＜正＞聚异腈能够形成稳定的螺旋构象引起了人们极大的研究兴趣,~1前期工作中,我们发展了炔钯配合物引发异腈活性聚合制备立构规整聚异腈的新方法。~2本文中,我们通过在端羟基化的立构规整聚异腈上引入三乙氧基硅片段,聚异腈端基的三乙氧基硅与硅纳米粒子表面羟基接枝以后,制备出聚异腈硅纳米粒子。通过在聚异腈侧基上引入手性的酰胺基团,聚合后诱导生成单手性螺旋聚异腈,与二氧化硅纳米粒子表面接枝后制备手性的硅纳米粒子(Scheme

近年来,自旋交叉材料在信息储存、分子开关、分子电子学及光电装置等领域已取得了很多成就。为了使这类材料得以成功应用于实际,即要求我们调控出自旋转变在室温附近且具有较大热迟滞回线的配合物。然而到目前为止,依旧只有少数的配合物具有此类优异的自旋交叉（SCO）性质,且在大多情况下,配合物的SCO行为尤其是转变温度依旧难以预测和进行调节。本文基于光学纯吡啶双噁唑啉配体（PyBox）构筑分子磁性材料,具体研究内容如下:一、以光学纯PyBox-Ph作为配体,采用ClO4-和BPh4-为抗衡离子,合成了含有硝基甲烷和乙腈共结晶溶剂的光学纯及外消旋体系Fe[（PyBox）2]2+配合物。通过分析研究我们发现由于光学纯和外消旋两体系手性的差异,在一个Fe（Ⅱ）离子中心上的两个配体苯环在空间中的堆叠方式差异很大,同时抗衡离子及溶剂分子在晶格中对Fe[（PyBox）2]2+配合物所造成的不同程度的挤压,使得配合物的空间结构进一步改变,导致它们的SCO性质发生了很大转变,且外消旋配合物展示出了非常强的溶剂依赖性。我们发现手性可以作为调节SCO行为的新手段,且SCO行为往往还伴随着相转变,并通过测试证明了这一点。二、我们对Fe[（PyBox）2]2+配合物体系做了进一步扩充:通过引入-Me、-Bn作为新的配体取代基,引入BF4-、PF6-作为新抗衡离子,更全面和有力的分析了配体取代基及抗衡离子对其相应的脱溶剂配合物SCO行为的影响。三、我们设计合成了内消旋PyBox配体,拟通过筛选出适宜的取代基、抗衡离子与之配位,辅以引入特定的共结晶溶剂分子,合成出内消旋Fe[（PyBox）2]2+体系配合物。综合光学纯、内消旋和外消旋这三种不同体系,通过横向的对比,我们可以推断出手性差异引起的空间变化对SCO性质转变的影响,纵向对比,亦可探究溶剂、抗衡离子等因素对同体系PyBox配合物SCO性质的影响,从而构筑出一个完整的手性Fe[（PyBox）2]2+配合物体系。

＜正＞随着微电子学的迅速发展,分子水平电子器件材料的研究受到人们的广泛关注,具有双稳态性质的自旋交叉类金属配合物是一类非常有希望应用于单分子器件研究的单分子材料[1]。自旋交叉（Spin Crossover,SCO）现象指的是对于某些第一过渡系金属离子dn（n=4-7）的配合物,在特定外界条件下（如热、压力、光等）

受到自然界中生物螺旋高分子的启发,人们对螺旋高分子产生了持续而广泛的研究兴趣,在螺旋高分子中,螺旋聚异腈主链由碳碳单键构成,具有较好的物理和化学稳定性。光学活性的螺旋聚异腈在手性识别、对映体分离以及液晶显示等多个研究领域都有重要的应用价值[1]。聚虽然多种金属配合物可以引发异腈聚合,但是活性/可控的聚合方法偏少,对聚异腈的结构控制还缺乏有效的手段。前期工作中,我们发展了一种新型的炔基钯配合物,这种配合物可以引发多种异腈单体活性聚合,生成的聚异腈具有非常高的立构规整度[2]。光学活性的螺旋聚异腈通常采用手性催化剂（引发剂）或手性单体聚合得到。但是,这些聚异腈通常都具有较为复杂的手性结构,如:螺旋主链、侧基上的手性基团以及手性端基等。发展新的合成方法制备只含有螺旋手性的聚合物、而没有其他手性元素的聚异腈具有重要的研究意义。我们在钯配合物引发非手性异腈聚合中加入手性磷配体（S-or R-BINAP）,通过配体的手性诱导作用,生成单手性螺旋过量的光学活性聚异腈。手性配体可以在聚合后脱除。这种聚合物的手性主要来自于主链的螺旋构象,而不含有任何手性原子。这种聚合方法不但具有螺旋选择性,而且还具有对映选择性,互为对映异构体的手性异腈聚合时,一种对映体会优先聚合,同时生成光学活性的聚异腈和手性的异腈单体。

聚异腈由于其独特的碳氮双键结构产生螺旋构象,使其在对手性分离,不对称催化,手性识别等方面有着广泛的应用[1]。而其合成具有螺旋结构的聚异腈,尤其是利用手性催化剂与不含手性基团的单体合成具有光学活性的聚异腈,仍然是一大挑战。我们最近报道了一系列钯催化剂,可以高效的、活性可控的聚合异腈单体[2]。本文中,我们用（S）-或（R）-2,2,-双（二苯膦）-1,1,-联萘作为手性配体,钯（II）配合物作为引发剂,形成含有手性的钯配合物,这种手性的钯配合物可以有效引发苯基异腈的聚合。通过改变单体和催化剂比例,我们可以有效控制所得聚合物的分子量,且分子量分布较窄。此外,利用圆二色光谱,我们发现形成的聚苯基异腈具有一定的光学活性,说明利用BINAP上的手性单元,可以合成X螺旋为主导的聚异腈。这在合成构建单一螺旋方向的螺旋聚合物上,具有一定的指导作用。

单分子磁体是一类在冻结温度以下可以表现超顺磁性质的单分子化合物。自从第一例单分子磁体Mn12OAc在1990年代被发现以来1,其独特的磁性质和在信息存储以及量子计算机潜在的应用吸引了化学家、物理学家和材料学家的广泛关注。近些年来,手性分子基磁体的研究引起了合成磁化学家的研究兴趣,手性磁体是一类同时具有磁性质和光学性质的分子基材料2。在手性磁体的合成研究中,一种实用的途径是对映选择性的合成手性配体,通过形成配合物将手性信息转移和放大到顺磁金属离子的配位环境中。在工作中,我们利用一类手性Schiff碱配体构筑了一系列具有优异磁性质的手性簇合物,包括:（1）立方体结构的手性Cu II4O4簇3;（2）四个Fe III离子呈中心三角形排列的Fe III4单分子磁体4;（3）边上三个抗磁Co III离子与中心顺磁Co II离子呈中心三角形排列的Co IICo III3单离子磁体5。在该系列配合物中,分子的磁各向异性可以通过配体的结构修饰得到显著的调控。

New synthetic methods are of great significance in enabling access to valuable compounds and materials. Although conjugated poly(3-hexylthiophene) (P3HT) has been widely investigated, P3HT copolymers containing functional groups (such as amino, imino, hydroxyl, etc.) are rarely reported because of inherent synthetic difficulties. Here P3HT copolymers bearing diverse functional pendants, which cannot be obtained by the direct block copolymerization of the corresponding monomers, were designed and facilely synthesized through the postpolymerization modification method. First, P3HT-b-poly(phenyl isocyanide) (P3HT-b-PPI) with pentafluorophenyl (PFP) ester was prepared in one-pot using Ni(dppp)Cl₂ as the catalyst. Then, through the postpolymerization modification of the copolymer with alcohols and amines, P3HT-b-PPIs copolymers bearing defined functional groups were facilely obtained. The introduction of functional pendants endowed P3HT-b-PPIs copolymers with diverse functionalities. When pyrene pendants were introduced into PPI block, the obtained copolymer presented both aggregation-induced emission (AIE) and aggregation-caused quenching (ACQ) properties when methanol was added into its THF solution. As for the copolymer containing chiral pendants, an excess of right-handed helix of the PPI backbone was induced after annealing in toluene at 100 °C for 7 days, and left-handed helical bundles were formed by the self-assembly of the annealed copolymer in THF. Meanwhile, the copolymer containing PEG pendants was amphiphilic and could self-assembled into worm-like or spherical structures in different solutions. In addition, cross-linked P3HT-b-PPI was obtained after postpolymerization modification of P3HT-b-PPI copolymer with glycol.
© 2018 American Chemical Society.

We herein report on the synthetic, structural, magnetic, and computational studies of six air-stable mononuclear Co(ii) complexes with distorted octahedral geometry from PyBox type ligands. Magnetic and theoretical studies reveal that these complexes all exhibit field-induced type single-molecule magnet behaviour and a large energy splitting between the ground and first excited Kramers doublets. Dynamic magnetic property analysis shows that the Raman relaxation process is the predominant process in all six compounds. For complexes 1, 2, 3, 5, and 6, the contribution of the direct process also existed. Importantly, the axial zero-field splitting parameter D in this series varies from positive to negative with the increased distortion of the octahedral geometry for the Co(ii) center, indicating that the fine-tuning of the molecular symmetry is an effective approach to manipulate the magnetic anisotropy in SIMs.
© 2017 the Partner Organisations.

Two pseudotetrahedral cobalt(II) complexes exhibiting slow magnetic relaxation under an applied direct-current field are investigated. The weak easy-plane anisotropy is accurately determined by high-field/high-frequency electron paramagnetic resonance spectroscopy as D = 2.57 cm(-1) and E = 0.82 cm(-1) for 1 and D = 5.56 cm(-1) and E = 1.05 cm(-1) for 2. In addition, hysteresis loops are observed for the two compounds at very low temperatures.

We herein report a "grafting from" strategy to immobilize optically active helical poly(phenyl isocyanide)s onto graphene oxide (GO) nanosheets. After covalently bounding alkyne-Pd(II) initiator onto GO nanosheets, the designed GO/polymer composites P1@GO and P1-b-P2@GO featuring single-handed helical poly(phenyl isocyanide)s growing from GO nanosheets were prepared by sequential addition of the chiral and achiral isocyanide monomers. Post-synthetic hydrolysis rendered P1-b-P3@GO to improve the hydrophilicity. The successful covalent bonding of poly(phenyl isocyanide)s chains onto GO nanosheets was certified by several cross evidences including scan emission microscopy, atomic force microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis. Circular dichroism spectra proved that the chiral information was introduced through the grafted single-handed helical polymer chains successfully. In addition, the resulting GO/polymer composites were explored as a chiral additive to induce enantioselective crystallization of racemic organic molecules. Preferential formation of rod-like L-alanine crystals was induced by composites bearing right-handed helical poly(phenyl isocyanide)s. The enantiomeric excess value of the induced crystals reached 76%, displaying the potential in future applications. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 2092–2103.
© 2017 Wiley Periodicals, Inc.