NMR研究N-甲基咪唑与双过氧钒配合物的相互作用

为探讨过氧钒配合物上有机配体对反应平衡的影响, 在模拟生理条件下(0.15 mol/L NaCl溶液), 应用多核(¹H, ¹³C和⁵¹V)多维(COSY) NMR以及变温技术等谱学方法研究双过氧钒配合物[OV(O₂)₂LL']ⁿ− [n＝1～3, LL'＝oxalate (缩写为oxa)、picolinate(缩写为pic)、bipyridine(缩写为bipy)和1,10-phenanthroline(缩写为phen), 与它们配位的含钒物种分别缩写为bpV(oxa), bpV(pic), bpV(bipy)和bpV(phen)]与N-甲基咪唑(缩写为N-Me-Im)的相互作用, 实验结果表明N-Me-Im与4种双过氧钒配合物的反应活性从强到弱的顺序为: bpV(oxa)＞bpV(pic)＞bpV(bipy)＞bpV(phen). 研究表明金属中心上配体的配位能力和空间位阻都对反应平衡产生较大的影响, 同时竞争配位的结果导致新的过氧物种[OV(O₂)₂(N-Me-Im)]⁻的生成, 而利用上述谱学方法则有助于揭示此类相互作用体系的反应过程和配位方式.     

香草醛缩多胺Schiff碱Co(II)配合物固相合成及氧合性能研究

采用固相反应合成了三个新的席夫碱钴(II)配合物, 在室温下, 将其与O₂作用, 1 mol配合物吸收2 mol O₂, 得到三种固态氧合配合物[Co•(L₁)₂•(O₂)₂](NO₃)₂•2H₂O [L₁＝N,N-二(4-羟基-3-甲氧基苯亚甲基)二乙烯三胺], [Co•(L₂)₂•(O₂)₂](NO₃)₂•2H₂O [L₂＝N,N-二(4-羟基-3-甲氧基苯亚甲基)三乙烯四胺]和[Co•(L₃)₂•(O₂)₂](NO₃)₂•2H₂O (L₃＝N,N-二(4-羟基-3-甲氧基苯亚甲基)四乙烯五胺]. 通过元素分析、红外光谱、核磁共振氢谱(¹H NMR), TG/DTA、摩尔电导率、紫外等测试手段确定了氧合配合物的组成. 采用失重法测定了氧合配合物中的配位氧, 确定1 mol钴配合物吸收2 mol O₂, 其中1 mol O₂用来和钴离子配位形成超氧配合物.     

具有C2对称的氮磷-氧磷配体双噁唑啉磷乙烷的合成及在不对称催化加氢中的应用

利用易得的光学纯N-甲基氨基醇与1,2-双(二氯磷)乙烷缩合合成了一类新的具有C₂对称轴的氮磷-氧磷配体(R,R)-双噁唑啉磷乙烷(BOAPE) 1～4. 该类配体不仅具有C₂对称结构和刚性五元环, 还具有富电子特性, 利用500 MHz进行了¹H NMR, ³¹P NMR, ¹³C NMR表征. 与这些配体配位形成的Rh配合物用于N-苯甲酰基脱氢丙氨酸衍生物和α-功能化酮不对称加氢, 分别可以得到99%和98%的ee. 这类配体比它们相对应的非C₂对称的氮磷-氧磷化合物(AMPP)配体具有更高的对映选择性. 在这四个新的配体中配体(R,R)-Ph-BOAPE (2)的催化性能最优. 催化剂[Rh(COD)(R,R)-Ph-BOAPE]BF₄的半反应周期t_1/2和周转频率(TOF)在N-苯甲酰基肉桂酸甲酯的不对称加氢反应中分别为12 min和6.5 min^－1.     

新型手性N,N′-双支套索冠醚的合成及其应用

(S)-苯丙氨醇和原氯乙酸三乙酯作用得到的手性酰胺醇和手性噁唑啉分别与1,7-二氮-12-冠-4反应, 得到了两种手性N,N′-双支套索冠醚N,N′-二[(S)-N-(1-羟甲基-2-苯基乙基)乙酰胺-2]-1,7-二氮-12-冠-4 (1a)和N,N′-二[(S)-4-苄基-噁唑啉-2-亚甲基]-1,7-二氮-12-冠-4 (1b). 前者应用于D/L-肉碱的手性分离; 后者的铜配合物用于重氮醋酸酯对烯烃的不对称环丙烷化反应.     

N-皮考林酰肼及其双核钯配合物的晶体结构和荧光性质

合成了配体N-皮考林酰肼(简写为Hphz)及其双核钯配合物[Pd₂(phz)₂Cl₂]. X射线衍射实验结果表明, 配体和配合物晶体均属于单斜晶系, 空间群分别为C 2/c和P 2₁/c, 分子式分别为C₆H₇N₃O和C₁₂H₁₂Cl₂N₆O₂Pd₂. 晶体学参数, Hphz, a＝1.9245(2) nm, b＝0.38927(2) nm, c＝1.8073(2) nm, b＝107.255(2)°, V＝1.2931(2) nm³, Z＝8, D_c＝1.409 Mg/m³, F(000)＝576, μ(Mo Kα)＝0.102 mm^－1, R＝0.0541, wR＝0.1762; [Pd₂(phz)₂Cl₂], a＝1.48274(9) nm, b＝1.44797(9) nm, c＝0.73951(5) nm, b＝92.719(3)°, V＝1.5860(2) nm³, Z＝4, D_c＝2.329 Mg/m³, F(000)＝1072, μ(Mo Kα)＝2.62 mm^－1, R＝0.0262, wR＝0.0555. 在配合物[Pd₂(phz)₂Cl₂]分子内, 两个钯(II)原子, 均呈畸变的N₃Cl平面正方形配位构型, 晶体内通过分子间氢键N—H…Cl 作用形成一维链状结构, 分子间吡啶环存在相互作用. 量子化学从头算方法计算结果表明, 分子内及分子间的金属钯之间也存在相互作用. 红外光谱表明, 配体在形成配合物后, ν(C＝O)和ν(C＝N)红移, ν(C—N)蓝移, 荧光光谱表明, 配合物金属对配体n-π*激发(310 nm)引起的发射峰有较大的影响.     

[1-芳基甲羰基-2-(1,2,4-三唑-1-基)]乙基-N,N-二烷基二硫代氨基甲酸酯衍生物的合成、结构表征及生物活性研究

以芳香基三唑类杀菌剂三唑酮为先导物设计并合成了5个含N,N-二烷基二硫代氨基甲酸酯的芳香三唑类化合物, 通过元素分析、红外光谱、核磁共振氢谱和质谱对其结构进行了表征. 用X射线单晶衍射测定了[α-(4-甲氧基苯甲酰基)-2-(1,2,4-三唑-1-基)]乙基-N,N-二甲基二硫代氨基甲酸酯的晶体结构, 晶体属于三斜晶系, 空间群, 晶胞参数为: a＝0.73482(15) nm, b＝1.1051(2) nm, c＝1.1209(2) nm, α＝90.32(3)°, β＝101.97(3)°, γ＝105.13(3)°, V＝0.8578(3) nm³, Z＝2, D_c＝1.357 g/cm³, F(000)＝368, µ＝0.324 mm^－1. 生物测试结果显示这5种有机化合物都具有杀菌性和植物生长调节活性     

Li＋在基于N,N-二甲基甲酰胺混合溶剂中的溶剂化

利用红外和拉曼光谱技术研究了Li^＋在不同浓度、不同溶剂组成的LiBF₄/N,N-二甲基甲酰胺-乙腈、LiBF₄/N,N-二甲基甲酰胺-四氢呋喃电解质溶液中的优先溶剂化现象. 红外和拉曼光谱的分析表明, Li^＋主要与DMF分子相互作用, 导致该分子的C＝O伸缩振动谱带、N—C＝O形变谱带、CH₃摇摆谱带等发生了分裂. Li^＋与其它溶剂分子的相互作用较弱, 谱带的分裂现象并不明显. Li^＋溶剂化数的计算显示, Li^＋第一溶剂化层内DMF分子的数目一般大于2, 这说明 Li^＋在混合溶剂体系内优先与DMF分子相互作用. 量子化学计算支持了这一结论.     

N-烷基-N-酰基磺酰胺聚苯乙烯基微球作为固相酰化剂的研究

一种可循环使用的固相试剂：N-烷基-N-酰基磺酰胺聚苯乙烯基微球(5), 通过对聚苯乙烯磺酰氯微球树脂进行两步功能基化的修饰反应来制备. 制备过程如下：聚苯磺酰氯树脂(1)与伯胺(2)反应得到聚苯乙烯基N-烷基磺酰胺树脂(3), 树脂3用酰氯(4)或酸酐酰化得到N-烷基-N-酰基磺酰胺聚苯乙烯基树脂(5). 酰化的树脂5作为酰基转移试剂与亲核试剂胺反应得到二级酰胺. 根据5上取代基对酰胺生成的程度的影响结果表明, 烷基R¹和酰基(R²CO)对酰基转移反应活性的大小依次分别为：苯基＞苄基＞甲基＞正丁基＞＞H和对硝基苯甲酰基(苯甲酰基＞乙酰基. 胺的亲核能力对酰胺的收率也有一定的影响. N-苯基-N-苯甲酰基磺酰胺树脂重复使用3次没有发现活性降低.     

1,3-二(乙氧基甲基)-5-N,N-二甲氨基-6-甲基尿嘧啶的合成

报道了1,3-二(乙氧基甲基)-5-N,N-二甲氨基-6-甲基尿嘧啶方便、高产率的合成方法. 以6-甲基尿嘧啶(1)为起始物, 经硝化、嘧啶N¹,N ³-烷基化、还原及氨基甲基化, 首次高产率合成了1,3-二(乙氧基甲基)-5- N,N -二甲氨基-6-甲基尿嘧啶(5), 并对其化学结构进行了表征.     

三个新的海绵Spongia suriganensis神经酰胺

报道从中国南海硇洲岛产海绵Spongia suriganensis的乙醇浸提物中分离得到3个新的同系列神经酰胺2-N-(1,3,4-三羟基-17-甲基)十八烷基-2'-羟基-18-甲基二十碳酰胺(1), 2-N-(1,3,4-三羟基-17-甲基)十八烷基-2'-羟基-19-甲基二十一碳酰胺(2)和2-N-(1,3,4-三羟基-17-甲基)十八烷基-2'-羟基-20-甲基二十二碳酰胺(3), 其结构经过MS, IR, ¹H NMR, ¹³C NMR (DEPT), HMQC及HMBC等现代光谱手段和水解化学方法来确定.     

NMR studies on interactions between diperoxovanadate and picolinamide-like ligands

To understand the effects of picolinamide-like ligands on reaction equilibrium, a series of picolinamide derivatives were synthesized and the interactions between the diperoxovanadate complex [OV(O₂)₂L]^? (L = D₂O or HOD, abbr. bpV) and picolinamide ligands in solution were explored using multinuclear (¹H, ¹³C, and ⁵¹V) magnetic resonance, COSY, and HSQC in 0.15 mol L^?1 NaCl ionic medium for mimicking physiological conditions. Formation constants among the picolinamide-like ligands are N-(1-hydroxypropan-2-yl)-picolinamide ≈N-(2-hydroxypropyl)-picolinamide>N-(3-hydroxypropyl)-picolinamide>N-propyl-picolinamide. The substituting group influences the equilibrium by electronic effects. The interactions result in a series of new seven-coordinate diperoxovanadate species [OV(O₂)₂L′]^? (L′ = picolinamide-like ligands).     

NMR and theoretical study on the linking properties of peroxovanadium(V) complexes with the 3-aminomethyl-pyridine derivatives

To understand the substitution effects of 3-aminomethyl-pyridine on the reaction equilibrium, the interactions between a series of 3-aminomethyl-pyridine derivatives and peroxovanadium(V) complex [OV(O₂)₂(D₂O)]^?/[OV(O₂)₂(HOD)]^? in solution were explored by the combined use of multinuclear (¹H, ¹³C, and ⁵¹V) magnetic resonance spectroscopy together with HSQC in 0.15 M NaCl ionic medium for mimicking the physiological conditions. Some direct NMR data are given for the first time. The relative reactivity among the 3-aminomethyl-pyridine derivative ligands are N-(pyridin-3-ylmethyl)acetamide (1) ≈ N-(pyridin-3-ylmethyl)propionamide (2) > N-(pyridin-3-ylmethyl)pivalamide (3) > t-butyl(pyridin-3-ylmethyl)carbamate (4). The competitive coordination results in the formation of a series of new six-coordinate peroxovanadium species [OV(O₂)₂L]^? (L = 1–4). The results of density functional calculations indicated that the solvation effects play an important role in these reactions, providing a reasonable explanation on the relative reactivity of the 3-aminomethyl-pyridine derivatives.     

NMR and theoretical study on the interaction between diperoxovanadate and 3-picoline derivatives

To understand the substituent effects of 3-picoline derivatives on reaction equilibrium, the interactions between a series of 3-picoline-like ligands and [OV(O₂)₂(D₂O)]^?/[OV(O₂)₂(HOD)]^? in solution were explored by multinuclear (¹H, ¹³C, and ⁵¹V) magnetic resonance, COSY, and HSQC in 0.15 mol L^?1 NaCl ionic medium for mimicking physiological conditions. The relative reactivity among the 3-picoline derivatives is 3-methyl pyridine > nicotinate >nicotinamide > ethyl nicotinate. Competitive coordination results in the formation of a series of new six-coordinated peroxovanadate species [OV(O₂)₂L] ^{n ?} (L = 3-picoline derivatives, n = 1 or 2). Density functional calculations provide a reasonable explanation on the relative reactivity of the 3-picoline derivatives. Solvation effects play an important role in these reactions.     

NMR and theoretical study on the coordination interactions between peroxovanadium(V) complex and bisubstituted pyridine ligands

To understand the substitution effects of pyridine ligands on coordination equilibrium, the coordination interactions between a series of bisubstituted pyridine ligands and peroxovanadium(V) [OV(O₂)₂(D₂O)]^?/[OV(O₂)₂(HOD)]^? in solution have been investigated by multinuclear (¹H, ¹³C, and ⁵¹V) magnetic resonance and HSQC. A series of new six-coordinate peroxovanadate complexes [OV(O₂)₂L] ^{n ?} (L?=?2, 3, 4, n?=?1 or 3) have been observed, and the coordination ability of the bisubstituted pyridines to peroxovanadium(V) is 3,4-dimethylpyridine (2)?>?3,5-dimethylpyridine (3)?>?pyridine-3,5-dicarboxylate (4)???2,3-dimethylpyridine (1). The coordination interactions among title system have been further studied by DFT (density functional theory) calculations, and the results indicate that solvent may play an important role in these coordination interactions.     

NMR and theoretical study on interactions between diperoxovanadate complex and pyrazole-like ligands

To understand the effects of pyrazole substitution on reaction equilibrium, the interactions between a series of pyrazole-like ligands and [OV(O₂)₂(D₂O)]^?/[OV(O₂)₂(HOD)]^? were explored by using multinuclear (¹H, ¹³C, and ⁵¹V) magnetic resonance, HSQC, and variable temperature NMR in 0.15 mol/L NaCl ionic medium mimicking physiological conditions. These results show that the relative reactivities among the pyrazole-like ligands are 3-methyl-1H-pyrazole ≈ 4-methyl-1H-pyrazole ≈ 1H-pyrazole > 1-methyl-1H-pyrazole. As a result, the main factor which affects the reaction equilibrium is the steric effect instead of the electronic effect of the methyl group of these ligands. A pair of isomers has been formed resulting from the coordination of 3-methyl-1H-pyrazole and a vanadium complex, which is attributed to different types of coordination between the vanadium atom and the ligands. Thus, the competitive coordination leads to the formation of a series of six-coordinate peroxovanadate species [OV(O₂)₂L]^? (L, pyrazole-like ligands). Moreover, the results of density functional calculations provided a reasonable explanation on the relative reactivity of the pyrazole-like ligands as well as the important role of solvation in these reactions.     

Multinuclear NMR and theoretical investigation on interactions between diperoxovanadate complex and 4-picoline-like ligands

To understand the 4-substituting group effects of organic ligands in pyridine ring on the reaction equilibrium, the interactions between a series of 4-picoline-like ligands and [OV(O₂)₂(D₂O)]^?/[OV(O₂)₂(HOD)]^? in solution were explored by the combined use of multinuclear (¹H, ¹³C, and ⁵¹V) magnetic resonance, DOSY, and variable-temperature NMR in 0.15 mol/L NaCl ionic medium for mimicking the physiological condition. Some direct NMR data are given for the first time. The reactivity among the 4-picoline-like ligands is 4-picoline > isonicotinate > isonicotinamide > ethyl isonicotinate. The competitive coordination results in the formation of a series of new six-coordinated peroxovanadate species [OV(O₂)₂L]^n? (L = 4-picoline-like ligands, n = 1 or 2). The results of density functional calculations provide a reasonable explanation on the relative reactivity of the 4-picoline-like ligands. Solvation effects play an important role in these reactions.     

双过氧钒配合物与3-取代吡啶相互作用的NMR研究

为探讨有机配体上取代基团对反应平衡的影响, 在模拟生理条件下(0.15 mol/L NaCl溶液), 应用多核(1H、13C和51V)多维(DOSY)以及变温NMR技术研究双过氧钒配合物[OV(O2)2(D2O)]－/[OV(O2)2(HOD)]－(简写为dpV)与3-取代吡啶的相互作用, 并首次报道了一些物种的NMR化学位移. dpV与有机配体的反应性从强到弱的顺序为: 吡啶＞烟酸 根＞烟酸甲酰胺≈烟酸甲酯, 这说明吡啶环上取代基影响反应平衡. 竞争配位导致一系列新的6配位的过氧钒物种生成. 密度泛函计算结果合理地解释了实验结果, 并表明溶剂化效应在反应中起重要作用.     

NMR and theoretical study on interactions between diperoxovanadate complex and 4-substituted pyridines

To understand the substituting group effects of organic ligands on the reaction equilibrium, the interactions between diperoxovanadate complex [OV(O2)2(D2O)]-/[OV(O2)2(HOD)](-) and a series of 4-substituted pyridines in solution were explored using multinuclear (1H, 13C, and 51V) magnetic resonance, DOSY, and variable temperature NMR in 0.15 mol/L NaCl ionic medium for mimicking the physiological condition. Some direct NMR data are given for the first time. The reactivity among the 4-substituted pyridines is pyridine > isonicotinate > N-methyl isonicotinamide > methyl isonicotinate. The competitive coordination results in the formation of a series of new six-coordinated peroxovanadate species [OV(O2)2L](n-) (L = 4-substituted pyridines, n = 1 or 2). The results of density functional calculations provide a reasonable explanation on the relative reactivity of the 4-substituted pyridines. Solvation effects play an important role in these reactions.     

Investigation on the complex of diperoxovanadate with picolinamide

A novel diperoxovanadate complex NH₄[OV(O₂)₂(picolinamide)]·H₂O was synthesized from aqueous solution under physiological conditions. The solution structure of the complex was characterized by multinuclear (¹H, ¹³C, ¹⁴N, and ⁵¹V), variable temperature as well as two-dimensional (DOSY) NMR techniques in the interaction system of NH₄VO₃/H₂O₂/picolinamide at room temperature. The crystal structure of the complex was determined at 223 K by single-crystal X-ray diffraction method. It belongs to the monoclinic space group P21/c with a = 7.323(3) Å, b = 14.255(7) Å, c = 10.022(5) Å, β = 99.524(9)°, V = 1031.7(8) Å³, and Z = 4. The crystal is composed of ammonium ions, picolinamide oxodiperoxovanadate(V) ions, and water molecules, which are held together by ionic and hydrogen bond forces. The species [OV(O₂)₂(picolinamide)]⁻ is seven-coordinated with a distorted pentagonal bipyramidal geometry both in solution and in crystal.