Phosphine-substituted diiron 1,2-dithiolate complexes as the models for the active site of [FeFe]-hydrogenases

Abstract

In this article, five diiron 1,2-dithiolate complexes containing phosphine ligands are reported. Treatment of complex [Fe₂(CO)₆(μ-SCH₂CH₂S)] (1) with the phosphine ligands tris(4-methylphenyl)phosphine, tris(4-methoxyphenyl)phosphine, tris(3-chlorophenyl)phosphine, tris(3-methylphenyl)phosphine, or 2-(diphenylphosphino)biphenyl in the presence of Me₃NO·2H₂O as the decarbonylating agent afforded the target products [Fe₂(CO)₅(L)(μ-SCH₂CH₂S)] [L?=?P(4-C₆H₄CH₃)₃, 2; P(4-C₆H₄OCH₃)₃, 3; P(3-C₆H₄Cl)₃, 4; P(3-C₆H₄CH₃)₃, 5; Ph₂P(2-C₆H₄Ph), 6] in 80–93% yields. Complexes 2–6 have been characterized by elemental analysis, spectroscopy, and X-ray crystallography. Additionally, the electrochemical properties were studied by cyclic voltammetry.     

6-氨基己酸及2-氨基乙磺酸C60加成物的合成及溶解性

水溶性Fullerenes (C₆₀)衍生物的制备对于C₆₀的生物学研究具有十分重要的意义. 氨基酸与C₆₀的胺化反应可得到水溶性的氨基酸C₆₀衍生物. 以C₆₀与过量6-氨基己酸或2-氨基乙磺酸(摩尔比为1∶10)于80 ℃搅拌反应24 h, 分别得到加成度为5和4的氨基酸C₆₀主产物, 产率按加入的C₆₀计算分别为30%, 28%. 氨基酸碳链的长度及加成产物在反应体系中能否及时沉淀析出影响和控制着加成度的大小. C₆₀[NH(CH₂)₅COOH]₅H₅ (3a), C₆₀(NHCH₂CH₂SO₃H)₄H₄ (6a)用柱层析进一步纯化, 其结构组成经元素分析, ¹H NMR, ¹³C NMR, IR所证实. 6a的水溶性受溶液pH的影响较小, 3a在不同pH缓冲溶液中的溶解性用光谱法测定, 分别为: pH＝10.25时为71.81 mg•mL^－1, pH＝7时为23.68 mg•mL^－1, pH＝3.36时为10.12 mg•mL^－1. 在波长273 nm处, 3a的摩尔消光系数为ε＝3.43×10⁴ L•mol^－1•cm^－1.     

Photophysical Properties and Photoinduced Electron Transfer between[60]Fullerene—containing Cyclic Sulphoxide [C60—C60H8SO]and Tetrathiafulvalene（TTF） by Laser Flash Photolysis

Photoinduced electron transfer(PET) processes between C60-C6H8SO and Tetrathiafulvalene(TTF) have been studied by nanosecond laser photolysis.Quantrm yiekds(φet) and rate constants of electron transfer(ket) from TTF to excited triplet state of[60] fullerene-containing cyclic sulphoxide in benzonitrile(BN) have been evaluated by observing the transient absorption bands in the NIR region.With the decay of excited triplet state of [60]fullerene-containing cyclic suplhoxide,the rise of radical anion of [60]fullerene-containing cyclic sulphoxinde is observed.     

Synthesis and structural characterization of diiron azadithiolate complexes relevant to the active site of [FeFe] hydrogenases

Two N-functionally substituted diiron azadithiolate complexes, [(µ-SCH₂)₂NCH₂CH₂OC(O)C₆H₄I-p]Fe₂(CO)₆ (1) and {[(µ-SCH₂)₂NCH₂CH₂OC(O)C₆H₄I-p]Fe₂(CO)₅Ph₂PCH}₂ (2) as models for the active site of [FeFe] hydrogenases, have been prepared and fully characterized. Complex 1 was prepared by the reaction of [(µ-SCH₂)₂NCH₂CH₂OH]Fe₂(CO)₆ with p-iodobenzoic acid in the presence of 4-dimethylaminopyridine (DMAP) and N,N′-dicyclohexylcarbodiimide (DCC) in 78% yield. Further treatment of 1 with 1 equiv. of Me₃NO?·?2H₂O followed by 0.5 equiv. of trans-1,2-bis(diphenylphosphino)ethylene (dppe) affords 2 in 60% yield. The new complexes 1 and 2 were characterized by IR and ¹H (¹³C, ³¹P) NMR spectroscopic techniques and their molecular structures were confirmed by X-ray diffraction analysis. The molecular structure of 1 has two conformational isomers, in one isomer its N-functional substituent is axial to its bridged nitrogen and in the other isomer its N-functional substituent is equatorial. The crystal structure of 2 revealed that its N-functional substituents are equatorial to its nitrogens and dppe occupies the two apical positions of the square-pyramidal irons.     

Solvent and Concentration-Dependent Aggregation Study of C 60 Dyads and Multiads on Nonlinear Photonic Properties

We have studied the molecular self-assembly tendency of C₆₀(> DPAF-C₉) dyad, C₆₀(> DPAF-C₉)₂ triad, and C₆₀(> DPAF-C₉)₄ pentads in a solvent-dependent and concentration-dependent manner. The evaluation was performed by the particle-size measurements on molecular assemblies in either toluene or CS₂ using the dynamic light scattering technique. As a result, we observed a strong bimodal particle size distribution in most cases of the samples in both nonpolar solvents. In the instance of C₆₀(> DPAF-C₉) dyad, the first group of small nanoparticles exhibited a particle diameter size of 3.0–4.0 nm in good agreement with the estimated long axis length of C₆₀(> DPAF-C₉) (～ 2.7 nm), using 3D molecular modeling technique. Similar observation of a bimodal particle size distribution was detected on C₆₀(> DPAF-C₉)₄ pentads in toluene with a small nanoparticle diameter size of ～ 8.0 nm fitting well with the estimated dimension length of ～ 9.8 nm for loosely packed 3–6 C₆₀(> DPAF-C₉)₄ molecular assemblies. Furthermore, the tendency of forming large aggregation particles in a particle diameter of more than 4.0 μ m was significantly enhanced at a concentration of 1.0 × 10^–2 M.     

Synthesis of 1,2-Disubstituted Ferrocene Containing a Heteroaryl Group

A convenient synthesis of [C₅H₅Fe(1,2-C₅H₃(CH₂R)(Heteroaryl)], (R=NMe₂, Heteroaryl=5-benzoylthien-2-yl(3a), 2-nitropyrid-5-yl(3b), 5-nitrothien-2-yl(3c), 6-methoxy-8-nitroquino-3-yl(3d); R=MeO, Heteroaryl=5-benzoylthien-2-yl(6a), 2-nitropyrid-5-yl)(6b) from [C₅H₅Fe(1,2-C₅H₃(CH₂R)(SnBu₃)], (R=NMe₂, OMe), via Stille coupling reaction is described.     

Oxygen- versus carbon-coordination of the alpha-stabilized phosphorus ylide Ph<Subscript>3</Subscript>P=C(H)R in palladacycles bearing secondary amines

The ortho-metalated complex [Pd(x){κ ² (C,N)-[C₆H₄CH₂NRR′ (Y)}] (2a–4a and 2b–3b) was prepared by refluxing in benzene equimolecular amounts of Pd(OAc)₂ and secondary benzylamine [a, EtNHCH₂Ph; b, t-BuNHCH₂Ph followed by addition of excess NaCl. The reaction of the complexes [Pd(x){κ ² (C,N)-[C₆H₄CH₂NRR′ (Y)}] (2a–4a and 2b–3b) with a stoichiometric amount of Ph₃P=C(H)COC₆H₄-4-Z (Z = Br, Ph) (ZBPPY) (1:1 molar ratio), in THF at low temperature, gives the cationic derivatives [Pd(OC(Z-4-C₆H₄C=CHPPh₃){κ ² (C,N)-[C₆H₄CH₂NRR′(Y)}] (5a–9a, 4b–6b, and 4b′–6b′), in which the ylide ligand is O-coordinated to the Pd(II) center and trans to the ortho-metalated C(6)H(4) group, in an “end-on carbonyl”. Ortho-metallation, ylide O-coordination, and C-coordination in complexes (5a–9a, 4b–6b, and 4b′–6b′) were characterized by elemental analysis as well as various spectroscopic techniques.     

Reaction of fullerene C60 with 2-azido-4,6-diphenylpyrimidine

The first representative of the pyrimidine-substituted [60]fullereno[1,2-b]aziridines was synthesized by the reaction of fullerene C₆₀ with 2-azido-4,6-diphenylpyrimidine. 2-(Azahomo[60]fullereno)-4,6-diphenylpyrimidine was found to be formed as a by-product. The electrochemical properties of the adducts were studied.     

Synthesis and structural characterization of new multiferrocenyl diyne ligands and their cobalt carbonyl complexes

New multiferrocenyl diyne ligands FcC(CH₃)₂Fc′–C≡C–C≡C–Fc [L ₁ ; Fc?=?C₅H₅FeC₅H₄; Fc′?=?C₅H₅Fe(1,3-disubstituted)C₅H₃], FcC(CH₃)₂Fc′–C≡C–C≡C–Fc′C(CH₃)₂Fc (L ₂ ) and their complexes [FcC(CH₃)₂Fc′–C≡C–C≡C–Fc][Co₂(CO)₆] _n [n?=?1, (1); n?=?2, (2)], [FcC(CH₃)₂Fc′–C≡C–C≡C–Fc′C(CH₃)₂Fc][Co₂(CO)₆] _n [n?=?1, (3); n?=?2, (4)] have been synthesized by the coupling reaction of terminal ferrocenylacetylene and the reaction of ligands L₁ and L₂ with Co₂(CO)₈. The composition and molecular structure of the ligands L₁ , L₂ and their cobalt complexes were characterized by element analysis, IR, ¹H(¹³C)NMR and MS. The electrochemical properties of compounds L₁ , L₂ , 1, 2, 3, 4 were studied by cyclic voltammetry(CV). The results of the electrochemical research reveal that all three ferrocenyl groups in L₁ become redox active centers, but there are only two (not four) ferrocenyl redox active centers in L₂ .     

Synthesis,characterization, and electrochemistry of diiron ethane-1,2-dithiolate complexes with monosubstituted ethyldiphenylphosphine or dicyclohexylphenylphosphine

Abstract

In this contribution, two diiron ethane-1,2-dithiolate complexes with one ethyldiphenylphosphine or dicyclohexylphenylphosphine ligand have been synthesized and characterized as mimics for the active site of [FeFe]-hydrogenases. Treatment of complex [Fe₂(CO)₆(μ-SCH₂CH₂S)] (1) with ethyldiphenylphosphine or dicyclohexylphenylphosphine and Me₃NO · 2?H₂O as decarbonylating agent gave complexes [Fe₂(CO)₅(Ph₂PCH₂CH₃)(μ-SCH₂CH₂S)] (2) and [Fe₂(CO)₅{PhP(C₆H₁₁)₂}(μ-SCH₂CH₂S)] (3) in 93% and 86% yields, respectively. Complexes 2 and 3 were characterized by elemental analysis, IR, and NMR spectroscopy. X-ray crystallographic studies confirmed the molecular structures of complexes 2 and 3, indicating that they contain a butterfly diiron ethane-1,2-dithiolate cluster with five terminal carbonyl ligands and an apically-coordinated phosphine ligand. Additionally, the electrochemical properties of these complexes were investigated by cyclic voltammetry, suggesting that they can be regarded as electrocatalysts for the reduction of protons to H₂ in the presence of HOAc. A possible mechanism for the proton reduction was proposed.     

Synthesis and Anticancer Activity of Novel Nonfused Bicyclic Thiazolidinone Derivatives

A series of new 2-{4-oxo-2-[(4-oxothiazolidin-2-ylidene)-hydrazono]-thiazolidin-5-yl}-N-arylacetamides ( 4a–e ), 5-(2-oxo-2-aryl-ethyl)-2-[(4-oxothiazolidin-2-ylidene)-hydrazono]-thiazolidine-4-ones ( 5a–d ), 2-(4-oxo-2-[(2-oxothiazolidin-4-ylidene)-hydrazono]-thiazolidin-5-yl)-N-arylacetamides ( 7a–e ), and 5-(2-oxo-2-aryl-ethyl)-2-[(2-oxothiazolidin-4-ylidene)-hydrazono]-thiazolidine-4-ones ( 8a–d ) have been synthesized starting from 2-thioxothiazolidin-4-one and 4-thioxothiazolidin-2-one through a multistep reaction sequence. 2-Thioxothiazolidin-4-one was alkylated via the intermediate formation of the triethylammonium salt 1 by ethyl chloroacetate. Compound 2 and 4-thioxothiazolidin-2-one reacted with thiosemicarbazides to give the 1-(4-thiazolidinone-2-ylidene)-4-R-thiosemicarbazones ( 3a,b ) and 1-(2-thiazolidinone-4-ylidene)thiosemicarbazones ( 6a,b ), respectively. Following [2+3]-cyclization of thiazolidinone-substituted thiosemicarbazones ( 3a,b and 6a,b) with N-arylmaleimides and aroylacrylic acids as equivalents of dielectrophilic synthon [C₂]^{2 +}, novel non-fused bicyclic thiazolidinones ( 4a–e, 5a–d, 7a–e, 8a–d ) were synthesized. The structures of the new compounds ( 4a–e, 5a–d, 7a–e, 8a–d ) were established on the basis of their elemental analysis and ¹H NMR and mass spectral data. Eight of the synthesized compounds were tested, and three of them displayed different levels of antitumor activity. The most efficient antitumor agent—2-{4-oxo-3-furylmethyl-2-[(4-oxothiazolidin-2-ylidene)-hydrazono]-thiazolidin-5-yl}-N-4-chlorophenylacetamide ( 4d ) was found to be active against leukemia, melanoma, lung, colon, CNS, ovarian, renal, prostate, and breast cancer cell lines with mean lgGI₅₀ and lgTGI values of –5.35 and –4.78, respectively.     

Bis(diphenylphosphino)ferrocene as an intramolecular bridging ligand in N-functionally substituted 1,3-azapropanedithiolate diiron complexes: synthesis and catalysis of proton reduction

Reaction of 1,1′-bis(diphenylphosphino)ferrocene (dppf) with [μ-(SCH₂)₂NCH₂CH₂OH]Fe₂(CO)₆ (A) or [μ-(SCH₂)₂NCH₂CH₂SAc]Fe₂(CO)₆ (C) in refluxing xylene yielded an intramolecular bridging complex [μ-(SCH₂)₂NCH₂CH₂OH]Fe₂(CO)₄(μ-dppf) (1) or [μ-(SCH₂)₂NCH₂CH₂SAc]Fe₂(CO)₄(μ-dppf) (2) in moderate yield. The structures of both complexes were fully characterized by spectroscopic methods and X-ray crystallography, and the electronic structure of 2 was further investigated by UV–vis. The cyclic voltammetry was conducted and the reduction of protons from CF₃SO₃H (TfOH), HBF₄·Et₂O, or CF₃COOH (TFA) catalyzed by 2 was observed.     

Synthesis of highly water soluble C60 end‐capped vinyl ether oligomers with well‐defined structure

Highly water soluble [60]fullerene (C₆₀) end‐capped vinyl ether (VE) oligomers with well‐defined structure were synthesized by living cationic polymerization technique. The addition reaction between 1‐octynylfulleride anion and oligomeric cationic species of VEs with pendant acetoxyl or malonic ester functions afforded the precursor C₆₀ end‐capped oligomers. The living VE oligomers were prepared by living cationic polymerization of diethyl 2‐(vinyloxy)ethylmalonate (VOEM) and 2‐acetoxyethyl vinyl ether (AcOVE) by the CH₃CH(OR)Cl/ZnI₂ [R = CH₂CH₂OCOCH₃ and CH₂CH₂CH(COOEt)₂, respectively] initiating system. The precursors were obtained as dark brown gummy solid in 33 and 72% yield for AcOVE and VOEM, respectively. UV‐vis and ¹³C NMR spectroscopy indicated the formation of 1,2‐disubstituted dihydrofullerene derivatives. Hydrolysis of the precursors proceeded quantitatively to give the water‐soluble C₆₀ end‐capped oligomers having oligo(sodium 2‐vinyloxyethylmalonate) [oligo(VOEMNa)] and oligo(2‐hydroxyethyl vinyl ether) [oligo(HOVE)] moieties. Solubility measurements revealed the water‐soluble C₆₀ end‐capped oligomer with oligo(VOEMNa) chain to have the excellent aqueous solubility compared to that of the water‐soluble C₆₀ derivatives thus far known; the maximum solubility in water is 96.6 mg/mL, which corresponds to 25.9 mg/mL of the C₆₀ moiety. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 3578–3585, 2000     

Syntheses,characterization and crystal structures of two square-planar Ni(II) complexes with unsymmetrical tridentate Schiff base ligands and monodentate pseudohalides

Two new square-planar Ni(II) complexes, [NiL¹(NCS)] (1) and [NiL²(N₃)] (2) have been synthesized with the unsymmetrical tridentate Schiff base ligands [(CH₃)₂NCH₂CH₂N=C(CH₃)CH=C(OH)(C₆H₅)], L ¹ H, derived from benzoylacetone and 2-dimethylaminoethylamine and [(CH₃CH₂)₂NCH₂CH₂N=C(CH₃)CH=C(OH)(C₆H₅)], L ² H, derived from benzoylacetone and 2-diethylaminoethylamine, respectively. The complexes have been characterized by elemental analysis, FT-IR, UV-Vis spectroscopy, electrochemical and thermal methods (where applicable). Structures have been established by the single-crystal X-ray diffraction technique which reveals the discrete nature of the complexes in which the metal centers adopt a distorted square planar geometry. Coordination environments of the metal ions in the complexes are satisfied with two different unsymmetrical Schiff base ligands having similar N₂O donor sets and a terminal pseudohalide anion (thiocyanate for 1 and azide for 2).     

含卤素端基的单取代对-叔丁基杯[6]芳烃的合成与表征

用THF作为反应溶剂, K₂CO₃作碱, 对-叔丁基杯[6]芳烃与二溴丁烷、二溴己烷和1,4-二氯丁炔-2反应以中等产率选择性地合成了含有卤素端基的单取代对-叔丁基杯[6]芳烃2a～2c. 2a和2b可与对甲苯磺酸甲酯(MeOTs)反应高产率地得到全甲基化产物3a和3b. 通过核磁共振谱(¹H NMR)和质谱(FAB-MS)表征, 发现所有化合物都具有预期结构, 2a～2c和3b在室温下是锥式构象, 而3a没有固定构象.     

Synthesis of Fullerene-Containing Sol-Gel Glasses

Macroscopically homogeneous and visually transparent fullerene-containing glasses are fabricated from sol-gel mixtures of aminated C₆₀ derivatives and tetraethyl orthosilicate (TEOS) through physical blending and chemical reaction. The aminated fullerenes are synthesized by the amination reactions of C₆₀ with 6-amino-1-hexanol, cyclohexylamine, 2-(2-aminoethoxy)ethanol, and 3-aminopropyltriethoxysilane at 100°C under nitrogen. The amination products are purified by filtration, precipitation, and column chromatography and are isolated in good to excellent yields (32–82%). Characterization by NMR, MS, and TGA analyses reveals that the aminated fullerenes possess molecular structures H _x C₆₀[NH(CH₂)₆OH] _x , H _x C₆₀(NH-cyclo-C₆H₁₁) _x , H _x C₆₀[NH(CH₂CH₂O)₂H] _x , and H _x C₆₀[NH(CH₂)₃Si(OCH₂CH₃)₃] _x . All the aminated fullerenes except 2 are completely soluble in aqueous alcoholic solutions of TEOS and can be incorporated into silica gel networks by sol-gel process in the absence or presence of drying-control chemical additives, giving crack-free monoliths of large sizes (up to 60 mm). Electronic absorption spectrum of the fullerene glass continuously red shifts with an increase in the C₆₀ content, suggesting the formation of fullerene nanoclusters in the sol-gel process. The fullerene glasses are thermally and optically stable, resisting continuous attack of strong laser pulses of 532 nm for a prolonged period of time without losing their optical limiting power.     

Synthesis and characterization of diiron(I) 1,2-dimethylethanedithiolate complexes with bridging or chelating 1,2-bis(diphenylphosphino)ethylene

The reaction of complex [μ-SCH(CH₃)CH(CH₃)S-μ]Fe₂(CO)₆ (1) with trans-1,2-bis(diphenylphosphino)ethylene (trans-dppv) in the presence of Me₃NO?2H₂O in CH₂Cl₂/CH₃CN afforded complex {[μ-SCH(CH₃)CH(CH₃)S-μ]Fe₂(CO)₅}₂(trans-dppv) (2) with a bridging dppv. Complex [μ-SCH(CH₃)CH(CH₃)S-μ]Fe₂(CO)₄(cis-dppv) (3) was prepared by the reaction of 1 with cis-dppv and Me₃NO?2H₂O. The new complexes 2 and 3 were characterized by elemental analysis, spectroscopy, and X-ray diffraction analysis.     

Octapalladium Strings Trap C60 and C70 Fullerenes Affording Metal-Chain-Wired Bucky Balls

Reactions of Pd₈ strings supported by meso-Ph₂PCH₂P(Ph)CH₂P(Ph)CH₂PPh₂ (meso-dpmppm) ligands, [Pd₈(meso-dpmppm)₄(L)₂]⁴⁺ (L=CH₃CN ( 1 ), XylNC ( 2 )) with C₆₀ resulted in the exclusive formation of unprecedented metal-chain-wired C₆₀ bucky balls, [{Pd₄(meso-dpmppm)₂(L)}₂(C₆₀)]⁴⁺ (L=CH₃CN ( 11 ), XylNC ( 12 )), in which a C₆₀ fullerene is trapped in the central Pd–Pd junction, as unambiguously established by spectroscopic, X-ray crystallographic, and theoretical techniques. The similar reaction of Pd₈ strings supported by rac-dpmppm, [Pd₈(rac-dpmppm)₄(CH₃CN)₂]⁴⁺ ( 3 ) also afforded a racemic mixture of [{Pd₄((R*,R*)-dpmppm)₂(CH₃CN)}₂(C₆₀)]⁴⁺ ( 13 ) without scrambling the Pd₄ fragments with (R,R)- and (S,S)-dpmppm ligands. Consequently, those of enantiopure chiral Pd₈ strings, [Pd₈((R*,R*)-dpmppm)₄(CH₃CN)₂]⁴⁺, certainly afforded chiral bucky balls of [{Pd₄((R*,R*)-dpmppm)₂(CH₃CN)}₂(C₆₀)]⁴⁺ ( 13 _RR and 13 _SS ), that exhibit mirror-image circular dichroism spectra. The reactions of 1 and 2 were also applied for trapping a C₇₀ fullerene to give 2 : 1 adducts of [{Pd₄(meso-dpmppm)₂(L)}₂(C₇₀)]⁴⁺ (L=CH₃CN ( 21 ), XylNC ( 22 )). These results provide useful information for creating a platform to develop dimensionally and chirality controlled metal–carbon nanocomposite materials.     

Complexes of nickel(II) carboxylates with pyridine and cyclam: crystal structures,mesomorphisms, and thermoelectrical properties

Nickel(II) carboxylates [Ni(CH₃(CH₂)₁₄COO)₂(H₂O)₂] (1) and [Ni(C₆H₅COO)₂(H₂O)₂] (2) were obtained from reactions of NiCl₂·6H₂O with CH₃(CH₂)₁₄COONa and C₆H₅COONa, respectively. Complex 1 reacted with pyridine (pyr) to form [Ni(CH₃(CH₂)₁₄COO)₂(pyr)₂(H₂O)₂] (3) and [Ni₂(μ₂-H₂O)(CH₃(CH₂)₁₄COO)₄(pyr)₄] (4) in the same reaction mixture, and reacted with cyclam to form an ionic complex, [Ni(CH₃(CH₂)₁₄COO)(cyclam)(H₂O)]CH₃(CH₂)₁₄COO·4H₂O (5). In contrast, 2 reacted with cyclam to form [Ni(C₆H₅COO)₂(cyclam)] (6). Finally, 6 reacted with p-(hexadecyloxy)pyridine (L) to form an ionic complex, [Ni(cyclam)(L)₂](C₆H₅COO)₂ (7). Complexes 3–6 were single crystals. All complexes have octahedral Ni(II) center(s) and were magnetic. Complexes with cyclam as co-ligand were more thermally stable than those with pyridine and its derivative, L. Complexes 3 and 4 were mesomorphic after partial loss of water and/or pyridine ligands on heating. The ionic complexes 5 and 7 were not mesomorphic, but showed good thermoelectrical behavior with negative S_e values in CHCl₃ (?0.28 mV K^?1 for 5; -0.39 mV K^?1 for 7) and positive S_e values in C₂H₅OH (+0.25 mV K^?1 for 5; +0.20 mV K^?1 for 7).     

Synthesis,structure, and fungicidal activity of thia- and aza-ferrocenophanes

Reaction of bridging dicyclopentadienyl disodium E(CH₂COCpNa)₂ (E = S or NPh, Cp = cyclopentadienyl) with FeCl₂ yields thia- and aza-[5]ferrocenophanes E(CH₂COCp)₂Fe [E = S (1) and NPh (2)]. Treatment of C₁₄H₈(CH₂SCH₂COCpNa)₂ (C₁₄H₈ = 9,10-anthracenyl) with FeCl₂ affords dithia-[12]ferrocenophane C₁₄H₈(CH₂SCH₂COCp)₂Fe (3), while similar reaction of C₆H₄(CH₂SCH₂COCpNa)₂ (C₆H₄ = 1,4-phenyl) with FeCl₂ provides a mixture of dithia-[12]ferrocenophane C₆H₄(CH₂SCH₂COCp)₂Fe (4) and tetrathia-[12,12]ferrocenophane [C₆H₄(CH₂SCH₂COCp)₂Fe]₂ (5), which are separated easily by column chromatography. These five compounds were characterized by IR and NMR spectroscopic analyses and the structures of 2 and 3 were further confirmed by single crystal X-ray diffraction. The electrochemical behaviors of 1–4 were investigated by cyclic voltammetry. In addition, their fungicidal activities against Alternaria solani, Cercospora arachidicola, Physalospora piricola, and Botrytis cinerea were tested in vitro.