二茂铁亚胺及其环汞化合物的薄层色谱及紫外—可见,红外光…

通过测定Ｒｆ值对比研究了二茂铁亚胺及其环汞化合物的色谱亲和性，发现环汞化合物比未汞化的二茂铁亚胺具有较高Ｒｆ值，并用Ｎ→Ｈｇ分子内配位作用给予解释，分析取代基效应表明，亚胺氮上电子密度越高，Ｒｆ值越小，紫外可见光谱表明，环汞化合物人子中存在有Ｎ→Ｈｇ分子内配位作用，研究了Ｎ－Ａｒ环和亚胺碳上的取代基效应对紫外光谱的影响，与Ｎ－Ａｒ环上无取代基时相比，π→πＣＴ跃进带的最大吸收波长移动值△λｍａｘ和     

二茂铁亚胺及其环汞化合物的薄层色谱及紫外-可见、红外光谱特征

通过测定R^f值对比研究了二茂铁亚胺及其环汞化合物的色谱亲和性,发现环汞化合物比未汞化的二茂铁亚胺具有较高的R_f值,并用N→Hg分子内配位作用给予解释。分析取代基效应表明,亚胺氮上电子密度越高,R_f值越小。紫外可见光谱表明,环汞化合物分子中存在有N→Hg分子内配位作用。研究了N-Ar环和亚胺碳上的取代基效应对紫外光谱的影响,与N-Ar环上无取代基时相比,π→π^*CT跃迁带的最大吸收波长移动值△λ_max和Hammett-Brown常数σ⁺之间存在良好的线性关系。考察了二茂铁红外光谱规则对所研究体系的适用情况。     

氮磷配位的钛酸酯络合物的X射线光电子能谱研究

制备了单烷基羧酸型和磺酸型钛酸酯氮配位与磷配位的配合物.用XPS法证明有N→Ti或P→Ti配位键生成,并从化学位移量推测了键的强度,磺酸型较羧酸型易配位,羟基取代胺的氮配体配位较容易发生;磷配位由于存在Ti→P的反馈作用,使化学位移不如氮配位明显.此外,异丙基钛酸酯与乙醇胺的反应物,证明分子内有N→Ti配位键生成.     

混合三聚反应及结构的研究 II: 单核及双核铁混合三聚反应的研究

通过甲酰基二茂铁与取代水杨醛和氨反应, 直接合成了含一个二茂铁的混合三聚产物, N,N'-二[2-羟基-5-取代苄烯]二茂铁甲二胺. 茂环上碳原子的化学位移^1^3C NMR与苯环上R取代基的Hammett常数之间存在着很好的线性关系. 循环伏安法测出的E1/2也与hammett常数之间存在着很好的线性关系. 通过混合三聚反应, 也合成了另一类含两个二茂铁化合物, N,N'-二[二茂铁甲烯]-2-羟基-5-特丁基苯甲二胺. ^1H及^1^3C NMR表明, 分子内由于氢键和立体效应的影响, 导致两个茂环上的化学环境不等性.     

混合三聚反应及结构的研究 II: 单核及双核铁混合三聚反应的研究

通过甲酰基二茂铁与取代水杨醛和氨反应, 直接合成了含一个二茂铁的混合三聚产物, N,N'-二[2-羟基-5-取代苄烯]二茂铁甲二胺. 茂环上碳原子的化学位移^1^3C NMR与苯环上R取代基的Hammett常数之间存在着很好的线性关系. 循环伏安法测出的E1/2也与hammett常数之间存在着很好的线性关系. 通过混合三聚反应, 也合成了另一类含两个二茂铁化合物, N,N'-二[二茂铁甲烯]-2-羟基-5-特丁基苯甲二胺. ^1H及^1^3C NMR表明, 分子内由于氢键和立体效应的影响, 导致两个茂环上的化学环境不等性.     

2,2'-联喹啉-4,4'-二羧酸构筑的一维钴(Ⅱ)配位聚合物

利用2,2'-联喹啉-4,4'-二羧酸钠(Na2bqdc),2,2-联吡啶与硫酸钴在溶剂热作用下合成了1个一维配位聚合物[Co(bqdc)(bipy)(H20)]n(1).通过元素分析、粉末衍射、红外、紫外光谱对配合物进行了表征,利用X射线单晶衍射仪测定了其晶体结构.中心CoⅡ离子分别与2个来自2,2-联喹啉-4,4-二羧酸钠配体的双齿羧基氧原子和1个来自配体的单齿羧基氧原子、辅助配体2,2-联吡啶上的2个N原子和1个水分子的氧原子配位,形成了1个稍微扭曲的八面体配位构型.紫外光谱实验表明,相对2,2'-联喹啉-4,4'-二羧酸钠配体,配合物的紫外光谱发生了少量的蓝移.对该配合物多晶样品的差热分析(TGA)表明该化合物在217℃后开始分解.     

2，2′-联喹啉-4，4′-二羧酸构筑的一维钴(Ⅱ)配位聚合物

利用2,2′-联喹啉-4,4′-二羧酸钠(Na2bqdc),2,2-联吡啶与硫酸钴在溶剂热作用下合成了1个一维配位聚合物[Co(bqdc)(bipy)(H2O)]n(1)。通过元素分析、粉末衍射、红外、紫外光谱对配合物进行了表征,利用X射线单晶衍射仪测定了其晶体结构。中心CoⅡ离子分别与2个来自2,2-联喹啉-4,4-二羧酸钠配体的双齿羧基氧原子和1个来自配体的单齿羧基氧原子、辅助配体2,2-联吡啶上的2个N原子和1个水分子的氧原子配位,形成了1个稍微扭曲的八面体配位构型。紫外光谱实验表明,相对2,2′-联喹啉-4,4′-二羧酸钠配体,配合物的紫外光谱发生了少量的蓝移。对该配合物多晶样品的差热分析(TGA)表明该化合物在217℃后开始分解。     

配合物Zn(II)-BPHA的^1H NMR谱

测定了各pD值下BPHA[BPHA是N,N'-bis(2-aminoethyl)-1,3-propanediaminehexaaceticacid的简称,中文名称为二胺乙基丙二胺六乙酸]和Zn^2^+-BPHA的^1HNMR谱。BPHA两端羧甲基上亚甲基质子的化学位移δ~a和中间羧甲基上亚甲基质子的化学位移δ~b随pD值交替变化。Zn^2^+-BPHA的^1HNMR谱有3种情况:pD<6,对应Zn(II)-H~2BPHA^4^-,有一特征尖峰,显示自由-NH^+(CH~2COO^-)~2残基存在;pD=6-9,对应Zn(II)-HBPHA^5^-,该峰消失,显示4个胺基全部配位;pD>9,对应Zn(II)-BPHA^6^-,该峰再次出现,1个N(CH~2COO^-)~2脱离配位体系。在3种形态的配合物中,Zn-N键都是非活性的,Zn-O键在后两种形态配合物中是非活性的。     

配合物Zn(II)-BPHA的^1H NMR谱

测定了各pD值下BPHA[BPHA是N,N'-bis(2-aminoethyl)-1,3-propanediaminehexaaceticacid的简称,中文名称为二胺乙基丙二胺六乙酸]和Zn^2^+-BPHA的^1HNMR谱。BPHA两端羧甲基上亚甲基质子的化学位移δ~a和中间羧甲基上亚甲基质子的化学位移δ~b随pD值交替变化。Zn^2^+-BPHA的^1HNMR谱有3种情况:pD<6,对应Zn(II)-H~2BPHA^4^-,有一特征尖峰,显示自由-NH^+(CH~2COO^-)~2残基存在;pD=6-9,对应Zn(II)-HBPHA^5^-,该峰消失,显示4个胺基全部配位;pD>9,对应Zn(II)-BPHA^6^-,该峰再次出现,1个N(CH~2COO^-)~2脱离配位体系。在3种形态的配合物中,Zn-N键都是非活性的,Zn-O键在后两种形态配合物中是非活性的。     

2-氨基-5-(对二甲氨基)苯基-1,3,4-噻二唑: Hg2+的选择性荧光传感分子

设计合成了结构简单的分子内电荷转移荧光传感分子1,3,4-噻二唑类衍生物(1), 实现了水-乙醇(体积比1∶9)混合溶剂中Hg2+的荧光猝灭型选择性灵敏传感, 荧光猝灭常数达5.5×105 mol-1·L, Hg2+线性响应范围为5.0×10-6～5.0×10-5mol/L. 基于等摩尔连续变化法、红外光谱和核磁滴定实验结果提出了传感分子1与Hg2+的1∶1型结合模式, 其中1-位S原子和2-位胺N原子为Hg2+配位原子; 结合光谱变化讨论了Hg2+结合显著增强分子内电荷转移的荧光猝灭机理.     

稀土单酞菁化合物的NMR研究

研究了从Sm^3^+到Lu^3^+(Gd^3^+除外)九个稀土单酞菁化合物的^1H NMR化学位移.发现对重稀土化合物,酞菁环上α、β质子诱导位移符号的变化呈现"三个一组效应".即,"Tb^3^+、Dy^3^+、Ho^3^+化合物,^1H共振谱线移向高场,而对Er^3^+、Tm^+^3、Yb^3^+化合物,则移向低场.化学位移的最大变化发生在4f^8构型(Tb^3^+)处.所得结果与Bleaney理论一致.测得部分稀土单酞菁化合物的^1^3C NMR谱,讨论了化学位移的变化.     

Paramagnetic NMR shift,spectroscopic and molecular modeling studies of lanthanide(III)-morin complexes

Studies on nine-coordinate lanthanide complexes of morin are described. The complexes were characterized by elemental analysis, molar conductance, UV–Vis spectra, IR spectra, thermal analysis and NMR spectra. Molecular modeling studies were also carried out. The complexes are non-electrolytes in DMSO. TGA showed anhydrous nature of the complexes. The electronic spectra of the complexes were recorded in methanol. ¹H NMR spectra of lanthanum, praseodymium, neodymium, samarium and dysprosium complexes have been studied in DMSO-d₆. The complexes do not dissociate in DMSO and retain their coordination. ¹H NMR spectra of paramagnetic and diamagnetic complexes exhibit downfield as well as upfield shifts of morin resonances that shows change in geometry during coordination.     

Mercury-199 NMR studies of thiacrown and related macrocyclic complexes: the crystal structures of [Hg(18S6)](PF6)2 and [Hg(9N3)2](ClO4)2

We wish to report the first measurements of (199)Hg NMR chemical shift data for a series of homoleptic Hg(II) complexes with thiacrown ligands and related aza and mixed thia/aza macrocycles. In mercury(II) complexes containing trithiacrown through hexathiacrown ligands, we observed (199)Hg NMR chemical shifts in the range of -298 to -1400 ppm. Upfield chemical shifts in these NMR spectra are seen whenever (a) the number of thioether sulfur donors in the complex is decreased, (b) a thioether sulfur donor is replaced by a secondary nitrogen donor, and (c) the size of the macrocycle ring increases without a change in the nature or number of the donor atoms. Changes in noncoordinating anions, such as hexafluorophosphate and perchlorate, have little effect on the (199)Hg chemical shift. For several complexes, we observed (3)J((199)Hg-(1)H) coupling in the range of 50-100 Hz, the first example of proton-mercury coupling through a C-S thioether bond. Also, we obtained unusual upfield (13)C NMR chemical shifts for methylene resonances in several of the thiacrown complexes which correspond to distortions within the five- and six-membered chelate rings bound to the mercury ion. We report the X-ray crystal structure of the complex [Hg(18S6)](PF(6))(2) (18S6 = 1,4,7,10,13,16-hexathiacyclooctadecane). The molecule crystallizes in the rare trigonal space group Pm1 with hexakis(thioether) coordination around the Hg(II) center confirming previous X-ray photoemission spectroscopic data on the compound. The lack of an observable (199)Hg NMR signal for the complex is the result of the identical length (2.689(2) Angstroms) of all six Hg-S bonds. We additionally report the X-ray structure of the complex [Hg(9N3)(2)](ClO(4))(2) (9N3 = 1,4,7-triazacyclononane) which shows hexakis(amine) coordination of the 9N3 to form a distorted trigonal prismatic structure. Solution dissociation of the one of the 9N3 ligands from the mercury ion is confirmed by multinuclear NMR experiments. For six-coordinate macrocyclic Hg(II) complexes, N6 donor sets have a preference for trigonal prisms while S6 donor sets favor octahedral structures.     

First synthesis of dodecasubstituted porphycenes

The synthesis of dodecasubstituted porphycenes has not been reported, to date. Herein, the preparation of tetramethyloctaethylporphycene by a McMurry‐type coupling of 3,3′,4,4′‐tetraethyl‐5,5′‐diformyl‐2,2′‐bipyrrole was attempted at first, but dodecasubstituted porphycene was not successfully obtained and only pyrrolocyclophene was obtained. The structure of the pyrrolocyclophene was determined by ¹H NMR spectroscopy, FAB MS, and X‐ray crystal‐structure analysis. The pyrrolocyclophene was not successfully oxidized to porphycene. Then, the McMurry‐type coupling of bicyclo[2.2.2]octadiene (BCOD)‐fused 5,5′‐diacyl‐2,2′‐bipyrroles was performed and tetra‐meso‐octa‐β‐substituted (dodecasubstituted) porphycenes were successfully obtained for the first time. The structures were determined by ¹H NMR spectroscopy and X‐ray crystal‐structure analysis. The crystal structures and NMR spectra were compared carefully with octasubstituted porphycenes, and there was a good correlation between the position of the substituents, the N1? N2 and N1? N4 distances of the porphycene inner nitrogen atoms, and NMR chemical shifts of the inner NH protons, which expressed the strength of N? H???N hydrogen bonding between N1 and N2. These results suggested that the BCOD structure was relatively compact compared with common alkyl groups and that was why the dodecasubstituted porphycenes were available this time. UV/Vis absorption and fluorescence properties are also discussed.     

抗癌药物冬凌草甲素的分子构型研究

本文用同核化学位移相关谱和二维J分解谱归属了冬凌草甲素的^1H谱, 测定了所有的质子标量偶合常数, 根据一系列的Karplus公式计算了二面角, 用自编WUPH计算程序, 计算出冬凌草甲素的分子构型。     

二氧六环-水体系的^1H和^1^7O NMR研究

本工作用配位平衡和快交换方法定量描述了二氧六环水体系中^1H和^1^7O化学位移随浓度的变化. 讨论了未配位水的结构破坏程度及其存在形式.     

镧系金属有机配合物的研究,XL.双(2-甲氧乙基环戊二烯基)钇和镱的硼氢配合物的合成及晶体结构

双(2-甲氧乙基环戊二烯基)氯化钇和镱, 在THF中, 室温与硼氢化钠发生置换反应, 生成双(2-甲氧乙基环戊二烯基)硼氢化钇(1)和镱(2), 产率分别为70和59%。它们都经红外光谱, 质谱, ^1HNMR和元素分析鉴定。将1和2在THF-己烷中重结晶,得到适用于X射线衍射分析的单品。1的空间群为Pna2~1, 晶胞参数:a=1.2390(3),b=1.1339(2), c=1.1919(2)nm, 晶胞体积,1.6745(6)nm^3,D~c=1.39g.cm^-3, z=4, R=0.061;2的空间群为Pna2~1, 晶胞参数:a=1.2399(6),b=1.1371(5),c=1.1897(2)nm, 晶胞体积, 1.6773(1)nm^3,Dc=1.72g.cm^-3, z=4, R=0.038, 1与2都是含有两个配位键(Ln-O)的双型的单体结构。     

Experimental and quantum-chemical studies of 1H, 13C and 15N NMR coordination shifts in Pd(II) and Pt(II) chloride complexes with quinoline, isoquinoline, and 2,2'-biquinoline

1H, 13C, and 15N NMR studies of platinide(II) (M=Pd, Pt) chloride complexes with quinolines (L=quinoline-quin, or isoquinoline-isoquin; LL=2,2'-biquinoline-bquin), having the general formulae trans-/cis-[ML2Cl2] and [M(LL)Cl2], were performed and the respective chemical shifts (delta1H, delta13C, delta15N) reported. 1H coordination shifts of various signs and magnitudes (Delta1Hcoord=delta1Hcomplex-delta1Hligand) are discussed in relation to the changes of diamagnetic contribution to the relevant 1H shielding constants. The comparison to the literature data for similar complexes containing auxiliary ligands other than chlorides exhibited a large dependence of delta1H parameters on electron density variations and ring-current effects (inductive and anisotropic phenomena). The influence of deviations from planarity, concerning either MN2Cl2 chromophores or azine ring systems, revealed by the known X-ray structures of [Pd(bquin)Cl2] and [Pt(bquin)Cl2], is discussed in respect to 1H NMR spectra. 15N coordination shifts (Delta15Ncoord=delta15Ncomplex-delta15Nligand) of ca. 78-100 ppm (to lower frequency) are attributed mainly to the decrease of the absolute value of paramagnetic contribution in the relevant 15N shielding constants, this phenomenon being noticeably dependent on the type of a platinide metal and coordination sphere geometry. The absolute magnitude of Delta15Ncoord parameter increased by ca 15 ppm upon Pd(II)-->Pt(II) replacement but decreased by ca. 15 ppm following trans-->cis transition. Experimental 1H, 13C, 15N NMR chemical shifts are compared to those quantum-chemically calculated by B3LYP/LanL2DZ+6-31G**//B3LYP/LanL2DZ+6-31G*, both in vacuo and in CHCl3 or DMF solution.     

Definition of an intramolecular Eu-to-Eu energy transfer within a discrete [Eu2L] complex in solution

Ligand L, based on two do3a moieties linked by the methylene groups of 6,6'-dimethyl-2,2'-bipyridine, was synthesized and characterized. The addition of Ln salts to an aqueous solution of L (0.01?M Tris-HCl, pH?7.4) led to the successive formation of [LnL] and [Ln(2)L] complexes, as evidenced by UV/Vis and fluorescence titration experiments. Homodinuclear [Ln(2)L] complexes (Ln = Eu, Gd, Tb, Yb, and Lu) were prepared and characterized. The (1)H and (13)C?NMR spectra of the Lu and Yb complexes in D(2)O solution (pD = 7.0) showed C(1) symmetry of these species in solution, pointing to two different chemical environments for the two lanthanide cations. The analysis of the chemical shifts of the Yb complex indicated that the two coordination sites present square antiprismatic (SAP) coordination environments around the metal ions. The spectroscopic properties of the [Tb(2)L] complex upon ligand excitation revealed conventional behavior with τ(H2O) = 2.05(1)?ms and ?(H2O) = 51%, except for the calculation of the hydration number obtained from the luminescent lifetimes in H(2)O and D(2)O, which pointed to a non-integer value of 0.6 water molecules per Tb(III) ion. In contrast, the Eu complex revealed surprising features such as: 1)?the presence of two and up to five components in the (5)D(0)→(7)F(0) and (5)D(0)→(7)F(1) emission bands, respectively; 2)?marked differences between the normalized spectra obtained in H(2)O and D(2)O solutions; and 3)?unconventional temporal evolution of the luminescence intensity at certain wavelengths, the intensity profile first displaying a rising step before the occurrence of the expected decay. Additional spectroscopic experiments performed on [Gd(2-x)Eu(x)L] complexes (x = 0.1 and 1.9) confirmed the presence of two distinct Eu sites with hydration numbers of 0 (site I) and 2 (site II), and showed that the unconventional temporal evolution of the emission intensity is the result of an unprecedented intramolecular Eu-to-Eu energy-transfer process. A mathematical model was developed to interpret the experimental data, leading to energy-transfer rates of 0.98?ms(-1) for the transfer from the site with q=0 to that with q=2 and vice versa. Hartree-Fock (HF) and density functional theory (DFT) calculations performed at the B3LYP level were used to investigate the conformation of the complex in solution, and to estimate the intermetallic distance, which provided F?rster radii (R(0)) values of 8.1?? for the energy transfer from site I to site II, and 6.8?? for the reverse energy transfer. These results represent the first evidence of an intramolecular energy-transfer equilibrium between two identical lanthanide cations within a discrete molecular complex in solution.