Synthesis, Crystal Structures, and Solid-State Polymerization of 8-[4-(Dimethylamino)phenyl]octa-5,7-diynyl Carbamates

Abstract

Six butadiyne monomers with (dimethylamino)­phenyl and N-substituted urethane substituents were synthesized and their crystal structures and solid-state polymerization were investigated. In five of the six monomers, directions of the butadiyne stacking and the intermolecular hydrogen bonding between urethane groups coincided, and translational distance d between adjacent butadiyne moieties was around 5 Å. Among them, four monomers showed angle θ between the translation axis of the monomers and the butadiyne moiety of around 45°, which is appropriated for regular 1,4-addition polymerization. These geometries resulted in formation of polydiacetylenes with characteristic excitonic absorption and relatively high conversion. One monomer was found to have large θ, and the regular polymerization was not recognized to be quite low conversion. However, in the remaining one monomer among six, the directions of butadiyne stacking and intermolecular hydrogen bonding were different and d was much longer than 5 Å. However, distance between reacting carbons for 1,4-addition was short enough resulting in comparable conversion without regular polymerization. Although introduction of urethane group is effective to increase probability of the solid-state polymerization of butadiynes, hydrogen bonding direction, methylene chain conformation, and disorder of the aromatic rings were found to afford the variation from the appropriate conditions.

Organic Polymers of an Angular Diene via Solid State [2 + 2] Polymerization: Coordination Polymers with Dicarboxylates as Templates

“…The design and synthesis of novel organic polymers through topochemical reactions, such as [2 + 2], [4 + 4], [4 + 2], and [1,4]-addition are of recent interest owing to ease of synthesis with deducible and tunable structural features in high yields and also due to the day-to-day applicative aspects of the organic polymers. − In particular, the synthesis of crystalline 1D and 2D organic polymers containing cyclobutanes in the backbone through [2 + 2] reactions of diene and trienes, respectively, are of immense interest given their uniqueness and difficulty in finding such monomers with requisite crystal structures. − Integrating such monomers of dienes into the network of coordination polymers was shown to promote [2 + 2] polymerization reactions to produce coordination polymers of organic polymers (CPOPs) in single crystal to single crystal transformations upon irradiation. − …”

Quantitative and Anisotropic Mechanochromism of Polydiacetylene at Nanoscale

“…Polydiacetylene (PDA) is a class of mechanochromic polymers, including nonamphiphilic and amphiphilic ones with hydrophobic (e.g., alkyl, aryl) chains on one end, and a hydrophilic headgroup (e.g., −COOH, −NH 2 , −ester) or other moieties (e.g., aryl, , etoxisilane, urethane, or isocyanate groups) on the other end, that was initially reported in the late 1960s . It is known to change color and become fluorescent when it is exposed to heat, pH variation, adsorption of ions, and other molecules. , Over the years, its monomer assembly, polymerization process, polymer structure, and mechanochromic properties have been characterized based on measurements via the Langmuir–Blodgett technique, electron paramagnetic resonance (EPR), X-ray crystallography, UV–vis, fluorescence, infrared (IR), Raman spectroscopy, nuclear magnetic resonance (NMR), scanning tunneling microscopy (STM), atomic force microscopy (AFM), fluorescence microscopy, and electrical conductivity .…”

Synthesis and Solid-State Polymerization of 5-(Pyren-1-yl)penta-2,4-diyn-1-ol Derivatives with an N-Phenylurethane or N-Benzylurethane Group

“…In this case, the polymerization scheme seems to be not as regular as for the compounds of type I. Actually, in our previous study, we confirmed by single-crystal X-ray crystallographic analysis that the butadiyne derivatives showing the polymer absorption of type II aligned under the conditions with a large deviation from d = 0.5 nm and θ = 45° in Figure …”

“…Actually, in our previous study, we confirmed by singlecrystal X-ray crystallographic analysis that the butadiyne derivatives showing the polymer absorption of type II aligned under the conditions with a large deviation from d = 0.5 nm and θ = 45°in Figure 1. 52 Powder X-ray diffraction patterns of the monomers were obtained as shown in Figure 4. Sharp diffraction peaks were observed for the compounds with phenyl or trimethoxyphenyl groups: i.e., H-0, H-1, C 1 O-0, and C 1 O-1.…”

“…One of the strategies is to use a supramolecular host–guest system. , The other is modification by specific groups, which tend to align monomers in one-dimensional (1D) arrays. We have used the latter strategy to prepare butadiyne monomers with π conjugation between the backbone and substituents. , For example, butadiyne derivatives directly bound to electron-donating aromatics such as pyrene, , N -phenylcarbazole, , aniline, , and tetrathiafluvalene (TTF) were recently synthesized, and some of them polymerized regularly to form PDAs with conjugated donors. Meanwhile, in order to improve the PDA processability, one of the potential approaches is its solubilization.…”