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Hybrids consisting of polyhedral oligomeric silsesquioxane (POSS) and hexa-peri-hexabenzocoronene (HBC) with a dumbbell topology and C2 symmetry were designed and synthesized. They self-assemble into 5 nm ordered structures. In particular, the increased steric effect with increasing POSS units stabilizes a square columnar phase (Colsqu) which is important in nanotemplating. These hybrids containing discotic liquid crystal HBC and POSS units have an excellent etching contrast and present an approach to obtain 5 nm nanopatterns.  相似文献   
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A hexa-peri-hexabenzocoronene derivative (HBC-1,2,4-Ph-DA-C12) with the central HBC core tethered with three diacetylene (DA)-containing chains and three saturated alkyl chains was applied for the anticorrosion of an iron surface. This compound, which exhibits a columnar liquid crystalline phase, could be polymerized by ultraviolet irradiation through reactions between the DA units. This polymer coating exhibited a good anticorrosion property with good hydrophobicity (contact angle [CA] ~ 84°–105°) and excellent mechanical property. It showed a high resistance of 149 kΩ/cm2, much higher than that of known anticorrosion materials.  相似文献   
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To address the effects of molecular symmetry on the phase of columnar liquid crystals, a series of unsymmetry (C1) and symmetry (D3h) hexa-peri-hexabenzocoronene derivatives was prepared. Compounds 3 and 4, as well as a mixture of compounds 3+4, all had a significantly lower melting temperature and clearing temperature than high-symmetry compounds (D6h), and all results show a strong dependence on molecular symmetry.  相似文献   
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设计合成了外围以0.5、1.5、2.5代聚酰胺-胺(PAMAM)树枝形聚合物修饰的六苯并蔻衍生物HBC-C6-PAMAM-Dm(m=0.5, 1.5, 2.5), 化合物结构通过了1HNMR、13CNMR、IR和MS的表征.测定了HBC-C6-PAMAM-Dm在四氢呋喃、乙腈和二氯甲烷中的吸收和荧光发射光谱, 三种溶剂中不同代数的HBC-C6-PAMAM-Dm均以聚集态形式存在,外围树枝形聚合物骨架与核心HBC发色团的振动耦合作用随代数增加而增强,导致HBC振动能级不均化,引起吸收和荧光光谱发生变化.  相似文献   
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We have designed and synthesized two new achiral hexa-peri-hexabenzocoronene (HBC) derivatives, HBCCE and HBCTEG-CE , which bear the crown ether as the pendant for the amino acid binding site. The HBCCE self-assembled into a racemic mixture of P- and M-handed helical nanocoils, however, in the presence of chiral amino acid guests, it formed helical nanocoils with one-handed screw sense. The effects of the concentration, type and configuration of the guests on the induced circular dichroism (ICD) during the co-assembly of HBCCE with chiral amino acids were also investigated. Additionally, after complete removal of the chiral guests, the optically active nanocoils did not racemize, even in the presence of excess amino acids with the opposite configuration. In contrast, HBCTEG-CE with a long triethylene glycol (TEG) chain between the crown ether group and the HBC unit did not exhibit ICD during the co-assembly with chiral amino acids.  相似文献   
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