共轭二茂铁基席夫碱的合成及电化学性质

以乙炔二茂铁为原料,通过Sonogashira和胺醛缩合反应合成了三个共轭二茂铁基席夫碱配合物,通过元素分析、1H和13C NMR对产物进行了表征,并用X射线单晶衍射测定了配合物I的晶体结构,电化学研究表明合成的配合物均经历一个可逆的单电子氧化还原过程。     

新型二茂铁三氮唑类Schiff碱的合成、晶体结构及其电化学性质

以乙酰二茂铁和氨基三氮唑为原料,合成了两种新型的二茂铁三氮唑Sch iff碱化合物,其结构通过IR,1H-NMR,元素分析和X-射线单晶衍射法确定。X射线单晶结构分析表明,固态时化合物1 a与一分子水通过分子间氢键形成-维无限链状结构,其晶体属单斜晶系,P21/n空间群,M r:312.16,a=11.679(2),b=9.862(2),c=12.717(3),β=108.60(3)0k,v=1388.3(5),Z=4,D c=1.493mg.m-3,μ=0.71073,F(000)=648,最终偏离因子R=0.0454,wR=0.0984。电化学分析表明1 a和1b的电化学性质相似,在电位0.4~1.1V范围内,都只有一对氧化-还原峰,对应于Fc/Fc 电对,且该过程是受扩散控制的可逆过程。     

三脚架结构的多二茂铁基化合物的晶体结构和电化学性质

合成了含有多二茂铁基团的化合物,测定了化合物的晶体结构.化合物为三斜晶系,P-1空间群,晶胞参数a=0.917 44(18)nm,b=1.240 7(3)nm,c=1.504 3(3)nm,α=106.53(3)°,β=101.82(3)°,γ=106.80(3),°对氮原子而言,形成了三角架结构.     

两种新型二茂铁衍生物的合成及其电化学性质

以二茂铁甲醛和三羟甲氨基甲烷为原料,经缩合,脱水和还原反应合成了两种新型的二茂铁衍生物,其结构经1H NMR, IR和MS表征,并利用循环伏安法研究了它们的电化学性质.     

新型双核二茂铁基席夫碱的合成及其电化学性质

乙炔二茂铁分别与对溴苯甲醛和对碘苯胺经Sonogashira反应制得中间体4-(2-二茂铁基-乙炔基)苯甲醛(2a)和4-(2-二茂铁基-乙炔基)苯胺(2b);2a和2b分别与对苯二胺和对苯二甲醛经胺醛缩合反应合成了两个新型的双核二茂铁基席夫碱类配合物(3a和3b),其结构经1H NMR和元素分析表征。电化学研究结果表明,3a(3b)的Epa,Epc,E1/2和ipc/ipa分别为0.279 V(0.311 V),0.195 V(0.196 V),0.238 V(0.260 V)和0.96(1.06);中间桥连基团对3的电化学性质影响显著。     

二茂铁基双酰肼化合物的制备及电化学性质

以二茂铁衍生物为原料合成了3个二茂铁基双酰肼类化合物(1,2,3);利用元素分析、红外光谱、核磁共振谱等分析了标题化合物的组成和结构,采用分光光度计测定了其紫外吸收光谱,利用循环伏安法测定了其电化学性质;并利用量子化学计算得到了1的稳定结构.结果表明,化合物1因酰基活性基团被氧化而在高电位区出现一个不可逆氧化峰;与此同时,其在低电位区出现一个不可逆的还原峰.     

两个新的双二茂铁硫脲衍生物FcL1和FcL2的合成、结构及电化学性质

以二茂铁苯甲酰氯和二茂铁间(对)苯胺为原料,合成了两个新的双二茂铁硫脲衍生物FcL₁和FcL₂.通过IR,¹HNMR和元素分析等手段确定了标题化合物的结构.X射线单晶结构分析表明,FcL₁属于三斜晶系,P1空间群,R₁=0.0786,wR=0.1762.电化学分析结果表明,FcL₁和FcL₂的电化学性质相似,说明化合物中的两个二茂铁基所处的化学环境基本相同.间苯胺取代和对苯胺取代对化合物在电极表面的扩散系数影响不大,但对其反应速率常数则有较大的影响.     

N-2-亚甲基-呋喃-二茂铁芳胺衍生物的合成与晶体结构及电化学性质

以邻、间、对-二茂铁苯胺为原料,合成了新的含呋喃二茂铁苯基席夫碱衍生物,还原得到N-2-亚甲基-呋喃-二茂铁芳胺衍生物,通过元素分析,IR,1H NMR和X-射线单晶衍射等分析手段,确证了标题化合物的组成和结构,化合物2 c单晶结构解析表明,2 c属于单斜晶系,P2/n空间群;其HOMO轨道主要由Fe原子及茂环上C的原子轨道组成,LUMO主要由O、N和苯环上C原子构成;电化学实验证明:邻、间、对化合物的电化学性质相似,苯环上取代基位置的不同,对化合物在电极表面的扩散系数影响不大,但对反应速率常数有较大的影响.     

两种取代二茂铁基三甲基硅烷基氰醇醚的合成及晶体结构

通过两种取代的乙酰基二茂铁与三甲基氰硅烷的加成反应, 得到两种取代二茂铁基三甲基硅烷基氰醇醚的晶体: 1-(1-氰基-1-三甲基硅烷氧基乙烷基)二茂铁(1), 1,1'-二(1-氰基-1-三甲基硅烷氧基乙烷基)二茂铁(2), 用X射线单晶衍射、元素分析、红外光谱和核磁共振氢谱对分子结构进行了表征. 测试结果表明: 晶体1属正交晶系, Pbca空间群, a＝1.1995 nm, b＝1.2441 nm, c＝2.2183 nm, Z＝8, R₁＝0.0456, wR₂＝0.0880; 晶体2属正交晶系, Pna2(1)空间群, a＝2.0715 nm, b＝0.6440 nm, c＝1.8411 nm, Z＝4, R₁＝0.0485, wR₂＝0.0866. 晶体结构表明, 分子中都存在超共轭效应.     

二茂铁基亮氨酸锌配合物的晶体结构与性质

二茂铁基手性氨基酸类化合物由于兼有二茂铁衍生物和手性氨基酸的特点,如稳定性高、氧化还原性、毒性低、能够提供较好的手性环境等优点,在不对称催化、识别等方面的研究逐渐引起了人们的关注.     

Synthesis,crystal structure,and properties of a binuclear Zn(II) macroheterocyclic complex based on ferrocene-thiocarbazide ligand

A binuclear macroheterocyclic complex Zn₂(FcL)₂ based on ferrocene-thiocarbazide (FcL) was synthesized. X-ray diffraction analysis shows that it belongs to the monoclinic system P2(1)/n space group, with a = 1.35379(17) nm, b = 2.6026(3) nm, c = 1.8693(2) nm, β = 95.687(2)° and final R indices R = 0.0796 and Rw = 0.2119. Two Zn(II) ions and two FcL ligands form a 22-membered macroheterocycle, further extended to an infinite 1-D helical chain by intermolecular hydrogen bonding. Spectral properties of the title complex and electrochemical properties of the ligand FcL are also discussed.     

Syntheses, crystal structures, and electrochemical properties of multi-ferrocenyl resorcinarenes

Tetraaryl and tetraferrocenyl resorcinarenes 1a-1c have been synthesized by the HCl-catalyzed condensation of resorcinol with aromatic aldehydes or ferrocenecarbaldehyde, which were fully alkylated with ethyl α-chloroacetate to give the activated ethyl resorcinarylacetates 2a-2c. Reaction of 2a-2c with hydrated hydrazine yielded the resorcinarene acylhydrazine derivatives 3a-3c, from which the multi-ferrocenyl functional groups were selectively and efficiently introduced on the upper rim, or on the lower rim, or both on the upper and lower rims of resorcinarenes 4a-4c and calixarenes 4d-4f based upon the condensation reactions of acylhydrazones with ferrocenecarboxaldehyde.     

Syntheses, crystal structure and electrochemical characterization of ferrocene-containing nickel(II) complexes with 4,11-dihydro-5,7,12,14-tetramethyldibenzo[b,i][1,4,8,11]tetraazacyclotetradecine

In the title complexes, {[(η-C₅H₅)Fe(η-C₅H₄)(CO)](C₂₂H₂₁N₄)Ni} (1) and {[(η-C₅H₅)Fe(η-C₅H₄)(CO)]₂(C₂₂H₂₀N₄)Ni} (2), one and two electroactive ferrocenes (Fc) were grafted onto the methine of the nickel complex Nitmtaa (H₂tmtaa = 4,11-dihydro-5,7,12,14-tetramethyldibenzo[b,i][1,4,8,11]tetraazacyclotetradecine) through the carbonyl groups. The two new complexes were characterized by IR, UV, MS and NMR spectra as well as by DSC measurements. The crystal structure of 1 was determined. Ni coordinates to four nitrogen atoms of tmtaa, and it is almost in the same plane as the N₄ plane. The mean Ni–N bond distance in the N₄ plane is 1.866 Å. The non-planar, saddle-shaped conformation of H₂tmtaa is almost retained in the nickel complex. The symmetry axis of ferrocene is almost parallel to the N₄ plane in Nitmtaa. The dihedral angle between the N₄ plane in Nitmtaa and the cyclopentadienyl ring in ferrocene is 98.5°. The electrochemistry of 1 and 2 was studied by cyclic voltammetry in CH₂Cl₂/1 × 10⁻¹ M n-Bu₄NClO₄ using a glass carbon working electrode. Because of the electron transfer between the electroactive ferrocene and the completely conjugated system of Nitmtaa, the complexes show novel electrochemical properties and the ferrocenes in 1 and 2 act as electron acceptors.     

Synthesis,crystal structures and electrocatalytic properties of bridgehead-C-functionalized diiron dithiolate complexes

To investigate the influence of bridgehead-C functionality in diiron dithiolate complexes on the molecular structure and electrocatalytic properties of [FeFe]-hydrogenase models, three new bridgehead-C-functionalized model complexes 1–3 have been synthesized and structurally characterized. Treatments of parent complex [(μ-SCH₂)₂CHCO₂H][Fe₂(CO)₆] (A) with the esterification agents o-MeC₆H₄OH, p-ClC₆H₄OH, or p-HOC₆H₄CHO in the presence of 4-dimethylaminopyridine and dicyclohexylcarbodiimide in CH₂Cl₂ at room temperature resulted in formation of [(μ-SCH₂)₂CHCO₂R][Fe₂(CO)₆] (R = o-MeC₆H₄–, 1; p-ClC₆H₄–, 2; p-OHCC₆H₄–, 3) in 53–55% yields. The new complexes 1–3 were characterized by elemental analysis, IR and NMR spectroscopy, and especially determined by X-ray crystallography. The electrochemical properties of 1–3 and the electrocatalytic H₂ evolution catalyzed by 1 have been investigated by cyclic voltammetry, where 1 is a catalyst for HOAc proton reduction to H₂ under electrochemical conditions.     

Synthesis, crystal structure, and electronic structure of RbVSe2

RbVSe₂ has been synthesized at 773 K through the reaction of V and Se with a Rb₂Se₃ reactive flux. The compound crystallizes in the orthorhombic space group D_2h²⁴-Fddd with 16 formula units in a cell of dimensions , , and at . The structure possesses infinite one-dimensional chains of edge-sharing VSe₄ tetrahedra separated from the Rb⁺ ions. These chains distort slightly to chains. The V-V distance within these chains is 2.8362(4) Å. First-principles total energy calculations indicate that a non-magnetic configuration for the V³⁺ cations is the most stable.     

Synthesis, crystal structure and density functional theoretical studies on phenyl-thiocarbamic acid-O-pyridin-4-ylmethyl ester

The title compound of phenyl-thiocarbamic acid-O-pyridin-4-ylmethyl ester has been synthesized and characterized by elemental analysis, IR, electronic spectroscopy and X-ray single crystal diffraction. Density functional theory (DFT) method calculations of the structure, atomic charge distributions and the thermodynamic properties at different temperatures have been performed. Calculated results show that DFT method at B3LYP/6-311G^** level can well reproduce the structure of the title compound. The predicted vibrational frequencies are compared with the experimental ones and they support each other on the whole. The atoms of sulfur, oxygen and the atom of nitrogen from pyridine ring all have bigger negative charges, which make the title compound become a multidentate organic ligand. The correlation equations of the thermodynamic properties of and with temperature are also obtained.     

Syntheses, structures, and electrochemical properties of four complexes based on 4-ferrocenylbutyrate ligand

Four ferrocenyl complexes with the formulas {[Mn(η²-OOC(CH₂)₃Fc)₂(bbbm)]·CH₃OH}_n (1), {[Co(OOC(CH₂)₃Fc)(η²-OOC(CH₂)₃Fc)(bbbm)]·CH₃OH}_n (2), {[Ni(OOC(CH₂)₃Fc)₂(bbbm)(CH₃OH)₂]·2CH₃OH}_n (3) and [Pb₆(μ₂-OOC(CH₂)₃Fc)₂(μ₃-OOC(CH₂)₃Fc)₂(μ₂-η²-OOC(CH₂)₃Fc)₂(η²-OOC(CH₂)₃Fc)₂(μ₄-O)₂] (4) (Fc = (η⁵-C₅H₅)Fe(η⁵-C₅H₄), bbbm = 1,1-(1,4-butanediyl)bis-1H-benzimidazole) have been synthesized and characterized by single crystal X-ray diffraction. Owing to the different conformations of the bbbm units in complexes 1 (or 2) and 3, complexes 1 and 2 possess 1D helical chain structure with 2₁ screw axes along the b-direction, while complex 3 shows a 1D linear chain structure with ferrocenylbutyrate groups hanging on the chain. Complex 4 is a hexanuclear complex and exhibits a nano-scale wheel-like framework with six Pb(II) ions as a core and eight 4-ferrocenylbutyrate ligands as branches. The cyclic voltammetric studies show that the formal potentials of the four complexes are close to the free ferrocenylbutyrate ligand, which indicates that the coordination of the metal ions to the ferrocenyl ligand does not have significant effects on the redox potential of the ferrocenylbutyrate ligand. Further investigations suggest that the redox processes of the ferrocenylbutyrate ligand and complexes 1-4 are all chemically quasi-reversible processes and controlled by diffusion.     

Synthesis and crystal structure of a new zinc diphosphonate

A new zinc diphosphonate [NH₃CH(CH₃)CH₂NH₃]₂Zn₂(edbbp)₂(HNO₃)₂·4H₂O [eddbp?= O₃PCH(Ph)NH(CH₂)₂NHCH(Ph)PO₃] was hydrothermally synthesized with Zn(NO₃)₂·6H₂O, ethane-1,2-diamino-N,N′-bis(benzylphosphonic acid) (H₄edbbp) and 1,2-propyldiamine. It consists of a centro-symmetric dimeric unit [Zn₂(edbbp)₂], in which each zinc ion adopts a distorted square-pyramidal coordination geometry. Hydrogen bonds formed between phosphonate groups and protonated 1,2-propyldiamine molecules link the dimeric units into one-dimensional chains. The doubly protonated 1,2-propyldiamine molecules serve not only as charge compensating counter ions, but also as bridging groups. Hydrogen-bonding interactions among the phosphonate oxygen atoms, water molecules, nitric acid molecules and protonated 1,2-propyldiamine result in the formation of a three-dimensional supramolecular network.