Synthesis and electrochemistry of a novel polyfluorenylidene containing ferrocene units

A novel fluorenylidene containing a ferrocene unit has been electropolymerized. In this polymer, the ferrocene unit is grafted to the main polyfluorenylidene chain as a pendant group. The polymer is electroactive in non-aqueous and aqueous media.     

Synthesis and properties of dendrimers possessing the same fluorophore(s) located either peripherally or off-center

Two series of phosphorus dendrimers functionalized by maleimide derivatives are synthesized, as well as three new monomeric maleimide derivatives, of which two are characterized by X-ray diffraction. The first series of phosphorus dendrimers possesses maleimide derivatives as end groups (6-48, from generation 0 to generation 3). The second series of dendrimers possesses a single copy of the same maleimide derivative linked "off-center" to a cyclotriphosphazene core, leading to dissymmetrical dendrimers; this series is synthesized from generation 0 to generation 2. The fluorescence properties of both series of dendrimers and of monomers are studied, affording new information. First, the presence of labile hydrogen extinguishes the fluorescence. Second, the grafting of the fluorophore(s) directly to the core affords highly fluorescent compounds. Finally, an original influence of the branches possessing phosphorhydrazone linkages toward the fluorescence properties is shown.     

Synthesis,crystal structure,electronic spectroscopy,electrochemistry and biological studies of carbohydrate containing ferrocene amides

A series of four new ferrocene–carbohydrate amides was prepared from pentose and hexose sugar derivatives. These include (5‐amino‐5‐deoxy‐1,2‐O‐isopropylidene‐α‐d ‐xylofuranose)‐1‐ferrocene carboxamide (2a), (5‐amino‐3‐O‐benzyl‐5‐deoxy‐1,2‐O‐isopropylidene‐α‐d ‐xylofuranose)‐1‐ferrocene carboxamide (2b), (methyl‐6‐amino‐6‐deoxy‐2,3‐O‐isopropylidene‐β‐d ‐ribofuranoside)‐1‐ferrocene carboxamide (2c) derived from furanose sugars and (6‐amino‐6‐deoxy‐1,2:3,4‐di‐O‐isopropylidene‐α‐d ‐galactopyranose)‐1‐ferrocene carboxamide (2d) derived from pyranose sugar. The compounds were characterized by spectroscopic means and the structure of amide derived from α‐d ‐xylofuranose (2a) was determined by X‐ray crystallography. The electronic and optical properties of the compounds were studied by means of cyclic voltammetry and absorption spectroscopy. The UV and electrochemical studies of these compounds, performed in aqueous solutions under physiological conditions (at pH 7.4), confirmed their stability. These results indicated that the compounds were suitable for conducting biological studies. The CD spectral analysis displays the effect of sugar substituents on the compounds. The cytotoxicity and antimicrobial activity of these conjugates were investigated on different cancer cell lines and microbes respectively. The degree of inhibition varied over a broad spectrum of Gram‐ positive and Gram‐negative bacteria. In addition, the compounds also exhibited antioxidant properties. Copyright © 2012 John Wiley & Sons, Ltd.     

New dendrimers containing a single cobaltocenium unit covalently attached to the apical position of Newkome dendrons: electrochemistry and guest binding interactions with cucurbit[7]uril

Two new dendrimer series were prepared and characterized. These dendrimers contain a single bis(cyclopentadienyl)cobalt(III) (cobaltocenium, Cob+) unit covalently attached to the apical (focal) position of Newkome-type dendrons, ranging in size from first to third generation. The dendrimers in the first series (1ECob+-3ECob+) are hydrophobic and have 3, 9, and 27 tert-butyl esters on their peripheries, whereas the dendrimers in the second series (1Cob+-3Cob+) are hydrophilic with 3, 9, and 27 carboxylic acid groups on their surfaces, respectively. In voltammetric experiments, all dendrimers showed the expected one-electron reversible reduction of the cobaltocenium center, and the heterogeneous rate of electron transfer decreased with generation in both dendrimer series. The host-guest binding interactions between water-soluble dendrimers 1Cob+-3Cob+ and the cucurbit[7]uril (CB7) host were investigated using 1H NMR spectroscopy, MALDI-TOF mass spectrometry, and electrochemical techniques. The association equilibrium constants (K) for all dendrimer guests were significantly lower than that measured for the inclusion complex between underivatized Cob+ and CB7 (K = 5.7 x 10(9) M(-1)). Nonetheless, among the three dendrimers surveyed, the second-generation dendrimer, 2Cob+, afforded optimum stabilization for the CB7 inclusion complex.     

Synthesis and characterization of ferrocene containing block copolymers

Narrowly dispersed diblock copolymers containing poly(methyl methacrylate) [PMMA] or poly(nonafluorohexyl methacrylate) [PF9MA] as the first block and poly(ferrocenylmethyl methacrylate) [PFMMA] as the second block, were prepared by anionic polymerization for the first time. Disordered bulk morphologies in the case of PMMA‐b‐PFMMA were observed and explained in terms of low Flory–Huggins interaction parameter (χ ≤ 0.04). In the case of PF9MA‐b‐PFMMA hexagonally packed cylinder morphology (HEX) was substantiated from TEM and SAXS observations. Furthermore, high incompatibility between PF9MA and PFMMA blocks allowed for the formation of well‐ordered ferrocene containing cylinders on silica substrate upon exposure of the thin films to a saturated solvent vapor. It was shown that the cylinder orientation, parallel or perpendicular to the surface, could easily be controlled by appropriate choice of the solvent and without the need for preliminary surface modification, for example by means of grafted brush layer. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 495–503     

Synthesis,characterization, and fire retardancy of ferrocene containing polyphosphate esters

Polyphosphate esters containing ferrocene structures were synthesized from 1,1′-bis (p-hydroxyphenylamido) ferrocene and 1,1′-bis (p-hydroxyphenoxycarbonyl) ferrocene with aryl phosphorodichloridates by interfacial polycondensation using a phase transfer catalyst. The polymers were characterized by infrared, ¹H-, ¹³C-, and ³¹-NMR spectroscopy. The molecular weights were determined by end group analysis using ³¹P-NMR spectral data. The thermal stability and fire retardancy were respectively determined by thermogravimetry and limiting oxygen index (LOI) measurements. The polyamide-phosphate esters showed better thermal stability and higher LOI values than the polyester-phosphate esters.     

Synthesis and circular dichroism of the optically active dendrimers with the planar chiral ferrocene core

The (S)- and (R)-enantiomers of new planar chiral enantiomerically enriched Frechet-type dendrimers with the 1,2-disubstituted ferrocene core were synthesized from one (S)-enantiomeric precursor. The synthesized compounds were characterized by the circular dichroism spectra.     

Synthesis,photochromic mechanism and properties of a novel biindenylidenedione compound containing ferrocene units

A novel biindenylidenedione compound, [2,2′‐bi‐1H‐indene]‐3,3′‐bis [(4‐oxo‐4‐ferrocenylbutanoyloxy)propyl]‐3,3′‐ dihydroxy‐1,1′‐dione was synthesized and characterized fully by ¹H NMR, IR, MS and elemental analysis. The photochromic and photo‐induced radical properties were investigated by means of UV–vis and electron spin resonance spectroscopy, respectively. The results show that the title compound simultaneously exhibits photochromism in the solid state as well as generating stable free radicals under irradiation with 330 nm light. This fact provides evidence for the photochromic mechanism of this kind of compounds. Copyright © 2008 John Wiley & Sons, Ltd.     

Electrochemical and guest binding properties of Frechet- and Newkome-type dendrimers with a single viologen unit located at their apical positions

Several new series of dendrimers containing a single redox-active 4,4'-bipyridinium (viologen) residue were synthesized and characterized. In these dendrimers, the viologen group is covalently attached to the apical position of a Newkome- or Frechet-type dendron, ranging in size from first to third generation of growth. The half-wave potentials corresponding to the two consecutive one-electron reductions of the viologen residue are affected by the size of the dendritic component. The size effects are more pronounced in the Newkome-type dendrimers and seem to result from the polarity contrast between the microenvironments provided by the solution and the internal phase of the dendrimer. Unlike in many other dendrimers having a redox-active core, the voltammetric behavior remains fast (reversible) even in third generation dendrimers. Pulse gradient stimulated echo NMR diffusion coefficient measurements on the Newkome-type dendrimers reveal that their hydrodynamic radii are relatively invariant in solvents of widely different polarities (dichloromethane to dimethyl sulfoxide). The host-guest binding interactions between the viologen residue in these dendrimers and the crown ether host bis-p-phenylene-34-crown-8 were also investigated. While in Newkome-type dendrimers the growth of the dendron caused a substantial attenuation of the binding constant values, this size effect was not observed in the Frechet-type dendrimers. These electrochemical and binding measurements underscore some of the structural differences between these two common types of dendritic architectures.     

Synthesis, properties and crystal structures of ferrocene derivatives containing pyrazinium and quinoxalinium units

The pyrazinium salt [FcCH₂pyz][BF₄] (1) and the quinoxalinium salt [FcCH₂quin][BF₄] (2) were prepared by the reaction of [FcCH₂][BF₄] with pyrazine and quinoxaline, respectively and characterised by spectroscopic methods, cyclic voltammetry and by single-crystal X-ray diffraction, which revealed the absence of any π-π-stacking motifs in the crystal structures.     

Synthesis,characterization and properties of novel polyamides containing ferrocene unit and flexible spacers

Synthesis and characterization of ferrocene‐containing main‐chain polyamides are reported in this article. A new, interesting type of organometallic monomer (FDADO) based on ferrocene was prepared by interfacial condensation of 1,1′‐dichlorocarbonyl ferrocene with 2 mol 1,8‐diamino‐3,6‐dioxaoctane (DADO). A series of ferrocene‐based polyamides was prepared via polycondensation of the ferrocenyl diamine (FDADO) with different diacid chlorides using two different methods. The monomer and polymers were characterized by elemental analysis, infrared and NMR spectroscopy. The thermal stability and behavior of the synthesized polymers were evaluated by thermal gravimetric analysis (TGA), dynamic mechanical thermal analysis (DMTA), and differential scanning calorimetry (DSC). The crystallinity of polymers was examined by X‐ray diffraction analysis. Inherent viscosity, solubility and flame‐retardancy of the polymers were also studied. The obtained polymers showed good heat‐resistance and flame‐retardancy, and improved solubility vs generally reported polyamides in some common organic solvents. Copyright © 2007 John Wiley & Sons, Ltd.     

Synthesis of mono-amino-functionalised ferrocene, ferrocene salts and ferrocenium salts

A number of mono-amino-functionalised ferrocenes, ferrocene salts and a mono-amino-functionalised ferrocenium salt have been synthesised and characterised. This represents a novel method of accessing these important classes of molecules. In the cases of some of the ferrocene salts, there are some interesting structural features in the solid state. These include N-H...O and N-H...F hydrogen bonds.     

Synthesis and properties of dumbbell-shaped dendrimers containing 9-phenylcarbazole dendrons

We report the synthesis and structural characterization of two dumbbell-shaped dendrimers incorporating 9-phenylcarbazole units as dendrons, as well as their thermal, morphological, photophysical, and electrochemical properties.     

Synthesis and conformational analysis of optically active ferrocene containing macrocyclic peptides

Two macrocyclic peptides 3 and 4 were formed during lactamization of 1,1'-ferrocenylbis(alanine) 1. Isolation, structure determination, and conformational analysis of 3 and 4 are reported as well as a controlled stepwise synthesis of 4 also including an improved route to 1. On the basis of their (1)H NMR spectra recorded at 300 K in DMSO-d(6), the dimer 3 and trimer 4 were found to be C(2) and C(3) symmetric, respectively. As appeared from computational analysis, the low-energy conformations of the macrocyclic peptides were nonsymmetric. Cyclic voltammetry revealed that the ferrocenyl moieties in 3 or 4 are electrochemically equal to ferrocene.     

Synthesis and anti-brucella activity of some new 1,3,4-oxadiazole derivatives containing a ferrocene unit

An isocyanide-based multicomponent reaction between cinnamic acid derivatives or 3-phenyl-2-propynoic acid, (N-isocyanimino)triphenylphosphorane, ferrocenecarbaldehyde, and dibenzylamine has been reported in excellent yields for the preparation of some new ferrocenyl-containing 1,3,4-oxadiazole derivatives. The anti-brucella activities of the products are investigated in in vitro and in vivo assays.     

Synthesis and antimicrobial activity of some novel ferrocene-based Schiff bases containing a ferrocene unit

In the present investigation, a series of ferrocene-based Schiff bases 5a?Cm were synthesized by the condensation of various chalcones 3a?Cm with S-benzyl dithiocarbazate in absolute ethanol using catalytic amount of glacial acetic acid, and characterized by element analysis,¹H NMR,¹³C NMR, and IR. The synthesized compounds were screened for their in vitro antimicrobial activity against four bacterias (Staphylococcus aureus ATCC 9144, Bacillus cereus ATCC 11778, Escherichia coli ATCC 25922, and Pseudomonas aeruginosa ATCC 43288) and two fungals (Aspergillus niger ATCC 9092 and Aspergillus fumigatus ATCC 46645) strains. The Schiff bases 5g, 5h, and 5m against Gram-positive bacterial (E. coli and P. aeruginosa) strains was found to be higher than that for the standard drug. They are potential new drugs in antibacterial activity aspects in further days.     

Synthesis,characterization, and antimicrobial activity of novel heterocyclic compounds containing a ferrocene unit via Michael addition reaction

Research on Chemical Intermediates - A series of novel heterocyclic compounds containing a ferrocene unit were synthesized by reacting ferrocenylchalcone with pyrazolyl amine or triazolyl amine via...     

Synthesis,structures, and electrochemistry of diiron toluene-3,4-dithiolate complexes containing phosphine ligands

Transition Metal Chemistry - In this paper, four diiron toluene-3,4-dithiolate complexes with phosphine ligands were synthesized and characterized. Treatment of complex...     

Synthesis, structures, and electrochemistry of gold(III) ethylenediamine complexes and interactions with guanosine 5'-monophosphate

[Au(en)Cl(2)]Cl.2H(2)O, where en = ethylenediamine (1,2-diaminoethane), has been synthesized, and its structure has been solved for the first time by the single-crystal X-ray diffraction method. The complex has square-planar geometry about Au(III), and the anionic Cl- is located in the apical position and at a distance of 3.3033(10) A compared to 2.2811(9) and 2.2836(11) A for the coordinated Cl-. [Au(en)Cl2]Cl.2H2O belongs to the space group Pbca with a = 11.5610(15) A, b = 12.6399(17) A, c = 13.2156(17) A, alpha = beta = gamma = 90 degrees , and Z = 8. Bond lengths of Au-N are 2.03 A. [Au(en)Cl2]Cl.2H2O is less thermally stable than [Au(en)2]Cl3 because of the replacement of two Cl ligands by a second en ligand in the latter. Cyclic voltammetry shows that the formal potential of Au(III)/Au(0) becomes more negative in the series [AuCl4]-, [Au(en)Cl2]+, and [Au(en)2]3+. 1H, 13C, and 31P NMR reveal that in an aqueous solution [Au(en)Cl2]+ bonds to guanosine 5'-monophosphate, 5'-GMP (1:1 mole ratio), via N7, although the stability is not very high. NMR data also indicate that N7-O6 or N7-phosphate 5'-GMP chelation, as found in some gold(III) nucleotide complexes, is not present. The gold(III) complex undergoes hydrolysis at pH >2.5-3.0 and, therefore, N1 coordination to 5'-GMP is not observed. No direct coordination between 5'-GMP and [Au(en)2]Cl3 is observed.     

Synthesis, structure, and both cathodic and anodic reversible redox reactions of benzochalcogenophenes containing ferrocene units

2,3-Diferrocenylbenzo[b]thiophene and 1,3-diferrocenylbenzo[c]thiophene have been systematically and selectively synthesized from benzo[b]thiophene and phthaloyl dichloride, respectively. Characterization of the molecules was performed by physical and spectroscopic means and X-ray crystallographic analyses. The cyclic voltammograms of the novel thiophene derivatives containing ferrocene fragments showed a well-defined reversible cathodic step derived from the unusually stable thiophene radical anions and two distinct reversible anodic steps derived from ferrocenium cations separated from each other by a thiophene heterocycle. 1,3-Diferrocenylbenzo[c]selenophene was also synthesized in a similar manner for formation of 1,3-diferrocenylbenzo[c]thiophene by the use of bis(dimethylaluminum) selenide as a selenating reagent.