金属离子与卟啉的嵌入反应动力学研究 4: Cu(II)Tβ-N-EAESPyP^4^+生成反应中的动力学盐效应

在不同离子强度的高氯酸钠水溶液中, 用分光光度法测量自由卟啉H2Ts-n-EAESPyPBr4(简记为H2P^4^+)与Cu(II)离子的配位反应动力学, 探讨高氯酸钠对Cu(II)离子嵌入自由卟啉反应的催化本质。在给定条件下, 高氯酸根与自由卟啉的缔合数n为1; 缔合平衡常数Ko=3.70±0.42dm^3.mol^-^1。配位反应实验动力学方程为d[Cu(II)P^4^+/dt=5.55×10^5γCu^2^+γH2P^4^+γ^8ClO4^-[ClO4^-]^3[Cu^2^+][H2P]总/(1.00+10^2^.^0^2{H^+}+10^4^.^3^6{H^+}^2, 反应的活化能E=53.30kJ.mol^-^1,活化焓变△H≠=50.31kJ.mol^-^1, 活化熵变△S≠=-77.65J.mol^-^1.K^-^1。提出了金属卟啉生成反应中的ClO4^-催化卟啉环变形的反应机理。     

金属离子与卟啉的嵌入反应动力学研究 4: Cu(II)Tβ-N-EAESPyP^4^+生成反应中的动力学盐效应

在不同离子强度的高氯酸钠水溶液中, 用分光光度法测量自由卟啉H2Ts-n-EAESPyPBr4(简记为H2P^4^+)与Cu(II)离子的配位反应动力学, 探讨高氯酸钠对Cu(II)离子嵌入自由卟啉反应的催化本质。在给定条件下, 高氯酸根与自由卟啉的缔合数n为1; 缔合平衡常数Ko=3.70±0.42dm^3.mol^-^1。配位反应实验动力学方程为d[Cu(II)P^4^+/dt=5.55×10^5γCu^2^+γH2P^4^+γ^8ClO4^-[ClO4^-]^3[Cu^2^+][H2P]总/(1.00+10^2^.^0^2{H^+}+10^4^.^3^6{H^+}^2, 反应的活化能E=53.30kJ.mol^-^1,活化焓变△H≠=50.31kJ.mol^-^1, 活化熵变△S≠=-77.65J.mol^-^1.K^-^1。提出了金属卟啉生成反应中的ClO4^-催化卟啉环变形的反应机理。     

气相中二氯苯的双电荷离子[C6H4CI2]^2+和[C6H3CI]^2+的动能谱研究

本文利用质量分析离子动能(MIKES)和碰撞诱导解离(CID)技术, 研究了邻、间、对二氯苯分子在电子轰击质谱(EIMS)中产生的[C6H4CI2]^2+和[C6H4CI]^2+双电荷离子的单分子电荷分离(CS)反应。根据测定和CS反应的动能释放值T和由此估算的反应过渡态的电荷间距的最小值R, 推测过渡态的结构。有趣的是, 可以利用双电荷离子[C6H4CI2]^2+的分解反应区分二氯苯的位置异构体。     

气相中二氯苯的双电荷离子[C6H4CI2]^2+和[C6H3CI]^2+的动能谱研究

本文利用质量分析离子动能(MIKES)和碰撞诱导解离(CID)技术, 研究了邻、间、对二氯苯分子在电子轰击质谱(EIMS)中产生的[C6H4CI2]^2+和[C6H4CI]^2+双电荷离子的单分子电荷分离(CS)反应。根据测定和CS反应的动能释放值T和由此估算的反应过渡态的电荷间距的最小值R, 推测过渡态的结构。有趣的是, 可以利用双电荷离子[C6H4CI2]^2+的分解反应区分二氯苯的位置异构体。     

苯二酚异构体双电荷离子和单电荷离子的动能谱研究

本文利用质量分析离子动能谱(MIKES)、碰撞诱导解离(CID)技术和电子捕获诱导解离(ECID)技术, 研究了邻、间、对苯二酚分子在电子轰击质谱(EIMS)中产生的双电荷离子[C6H6O2]^2^+, [C6H4O]^2^+和单电荷离子[C6H6O2]^+。根据测定的电荷分离反应动能释放值T和由此计算出的两电荷间距R, 推测出过渡态的结构。有趣的是, 可利用单电荷离子[C6H6O2]^+的MIKES/CID谱区分苯二酚异构体。     

环丙烷衍生物在CD3OD离子体系中的H/D交换反应

研究了环丙烷衍物生物在CD3OD离子体系中的H/D交换反应产物离子[M 1]^*,[M 2]^ 和[M 3]^*的碰撞诱民碎裂(CID)反应特征,实验结果表明这些产物离子是由反应物与试剂离子之间生H/D交换反应生成的,获得了环丙烷衍生物结构中活泼氢位置及其数量的信息.     

过渡金属离子与烷烃反应机理的理论研究: 镍离子与丙烷反应 中甲烷的还原消 除机理

用量子化学方法在B3LYP/6-311++g(3df,3pd)水平上研究了Ni^+与C3H8的反应,获得了[Ni,C3,H8]^+基态(双重态)势能面上CH4还原消除的详细机理。结果表明：该势能面上CH4消除反应经历两个基元步骤：Ni^+首先通过C—C活化过渡态形成插入型中间体,然后分别过不同的H-转移鞍点异构化为产物型中间体,并继而解离生成CH4,这些结果与以前从实验推测的反应机理明显不同。计算表明：对于该势面能上的甲烷消除反应,能量最有利的反应通道是Ni^+C3H8→Ni(C2H4)^++CH4,计算的反应热为127.85kJ/mol,与实验结果(106.13kJ/mol)符合较好。     

DBU及DBN与丙炔酸甲酯的迈克尔型加成及其产物的核磁共振谱学研究

1,8-二氮杂二环[5,4,0]十一碳-7-烯(DBU及1,5-二氮杂二环[4,3,0]壬碳-5-烯与丙炔酸甲酯反应可生成成环化合物。通过对成环产物的^1H NMR、^1H-^1H COSY、^13C NMR谱的分析,讨论了其化学位移及J-偶合特征。同时研究了整个反应可能的历程和机理。     

双－苯并噻唑非环冠醚的合成与表征

2-巯基苯并噻唑(MBT)与二溴缩甘醇在碳酸钾存在下发生S-烷基化反应生成双－苯并噻唑非环冠醚化合物1～4,并通过元素分析、IR、NMR(^1H,^13C)、MS波谱进行结构表征。     

含烯烃配体的过渡金属卡宾配合物的研究 XVI. 丁二烯-和异戊二烯二羰基[乙氧基(芳基)卡宾]铁配合物的异构化产物与三苯膦和亚磷酸三苯酯的反应研究

丁二烯二羰基[乙氧基(芳基)卡宾]铁配合物的异构化产物,C4H6(CO)2FeC(OC2H5)Ar(1,Ar=苯基, 2, Ar=对甲苯基),在己烷溶液中于-60到-40℃与三苯膦或亚磷酸三苯酯反应生产产物3-6。当1与三苯膦在己烷中于60-70℃反应时, 除了生成3外, 还获得双膦配位的产物7。而异戊二烯二羰基[乙氧基(芳基)卡宾]铁配合物的异构化产物与亚磷酸三苯酯反应则生成橙黄色结晶产物9,9的X射线衍射研究表明, 二烯配体的键型发生了有趣的变化, 即原铁配合物的π-烯丙基部分变为更有趣的含芳环的三烯体系和生成一个η^4配体以满足18电子规则。     

具有三维网络的新型配位聚合物[Nd(C7H6NO2)3.H2O]n的合成、结构和性质

以Nd(NO3).6H2O和NH2C6H4COOH为原料,经[Nd(C7H6NO2)3.H2O]的自组装,得到了具有三维网络结构的配位聚合物[Nd(C7H6NO2)3.H2O]n。该聚合物晶体属单斜晶系,空间群P2(1)/n,a=0.98069(5)nm,b=2.2736(2)nm,c=0.98254(8)nm,β=100.053(5)°,V=2.1571(3)nm^3,Z=4。最后的一致性因子R=0.038。磁性研究表明,该化合物在低温下表现出反铁磁性质。测定了化合物的UV-vis-NIR和IR光谱,进行了分析和指认。     

Thermische Zerfallsreaktionen von Nitroverbindungen in Stosswellen. III: Dissoziation von 1-Nitropropan und 2-Nitropropan

The pyrolysis of 1- and 2-nitropropane highly diluted in Ar has been studied in shock waves at temperatures K 915 < T < 1200 K and total gas concentrations 7 · 10^?6 mol cm^?3 < [Ar] < 1.5 · 10^?4 mol cm^?3. The reactions behind the shock waves have been followed by recording light absorption-time profiles of the decomposing molecules and the produced NO₂ Under the conditions of the experiments, the primary reaction step in both cases is the C? N bond:fission: \documentclass{article}\pagestyle{empty}\begin{document}$ \begin{array}{rcl} {\rm 1} - {\rm C}_{\rm 3} {\rm H}_{\rm 7} {\rm NO}_{\rm 2} {\rm (} + {\rm M)} &\to & n - {\rm C}_{\rm 3} {\rm H}_{\rm 7} + {\rm NO}_{\rm 2} {\rm (} + {\rm M)\quad k} = 2.3 \cdot 10^{15} {\rm exp }(- 55{\rm kcal mol}^{ - 1} /{\rm RT}){\rm s}^{ - 1} \\ 2 - {\rm C}_{\rm 3} {\rm H}_{\rm 7} {\rm NO}_{\rm 2} {\rm (} + {\rm M)} &\to & i - {\rm C}_{\rm 3} {\rm H}_{\rm 7} + {\rm NO}_{\rm 2} {\rm (} + {\rm M)\quad k} = 2.4 \cdot 10^{15} {\rm exp }(- 54{\rm kcal mol}^{ - 1} /{\rm RT}){\rm s}^{ - 1} \\ \end{array} $\end{document} (first order rate constants k measured at concentrations of [Ar] ? 10^?4 mol cm^?3). At these concentrations the reactions are near to the high pressure limit. By varying the Ar-concentrations over one order of magnitude, only a slight pressure dependence was found. Reaction mechanisms which account for NO₂ removal are discussed.     

New iridacyclohexadienes and iridabenzenes by [2+2+1] cyclotrimerization of alkynes and facile interconversion between iridacyclohexadienes and iridabenzenes

Iridabenzenes [Ir[=CHCH=CHCH=C(CH2R)](CH3CN)2(PPh3)2]2+ (R=Ph 4 a, R=p-C6H4CH3 4 b) are obtained from the reactions of H+ with iridacyclohexadienes [Ir[-CH=CHCH=CHC(=CH-p-C6H4R')](CO)(PPh3)2]+ (R'=H 3 a, R'=CH3 3 b), which are prepared from [2+2+1] cyclotrimerization of alkynes in the reactions of [Ir(CH3CN)(CO)(PPh3)2]+ with HC[triple chemical bond]CH and HC[triple chemical bond]CR. Iridabenzenes 4 react with CO and CH3CN in the presence of NEt3 to give iridacyclohexadienes [Ir[-CH=CHCH=CHC(=CHR)](CO)2(PPh3)2]+ (6) and [Ir[-CH=CHCH=CHC(=CHR)](CH3CN)2(PPh3)2]+ (7), respectively. Iridacyclohexadienes 6 and 7 also convert to iridabenzenes 4 by the reactions with H+ in the presence of CH3CN. Alkynyl iridacyclohexadienes [Ir[-CH=CHCH=CHC(=CH-p-C6H4R')](-C[triple chemical bond]CH)(PPh3)2] (8) undergo a cleavage of C[triple chemical bond]C bond by H+/H2O to produce [Ir[-CH=CHCH=CHC(=CH-p-C6H4R')](-CH3)(CO)(PPh3)2] (10) via facile inter-conversion between iridacyclohexadienes and iridabenzenes.     

A computational study of cycloaddition reactions of d8 metal tetroxide (iron, ruthenium, osmium) complexes with C60

The potential energy surfaces of the cycloaddition reactions MO(4)(NC(5)H(5))(2) + C(60)→ MO(4)(NC(5)H(5))(2)(C(60)) (M = Fe, Ru, and Os) have been studied at the B3LYP/LANL2DZ level of theory. It has been found that there should be two competing pathways in these reactions, which can be classified as a [6,5]-attack (path A) and a [6,6]-attack (path B). Our theoretical calculations indicate that, given the same reaction conditions, the cycloaddition reaction of C(60)via [6,6]-attack is more favorable than that via [6,5]-attack both kinetically and thermodynamically. This is in good agreement with the available experimental observations. A qualitative model, which is based on the theory of Pross and Shaik, has been used to develop an explanation for the barrier heights. As a result, our theoretical findings suggest that the singlet-triplet splitting ΔE(st) (= E(triplet)- E(singlet)) of the d(8) MO(4)(NC(5)H(5))(2) and C(60) species can be a guide to predict their reactivity towards cycloaddition. Our model results demonstrate that the reactivity of d(8) metal tetroxide cycloaddition to C(60) decreases in the order FeO(4)(NC(5)H(5))(2) > RuO(4)(NC(5)H(5))(2) > OsO(4)(NC(5)H(5))(2). In consequence, we show that both electronic and geometric effects play a decisive role in determining the energy barriers as well as the reaction enthalpy.     

[C6N2H18]2[Mo5O15(HPO4)2]·H2O的水热合成与结构表征

通过水热法合成了一个新化合物[C6N2H18]2[Mo5O15(HPO4)2]·H2O,并通过IR光谱、ICP、元素分析、差热与热重分析和X射线单晶衍射分析等手段进行了表征.结果表明,晶体属三方晶系,P3(2)21空间群,a=1.1231(1)nm,c=2.2802(5)nm,V=2.4911(7)nm3,Dx=2.835Mg/m3,Z=6,最后的一致性因子R=0.0227,wR=0.0675.阴离子中Mo5O15构成一环状结构,2个HPO4一个连在环的下方,一个连在环的上方,形成类似于“飞碟”状的结构,阳离子为2个质子化的四甲基乙二胺.     

Dienophilic behavior of the vinylic (C=C) and the carbonyl (C=O) bonds of ketenes in reactions with 1,3-diazabuta-1,3-dienes

[reaction: see text] Ab initio and density functional studies (DFT) on cycloaddition reactions of 1,3-diazabuta-1,3-dienes with ketenes are reported. The vinylic (C=C) and the carbonyl (C=O) units of the ketenes are found to participate in concerted asynchronous [4 + 2] cycloaddition reactions. The transition states (3t, 4t, and 7t) for these paths have been located on the PE surface at the correlated levels of ab initio calculations. A reasonable mechanism for the formation of [4 + 2] and [2 + 2] adducts is presented.     

Ring-opening protonolysis of sila[1]ferrocenophanes as a route to stabilized silylium ions

The ring-opening reactions of a series of sila[1]ferrocenophanes with protic acids of anions with various degrees of noncoordinating character have been explored. Ferrocenyl-substituted silyl triflates FcSiMe2OTf (5 a) and Fc(3)SiOTf (5 b) (Fc=(eta5-C5H4)Fe(eta5-C5H5)) were synthesized by means of HOTf-induced ring-opening protonolysis of strained sila[1]ferrocenophanes fcSiMe2 (3 a) and fcSiFc2 (3 b) (fc=(eta5-C5H4)2Fe). Reaction of 3 a and 3 b with HBF4 yielded fluorosubstituted ferrocenylsilanes FcSiMe2F (6 a) and Fc3SiF (6 b) and suggested the intermediacy of a highly reactive silylium ion capable of abstracting F- from the [BF4]- ion. Generation of the solvated silylium ions [FcSiMe2THF]+ (7a+), [Fc3SiTHF]+ (7b+) and [FcSiiPr2OEt2]+ (7c+) at low temperatures, by reaction of the corresponding sila[1]ferrocenophanes (3 a, 3 b, and fcSiiPr2 (3 c), respectively) with H(OEt2)(S)TFPB (S=Et2O or THF; TFPB=tetrakis[3,5-bis(trifluoromethyl)phenyl]borate) was monitored by using low-temperature 1H, 13C, and 29Si NMR spectroscopy. In situ reaction of 7a+, 7b+, and 7c+ with excess pyridine generated [FcSiMe2py]+ (8a+), [Fc3Sipy]+ (8b+), and [FcSiiPr2py]+ (8c+), respectively, as observed by 1H, 13C, and 29Si NMR spectroscopy. A preparative-scale reaction of 3 b with H(OEt2)(THF)TFPB at -60 degrees C and subsequent addition of excess pyridine gave isolable red crystals of 8b-[TFPB]CHCl3, which were characterized by 1H and 29Si NMR spectroscopy as well as by single-crystal X-ray diffraction.     

[60]富勒烯与1, 1'-联茚的Diels-Alder加成物的合成与结构表征

通过Diels-Alder环加成反应,发现可控制反应条件,使1,1'-联茚与C60反应,并高产率地得到具有新颖结构的单加成物。用HPLC,FT-IR,FD-MS及^1HNMR,^13CNMR,HMQC,HMBC等多种波谱技术对其结构进行表征,测得它的两个sp^3杂化的桥头碳的化学位移为σC:70.91,证明生成的衍生物为[6,6]闭式环加成。^13CNMR谱共给出38个信号,表明C601,1'-联茚衍生物分子具有Cs对称性;此外,还发现单加成衍生物C601,1'-联茚热稳定性好,在四氢呋喃、丙酮等极性溶剂中溶解性好,很适合于在LB膜及光限幅性能方面的研究。     

天然有机化合物X. 糖苷快原子轰击质谱中的碱金属加合离子应 用技术的研究

在对糖苷的FAB分析技术的研究中发现,如果在样品中同时加入适量的NaCl和LiCl水溶液进样时,其FAB谱中会出现[M+Na]^+和[M+Li]^+两个强峰,两峰之质量差为16(Na和Li原子量之差值),并且发现其谱图中找不到明显的碎片离子和Na^+及Li^+的加合离子,而只有糖苷分子和Na^+及Li^+的加合离子。所以很容易在FAB谱中识别它们。因而不需联谱解析而仅凭FAB谱就可准确、快速地定出糖苷的分子量。此技术国内外尚未见报道。     

二茂铁与HnXW12O40.mH2O(X=P,Si, Ge)电荷转移配合物的室温固相合 成与性质

用室温固相反应法合成了三种具有非线性光学性质的二茂铁-多金属氧酸盐电荷转移配合物[Fe(C5H5)2H]3PW12O40(Ⅰ),[Fe(C5H5)2H]4SiW12O40(Ⅱ)和[Fe(C5H5)2H]4GeW12O40(Ⅲ)。用元素分析、紫外漫反射电子光谱、红外光谱、穆斯堡尔谱、ESR、XRD、循环伏安等手段对其进行了表征和研究,确定了该配合物的组成与结构,结果表明二茂铁与杂多阴离子之间发生了电荷转移,在形成配合物过程中杂多阴离子发生单电子还原反应,生成了混合价化合物,非线性光学性质研究表明电荷转移配合物的倍频效应强度分别为IⅠ^2ω=0.27I~KDP,IⅡ^2ω=0.06I~KDP,IⅢ^2ω=0.10I~KDP;三阶非线性光学χⅠ^(3)=2.4×10^-^13esu,χⅡ^(3)=3.1×10^-^12esu,χⅢ^(3)=6.5×10^-^12esu.