4-二羟基硼酰苯丙氨酸与果糖结合物的结构特性研究

使用密度泛函方法对4-二羟基硼酰苯丙氨酸与果糖结合物的结构特性进行了理论计算,确定了3种稳定构型,分析了该结构具有良好水溶性的原因.计算结果表明,前2种结构的反应活性较强,而第3种结构中果糖的加入并未过多影响其化学活性,3种结构中果糖的加入只是改变了原有分子的极性,果糖部分容易从复合结构上脱落,因而起到了一个很好的类似催化剂的作用.     

羰基硼化合物B2n(CO)n (n＝1～6)的理论研究

运用密度泛函理论(DFT)的B3LYP/6-31G*方法, 对羰基硼化合物B_2n(CO)_n (n＝1～6)各种可能的结构进行了优化,对它们的几何构型、电子态、振动频率、核独立化学位移(NICS)和B₂CO的分子轨道进行了理论研究, 得到了B_2n(CO)_n (n＝1～6)结构的稳定性信息. 在它们的基态结构中, 羰基的配位方式是端配位(μ₁-CO), B_2n(CO)_n (n＝1～5)的基态构型是线形或平面结构, B₁₂(CO)₆的基态构型则较为复杂. B_2n(CO)_n (n＝1～3)的基态是三重态, B_2n(CO)_n (n＝4～6)的基态是单重态. 振动频率和轨道的研究为实验提供了重要的理论依据.     

硼中子捕获疗法中使用的1,2-C2B10H12异腈衍生物的结构和电子特性

利用密度泛函方法在B3LYP/6-31G(d)水平上对1,2-C2B10H12的两种异腈类衍生物的结构特性进行了研究. 结果表明, 1,2-C2B10H11NC的活性较强; 1,2-C2B10H11NC和1,2-C2B10H11CH2NC可以通过结构中的C4原子与过渡金属原子成键而形成碳硼烷异腈金属配合物. 1,2-C2B10H11NC和1,2-C2B10H11CH2NC的分子极性均比1,2-C2B10H12的弱, 这不利于它们在硼中子捕获疗法中的应用.     

α,ω-二(4-羟基丁基)二甲基硅氧烷低聚物的制备与研究

以二(4-羟基丁基)四甲基二硅氧烷(HT)为封端化合物,在催化剂四甲基氢氧化铵的催化下,八甲基环四硅氧烷(D4）开环聚合,制得α,ω-二(4-羟基丁基)二甲基硅氧烷低聚物(DMSO)。应用红外光谱、凝胶色谱和旋转粘度计等测试手段,研究了聚合温度、原料(HT和D4)配比以及催化剂除去方式等工艺条件对聚合反应和聚合产物分子量的影响。研究结果表明,聚合反应温度对聚合产物分子量没有明显的影响;HT为封端化合物,在聚合过程中起止链剂的作用,其在原料中所占比例越大,DMSO分子量越小,原料中D4含量越大,DMSO分子量越大;聚合反应完成后,应采用洗涤法去除催化剂,否则由于端羟基发生去水反应而失去端羟基,致使产率下降,甚至得不到预期的产物。研究表明DMSO通过端羟基形成氢键而聚集,使其黏度升高。DMSO分子量越小,氢键缔合作用越大。     

二安替比林基-4-羟基苯基甲烷及其与铬(Ⅵ)显色反应的研究

合成了二安替比林基-4-羟基苯基甲烷(DApHM),研究了它与铬(Ⅵ)的显色反应,建立了两个测定铬(Ⅵ)的新体系.在Mn(Ⅱ)和磷酸存在下,DApHM与 Cr(Ⅵ)反应生成橙红色产物,λ_max为435nm.CTMAB和Tween-80对该体系有明显增敏效果,其中CTMAB-DApHM-Cr(Ⅵ)体系ε为1.0 ×10~6;Tween-80-DApHM-Cr(Ⅵ)体系ε为6.9×10~5.Cr(Ⅵ)量在0.1～0.7μg/25mL间符合比尔定律.用于电镀废液和自来水中Cr(Ⅵ)的测定,结果满意.     

双-(取代)硼酸)-2-(取代)-8-羟基喹啉酯的结构研究

有机硼化合物是元素有机化合物的一个重要类别,早在1940年 Kruger 就提出在蛋白质中引入一定浓度的硼来作为医学上的一种疗法。六十年代以来化学家们合成了许多含硼的     

9-氯-9-硼芴与NaBH4反应的理论研究

采用密度泛函理论研究了9-氯-9-硼芴与NaBH₄反应的机理, 优化得到了10个中间体和12个过渡态, 并确定了可能的反应通道. 计算结果表明: 主反应通道包含了6个中间体和5个过渡态, 决速步活化能为80.35 kJ•mol^－1, 9-硼芴并非反应势能面上最稳定的中间体. 解释了实验上不能成功分离出稳定中间体9-硼芴的原因.     

9-氯-9-硼芴与NaBH4反应的理论研究

采用密度泛函理论研究了9-氯-9-硼芴与NaBH₄反应的机理, 优化得到了10个中间体和12个过渡态, 并确定了可能的反应通道. 计算结果表明: 主反应通道包含了6个中间体和5个过渡态, 决速步活化能为80.35 kJ•mol^－1, 9-硼芴并非反应势能面上最稳定的中间体. 解释了实验上不能成功分离出稳定中间体9-硼芴的原因.     

1-(4-安替比林偶氮)-2-羟基-4-二甲苯胺的合成及其与铜(Ⅱ)显色反应的研究

合成了新显色剂1-(4-安替比林偶氮)-2-羟基-4-二甲苯胺(APHMA),并研究了其与Cu(Ⅱ)的显色反应。在pH 4.0的HAc-NaAc缓冲介质中,APHMA与Cu(Ⅱ)生成2∶1稳定络合物,最大吸收波长为560 nm,摩尔吸光系数为2.36×104L.mol-1.cm-1,Cu量在0~1.0μg/mL内符合比耳定律。已用于食品中铜的分析。     

超声技术合成1,5-二-(4-羟基苯基)-1,4-戊二烯-3-酮

利用对羟基苯甲醛和丙酮为原料,以氯化氢气体为催化剂,超声波辐射下成功合成了1,5-二-(4-羟基苯基)-1,4-戊二烯3-酮(HPD).与传统方法相比,该方法具有反应时间短,操作简便及产率高等优点,并讨论了影响产率的因素.     

1,3-二氮杂薁类衍生物电子结构和光谱性质的理论研究

对1,3-二氮杂薁类衍生物采用密度泛函理论(DFT)在B3LYP/6-31G(d)的水平上进行了几何构型的全优化, 在此基础上探讨了分子结构和前线分子轨道能量等性质的变化规律, 采用含时密度泛函理论(TD-DFT)计算了分子的电子跃迁性质, 采用二维平面图和三维立体图来直观表示激发态的性质, 研究分子内电子转移特性. 跃迁密度矩阵的二维等高线图反映了电子-空穴相干性, 三维跃迁密度图反映了跃迁偶极矩的方向和强度, 三维电荷差异密度图说明了激发过程中分子内电子转移性质.     

C60异噁唑环衍生物的结构、电子光谱和非线性光学性质的研究

The AM1 semiempirical calculation method was employed to study the structures and electronic properties of a series of isoxazolo fullerene derivatives. Based on the AM1 geometry optimization, the electronic spectra of molecules were studied by using ZINDO/CIS methods. The results indicated the HOMO LUMO energy gaps of those isoxazolo fullerenes were lower than that of C60. There existed the intramolecular electron transfer from the additional section to C60 moiety. The electronic spectrum data showed that the exception of the absorption was beyond 400 nm.The results were in good accordance with the experiment results. Nonlinear optical susceptibilities α, β and γ of molecules were calculated according to Finite Field(FF)/AM1, and the influence of molecular structures on nonlinear optical properties was examined.     

Theoretical Studies on the Electronic Structures and Optical Properties of Tri-aryl End-capped Terthiophene Derivatives

The relationships between electronic structures and spectra properties are investigated by DFT/TDDFT for terthiophene derivatives, BMA‐3T (tri‐aryl amine end‐capped terthiophene), BBA‐3T (tri‐aryl amine and tri‐aryl boron end‐capped terthiophene) and BPB‐3T (tri‐aryl boron end‐capped terthiophene). The calculated results show that BMA‐3T, BBA‐3T and BPB‐3T have higher HOMO energy level and lower ionization potentials (IPs) than 3T. BMA‐3T has good hole injection ability and hole‐transport property as reported in experiment. The designed molecule of BBA‐3T and BPB‐3T own lower LUMO level and higher electron affinities (EAs) than BMA‐3T, which facilitate electron injection and improve their electron‐transport properties. Surprisingly, BPB‐3T has preferable charge equilibrium property since its hole reorganization energy (λ_h) is close to electron reorganization energy (λ_e). The ΔE (HOMO−LUMO) and E_g of these three derivatives are narrower compared to 3T, and the absorption as well as emission spectrum exhibited red‐shifts.     

噻唑衍生物电子光谱和二阶非线性光学性质的理论研究

采用量子化学密度泛函方法(DFT)在B3LYP/6-31G(d)水平上对有机二阶非线性光学生色团(E)-2-(5-(4-(双(4-甲氧苯基)氨基)苯乙烯基)噻唑-5)三氰乙烯(TPA-Ti2-TCV)(1)和(E)-2-(5-(4-(双(4-甲氧苯基)氨基)苯乙烯基)噻唑-2)三氰乙烯(TPA-Ti5-TCV)(2)进行几何构型的完全优化, 在优化所得构型的基础上, 采用含时密度泛函方法(TDDFT)在6-31G(d)基组水平上计算了电子吸收光谱的跃迁性质. 再采用有限场法(FF)在B3LYP/6-31G(d)水平上计算了分子的一阶超极化率β. 计算结果表明, 三芳胺在噻唑环上取代C5比取代C2有更大的一阶超极化率, 这是由于噻唑的区域化学性导致ΔE_HOMO-LUMO(TPA-Ti2-TCV)比ΔE_HOMO-LUMO(TPA-Ti5-TCV)大很多造成的.     

羧甲基壳聚糖衍生物及其振动光谱的理论研究

用量子化学从头算STO 3G法研究了羧甲基壳聚糖及其衍生物的结构和稳定性，计算结果表明:1)壳聚糖单体经羧甲基化后，得到2种可能的产物，其中羧甲基在壳聚糖单体2位氨基上的取代产物较6位羟基上的取代产物稳定； 2)以羧甲基壳聚糖为母体经加成反应，得到羧甲基壳聚糖衍生物（2 羟基 3 丁氧基）丙基 羧甲基壳聚糖的2个异构体， 其中构型1更稳定.在优化构型的基础上，计算所得的构型1的振动光谱与实验结果相吻合.     

四氢二嵌萘衍生物在不同环境中的电子结构及光谱特征的理论研究

采用密度泛函理论的B3LYP泛函和单激发组态相关方法(CIS)在6-31+G*基组水平下分别优化了四氢二嵌萘衍生物(THP)基态和第一单重激发态的结构,并在此基础上利用含时密度泛函理论计算了THP在不同环境中的电子结构和光谱性质.溶剂效应采用连续极化介质模型(PCM)计算.结构分析发现在酸性环境中,基态时THP二甲氨基上的N原子容易质子化.计算结果表明,尽管THP的第一单重激发态是一个电荷转移态,但是它本身并不发射双荧光.在酸性溶剂中,THP的双峰发射来源于两种物质:跃迁能为2.71eV的发射峰由激发的THP发射,而3.69eV的发射峰则来源于质子化的THP.根据计算结果,我们建议了THP在酸性溶剂中的激发与驰豫途径.理论预测的吸收和发射光谱与实验结果一致.     

The Role of Chemistry in the Development of Boron Neutron Capture Therapy of Cancer

A therapeutic method that selectively destroys malignant cells in the presence of normal cells is a highly valued goal of oncologists and the possible salvation of cancer patients afflicted with some incurable forms of the disease. Selective cell destruction is, in principle, possible with a binary therapeutic strategy based upon the neutron capture reaction observed with the ¹⁰B nucleus and a neutron of low kinetic energy (thermal neutron). This nuclear fission reaction produces both ⁴He and ⁷Li⁺ nuclei along with about 2.4 MeV of kinetic energy and weak γ-radiation. Since the energetic and cytotoxic product ions travel only about one cell diameter in tissue one may specify the cell type to be destroyed by placing innocent ¹⁰B nuclei on or within only the doomed cells. This article describes the current status of chemical research aimed at the eventual adoption of this therapeutic method (boron neutron capture therapy or BNCT). The multidisciplinary nature of this research effort involves chemistry, biology, nuclear physics, medicine, and related specialties. Methods devised for bringing ¹⁰B nuclei to tumor cells in therapeutic amounts are correlated with the structure of a generalized cell and the various cellular compartments available for boron localization. The synthesis methods employed for the creation of boron-containing biomolecules and drugs are presented along with representative data concerning their efficacy in tumor localization. The outlook for BNCT is especially bright at this time because of rapid developments in the fields of bioorganometallic chemistry, microbiology, immunology, and nuclear science, to name but a few. Very effective boron delivery vehicles have been demonstrated, and through the interaction of chemistry and biology these species are undergoing further improvement and evaluation of their suitability for BNCT.     

Boron complexes of S-trityl- -cysteine and S-tritylglutathione

S-Trityl- -cysteine and S-tritylglutathione have been converted to 1,3,2-oxazaborolidine-5-ones by reaction with B-methoxydialkylborane derivatives. The synthesis of dicyclohexyl[S-trityl-(R)-cysteinato-O,N]boron (2), diisopinocampheyl[S-trityl-(R)-cysteinato-O,N]boron (3) and 9-borabicyclo[3.3.1]non-9-yl[S-tritylglutathionato-O,N]boron (5), dicyclohexyl[S-tritylglutathionato-O,N]boron (6) and diisopinocampheyl[S-tritylglutathionato-O,N]boron (7) from S-trityl- -cysteine and S-tritylglutathione, respectively, with potential application in boron neutron capture therapy is reported. The structure of 9-borabicyclo[3.3.1]non-9-yl[S-trityl-(R)-cysteinato-O,N]boron 1 has been determined by X-ray diffraction.     

N－乙基吩噻嗪及其自由基正离子的结构和电子光谱的理论研究

用ＩＮＤＯ系列方法对Ｎ－乙基吩噻嗪及其自由基正离子进行了几何构型优化，得到中性分子为蝶状折叠形，自由基正离子为平面构型。以优化构型为基础计算其电荷密度、自旋密度、键序和电子光谱。对光谱进行理论指认并讨论了从中性分子到离子谱带红移的原因。理论计算结果均与实验结果一致。