Anion Effect on Structure of Silver(I) Complexes with New Unsymmetrical Tripodal Ligand

Reactions of new unsymmetrical pyridyl‐ and imidazoyl‐containing tripodal ligand, 3‐(1H‐imidazol‐1‐yl)‐N,N‐bis(2‐pyridylmethyl)propan‐1‐amine ( L ), with varied silver(I) salts result in formation of three supramolecular architectures [Ag₂L₂](BF₄)₂·H₂O ( 1 ), [Ag₂L₂](ClO₄)₂·H₂O ( 2 ) and [Ag₃L₂](CF₃SO₃)₃ ( 3 ). All the structures were established by single‐crystal X‐ray diffraction analysis. In the solid state, three complexes consist of one‐dimensional infinite chains, in which the conformation and the bridging mode of L for complexes 1 and 2 are the same but 3 different. There are Ag···Ag and π‐π interactions in 3 . The results imply that the shape and size of the anion have great impact on the structure of the complexes. The complexes were also characterized by electrospray mass spectrometry.     

The Complexation Reactions of N-methylated Polyamines with Silver(I) in Dimethylsulfoxide

Abstract

The thermodynamic parameters for the complex formation reactions in dimethylsulfoxide (dmso) between Ag(I) and the following polyamines: N,N′-dimethylethylenediamine (dmen), N,N,N′,N′-tetramethylethylenediamine (dmen), N,N″-dimethyl-diethylenetriamine (dmdien) and N,N,N′,N″, N″-pentamethyldiethylenetriamine (pmdien) have been determined by potentiometric and calorimetric techniques at 298 K and 0.1 mol dm^?3 ionic strength (NEt₄ClO₄). Only mononuclear complexes are formed (AgL_j ⁺ j = 1,2) where the ligands act prevalently as chelate agents. All the complexes are enthalpy stabilized whereas the entropy changes counteract the complex formation. The results are discussed in terms of different basicities and steric requirements of both the ligands and the complexes formed.     

新型热塑性淀粉的制备和性能

以二甲基亚砜(DMSO)为增塑剂, 通过熔融共混法制备了一种新型热塑性淀粉(TPS), 研究不同增塑剂含量对材料结构和性能的影响, 并与甘油及甘油/水复合增塑淀粉体系进行了比较. FTIR结果显示, DMSO能够与淀粉产生强烈而稳定的氢键相互作用. WAXD和SEM的研究结果表明, DMSO的加入破坏了淀粉的有序结构, 实现了淀粉的塑化, 形成均一的非晶连续相. 同甘油及甘油/水增塑体系相比, DMSO与淀粉的羟基形成更为稳定的氢键, 能够有效抑制淀粉的重结晶. 动态力学和拉伸力学性能测试结果表明, 经过DMSO的增塑, 有效降低了淀粉的玻璃化转变温度, 改善了材料的韧性, 增塑效率要好于甘油及甘油/水复合增塑体系.     

二甲基亚砜在锂二次电池中的应用

采用二甲基亚砜(DMSO)作为锂二次电池的电解液, 研究了锂在DMSO中的沉积形貌和循环效率. 比较了六氟磷酸锂(LiPF₆)在DMSO、 碳酸丙烯酯(PC)和1,3-二氧环戊烷(DOL)3种溶剂中的沉积形貌和循环效率, 并研究了LiPF₆、 四氟硼酸锂(LiBF₄)、 高氯酸锂(LiClO₄)和二(三氟甲基磺酰)亚胺锂(LiTFSI)4种锂盐在DMSO中的沉积形貌和循环效率. 结果表明, 锂在DMSO中沉积得到的表面光滑平整且致密均匀, 循环效率在前10周要高于在PC中的, 溶剂DMSO有望用于金属锂二次电池中.     

Silver(I) and copper(I) complexes with ferrocenyl ligands bearing imidazole or pyridyl substituents

The reactions between five ferrocenyl derivatives containing both a CO and at least an imidazole or pyridine nitrogen atom and AgPF₆, AgOTf, or [Cu(NCCH₃)₄]PF₆ precursors were studied. The ligand {[bis(2-pyridyl)amino]carbonyl}ferrocene (L3), derived from (2-pyridyl)amine, favored tetrahedral coordination of Ag⁺ (with two ligands) and of Cu⁺ (with two acetonitrile ligands left from the precursor). In all the other ligands, both metal centers coordinated linearly to two ligands, preferring the imidazole or pyridinic nitrogen to other nitrogen atoms (amine) or oxygen donors.When the counter anions were triflate, the crystal structure showed a dimerization of the complex, with the ferrocenyl moieties occupying cis positions, by means of a weak Ag?Ag interaction. This was shown experimentally in the crystal structure of complex [Ag(L1)₂]OTf (L1 = ferrocenyl imidazole) and in the presence of peaks corresponding to {Ag₂(L2)₃(OTf)}⁺ and {Ag₂(L2)₄(OTf)}⁺ in the mass spectra of [Ag(L2)₂]OTf (L2 = ferrocenyl benzimidazole). In all complexes containing PF₆, there was no evidence for dimerization. Indeed, in the crystal structure of [Ag(L2)₂]PF₆, the ferrocenyl moieties occupy trans positions and the metal centers are far from each other. DFT calculations showed that the energy of the cis and trans conformers is practically the same and the balance of crystal packing forces leads to dimerization when triflate is present.     

Anion and Additive Effects on the Structure of Mercury(II) Halides Complexes with Tripodal Ligand

The metal complexes [Hg₂(tbim)₂Br₄]·2DMF ( 1 ) and [Hg₂(tbim)I₄]·1.5DMF ( 2 ) were prepared by reactions of 1,3,5‐tris(benzimidazol‐1‐ylmethyl)‐2,4,6‐trimethylbenzene (tbim) with HgBr₂, HgI₂, respectively, and [Hg₂(tbim)I₄]·0.5(FeCp₂)·H₂O ( 3 ) was obtained by the same method with addition of ferrocene (FeCp₂) as additive. Their structures were determined by X‐ray crystallographic analyses. Complex 1 has a macrocyclic binuclear structure with one benzimidazole arm of the ligand free of coordination and the binuclear units are further connected by C‐H···N hydrogen bonds to give an infinite zigzag chain. Complexes 2 and 3 have a 2D network structure in which tbim serves as a tridentate ligand. The results showed that the halides of bromide and iodide have remarkable impact on the structure of the complexes. The FeCp₂ molecules are trapped in the voids of framework 3 .     

Synthesis of the monosubstituted arylcyanoxime and its Na,Tl(I) and Ag(I) compounds

Nitrosation of 2-chlorophenyl acetonitrile with t-butylnitrite under basic conditions (Meyer reaction) resulted in a high-yield preparation of the first substituted arylcyanoxime, 2-chlorophenyl(oximino)acetonitrile, H(2Cl–PhCO) (HL). The obtained cyanoxime is readily deprotonated in solution by metal hydroxides or carbonates with the formation of yellow sodium, tetrabutylammonium, thallium(I) and silver(I) derivatives. The crystal structure of the Tl(I) complex was determined. Thallium(I) salt (TlL) crystallizes in the monoclinic space group P2₁ n with a?=?3.8382(7), b?=?11.0065(18), c?=?20.901(4)?Å, and β?=?92.447(3)°, V?=?882.2(3) ų, Z?=?4; T?=?193?K (Mo?Kα radiation). The structure was solved by direct methods to a final R of 0.0689 (wR2?=?0.1650) for I?>?2σ(I). The crystal structure of the complex is a one-dimensional coordination polymer that consists of centrosymmetric [TlL]₂ dimers in which Tl₂O₂ rhombohedra are connected to each other at 90.72°. The crystal structure of TlL is an interesting example of the ruffled metal-organic network composed of Tl–O–Tl–O zigzag chains with close (3.838?Å) intermetallic distances comparable to those in metallic thallium (3.42?Å). The cyanoxime anion bridges metal centers and acts as a tridentate ligand where oxygen atoms of the oxime group bond to three different Tl(I) cations with three different bond lengths.     

Measurement and Prediction on the Surface Properties of Dimethyl Sulfoxide/Water Mixtures

Pendent drop method was adopted to measure the surface tension of dimethyl sulfoxide(DMSO)/water mixtures. A new pendent drop apparatus was built up and checked with water, and a good agreement of our data with literature could be found. With the new apparatus, the surface tensions of nine DMSO/water mixtures with mass fractions of water from 0.1 to 0.9 were investigated in a temperature range of 298-338 K. The expanded uncertainty for surface tension measurement was estimated to be 0.5% at a confidence level of 95%(k=2) in the whole temperature range. A thermodynamic-based relation was used to predict the surface properties of DMSO/water mixtures. Based on the relation and Gibbs adsorption theory, a prediction model was proposed for the calculation of surface relative excess and the thickness of the surface molecule layer.     

二甲基亚砜和四氢呋喃对胃蛋白酶催化动力学和分子光谱的影响

为了研究二甲基亚砜(DMSO)和四氢呋喃(THF)对胃蛋白酶(Pepsin, PP)催化活性的影响及其作用本质, 测定了在这两种有机溶剂的作用下胃蛋白酶的催化活性、 动力学参数、 紫外吸收光谱、 紫外差示光谱和荧光发射光谱的变化. 结果表明, 体积分数为9%的DMSO使PP活性提高83.4%; 而体积分数为1%的THF只能使PP活性提高3.59%. 在盐酸溶液中, PP的动力学参数K_m=2.22 mg/mL, v_max=1.1×10⁶ U/mg Pro; 在9%DMSO中, 其K_m=1.50 mg/mL, v_max=0.5×10⁶ U/mg Pro; 在1%THF中的K_m=1.91 mg/mL, v_max=0.51×10⁶ U/mg Pro. 9%DMSO强烈抑制PP分子肽键的紫外吸收, 而对芳香族氨基酸无影响; 1%THF则对PP的紫外吸收光谱影响不大. 9%DMSO和1%THF都使PP的紫外差示光谱出现明显的负吸收峰和正吸收峰. 9%DMSO使酶分子的荧光发射峰向短波方向移动1 nm; 而1%THF则对其无影响. 实验结果表明, 在9%DMSO和1%THF中, PP分子的立体构象发生了变化, 使酶分子的K_m下降, 酶分子对底物的亲和力有所升高, 从而导致酶分子的催化活性有不同程度的提高.     

Silver(I) ion selective ionophores containing dithiocarbamoyl moieties on steroid backbone

Tweezer-type and non-tweezer-type ionophores containing dithiocarbamoyl groups on a 7-deoxycholic amide or cholane derivatives were designed and synthesized. Potentiometric evaluation of the poly(vinyl chloride) (PVC) membranes containing those deoxycholic amides/cholanes linked with tweezer-type dithiocarbamoyl moieties showed excellent affinity and selectivity to silver(I) ion over alkali, alkaline earth and other transition metal cations. On the other hand, deoxycholic amides/cholanes substituted with one dithiocarbamoyl group, i.e., non-tweezer-type ionophores, resulted in relatively poor potentiometric sensitivity and detection limits. The enhanced potentiometric properties of newly synthesized tweezer-type dithiocarbamoyl containing ionophores have been further improved by employing silver ion complexing reagent in the internal reference solution, which resulted in greatly reduced detection limit (∼100 ppt) for the electrodes based on them.     

Synthesis, characterization, electrochemistry and luminescence studies of heterometallic gold(I)-rhenium(I) alkynyl complexes

The present work provides a brief summary review of the chemistry of luminescent gold(I) alkynyls and their ability to form heterometallic complexes. A series of luminescent heterometallic gold(I)-rhenium(I) alkynyl complexes has been synthesized and characterized. Their electrochemical and photophysical properties have been studied and their emission origins elucidated.     

Silver(I) and gold(I)-promoted synthesis of alkylidene lactones and 2H-chromenes from salicylic and anthranilic acid derivatives

Ag(I) and Au(I) efficiently catalyze the cycloisomerization of terminal alkynoic acids into methylene seven-membered ring lactones. Depending on the metal, divergent reaction pathways were found for non terminal alkynoic acids. While Ag(I) led to lactones, Au(I) led to 2H-chromenes coming from the hydroarylation of the alkyne.     

Synthesis and Coordination of Tripodal-Containing Copper(I) Complexes

Reaction of copper(I) chloride with 2,2-bis(diphenylphosphinomethyl)-l-phenylthiopropane P₂S produced a dimeric species [(P₂S)CuC1]₂ (2). Treatment of 2 with silver nitrate in acetonitrile gave a hexameric crystalline metal complex {[(P₂S)Cu(CH₃CN)]₆⁺6NO₃} (4), which had a “cyclodextrin-type” structure. A linear polymeric copper complex [(P₂S)Cu(NO₃)]_n was obtained by recrystallization of 4 in chloroform. These complexes were characterized by single crystal analyses, and their coordination behaviors in solution are discussed.     

First Copper(I) and Silver(I) Complexes Containing Phosphanylphosphido Ligands

Three new complexes with phosphanylphosphido ligands, [Cu₄{μ₂‐P(SiMe₃)‐PtBu}₄] ( 1 ), [Ag₄{μ₂‐P(SiMe₃)‐PtBu₂}₄] ( 2 ) and [Cu{η¹‐P(SiMe₃)‐PiPr₂}₂]^–[Li(Diglyme)₂]⁺ ( 3 ) were synthesized and structurally characterized by X‐ray diffraction, NMR spectroscopy, and elemental analysis. Complexes 1 and 2 were obtained in the reactions of lithium derivative of diphosphane tBu₂P‐P(SiMe₃)Li · 2.7THF with CuCl and [iBu₃PAgCl]₄, respectively. The X‐ray diffraction analysis revealed that the complexes 1 and 2 present macrocyclic, tetrameric form with Cu₄P₄ and Ag₄P₄ core. Complex 3 was prepared in the reaction of CuCl with a different derivative of lithiated diphosphane iPr₂P‐P(SiMe₃)Li · 2(Diglyme). Surprisingly, the X‐ray analysis of 3 revealed that in this reaction instead of the tetramer the monomeric form, ionic complex [Cu{η¹‐P(SiMe₃)‐PiPr₂}₂]^–[Li(Diglyme)₂]⁺ was formed.     

钨钼杂多酸及其盐与二甲基亚砜加合物的制备和性质研究

在乙腈和水的混合溶剂中制备了9种钨钼杂多酸和杂多酸盐的二甲基亚砜加合物。研究结果表明,加合物中杂阴离子的Keggin结构基本不变。配体DMSO以S=O键上的氧作为配位原子,它不直接与杂阴离子骨架结构发生配位作用,而是与杂多酸中的质子氢或杂多酸盐中的金属阳离子以氢键或配位键相配位,生成的质子(钅羊)离子和金属配离子再通过离子缔合键与杂阴离子相结合,形成杂多酸或杂多酸盐加合物。     

Synthesis and Spectroscopic Characterization of Silver(I) Complexes of Selenones

Silver(I) complexes of selenones, [LAgNO₃] and [AgL₂]NO₃ (where L is imidazolidine-2-selenone or diazinane-2-selenone and their derivatives) have been prepared and characterized by elemental analysis, IR and NMR (¹H, ¹³C and ¹⁰⁷Ag) spectroscopy. An upfield shift in the C=Se resonance of selenones in ¹³C NMR and a downfield shift in N-H resonance in ¹H NMR are consistent with selenium coordination to silver(I). In ¹⁰⁷Ag NMR, the AgNO₃signal is deshielded by 450-650 ppm on coordination to selenones. Greater upfield shifts in ¹³C NMR were observed for [LAgNO₃] compared to [AgL₂]NO₃complexes, whereas the opposite trend was observed for ¹H and¹⁰⁷Ag NMR chemical shifts.     

Synthesis and Crystal Structure of a New Silver(I) Complex

The reaction of 4-amino-6-methyl-1,2,4-triazine-3(2 H)-thione-5-one (AMTTO) with silver(I) nitrate in methanol gives the complex [Ag(AMTTO)₂]NO₃ ( 1 ). 1 was characterized by IR and ¹³C NMR spectroscopy and by an X-ray structure analysis [space group C2/c, Z = 4, lattice dimensions at –80 °C: a = 1306.7(2), b = 1139.0(2), c = 1089.2(1) pm, β = 94.54(1)°, R₁ = 0.0294]. The cation possesses a highly distorted linear coordination sphere in the solid state.     

温度对二甲基亚砜水溶液的结构和热力学性质的影响

应用参考作用格位模型理论计算了二甲基亚砜(DMSO)摩尔分数为0.002时不同温度下溶液的微观结构和热力学性质. 计算结果表明, DMSO加入到水中能够增强溶液的分子网络结构. 温度升高, 配位数减小, 溶液中分子排布趋向无序. 平均力势的波动增大表明分子间的诱导力表现为斥力. 计算得到的各种热力学性质显示: 温度升高, 溶液的熵和溶剂化自由能增加, 相互作用能和过剩化学位也增加, 即高温下溶液越来越偏离理想溶液; 空位形成能降低表明溶液分子结构在高温下更容易重组.     

稀土异硫氰酸盐与二甲基亚砜配合物的合成,性质及热分析研究

合成了15种稀土异硫氰酸盐与二甲基亚砜(DMSO)的配合物,经化学分析和元素分析确定其组成为RE(NCS)_s·mDMSO(RE=La,Ce,Pr,Nd,Sm,Eu,Gd;m=5.RE=Tb,Dy,Ho,Er,Tm,Yb,Lu,Y;m=4).用红外光谱及X射线衍射技术进行了表征.运用TG-DTA-DTG联用技术研究了该系列配合物的热分解过程,求算热重动力学参数发现,第一步热分解阶段的活化能随着中心高子——镧系元素原子序数的依次递增呈现“双峰现象”.     

Linear Pyrazole‐bridged Tetra(N‐heterocyclic carbene) Ligands and Their Hexanuclear Silver(I) Complexes

New hybrid ligands are reported that combine two types of popular donor groups within a single linear scaffold, viz., a central pyrazolate bridge and two appended bis(N‐heterocyclic carbene) units; the ligand strands thus provide two potentially tridentate {NCC} compartments. The pyrazole/tetraimidazolium proligands, [H₅L¹](PF₆)₄ and [H₅L²](PF₆)₄ , were synthesized via multi‐step protocols, and the NH prototropy of [H₅L¹](PF₆)₄ was examined by variable temperature (VT) NMR spectroscopy, giving solvent dependent activation parameters (ΔH^? = 27.6 kJ · mol^–1, ΔS^? = –125 J · mol^–1 · K^–1 in [D₃]MeCN; ΔH^? = 40.4 kJ · mol^–1, ΔS^? = –86.9 J · mol^–1 · K^–1 in [D₆]DMSO) that are in the range typical for pyrazoles. Reaction of the proligands with Ag₂O gave hexametallic complexes [Ag₆(L¹)₂](PF₆)₄ and [Ag₆(L²)₂](PF₆)₄ that involve all six potential donor atoms of the ligands, viz. the four C^NHC and two N^pz donors, in metal coordination. X‐ray crystallography revealed a chair‐like central {Ag₆} deck in both complexes but different arrangements of the ligand strands, which goes along with significantly different Ag^I ··· Ag^I distances that indicate more pronounced argentophilic interactions in case of [Ag₆(L¹)₂]^{4 +}.