moderate to high yield (50%–90%, Table 1) as fluorescent yellowish solids. Poorly resolved 1 H NMR spectra (Figure 1) prove configurational ( cis – trans ) and orientational (head–tail) nonuniformity of all PDAs prepared, which is typical of polymers prepared with W‐, Ta‐, and Nb‐based catalysts 9, 11–14, 29, 41, 70. Each spectrum contains a broad unresolved signal of aromatic (6 –8 ppm) and aliphatic protons (0.5–2 ppm) and, except for spectrum of A0 , also relatively well‐resolved signal of protons of CH 2 Cl groups at 3.2 ppm.…”

“…This could be achieved by direct (co)polymerization of a monomer carrying the corresponding fluorophore. However, this approach has limited applicability because PDAs are typically prepared by coordination polymerization catalyzed by high‐valent W, Ta, and Nb complexes,2, 38–41 which are mostly incompatible with polar groups present in fluorophores. Therefore, the strategy based on the modification of PDAs that contain reactive groups tolerated by the above catalysts, such as halogenalkyl groups, seems to be favorable.…”

Ionic π‐Conjugated Polyelectrolytes by Catalyst Free Polymerization of Bis(pyridyl)acetylenes and Bis[(pyridyl)ethynyl]benzenes

“…On the contrary, all the polymers emit the visible light upon the UV excitation (see Figure 9 for the photoluminescence emission spectra of the polymers). The emission of the polymers can originate from the excitation of the partly conjugated polymer chains of polyacetylene type [ 43 ] and/or the transition of the CT complex N -benzylpyridinium/Br − . [ 44,45 ] The emission spectrum of poly(2PM) shows maximum in the yellow region ( λ max = 560 nm) (see Figure 9 ).…”

Homo‐ and Copolycyclotrimerization of Aromatic Internal Diynes Catalyzed with Co2(CO)8: A Facile Route to Microporous Photoluminescent Polyphenylenes with Hyperbranched or Crosslinked Architecture

“…However, the possibility of this reaction has been mentioned by Häußler et al, [9] and substrates with internal ethynyl groups are frequently and successfully used in cyclotrimerizations and cocyclotrimerization toward preparing low molecular weight products (e.g., the cyclotrimerization of 1,2-diphenylacetylene and its derivatives to hexaphenylbenzenes catalyzed with Co-based catalysts). [17][18][19] It should be noted that the internal ethynyl groups of monoethynylated and diethynylated monomers are by no means inactive in the polymerizations [e.g., 1,2-diarylacetylenes are well polymerized, with selected metathesis catalysts, to high molecular weight linear poly(disubstituted acetylene)s, [20][21][22][23] and bis(alkylethynyl)arenes polymerize with other metathesis catalysts to the lower molecular weight linear poly(arylene ethynylene)s]. [24,25] Thus, we decided to study the Co 2 (CO) 8 -catalyzed polycyclotrimerization of aromatic monomers with internal ethynyl groups.…”