摘要：化学取代是有效调节分子电导,产生多通道输运、量子干涉效应和其他机制的关键方法.但分子骨架和侧基之间存在复杂的相互作用,目前仍未被研究清楚.在本工作中,我们结合扫描隧道显微镜裂结实验技术和第一性原理计算方法,深入研究了具有不同σ和π侧基的分子电导.实验结果及理论分析表明,σ侧基的加入引起了分子前线轨道的对称性破缺并加剧了分子内散射,从而导致电导的降低.相反,π侧基引入了额外的电荷传输通道,实现了电荷传输的多通道效应,增加了分子的电导.这些发现为未来分子功能化和分子电子器件的设计提供了坚实的基础.

摘要：空气稳定有机自由基的发现引起了人们对探究其在分子电子学和自旋电子学中应用的兴趣.这些自由基具有独特的开壳层电子结构,因而表现出特殊的电学特性.由于其较弱的旋轨耦合特性,也使得其成为自旋电子学的重要研究对象.此外,自由基还可以通过二聚、分子识别和机械互锁等分子间相互作用来构筑超分子器件.本文综述了空气稳定有机自由基在电子学及自旋电子学中的应用,通过详述其卓越的电磁性能来拓展启发分子设计的多样性.本综述还概述了超分子自由基的制备方法和相关性质的研究进展,拓宽了单分子研究的范围.此外,自由基介导的单分子反应是一个新兴的研究方向,本文也对该领域的未来发展方向进行了展望.通过阐明空气稳定有机自由基的应用潜力,本文将有望对分子电子学和自旋电子学的研究产生一定的指导意义.

摘要：本文报道了一类兼具超长有机磷光(UOP)和强圆偏振发光(CPL)性质的蓝光轴手性材料.这类材料不仅具有极小的单重态(S1)-三重态(T1)能隙差(ΔE_(ST),0.03 eV),能够极大地促进系间窜越过程以产生更多的三重态激子,而且还具有超长的磷光衰减寿命(5.5 s).因此,这类材料在77 K下的2-MeTHF稀溶液中显示长达60 s的亮蓝色余辉.我们进一步提出了“激子沙漏”模型来描述内部的光物理过程和解释产生超长余辉的原因.此外,由于刚性的轴手性骨架,这类UOP材料还表现出强的CPL活性,尤其是将它们用作液晶材料的手性诱导剂时,能够获得0.34的g_(lum)值.本工作对于进一步设计兼具UOP和强CPL性质的新型纯有机分子材料具有重要的指导意义.

摘要：设计并且调制材料，形状，热转移，和团在开发化学反应堆的过程期间混合的能力允许研究人员探索百万化学反应和试金。尽管有在设计基于数组的 microreactors 或 microfluidic 系统的优点，然而，在试剂 / 产品和玻璃或集装箱的聚合物底层的答案之间的弄湿的附件在有效地收集产品并且阻止隧道阻塞导致困难。此处我们在场利用导出 nanoparticle 的 superhydrophobic 柱脚的弄湿反、低粘合剂的性质的一个缩小的微滴反应堆，允许水的微滴自由地被操作而且为在小规模上执行一系列水的阶段化学药品反应提供限制环境。煤气形成或猛抛形成反应能也在这个缩小的反应堆内被执行。最重要地，在液体，固体或气体的状态的反应产品能有效地被收集，它允许收获在有限数量形成的珍贵产品。在 superhydrophobic 柱脚上造的如此的一个缩小的反应堆提供执行普通化学反应的一个新方法并且可以打开门到下一代的 microreaction 系统的设计。

摘要：The strontium ions extracted from the aqueous phase into 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide(C_2mimNTf2) with dicyclohexyl-18-crown-6(DCH18C6) was stripped effectively by supercritical CO_2(sc-CO_2).Hexafluoroacetylacetone(HFAA)-acetonitrile was found to be an excellent modifier of sc-CO_2 to enhance the stripping *** the orthogonal array design(OAD),OA_(25)(5~5)matrix was employed to optimize the stripping of Sr(Ⅱ) from the DCH 18C6-C_2mimNTf_2 *** of five experimental factors:temperature,pressure,concentration of HFAA,static and dynamic extraction times as well as each factor at five-levels on the stripping of Sr(Ⅱ) were *** effects of these parameters were treated by the analysis of variance(ANOVA).The results showed that Sr(II) could be nearly 100%extracted from the IL phase at 308 K,30 MPa,40 min of dynamic extraction and 60 mmol·L^(-1) HFAA in acetonitrile,***,the stripping mechanism was studied by ESI-MS.

摘要：A biosensor device, built from graphene nanoribbons （GNRs） with nanopores, was designed and studied by first- principles quantum transport simulation. We have demonstrated the intrinsic transport properties of the device and the effect of different nucleobases on device properties when they are located in the nanopores of GNRs. It was found that the device＇s current changes remarkably with the species of nucleobases, which originates from their different chemical compositions and coupling strengths with GNRs. In addition, our first-principles results clearly reveal that the distinguished ability of a device＇s current depends on the position of the pore to some extent. These results may present a new way to read off the nucleobases sequence of a single-stranded DNA （ssDNA） molecule by such GNRs-based device with designed nanopores

摘要：Natural enzymes have been praised highly as ideal catalysts, presumably owing to their remarkable advantages of high efficiency,high selectivity, and mild reaction conditions. The reports of chemical simulation and systematic synthesis of natural enzymes such as peroxidase(POD) are rare because of their complex biological structures. POD represents a large family of oxidoreductases and offers a wide range of applications in many fields of science. Recent advance in the fusion of nanomaterial, catalysis, and biochemistry has inspired the development of artificial enzymes implemented with desired catalytic features of natural ***, we review the redox chemistry of POD and compare its catalytic performance to graphene-based nanomaterials(G-NMs)as POD mimetic nanoenzymes bases on catalytic center, binding site, and carrier function. Based on the viewpoints of stereo chemistry and molecular kinetic and dynamics in heterogeneous system, we evaluate and compare the suitability of different NMs as artificial enzyme constituent. We propose that reevaluates design strategies of graphene-based peroxidase(G-POD) mimetic materials and emphasizes on their selectivity(role as catalytic center, binding site, or carrier) is of uttermost.

摘要：本文设计并合成了一种新型喹喔啉类聚合物给体PBQ8,其在喹喔啉单元上具有正辛基侧链,与先前报道的PBQ5(异辛基侧链)具有相同的聚合物骨架结构.与PBQ5相比,PBQ8表现出更强的分子间相互作用和更好的分子堆积.当其与聚合物受体PY-IT共混时,基于PBQ8:PY-IT的全聚合物太阳能电池表现出远高于PBQ5:PY-IT器件效率,其能量转化效率为17.04%,这是目前全聚合物太阳能电池中的最高效率之一.结果表明,聚合物给体的侧链工程是进一步提高全聚合物太阳能电池光伏性能的有效途径.

摘要：降低固体氧化物燃料电池(SOFCs)的工作温度正在推动新型氧离子导体材料的开发.在此,受氧离子导体材料结构共性的启发,基于Sr(Si/Ge)O_(3)材料中刚性(Si/Ge)_(3)O_(9)基团无法容纳氧空位,以及BO_(n)多面体在配位数、旋转、变形和连接上的巨大灵活性,我们首次通过计算预测和实验验证,报道了基于硼酸盐的新型氧离子导体材料(Gd/Y)_(1−x)-Zn_(x)BO_(3−0.5x).(Gd/Y)BO_(3)中的氧空位可以通过孤立的B_(3)O_(9)三元环形成B_(3)O_(8)结构单元来容纳,并通过B_(3)O_(9)和B_(3)O_(8)单元之间的氧交换合作机制来传输,而这些结构单元作为过渡态的打开和伸展则有助于氧的传输.这项研究为设计和开发新型氧离子导体开辟了新方向,有望从硼酸盐家族发现更多新的氧离子导体.

摘要：二维分子晶体是一类具有优异光电性能的新兴材料.然而,由于人们对决定二维结晶的因素知之甚少,二维分子晶体的生长极具挑战.我们研究了有机半导体的二维结晶和表面自由能之间的关系,提出了利用表面自由能各向异性因子来衡量二维结晶趋势的设想.以两个BTBT衍生物为例,我们发现具有大的g因子的分子有不受外界条件干扰的二维结晶趋势.这项工作为合理设计可二维结晶的有机半导体提供了指导.