化学键是整个化学领域的核心概念之一，但必须清楚的是，化学键是人为抽象出来的概念，而不是物理现实。为正确描述化学键，历史上各种化学键模型或者理论被提出，其中基于经验规则的电子对成键模型和杂化轨道理论目前最广为接受。然而，经验规则毕竟有其适用范围，譬如对于超价分子的解释就存在不合理之处。我们建议在教学中以超价分子为例，对低年级学生明确指出经验规则在化学成键描述中的不足，高年级时运用分子轨道理论或现代价键理论开展成键分析的专题讨论。期望学生在掌握化学键概念的同时，对分子成键行为的见解持开放态度，培养其科学求知的精神。

通过自由基途径的烯烃1,2-双官能团化反应是有机合成中从烯烃直接构建C—X (X = C, N, O…)键的重要手段，其优点包括良好的区域选择性、步骤经济性和原子经济性，符合绿色化学的发展要求。含有碳-氧键的有机功能化合物种类很多，发展简单高效构建碳-氧键的合成方法是有机化学家广泛关注的研究领域。本文综述了在构建碳-氧键的同时，构建碳-碳键、碳-氮键、碳-硫键和碳-卤键的反应研究进程，并对该领域的未来发展方向进行了展望。

铬族元素的Cr₂、Mo₂、W₂基团具有相对稳定性，科学家对此做了实验验证和理论计算，试图找出原因。本文梳理了相关研究脉络及最新进展，从“它们的成键方式如何？”以及“可以怎样被进一步稳定？”两个问题出发，对铬族元素中的双原子基团六重键作用进行了分析、归纳和讨论。作者认为，Cr₂、Mo₂、W₂基团的不稳定性来源于两原子间密集电子的斥力；因此，各种稳定该基团的方法本质上都是从减小电子密度、解决电子斥力入手。

超大硅胺基取代的低价锗化合物可以构建新颖的化学结构，提供有学术价值的新发现。二配位的超大硅胺基氯锗宾Ge(N(SiⁱPr₃)₂)Cl (1)具有空的4p轨道和孤电子对。针对这2个特点，研究了化合物1的热构型转换和菲醌氧化加成反应。1的温热分解生成了立方四锗卡宾Ge₄(NSiⁱPr₃)₄ (2)，与菲醌(L)定量氧化加成生成了胺基一氯菲二酚合锗(IV)：[Ge(N(SiⁱPr₃)₂)(L)Cl] (3)。表征了2个产物的单晶结构与组成。四锗卡宾2本质上是锗异腈的四聚体，分子呈现出畸变的立方体构型，4个Ge原子和4个N原子构成了中心立方体的8个顶点。其中Ge—N键长为0.203 6(3) nm，N—Ge—N与Ge—N—Ge的键角分别为85.51(18)°和94.32(16)°，立方体的侧面接近平行四边形。理论计算首次揭示了四锗卡宾2的成键面貌。自然键轨道(NBO)给出Ge₄N₄骨架上的20个分子轨道。轨道定域化的计算结果完好地呈现出4对Ge孤对电子、12个Ge—N键和4个Si—N键的定域轨道，能量分别为-12.22、-15.12和-20.12 eV。Ge孤对电子主要保留了4s电子的特性，而Ge—N键主要由N的2s轨道(18.4%)和2p轨道(71.3%)、Ge的4s轨道(0.75%)和4p轨道(9.43%)综合贡献形成。在化合物3的分子中，Ge^Ⅳ采取sp³杂化，由于空间位阻与非对称配位，与另外4个配位原子形成非对称四面体构型。

To expand the study on the structures and biological activities of the anthracyclines anticancer drugs and reduce their toxic side effects, the new anthraquinone derivatives, 9-pyridylanthrahydrazone (9-PAH) and 9, 10-bispyridylanthrahydrazone (9, 10-PAH) were designed and synthesized. Utilizing 9-PAH and 9, 10-PAH as promising anticancer ligands, their respective copper complexes, namely [Cu(L1)Cl₂]Cl (1) and {[Cu₄(μ₂-Cl)₃Cl₄(9, 10-PAH)₂(DMSO)₂]Cl₂}_n (2), were subsequently synthesized, where the new ligand L1 is formed by coupling two 9-PAH ligands in the coordination reaction. The chemical and crystal structures of 1 and 2 were elucidated by IR, MS, elemental analysis, and single-crystal X-ray diffraction. Complex 1 forms a mononuclear structure. L1 coordinates with Cu through its three N atoms, together with two Cl atoms, to form a five-coordinated square pyramidal geometry. Complex 2 constitutes a polymeric structure, wherein each structural unit centrosymmetrically encompasses two five-coordinated binuclear copper complexes (Cu1, Cu2) of 9, 10-PAH, with similar square pyramidal geometry. A chlorine atom (Cl2), located at the symmetry center, bridges Cu1 and Cu1A to connect the two binuclear copper structures. Meanwhile, the two five-coordinated Cu2 atoms symmetrically bridge the adjacent structural units via one coordinated Cl atom, respectively, thus forming a 1D chain-like polymeric structure. In vitro anticancer activity assessments revealed that 1 and 2 showed significant cytotoxicity even higher than cisplatin. Specifically, the IC₅₀ values of 2 against HeLa-229 and SK-OV-3 cancer cell lines were determined to be (5.92±0.32) μmol·L^-1 and (6.48±0.39) μmol·L^-1, respectively. 2 could also block the proliferation of HeLa-229 cells in S phase and significantly induce cell apoptosis. In addition, fluorescence quenching competition experiments suggested that 2 might interact with DNA by an intercalative binding mode, offering insights into its underlying anticancer mechanism.