15570-45-3Relevant academic research and scientific papers
Interactions in molecular crystals, 126 [1,2] the cation solvation in solvent-shared and solvent-separated ion multiples of 1,2,3,4-tetraphenylcyclopentadienyl-sodium salts
Bock, Hans,Hauck, Tim,N?ther, Christian,Havlas, Zdenek
, p. 524 - 534 (1997)
The 1,2,3,4-tetraphenyl-shielded sodium cyclopentadienide, Na⊕[HC5?(C6H5)4], demonstrates essential facets of structure-determining cation solvation. The following solvent-shared or solvent-separated ion multiples have been crystallized from the respective aprotic ether solutions and structurally characterized: [(C29H21?)Na⊕ (THF)7/2], [(C29H21?)Na⊕(DME)2], [(C29H21?)]?[Na⊕(diglyme) 2]⊕, [(C29H21?)]?[Na⊕(triglyme) 2]⊕ and, from 18-crown-6 solution, the novel tripeldecker ion triple, [(C29H21?)]? 2[Na⊕(18-crown-6)Na⊕(18-crown-6)Na⊕(18-crown-6)] ⊕⊕, which contains two Na⊕ counter cations between three 18-crown-6 discs. The structures, discussed in comparison with literature data and based on MNDO calculations, demonstrate the essential effects of Na⊕ counter cation solvation by various ether ligands.
A soluble conjugated porous organic polymer: efficient white light emission in solution, nanoparticles, gel and transparent thin film
Pallavi, Pragyan,Bandyopadhyay, Sujoy,Louis, Jesna,Deshmukh, Arundhati,Patra, Abhijit
, p. 1257 - 1260 (2017)
A tetraphenylcyclopentadiene based multifunctional, solution processable, fluorescent, ultramicroporous polymer exhibiting high hydrogen uptake was employed for encapsulation of dyes to obtain enhanced white light emission in solution, nanoparticles, gel and transparent thin film. Hybrid nanoparticles showed a quantum yield of 35% with a high color rendering index.
1,2,3,4-Tetrasubstituted cyclopentadienes and their applications for metallocenes: Efficient synthesis through zirconocene- and CuCl-mediated intermolecular coupling of two alkynes and one diiodomethane
Geng, Weizhi,Wang, Chao,Guang, Jie,Hao, Wei,Zhang, Wen-Xiong,Xi, Zhenfeng
, p. 8657 - 8664 (2013/07/26)
1,2,3,4-Tetrasubstituted cyclopentadienes and indene derivatives with identical or different substituents were obtained in good to excellent isolated yields through a zirconocene- and CuCl-mediated intermolecular coupling process. This synthetic procedure involved three organic partners, including one CH 2I2, and two different or identical alkynes. Two alkynes or one diyne undergo Cp2ZrII-mediated (Cp= η5-C5H5) pair-selective reductive coupling to afford the corresponding zirconacyclopentadiene derivatives, which react, in the presence of CuCl and 1,3-dimethyl-3,4,5,6-tetrahydro-2(1 H)-pyrimidinone (DMPU), with CH2I2 through intermolecular followed by intramolecular coupling to afford the cyclopentadiene derivatives. An application of the prepared tetrasubstituted cyclopentadiene derivatives was demonstrated by the facile synthesis of the corresponding zirconocene complexes [(4RCp)2ZrCl2] and [(4RCp) 2ZrR′2] (R′=Me, Et, or nBu). The unique 1,2,3,4-tetrasubstituted cyclopentadiene ligands and the corresponding metallocenes are expected to have further applications in organometallic chemistry and organic synthesis. Ringing in the changes: A one-pot synthesis of 1,2,3,4-tetrasubstituted cyclopentadienes by zirconocene- and CuCl-mediated intermolecular coupling of two alkynes and diiodomethane (see scheme; Cp=η5-C5H5; DMPU=1,3-dimethyl-3,4,5,6- tetrahydro-2(1 H)-pyrimidinone) gave products that were successfully applied for the synthesis of the corresponding zirconocene derivatives. Copyright
Nickel(II)-carbene intermediates in reactions of geminal dihaloalkanes with nickel(0) reagents and the corresponding carbene capture as the phosphonium ylide
Eisch, John J.,Qian, Yun,Rheingold, Arnold L.
, p. 1576 - 1584 (2008/02/06)
In a previous study of geminal bond cleavages of substrates of the type R2CE2 [E2 = X2, O, S, Li(SO 2Ph)] by nickel(0) reagents [LnNi, Ln = (Cod)2, (Et4P)4], leading to R 2C=CR2 as products, the tentative hypothesis had been proposed that such reactions likely proceed via nickel(0)-carbene intermediates (J. J. Eisch, Y. Qian, M. Singh, J. Organomet. Chem. 1996, 512, 207). Because such proposed nickel(0)-carbenes do not satisfactorily account for reactions encountered with such α-eliminations, a detailed reexamination of the reaction of these nickel(0) reagents with geminal dihalides has been undertaken. For example, two reactions of such presumed nickel(0)-carbenes remained anomalous: (1) the failure of 5,5-dibromotetraphenylcyclopentadiene to form its expected dimer, octaphenylphenylfulvalene and instead the formation of triethylphosphonium tetraphenylcyclopentadienide in its reaction with (Et 3P)4Ni; and (2) the presumed capture of intermediate R2C=Ni0 in presence of the trapping agent (benzaldehyde or benzophenone). As to the first anomaly, a detailed study has shown that no trace of octaphenylfulvalene was formed. As to the second anomaly, the R 2C fragment could be trapped by the carbonyl reagents only in reactions involving (Et3P)4Ni, but not in reactions with (Cod)2Ni. This finding compels one to conclude that the carbonyl reagent is capturing the Wittig reagent, R2C=PEt3, and not R2C=Ni0. Based upon all present data, the mechanism of such C=C bond dimerizations is best explicable in terms of nickel(II)-carbenes. The triethylphosphonium tetraphenylcyclopentadienide formed here has by single-crystal X-ray structure determination, complemented by 13C NMR spectroscopic data, been found to have the zwitterionic structure Ph 4Cp--+PEt3 as its paramount resonance contributor. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
Volume parameters of some Diels - Alder reactions involving C=C, C=S, and N=N bonds
Kiselev,Kashaeva,Potapova,Iskhakova,Konovalov
, p. 2034 - 2041 (2007/10/03)
The effect of a hydrostatic pressure of up to 1000 kg cm-2 on the rate constants of the Diels - Alder reactions of maleic anhydride with 1,2,3,4-tetraphenylcyclopentadiene and with 6,13-dichloropentacene, of 4-phenyl-1,2,4-triazoline-3,5-dione with hexachlorocyclopentadiene, and of thiobenzophenone with isoprene was studied at 25°C. The volume parameters and ratios of the activation to reaction volumes make it possible to exclude electrostriction of the solvent during transition state solvation in all the reactions studied, which corresponds to the nonpolar nature of the transition state.
Use of polymeric reaction product
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, (2008/06/13)
A reaction product (A) which can be prepared by reaction, under free radical conditions, of at least one monomer (a) capable of free radical reaction, in the presence of at least one free radical initiator and of a radical of the formula (III) where R1 to R3, in each case independently of one another, are hydrogen, methyl or a radical-stabilizing and/or bulky group selected from an unsubstituted or substituted, linear or branched alkyl of two or more carbon atoms, cycloalkyl, alcohol, ether, polyether, amine, aralkyl radical, a substituted or unsubstituted aromatic, heterocyclic or olefinic hydrocarbon, a halogen atom, a substituted or unsubstituted, linear or branched alkenyl or alkynyl group, —C(O)R5, —C(O)OR5, —CR5R6—O—R7, —O—C(O)R5, —CN, —O—CN, —S—CN, —O—C═NR5, —S—C═NR5, —O—CR5R6—CR7R8NR9R10, —N═C═O, —C═NR5, —CR5R6-Hal, —C(S)R5, —CR5R6—P(O)R7R8, —CR5R6—PR7R8, —CR5R6—NR7R8, —CR5R6(OR7)(OR8), —CR5R6(OR7)(NR8), —CR5R6(NR7)(NR8), an anhydride, acetal or ketal group, —SO2R5, an amidine group, —NR5C(S)NR6, —NR5C(S)—OR6, —N═C═S, —NO2, —C═N—OH, —N(R5)═NR6, —PR5R6R7, —OSiR5R6R7 or —SiR5R6R7, where R5 to R10, independently of one another in each case, are defined in the same way as R1 to R5, or two of the radicals R1 to R4 form a C4- to C7-ring which in turn may be substituted or unsubstituted and, if required, may contain one or more heteroatoms, with the proviso that at least two of the radicals R1 to R3 are a radical-stabilizing and/or bulky group as defined above, has various uses.
Palladium-catalyzed arylation of cyclopentadienes
Dyker, Gerald,Heiermann, Joerg,Miura, Masahiro,Inoh, Jun-Ichi,Pivsa-Art, Sommai,Satoh, Tetsuya,Nomura, Masakatsu
, p. 3426 - 3433 (2007/10/03)
Cyclopentadiene and metallocenes, typically zirconocene dichloride, are suitable substrates for multiple arylations with aryl bromides in palladium-catalyzed reactions. Thus, various aryl bromides bearing either an electron-donating or an electron-withdrawing substituent can react with these substrates to afford the corresponding 1,2,3,4,5-pentaaryl-1,3-cyclopentadienes in a single preparative step. Derivatives of cyclopentadiene, including di- and trisubstituted cyclopentadienes, and indene are arylated in a similar fashion.
Palladium-catalysed reaction of aryl bromides with metallocenes to produce pentaarylated cyclopentadienes
Miura, Masahiro,Pivsa-Art, Sommai,Dyker, Gerald,Heiermann, Joerg,Satoh, Tetsuya,Nomura, Masakatsu
, p. 1889 - 1890 (2007/10/03)
Aryl bromides can efficiently react with some metallocenes, typically zirconocene dichloride, in the presence of a palladium/phosphine catalyst system and an appropriate base to produce the corresponding pentaarylated cyclopentadienes.
Synthesis of trans-(±)-1,2,3,3a,4a,5,6,7-Octaphenyl-3aH,4aH-dicyclopenta[b,e][1,4] dithiin by dimerization and further rearrangement of the transient 2,3,4,5-tetraphenyl-2,4-cyclopentadiene-1-thione
Henriksen, Michael,Hazell, Rita G.,Larsen, Finn Krebs,Schultz, Thomas,Sylvester-Hvid, Kristian O.,Klabunde, Kenneth J.,Mikkelsen, Kurt V.,Senning, Alexander
, p. 950 - 957 (2007/10/03)
Thionation of 2,3.4,5-tetraphenyl-2,4-cyclopentadien-1-one and of 5-diazo1,2,3,4-tetraphenyl-1,3-cyclopentadiene gives trans-(±)-1,2,3,3a,4a,5,6,7-octaphenyl-3aH,4aH-dicyclopenta[b,e]-[1,4] dithiin, most likely by dimerization of the primarily formed 2,3,4,5-tetraphenyl-2,4-cyclopentadiene-1-thione and sub-sequent phenyl migration. Characterization has been performed using X-ray crystallography. Calculations have been performed on derivatives of 2,4-cyclo-pentadien-1-one and -1-thione. Acta Chemica Scandinavica 1998.
Structures and Molecular Properties of Charge-Perturbed Molecules, 54. - Pyridinium-Tetraphenylcyclopentadienide Betaine and the Single-Electron Oxidation to Its Radical Cation
Bock, Hans,Nick, Sabine,Naether, Christian,Goebel, Ilka,John, Andreas,Kleine, Markus
, p. 105 - 114 (2007/10/02)
The single-crystal structure of the dark-blue pyridinium-tetraphenylcyclopentadienide betaine shows the pyridine ring and the phenyl substituents twisted between 37 and 55 deg, indicating reduced ? interactions between cos2 ω = 0.6 and 0.4.According to AM1 calculations based on the structure coordinates, the total charges of the pyridinium cation acceptor and the cyclopentadienyl anion donor amount to +0.62 and -0.53.This pronounced betaine zwitterionic character causes a 0.5 eV (!) bathochromic shift from 22000 cm-1 in aqueous to 18000 cm-1 in n-heptane solution, which can be correlated with the respective ET solvent parameters.Cyclovoltammetry in H2CCl2 / 0.1M R4N(+)ClO4(-) yields an irreversible reduction potential at -1.5 V and two oxidation potentials at +0.36 and +1.28 V, of which the lower one is reversible.With F3CCOO(-)Ag(+), therefore, a radical cation can be generated and is characterized by ESR / ENDOR spectra.The coupling constants are satisfactorily reproduced by McLachlan calculations, which also suggest that most of the spin population should be localized within the five-membered ring. - Key Words: Pyridinium-cyclopentadienide betaine structure / Redox potentials / ESR-ENDOR spectra / Radical cation
