Semi-rigid N-para-ferrocenyl(benzoyl)amino-acid esters for biomaterials: synthesis and characterization of Fc-C6H4CONHCH(R)CO2Me where Fc = (η5-C5H5)Fe(η5-C5H4) and R=H,CH3,CH2CH(CH3)2,CH2C6H5 and the X-ray crystal structures of Fc-C6H4CO2Me and the l-alanine derivative Fc-C6H4CONHCH(CH3)CO2Me

A series of N-para-(ferrocenyl)benzoyl amino-acid esters, para-Fc(C₆H₄)CONHCH(R)CO₂CH₃ {Fc = (η⁵-C₅H₅)Fe(η⁵-C₅H₄); R = H, CH₃, CH₂CH(CH₃)₂, CH₂C₆H₅}, 3–6 have been prepared by coupling para-(ferrocenyl)benzoic acid to the amino-acid esters (gly, l-Ala, l-Leu, l-Phe) using the standard 1,3-dicyclohexylcarbodiimide (DCC), 1-hydroxybenzotriazole (HOBt) protocol. The compounds were fully characterized by a range of spectroscopic techniques including FAB-MS. The X-ray crystal structures of the parent para-(ferrocenyl)benzoyl methyl ester, Fc-C₆H₄CO₂Me, 1 and a chiral derivative N-{para-(ferrocenyl)benzoyl}-l-alanine methyl ester, Fc-C₆H₄CONHCH(CH₃)CO₂Me, 4 have been determined.     

Theoretical investigation of mixed-ligand lanthanocene complexes, (η5-C5H5)2LnX · OC4H8 (Ln=La,Gd, Lu; X=F,Cl, Br,I)

For the first time, density functional theory (DFT) calculation was performed on the titled complexes and the calculated geometries are in good agreement with the available experimental data. The decrease in the bond distances (Ln–X) as well as the increase in the Hirshfeld charges and the chemical hardness from La to Lu indicates an increase in ionic character on going from La to Lu. The lanthanide contraction and ionic character of metal–ligand bond are found to follow the order: Ln–X > Ln–Cp > Ln–O.     

Zirconocene complexes of the sterically demanding pentaphenylcyclopentadienyl ligand,CpPRO. Synthesis and characterization of CpPROZrCl3 and CpCpPROZrCl2 (Cp=η5-C5H5; CpPRO=η5-C5(C6H5)5)

The synthesis, characterization and X-ray structures of two zirconium complexes of the bulky pentaphenylcyclopentadienyl ligand, Cp^PRO, are reported. The monocyclopentadienyl 12 electron complex, Cp^PROZrCl₃ (I), has an unusual monomeric structure in the solid state and has short Zr–ligand distances. The Lewis acidity of this complex is manifested in its ability to catalyze the [4+2] cycloadditions of methyl- and ethylmethacrylate to cyclopentadiene. The sandwich complex, Cp^PROCpZrCl₂ (II), has more typical Zr–ligand distances, but has a more parallel arrangement of the two cyclopentadienyl rings.     

Theoretical study of the reactive intermediate Si2Me4[(η5-C5H4) Fe(CO)2] 2 2−

In two previous papers (Kinget al., J. Organomet. Chem. 19, 327, 1969; Pannellet al., Organometallics 9, 859, 1990), the synthesis and X-ray structure of the two tetramethyl disilyl complexes [(η⁵-C₅H₅) Fe(CO)₂]₂Si₂Me₄ (I) and Si₂Me₄[(η⁵-C₅H₄) Fe(CO)₂CH₃]₂ (II) were reported. ComplexII is obtained fromI [2]. However, attempts to form other derivatives fromI have generally failed. In the chemical process to getII fromI, an intermediate complex, Si₂Me₄[(η⁵-C₅H₄) Fe(CO)₂] ₂ ^2? (III), is probably formed. This is similar to complexII without the two methyl groups bonded to the Fe atoms. Therefore, a theoretical study that may shed some light on the intermediate structure, stability, and reactivity is justified. We have developed theoretical studies consisting of extended Huckel electronic structure calculations on the simulated intermediate geometry. The results obtained from these calculations suggest that it might be stable enough to form during reactions of complexI. The more reactive sites, which suggest reaction alternatives, are pointed out.     

Synthesis and structure of the cubane type [Fe2Sb(CO)5(η5-C5H5)]4 cluster

The [Fe₂Sb(CO)₅Cp]₄ (Cp=η⁵-C₅H₅) cluster has been obtained by the thermolysis of [Et₄N][{Fe(CO)₄}₂{Fe(CO)₂Cp}SbI]. The structure of the [Fe₂Sb(CO)₅Cp]₄·2toluene solvate has been determined by X-ray analysis. The cluster contains the cubane [Fe₄Sb₄] core. Each Sb serves as a μ₄-ligand between three iron atoms of the core and one of a terminal [Fe(CO)₂Cp] group.     

Theoretical investigation of molecular interactions between sulfur ylide and hypohalous acids (HOX,X═F,Cl, Br,and I)

In the present study, the complexes of sulfur ylide (SY) with hypohalous acids (HOX; X═F, Cl, Br, and I) were theoretically studied using the MP2/aug-cc-pVTZ computational level. Four types of structures were obtained for these complexes including two kinds of hydrogen bonds (HBs) (SY: HOX─I and SY: HOX─II) and two kinds of halogen bonds (SY: XOH─I and SY: XOH─II). According to the energetic results, the SY:XOH─I complexes are stronger for X═Br and I, while the SY:HOX─I complexes are favorable for X═Cl and Br; also, the SY:HOX─II complexes are stronger than SY:XOH─II except for SY:IOH─II, which is stronger than its counterpart (SY:HOI─II). Moreover, on comparing SY:HOX─I and II HBs complexes, the former is more stable than the latter, while between the SY:XOH─I and II halogen bond complexes (X═Cl, Br, and I), the SY:XOH─I ones are more stable. The strength, properties, and nature of interactions were also analyzed using the natural bond orbital and atoms in molecules theories.     

Sulfur-assisted chloride and triphenylphosphine dissociation of palladium(II) complex [Pd(PPh3)2(η1-SCNMe2)(Cl)]. X-ray structures of [Pd(PPh3)2(η1-SCNMe2)(Cl)], [Pd(PPh3)(Cl)]2(μ,η2-SCNMe2)2, and [Pd(PPh3)2(η2-SCNMe2)][PF6]

Treatment of Pd(PPh₃)₄ with Me₂NC(S)Cl in dichloromethane at −20 °C produces the complex [Pd(PPh₃)₂(η¹-SCNMe₂)(Cl)], 2. Variable temperature ¹H and ³¹P{H} NMR experiments of complex 2 shows the dissociation of either the chloride or the triphenylphosphine ligand to form complex [Pd(PPh₃)₂(η²-SCNMe₂)][Cl], 3 or the dipalladium complex [Pd(PPh₃)Cl]₂(μ,η²-SCNMe₂)₂, 4. The reaction of complex 2 with NaPF₆ affords complex [Pd(PPh₃)₂(η²-SCNMe₂)][PF₆], 5. Complexes 2, 4, and 5 are characterized by X-ray diffraction analyses.     

The synthesis and characterization of two new 19-vertex metallaborane clusters: [B18H20Ni(η5-C5H5)]−1 and [B18H19(2-THF)Ni(η5-C5H5)]

Two new 19-vertex metallaboranes, [B₁₈H₂₀Ni(η⁵-C₅H₅)][N(CH₃)₄] and [B₁₈H₁₉(2-THF)Ni(η⁵-C₅H₅)], were isolated from the reaction of anti-B₁₈H₂₂ with nickelocene, [Ni(η⁵-C₅H₅)₂], in high yields. The complexes were characterized by multinuclear NMR (¹H, ¹³C, ¹¹B), IR and UV–vis spectroscopy. Single-crystal X-ray diffraction analyses of these new complexes confirmed their structures as 19-vertex conjuncto-metallaborane clusters.     

A fast route to the potential biological reagent (η5-C5H4COOH)Re(CO)3 from [NH4] [ReO4]

The rhenium carbonyl carboxylic acid (η⁵-C₅H₄COOH)Re(CO)₃ (Re + 1) is readily accesssible in a rapid fashion starting from perrhenate (Re + 7). This complex can be conjugated to amino acids and proteins opening the way to a robust small radiopharmaceutical.     

Ru4(μ-CO)(CO)9(η4-μ4-C6H4)(η2-μ1,μ4-PPhCH2CH2PPh2): an unusual pyrolysis product of Ru3(CO)10(dppe) containing a benzyne ligand

The thermal decomposition of Ru₃(CO)₁₀(dppe) in refluxing benzene gives, in contrast to the pyrolysis of the dppm analogue, the tetranuclear cluster Ru₄(μ-CO)(CO)₉(η⁴-μ₄-C₆H₄)(η²-μ₁,μ₄-PCH₂CH₂PPh₂) (1) along with Ru₃(CO)₉(η²-μ₁,μ₂-C₆H₅)(η³-μ₁,μ₂-PPhCH₂CH₂PPh₂) (2). The single-crystal structure analysis of 1 reveals a square-planar tetraruthenium skeleton containing a η⁴-μ₄-benzyne ligand as well as a η²-μ₁,μ₄-phosphinidene–phosphine ligand.     

无铅或少铅钙钛矿CH3NH3M1-xPbxX3(M=Sn,Sr;X=Cl,Br,I)太阳能电池的研究进展

本文综述了Sn2+或Sr2+取代的无铅或少铅钙钛矿CH3NH3PbX3 (X=Cl,Br,I)的结构及其主要的制备方法,评述了各种方法的优缺点.简要介绍了无铅或少铅钙钛矿材料的能隙以及材料的稳定性对太阳能电池的影响,并对其发展前景进行了展望.     

Electrochemical anion recognition by redox-responsive unnatural amino acid derivatives; the X-ray crystal structure of N-ferrocenoyl glycine methyl ester, (η5-C5H5)Fe(η5-C5H4)CONHCH2COOMe

N-Ferrocenoyl glycine ester derivatives FcCONHCH₂COOR (Fc=(η⁵-C₅H₅)Fe(η⁵-C₅H₄); R=methyl (1), ethyl (2) and benzyl (3)) have been prepared by coupling ferrocene carboxylic acid to a series of glycine esters using 1,3-dicyclohexylcarbodiimide (DCC), 1-hydroxybenzotriazole (HOBT) and Et₃N in CH₂Cl₂. The electrochemical anion sensing using a platinum microdisk working electrode of these N-ferrocenoyl glycine ester derivatives is reported. The crystal structure of 1 has been determined; principal dimensions are amide N(H)CO 1.229(3) Å, ester CO 1.183(3) Å with N–H⋯OC(amide) as the primary intermolecular hydrogen bond, N⋯O 2.804(3) Å.     

LiX(X=Cl,Br,I)在乙醇、异丙醇及三氟乙醇中的电导率实验研究

为了研发逆电渗析法闭式热–电转换系统匹配工作溶液,选取强电解质LiCl、LiBr和LiI为溶质,低气化潜热的乙醇、异丙醇及三氟乙醇为溶剂,利用所建立的电导率测试装置进行实验研究。通过数据拟合(修正高斯振幅方程法)和溶液热力学、电化学理论分析,获得溶质、溶剂、温度以及添加剂对溶液电导率的影响规律及作用机理。结果表明:当溶质相同时,LiX–乙醇体系电导率最大,LiX–异丙醇体系最小;而当溶剂相同时,LiI–溶剂体系电导率最大,LiCl-溶剂体系最小。实验还发现提升溶液温度或加入强极性添加剂(H_2O、二甲基乙酰胺)均可强化溶液电导性,而添加N-甲基吡咯烷酮和二氯甲烷对体系电导率影响非常微弱。     

A convenient method for the synthesis of [Pd{[(η5-C5H3)–CHN–(CH2)2–NMe2]Fe(η5-C5H5)}Cl] and the study of its reactivity with diphosphines

A one-pot method for the preparation of [Pd{[(η⁵-C₅H₃)–CHN–(CH₂)₂–NMe₂]Fe(η⁵-C₅H₅)}Cl] is described. Its X-ray crystal structure and its reactions with the diphosphines Ph₂P–(CH₂)_n–PPh₂ {with n=1 (ddpm) or 2 (dppe)} are also reported.     

Influence of NaX (X=Cl,Br, I) additive on phase composition,thermostability and high infrared performances of γ-La2S3 transparent ceramics

A simple method to synthesize Na⁺-doped La₂S₃ powder with only γ phase was developed where NaX (X = Cl, Br, I) served as sodium source. In initial molar ratio Na/La ≥ 0.8 of the mixed raw materials, γ-La₂S₃:Na⁺ tended to reach a constant ratio Na/La = 0.2 and could be represented as Na_0.5La_2.5S₄, which exhibited enough high-temperature stability available for sintering. A modified process was designed to prepare γ-La₂S₃ ceramics with NaCl additive. The microstructure, typical grain boundary composition, photoluminescence and IR performance of as-sintered γ-La₂S₃ ceramics were investigated in details. The optical transparency with mean transmittance 61.3% in 8–14 μm and maximum 64.03% at 13.1 μm was achieved for pellet with Na:La = 0.2 and 1.0 wt% NaCl nanocrystals. NaCl was proved to play multiple roles in governing phase composition, enhancing stability, optimizing microstructure, improving IR properties and affecting luminescence of γ-La₂S₃ ceramics. The mechanisms of action of NaCl additive are proposed by combining the defects reaction, ionic radius and the diffusion behavior of related ions with the cation-deficient structure of γ-La₂S₃.     

Comparison of the structural properties of compounds containing the XSSX moiety (X = H,Me, R,Cl, Br,F, OR)

A comparison of the structural parameters of a wide variety of compounds containing the S–S bond is summarized.     

An unusual intramolecular metallalactone formation from coordinated alkoxide and CO: molecular structure of Au3Ru3{μ3-η1:η1:η1,η2-CCHCPh2OC(O)}(CO)8(PPh3)3

Sequential treatment of Ru₃(μ-H){μ₃-C₂CPh₂(OH)}(CO)₉ with K[BHBu^s₃] and AuCl(PPh₃) afforded Au₃Ru₃{μ₃-η¹:η¹:η¹,η²-CCHCPh₂OC(O)}(CO)₈(PPh₃)₃, formed by intramolecular attack of alkoxide on an adjacent CO ligand, and characterised by a single-crystal X-ray study.