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1.
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. 相似文献
2.
DA Khobragade SG Mahamulkar L Pospíšil I Císařová L Rulíšek U Jahn 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(39):12267-12277
A series of mono- and 1,1'-diheteroatom-substituted ferrocene derivatives as well as acylated ferrocenes was prepared efficiently by a unified strategy that consists of selective mono- and 1,1'-dilithiation reactions and subsequent coupling with carbon, phosphorus, sulfur and halogen electrophiles. Chemical oxidation of the ferrocene derivatives by benzoquinone, 2,3-dichloro-5,6-dicyanobenzoquinone, AgPF(6) , or 2,2,6,6-tetramethyl-1-oxopiperidinium hexafluorophosphate provided the corresponding ferrocenium salts. The redox potentials of the synthesized ferrocenes were determined by cyclic voltammetry, and it was observed that all new ferrocenium salts have stronger oxidizing properties than standard ferrocenium hexafluorophosphate. An initial application of selected derivatives in an oxidative bicyclization revealed that they mediate the transformation under considerably milder conditions than ferrocenium hexafluorophosphate. Quantum chemical calculations of the reduction potentials of the substituted ferrocenium ions were carried out by using a standard thermodynamic cycle that involved the gas-phase energetics and solvation energies of the contributing species. A remarkable agreement between theory and experiment was found: the mean average deviation amounted to only 0.030?V and the maximum deviation to 0.1?V. This enabled the analysis of various physical contributions to the computed reduction potentials of these ferrocene derivatives, thereby providing insight into their electronic structure and physicochemical properties. 相似文献
3.
Dr. Dushant A. Khobragade Shraddha G. Mahamulkar Dr. Lubomír Pospíšil Dr. Ivana Císařová Dr. Lubomír Rulíšek Dr. Ullrich Jahn 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(39):12267-12277
A series of mono‐ and 1,1′‐diheteroatom‐substituted ferrocene derivatives as well as acylated ferrocenes was prepared efficiently by a unified strategy that consists of selective mono‐ and 1,1′‐dilithiation reactions and subsequent coupling with carbon, phosphorus, sulfur and halogen electrophiles. Chemical oxidation of the ferrocene derivatives by benzoquinone, 2,3‐dichloro‐5,6‐dicyanobenzoquinone, AgPF6, or 2,2,6,6‐tetramethyl‐1‐oxopiperidinium hexafluorophosphate provided the corresponding ferrocenium salts. The redox potentials of the synthesized ferrocenes were determined by cyclic voltammetry, and it was observed that all new ferrocenium salts have stronger oxidizing properties than standard ferrocenium hexafluorophosphate. An initial application of selected derivatives in an oxidative bicyclization revealed that they mediate the transformation under considerably milder conditions than ferrocenium hexafluorophosphate. Quantum chemical calculations of the reduction potentials of the substituted ferrocenium ions were carried out by using a standard thermodynamic cycle that involved the gas‐phase energetics and solvation energies of the contributing species. A remarkable agreement between theory and experiment was found: the mean average deviation amounted to only 0.030 V and the maximum deviation to 0.1 V. This enabled the analysis of various physical contributions to the computed reduction potentials of these ferrocene derivatives, thereby providing insight into their electronic structure and physicochemical properties. 相似文献
4.
Gary J. Tustin Craig E. Banks Robert B. Smith Nathan S. Lawrence 《Journal of organometallic chemistry》2007,692(23):5173-5182
A range of novel water-soluble alkylated ferrocene sulfonate compounds are reported. Mono- and di-sulfonation on a series of alkyl ferrocenes produced 1,1′-dimethyl ferrocene sulfonate, 1,1′-dimethyl ferrocene disulfonate, 1,1′-diethyl ferrocene sulfonate, 1,1′-diethyl ferrocene disulfonate, t-butyl ferrocene sulfonate, t-butyl ferrocene disulfonate, ethyl ferrocene sulfonate, ethyl ferrocene disulfonate, n-butyl ferrocene sulfonate and n-butyl ferrocene disulfonate. All compounds were characterized by NMR spectroscopy, UV/Vis spectroscopy and electrochemical analysis. 1H and 13C NMR studies have revealed the formation of several isomers with sulfonation occurring on positions α and β to the alkyl substituent or on the unsubstituted cyclopentadienyl ring. Variation of the alkyl group allowed the isomeric pattern to be tuned such that the final products followed either electronic or steric control. Cyclic voltammetry of the resulting products showed that the redox potential of the iron centre can be easily manipulated by changing the substituents on the cyclopentadienyl rings. This result has significant implications in the future development of homogenous redox mediators for sensing applications. 相似文献
5.
Roemer M Kang YK Chung YK Lentz D 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(11):3371-3389
Trifluorovinyl groups are introduced onto the cyclopentadienyl ligands of ferrocene at the 1-, 1,1'-, and 1,2-positions by Negishi-type and Stille-type coupling reactions of trifluorovinylzinc chloride and tri-n-butyltrifluorovinyl stannane with several iodoferrocenes. Modification of the trifluorovinyl group by nucleophilic substitution and [2+2] cycloaddition make them versatile building blocks for synthetic transformations. 1,1'-Bis(trifluorovinyl) ferrocene reacts upon contact with silica or oxidizing agents and in the presence of a suitable nucleophile through a redox autocatalytic mechanism to afford ferrocenophanes with fluorinated handles. C(F)(H) and C(F)(OMe) moieties in α-positions allowed further modifications to be performed by nucleophilic substitution of the fluorine atoms. A series of ferrocenes with fluorinated side chains and ferrocenophanes with fluorinated handles were isolated and characterized. Several molecular structures were determined by single-crystal X-ray diffraction. The influence of the fluorine substituents on the redox properties of the iron center were studied by cyclic voltammetry. 相似文献
6.
1 INTRODUCTION In recent years, the rational design and synthesisof metal-directed supramolecular frameworks throughintermolecular hydrogen bonds, π-π stacking interac-tion or other weak interactions have received muchattention because of their interesting molecular topo-logies and various potential applications in catalysis,superconductor, magnetism, nonlinear optics, sen-sors and molecular recognition[1~4]. On the otherhand, the attachment of mono- or polypyridyl frag-ments to a ferr… 相似文献
7.
Mom S Beaupérin M Roy D Royer S Amardeil R Cattey H Doucet H Hierso JC 《Inorganic chemistry》2011,50(22):11592-11603
The synthesis of novel substituted cyclopentadienyl salts that incorporate both a congested branched alkyl group (tert-butyl, (triphenyl)methyl, or tri(4-tert-butyl)phenylmethyl) and a phosphanyl group is reported. The introduction of either electron-withdrawing or electron-donating substituents (furyl, i-propyl, cyclohexyl, tert-butyl) on P atoms was generally achieved in high yield. The modular synthesis of ferrocenyl polyphosphanes from an assembly of these cyclopentadienyl salts was investigated, leading to the formation of new triphosphanes (denoted as 9-12) and diphosphanes (denoted as 14-16). The resulting phosphanes are not sensitive to air or moisture, even when electron-rich substituents are present. This set of polyphosphanes displays varied conformational features, which are discussed in the light of their multinuclear NMR characterization in solution and of the X-ray solid state structure of the representative triphosphane 1,2-bis(diphenylphosphanyl)-1'-(diisopropylphosphanyl)-3'-(triphenyl)methyl-4-tert-butyl ferrocene, 11. In particular, the existence of a range of significantly different nonbonded ("through-space", TS) spin-spin coupling constants between heteroannular P atoms, for the triphosphanes of this class, allowed their preferred conformation in solution to be appraised. The study evidences an unanticipated flexibility of the ferrocene platform, despite the presence of very congested tert-butyl and trityl groups. Herein, we show that, contrary to our first belief, the preferred conformation for the backbone of ferrocenyl polyphosphanes can not only depend on the hindrance of the groups decorating the cyclopentadienyl rings but is also a function of the substituents of the phosphanyl groups. The interest of these robust phosphanes as ligands was illustrated in palladium catalysis for the arylation of n-butyl furan with chloroarenes, using direct C-H activation of the heteroaromatic in the presence of low metal/ligand loadings (0.5-1.0 mol?%). Thus, 4-chlorobenzonitrile, 4-chloronitrobenzene, 4-chloropropiophenone, and 4-(trifluoromethyl)chlorobenzene were efficiently coupled to n-butyl furan, using Pd(OAc)(2) associated to the new diphosphane ligands 1,1'-bis(diisopropylphosphanyl)-3,3'-di(triphenyl)methyl ferrocene (15) or 1,1'-bis(dicyclohexylphosphanyl)-3,3'-di(triphenyl)methylferrocene (16), which respectively hold the electron-rich -Pi-Pr(2) and -PCy(2) groups. 相似文献
8.
9.
Monisola I. Ikhile Muhammad D. Bala Vincent O. Nyamori J. Catherine Ngila 《应用有机金属化学》2013,27(2):98-108
Ferrocenylimidazolium salts with methylene and phenyl groups bridging the ferrocenyl and alkylimidazolium moieties were synthesized and characterized by spectroscopic and analytical methods. Crystal structures of two new compounds are also reported. Cyclic voltammetry was used to analyze the influence of the two bridging groups or spacers on electrochemical properties of the salts relative to the shifts in the formal electrode or peak potentials (E0 or E1/2) of the ferrocene/ferrocenium redox couple. Results from this study showed that all the salts exhibited higher electrode potentials relative to ferrocene, which is due to the electron‐withdrawing effect of the imidazolium ion on the ferrocenyl moiety. Application of the salts as catalysts in transfer hydrogenation of ketones resulted in high conversion of saturated ketones to corresponding alcohols and turnover numbers as high as 1880. The catalysts were chemoselective towards reduction of the C═C bonds of conjugated 3‐penten‐2‐one and 4‐hexen‐3‐one to yield saturated ketones, while unconjugated 5‐hexen‐2‐one was hydrogenated to an unsaturated alcohol. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
10.
Ilkhechi AH Mercero JM Silanes I Bolte M Scheibitz M Lerner HW Ugalde JM Wagner M 《Journal of the American Chemical Society》2005,127(30):10656-10666
A systematic study of cation-pi interactions between alkali metal ions and the cyclopentadienyl ring of ferrocene is presented. The alkali metal (Li+, Na+, K+, Rb+, Cs+) salts of the ditopic mono(pyrazol-1-yl)borate ligand [1,1'-fc(BMe2pz)2]2- crystallize from dimethoxyethane as multiple-decker sandwich complexes with the M+ ions bound to the pi faces of the ferrocene cyclopentadienyl rings in an eta5 manner (fc = (C5H4)2Fe; pz = pyrazolyl). X-ray crystallography of the lithium complex reveals discrete trimetallic entities with each lithium ion being coordinated by only one cyclopentadienyl ring. The sodium salt forms polyanionic zigzag chains where each Na+ ion bridges the cyclopentadienyl rings of two ferrocene moieties. Linear columns [-CpR-Fe-CpR-M+-CpR-Fe-CpR-M+-](infinity) (R = [-BMe2pz]-) are established by the K+, Rb+, and Cs+ derivatives in the solid state. According to DFT calculations, the binding enthalpies of M+-eta5(ferrocene) model complexes are about 20% higher as compared to the corresponding M+-eta6(benzene) aggregates when M+ = Li+ or Na+. For K+ and Rb+, the degree of cation-pi interaction with both aromatics is about the same. The binding sequence along the M+-eta5(ferrocene) series follows a classical electrostatic trend with the smaller ions being more tightly bound. 相似文献
11.
Chamkin A. A. Krivykh V. V. Shtel′tser N. A. Utegenov K. I. Dolgushin F. M. Ustynyuk N. A. 《Russian Chemical Bulletin》2019,68(7):1380-1383
Russian Chemical Bulletin - The reactions of ferrocenium salts with secondary phosphines Ph2PH, Cy2PH, and Et2PH proceed as replacement of the cyclopentadienyl ring to afford half-sandwich... 相似文献
12.
1 INTRODUCTION Recently, there is great current interest in the possibility of using organometallic complexes as ligands to construct mixed-metal suprastructures[1], and ferrocenyl compounds containing mono-or poly- pyridyl fragments have also attracted much attention due to their strong coordinate abilities. For example, Grepioni and coworkers have described the design, synthesis and structure characterizations of several complexes [Fe(η5-C5H4-1-C5H4N)2](AgI)22 /(CuII)24 / (ZnII)24… 相似文献
13.
Protonation of p-xylylaminomethylferrocene (1) and n-hexylaminomethylferrocene (2) by HCl and NH(4)PF(6) forms the ferrocenylmethyl(alkyl)ammonium salt. Inclusion of the compounds by dibenzo[24]crown-8 (DB24C8) produces [2]pseudorotaxanes, [(DB24C8)(1-H)](+)(PF(6)) and [(DB24C8)(2-H)](+)(PF(6)), respectively. X-ray diffraction of the former product indicates an interlocked structure composed of the axis and the macrocyclic molecule. Intermolecular N-H...O and C-H...O interactions and stacking of the aromatic planes are observed. [(DB24C8)(1-H)](+)(PF(6)), in the solid state, is characterized by IR spectroscopy and elemental analyses. A similar reaction of 1,1'-bis(p-xylylaminomethyl)ferrocene (3) forms a mixture of [2] and [3]pseudorotaxanes, [(DB24C8)(3-H(2))](2+)(PF(6))(2) and [(DB24C8)(2)(3-H(2))](2+)(PF(6))(2). The latter product having two DB24C8 molecules is isolated and characterized by X-ray crystallography. Formation of these pseudorotaxanes in a CD(3)CN solution is evidenced by (1)H NMR and mass spectrometry. Electrochemical oxidation of 1-3 at 0.4 V (vs Ag(+)/Ag) in the presence of TEMPOH (1-hydroxy-2,2,6,6-tetramethylpiperidine) and DB24C8 affords the corresponding pseudorotaxanes. The ESR spectrum of the reaction mixture indicates the formation of a TEMPO radical in high yield. Details of the conversion of the dialkylamino group of the ligand to the dialkylammonium group are investigated by using a flow electrolysis method linked to spectroscopic measurements. The proposed mechanism for the reaction involves the ferrocenium species, formed by initial oxidation, which undergoes electron transfer from nitrogen to the Fe(III) center, producing a cation radical at the nitrogen. Transfer of hydrogen from TEMPOH to the cation radical and inclusion of the resulting dialkylammonium species by DB24C8 yields the pseudorotaxanes. 相似文献
14.
Wrackmeyer B Klimkina EV Maisel HE Tok OL Herberhold M 《Magnetic resonance in chemistry : MRC》2008,46(Z1):S30-S35
Three series of ferrocenes, derived from aminoferrocene Fc-NH2 and 1,1'-diaminoferrocene fc(NH2)2, were studied by 57Fe NMR spectroscopy. A marked decrease in 57Fe magnetic nuclear shielding with respect to ferrocene is observed if the nitrogen atom becomes part of a pi-acceptor linked to one or both cyclopentadienyl rings. In contrast, pi-donor properties of the amino group(s) affect delta57Fe to a much smaller extent. In the case of the fairly rigid structures of 1,3-diaza-2-element-[3]ferrocenophanes, a significant increase of 57Fe nuclear magnetic shielding is observed, in contrast to the corresponding [n]ferrocenophanes with n > 3. Structures of numerous of the ferrocene derivatives have been optimized for the gas phase by calculations (B3LYP/6-311 + G(d,p) level of theory), and 57Fe nuclear magnetic shieldings were calculated using these geometries. There is reasonable agreement in the trends for experimental and calculated data. 相似文献
15.
Mono- or 1,1′-bis-acylation of ferrocene, its mono and 1,1′-dimethyl and phenyl derivatives and of [3]ferrocenophane with o-chlorobenzoyl chloride/AlCl3 affords the corresponding (isomeric) chlorobenzoyl ferrocenes in high yields which can be separated by column, layer or high pressure liquid chromatography and in the case of the monomethylferrocene monoketones also by crystallization. The cleavage of the (o-chlorobenzoyl)ferrocenes by potassium-t-butoxide (and traces of water) yields the corresponding ferrocene carboxylic acids except for the α-phenyl derivatives in almost quantitative yields, thus offering a very convenient access to these acids. In all cases the isomer distribution and thereby the relative site reactivities were determined. 相似文献
16.
Double or successive bridge-enlargement reactions were used on appropriate α-ketones followed by reduction to prepare 1,1′-pentamethyleneferrocene, VIII, 1,1′,3,3′-bis(pentamethylene)ferrocene, XX, and 1,1′,2,2t?,4,4′-tris(penta-methylene)ferrocane, XXX. The bridge-enlarging reactions are discussed, and the PMR spectral behavior of the polybridged ferrocenes is briefly discussed. 相似文献
17.
Kowalski K Zakrzewski J Long NJ Suwaki N Mann DJ White AJ 《Dalton transactions (Cambridge, England : 2003)》2006,(4):571-576
The reaction of lithiated 2,5-dimethylazaferrocene 1 with diethyl chlorophosphate proceeds to give lateral and ring phosphonate products. The products 2 and 3 were characterized by spectroscopic (1H, 31P{1H} NMR, MS, IR) methods and 3 was treated with W(CO)5(thf) to form a crystalline W(CO)5-complex 4 which was characterized by single-crystal X-ray analysis. The new 2,5-dimethylazaferrocenyl phosphonates were transformed into the corresponding N-methyl iodide salts 5 and 6 in quantitative yields. Both salts are water soluble and stable compounds and an analysis of their cytotoxic and anti-proliferative activity was carried out. Compound 6 possesses anti-metabolic activity which exhibited some preference towards the cancerous HeLa cell line over the non-cancerous NIH 3T3 cell line. These new compounds are the first examples of azaferrrocene (i.e. non-ferrocene) derivatives featuring biologically important phosphonate groups. The preliminary studies into cytotoxic activity indicates that as with ferrocene, azaferrocene can also be regarded as a potential source for organometallic anticancer agents, featuring the iron centre in the +2 oxidation state rather than the often utilized ferrocenium +3 species. 相似文献
18.
Markus Sailer 《Journal of organometallic chemistry》2006,691(3):299-308
Oligomeric ferrocene-phenothiazine systems, a novel class of organometallic-organic hybrid electrophores, are easily accessible by Suzuki coupling of iodo ferrocenes and phenothiazinyl and diphenothiazinyl pinacolyl boronates. The triad and the pentad with 1,1′-disubstitution on ferrocene adopt preferentially an eclipsed orientation as a consequence of partial intramolecular π-stacking. In cyclic voltammetry the central ferrocenyl unit acts as an electronic communicator between phenothiazinyl side chains. 相似文献
19.
Lee KM Chang HC Jiang JC Lu LC Hsiao CJ Lee YT Lin SH Lin IJ 《The Journal of chemical physics》2004,120(18):8645-8650
We have probed under high pressure the C-H hydrogen bonds formed by N,N(')-disubstituted imidazolium ions having PF(6) (-) and Br(-) counterions. High-pressure infrared spectral profiles, x-ray crystallographic analysis, and ab initio calculations allow us to make a vibrational assignment of these compounds. The appearance of a signal for the free-NH unit (or weakly bonded N-H...F unit) in the infrared spectrum of the PF(6) (-) salt indicates that conventional N-H...O and N-H...N hydrogen bonds do not fully dominate the packing. It is likely that the charge-enhanced C(2)-H...F interactions, combined with other weak hydrogen bonds, disturb the formation of N-H hydrogen bonds in the PF(6) (-) salt. This finding is consistent with the pressure-dependent results, which reveal that the C(2)-H...F interaction is enhanced upon increasing the pressure. In contrast to the PF(6) (-) salt, the imidazolium C-H bonds of the Br(-) salt have low sensitivity to high pressure. This finding suggests that the hydrogen bonding patterns are determined by the relative hydrogen bond acceptor strengths of the Br(-) and PF(6) (-) ions. 相似文献
20.
V. A. Nefedov 《Russian Journal of General Chemistry》2011,81(3):517-520
Two absorption bands of ferrocene, the in-plane bending C-H vibrations (βCH) at 1002 cm?1 and out-of-plane C-H vibration (γCH) at 816 cm?1, are accompanied with high-frequency satellites βCH (1055) and γCH (837 cm?1). In the spectrum of 1,1′-dideuteroferrocene, only the high-frequency bands suffer an isotopic shift, from 1055 to 859 cm?1, and from 837 to 668 cm?1. Only additional incorporation of deuterium into 1,1′-dideuteroferrocene results also in an isotopic shift of the basic bands: 1002 to 771 and 816 to 632 cm?1. Therefore, one of the five carbon atoms of cyclopentadienyl ring of ferrocene differs from the other in the static state. It is assumed that just this carbon atom is bonded with the iron atom by the σ-bond. 相似文献