
	Where results make sense

Topic: Cyclopentadiene

Related Topics

Ferrocene

Metallocene

Inorganic chemical reaction

Diene

Hydrogen

Organometallic chemistry

Benzene

Organic chemistry

Carbon

Spalding Gray

Miguel Ferrer

Hawaiian Islands

Rear wheel drive

	Text of MIJ-NSR Volume 5, Article 4
		In addition, the cyclopentadiene peak was decreased substantially and the pressure observed in the sampling manifold was lowered to that of the vapor pressure of MgCp2 (~40 mTorr [4]).
		Further, the slight plateau in intensity near the baseline is the characteristic line-shape for the on-going decomposition of a reactive compound in the chromatographic column.
		Therefore, the presence of additional cyclopentadiene (relative to figure 3 as seen by the signal-to-noise) is due to MgCp2 decomposition in the bubbler.
	nsr.mij.mrs.org /5/4/text.html (1932 words)

	[No title] (Site not responding. Last check: 2007-10-18)
		Cyclopentadienes having one to four ring positions substituted by alkyl groups are appropriate.
		The alkyl cyclopentadiene produced by this invention may be converted in known manner to bis alkyl cyclopentadienyl Group IV metal dihalides.
		In a method of synthesizing an alkyl cyclopentadiene by reaction of a cyclopentadiene Grignard with an alkyl halide, wherein a reaction mixture containing said alkyl cyclopentadiene is produced, the improvement which comprises introducing said cyclopentadiene Grignard to a refluxing solution of said alky halide in tetrahydrofuran.
	www.wipo.int /cgi-pct/guest/getbykey5?KEY=00/73248.001207&ELEMENT_SET=DECL (2230 words)

	United States Patent Application: 0020006978
		In such process, the cyclopentadiene is hydrogenated to cyclopentane, and the pentadiene may undergo hydrogenation and cyclization to cyclopentane using a catalyst, e.g., a transition metal (or adducts thereof) catalyst.
		The liquid cyclopentadiene and cyclopentane mixture is taken as bottoms from tower 7 via conduit 13, and delivered to separator drum 15 where it is further diluted with cyclopentane-rich recycle liquid obtained from product stripping tower 17 via conduits 19 and 21.
		The cyclopentadiene/cyclopentane stream having a cyclopentadiene content of between about 15-50% is taken overhead from separator drum 15 via conduit 23 and mixed with a stoichiometric excess of hydrogen from conduit 24.
	appft1.uspto.gov /netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=/netahtml/PTO/search-bool.html&r=1&f=G&l=50&co1=AND&d=PG01&s1=20020006978.PGNR.&OS=DN/20020006978&RS=DN/20020006978 (6095 words)

	[No title] (Site not responding. Last check: 2007-10-18)
		Cyclopentadiene spontaneously dimerizes at room temperature to form dicylopentadiene by a Diels-Alder reaction.
		Cyclopentadiene can be synthesized from dicyclopentadiene by "cracking" it which just means heating it above the boiling point of cyclopentadiene.
		Because the Diels-Alder reaction is a reversible equilibrium, the cyclopentadiene is removed by boiling and the equilibrium is driven to the right.
	web.centre.edu /muzyka/organic/lab/diels.htm (641 words)

	L3. High Temperature Pyrolysis and Oxidation of Cyclopentadiene
		The initial concentrations of cyclopentadiene for the decomposition experiments were varied between 0.5 to 10 ppm, the pressures between 0.8 to 5.6 bar.
		Ethyl iodide served as a thermal H-atom source, and mixtures of cyclopentadiene and ethyl iodide were prepared.
		For the investigation of cyclopentadiene oxidation, O-profiles are measured during the experiments with mixtures of cyclopentadiene and oxygen.
	www.cstl.nist.gov /div838/kinet_conf/agenda/l_session/l3/l3.html (632 words)

	Diels-Alder (Site not responding. Last check: 2007-10-18)
		The most difficult of this experiment is the cracking of dicyclopentadiene to form cyclopentadiene.
		Cyclopentadiene undergoes a reverse Diels-Alder reaction and must be made immediately before use.
		The energy of cyclopentadiene is -191.7171 au and the energy of maleic anhydride is -375.1035 au.
	acad.udallas.edu /chemdept/hendrickson/3121/Diels-Alder.htm (147 words)

	High unsaturation butyl rubbers - Patent 4151343
		However, where the diene is a cyclic diene such as cyclopentadiene, it is present in considerably higher amounts, e.g., 3 to 4 times, in the copolymer as in the feed.
		The term "D#" where # is an integer means the volume % cyclopentadiene in a monomer mixture wherein D represents cyclopentadiene and the integer is the volume % diene.
		Since many modifications and variations of this invention may be made without departing from the spirit or scope of the invention thereof, it is not intended to limit the spirit or scope thereof to the specific examples thereof.
	www.freepatentsonline.com /4151343.html (7239 words)

	Production of transition metal complexes - Patent 4556719
		A process as claimed in claim 1 for the production of cyclopentadienyl cobalt olefin half-sandwich compounds, characterized in that cyclopentadiene or derivatives thereof and another olefin are used as complexing agent, in the presence of which cobalt salts are reacted with the activated magnesium.
		C., the reaction mixture is concentrated to dryness in vacuo and the residue is extracted with a total of 500 ml of pentane.
		Following the procedure of Example 1, 1.1 g (6.2 mMoles) of anthracene and 42.7 g of cyclopentadiene are added to 10.94 g (450 mMoles) of fine magnesium powder in 300 ml of THF, followed by activation with 0.1 ml of methyliodide and by treatment for 3 hours in an ultrasonic bath.
	www.freepatentsonline.com /4556719.html (9762 words)

	Chemical Fact Sheets -- Cyclopentadiene
		If levels of cyclopentadiene are very high in your water, you may also need to avoid washing, bathing or using the water for other purposes.
		It is also important to consider the length of exposure to the chemical; the amount of chemical exposure; and whether the chemical was inhaled, touched, or eaten.
		If you develop symptoms following exposure to cyclopentadiene, or if you suspect that you have been exposed to high levels of this chemical, doctors can use tests of liver and kidney function to check for any damage to these organs.
	www.dhfs.state.wi.us /eh/chemfs/fs/cyclopen.htm (642 words)

	Re: How do they make linseed-oil more reactive ?
		Cyclopentadiene is a five carbon cyclic hydrocarbon containing two double bonds in conjugation.
		Cyclopentadiene may be recovered by heating the dimer to >150 degrees C causing the retro-Diels Alder to occur then distilling off the monomeric cyclopentadiene (bp is around 30 degrees C I think) into a cooled receiver flask.
		I can guess that if linseed oil was treated with cyclopentadiene (in the monomeric form only) then Diels-Alder reaction would occur between the double bonds in the unsaturated oils and the two double bonds in the cyclopentadiene.
	www.madsci.org /posts/archives/dec97/877614025.Ch.r.html (394 words)

	NTP: Executive Summary Dicyclopentadiene: I through IV
		Dicyclopentadiene is formed when cyclopentadiene spontaneously polymerizes at ordinary temperatures, with the rate of polymerization increasing with increasing temperature.
		Cyclopentadiene is produced during the carbonization of coal, and as a by-product of thermal cracking of hydrocarbons such as gas oil and naphtha in the presence of steam.
		Following the distillations, high purity dicyclopentadiene is obtained by cracking the dicyclopentadiene in the crude stream, separating the low-boiling cyclopentadiene by distillation, and allowing the concentrated cyclopentadiene to dimerize under controlled conditions [Kirk-Othmer, 1979].
	ntp-server.niehs.nih.gov /index.cfm?objectid=6F5F5E1A-F1F6-975E-7B0494CCCDE3B720 (1749 words)

	Ferrocene (Site not responding. Last check: 2007-10-18)
		Cyclopentadiene undergoes a 4+2 cycloaddition to form dicyclopentadiene.
		Dicyclopentadiene boils at 170C and cyclopentadiene boils at 42.5 C. For efficiency, the dicyclopentadiene dimer is thermally cracked using a fractional distillation apparatus in advance by the teaching assistant.
		While this is usually done on the day of the experiment, we have found that cyclopentadiene may be stored without significant dimerization in a foil covered container in a freezer for several days.
	imr.chem.binghamton.edu /labs/ferrocene/ferrocene.html (3209 words)

	Our Mission (Site not responding. Last check: 2007-10-18)
		Cyclopentadiene is a carbon acid with a pKa of about 15, comparable to methanol.
		We are exploring the effects of fluoroaromatic substituents on the acidities of substituted cyclopentadienes.
		For that reason we have targeted fluoroarylated cyclopentadiene compounds that are soluble in water.
	www.chem.vt.edu /chem-dept/deck/physorg.html (516 words)

	Projection Experiment: (4+2)-Cycloadditions (Diels-Alder)
		Note: The freshly distilled cyclopentadiene must be kept on ice or it will react with itself within an hour (dimerization).
		A drop of anthracene solution is added to the solution in T1 and a drop of the solution of cyclopentadiene is given to the solution in T2.
		The dimerization of cyclopentadiene already proceeding at room temperature is a Diels-Alder reaction.
	www.uni-regensburg.de /Fakultaeten/nat_Fak_IV/Organische_Chemie/Didaktik/Keusch/p2_cyclo_add-e.htm (504 words)

	[No title] (Site not responding. Last check: 2007-10-18)
		An example of this concept is the ligand Li-1 where the isopropyl group shields one face of the cyclopentadiene in the favoured rotomer about the indenyl-neomenthyl bond giving a single diastereoisomer of the complex 2 on reaction with CpZrCl3.2THF.
		A second design parameter is for the cyclopentadiene to contain both the control elements needed for asymmetric induction (a `wall', and `roof', Fig 2) allowing freedom in selection of other ligands on the metal including application to monocyclopentadienyl complexes.
		Fusing the chiral moiety to the cyclopentadiene to avoid the need for a favoured rotomer (crucial for non-indenyl systems).
	www.soton.ac.uk /~rjw1/ZenCpPro/ZenCpPro.html (493 words)

	Dixie Meiners 2003 Oscar Presentation
		Since cyclopentadiene is locked in the cis- position, the diradical mechanism is predicted to be unimportant for the present reaction, and only six-membered products should be formed.
		The goal of this project was to investigate the Diels-Alder reaction between a chlorinated difluoropropadiene and cyclopentadiene.
		In the reaction between 1,1-difluoro-3-chloropropadiene and cyclopentadiene, cyclopentadiene is locked in the cis position, therefore the diradical mechanism is no longer in competition with the concerted mechanism.
	www.selu.edu /Academics/ArtsSciences/oscar/journal11/meiners/meiners.htm (1534 words)

	Cycloaddition of Cyclopentadiene and Dicyclopentadiene on Si(100)-2×1: Comparison of Monomer and Dimer Adsorption (Site not responding. Last check: 2007-10-18)
		The adsorption of cyclopentadiene and its dimer form, dicyclopentadiene, on the Si(100)-2×1 surface has been investigated using polarized multiple internal reflection Fourier transform infrared (MIR-FTIR) spectroscopy together with ab initio quantum chemistry calculations.
		The results show that cyclopentadiene adsorbs at room temperature to form a [4 + 2] cycloaddition product and at saturation covers less than two-thirds of the surface.
		Dicyclopentadiene is not found to react via a surface-catalyzed retro-Diels-Alder pathway whereby it splits into cyclopentadiene while chemisorbing, even though this pathway is theoretically predicted to be much more thermodynamically favored.
	pubs.acs.org /cgi-bin/abstract.cgi/jpcbfk/1999/103/i32/abs/jp991528x.html (185 words)

	Parallel Quantum Monte Carlo For Molecules
		The reaction pathway for ground-state oxygen atom, O(P), reacting with cyclopentadiene, C
		Our calculations show that the reaction for the formation of 2-cyclopentenone and 3-cyclopentenone arising from the electrophilic addition of O(P) to a double bond of cyclopentadiene proceeds through an initially formed triplet diradical, undergoes triplet-singlet intersystem crossing to an open-shell diradical singlet, and progresses along the singlet manifold through transition states to the appropriate products.
		In the case of D-3CP, the second electron is partially delocalized across the three carbon atoms indicated, with more charge on the outer atoms than the center one.
	www.nersc.gov /news/annual_reports/annrep98/lester.html (429 words)

	DICYCLOPENTADIENE [BIS(CYCLOPENTADIENE)]
		It is prepared by the Diels-Alder reaction of two diene hydrocarbons, cyclopentadiene and ethylene.
		Norbornadiene which has the same carbon skeleton but with two double bonds is produced from cyclopentadiene and an alkyne.
		Norbornane is a bridged cyclic hydrocarbon, saturated without double bonds.
	www.chemicalland21.com /arokorhi/industrialchem/organic/DICYCLOPENTADIENE.htm (421 words)

	D6. High Temperature Pyrolysis of Phenol
		If the abstraction of the hydroxylic H was the initiation step as suggested by the two other studies, H production would be followed by CO production from the thermal decay of the phenoxy radical.
		Using the recently developed mechanism for the thermal decay of cyclopentadiene by Roy et al.
		Their H profiles recorded during the decay of cyclopentadiene could be modelled very well.
	www.cstl.nist.gov /nist838/kinet_conf/agenda/d_session/d6/d6.html (2293 words)

	QUESTION NO (Site not responding. Last check: 2007-10-18)
		Especially, the cyclobutadienecobalt-containing polymers prepared by the polycondensations of regioregular organocobalt monomers revealed liquid crystalline property which might be of importance for the further investigation on the functions of the polymers.
		A method according to claim 4 or claim 5 of synthesizing an alkyl cyclopentadiene by reaction of a cyclopentadiene Grignard with an alkyl halide, wherein a reaction mixture containing said alkyl cyclopentadiene is produced, the improvement which comprises introducing said cyclopentadiene Grignard to a refluxing solution of said alky halide in tetrahydrofuran.
		A method according to claim 10 wherein said step (i) n-alkyl cyclopentadiene is n-propyl or n-butyl cyclopentadiene, and wherein said step (ii) Group IV metal tetrahalide is zirconium tetrachloride or hafnium tetrachloride.
	www.nerac.com /site_2/solutions/industries/chem/tt_metallocenes.htm (5046 words)

	Pericyclic Reaction Chemistry
		The compound cyclopentadiene slowly undergoes cycloaddition with itself: one molecule of cyclopentadiene acts as a 4 pi-electron diene and the other as a 2 pi-electron dieneophile.
		This dimeric material can be cracked back to cyclopentadiene by heating at 150°C for an hour and then distilling off the diene monomer.
		Maleic anhydride is an electron poor dieneophile which reacts with cyclopentadiene to give an endo Diels-Alder adduct.
	www.meta-synthesis.com /webbook/49_pericyclic/pericyclic.html (1544 words)

	CHM238-01 S99
		Cyclopentadiene has a pKa = 15, while the usual C-H bond is pKa = 45.
		Which proton is the most acidic in cyclopentadiene and why?
		O = 16, and pKa for NH,pick the appropriate base that will convert cyclopentadiene to the cyclopentadienyl anion in overwhelming amounts.
	jan.ucc.nau.edu /~jmaxka/chm238/practice/practice_exams/exam1/f02.pracexam1ans.htm (488 words)

	Chemistry 2262 Practice Exam #1
		A) The carbon atoms of cyclopentadiene are all sp2-hybridized.
		C) Removal of a proton from cyclopentadiene yields an aromatic anion.
		D) Removal of a hydrogen atom from cyclopentadiene yields a highly stable free radical.
	www.chem.lsu.edu /lucid/oldexams/2262/practice1.html (578 words)

	REACTIONS IN SUPERCRITICAL CARBON DIOXIDE (Site not responding. Last check: 2007-10-18)
		It is well known that many Diels-Alder reactions result in formation of variable mixtures of endo- and exo-isomers.
		Some time ago, we showed that the endo/exo selectivity for the reaction between methyl acrylate and cyclopentadiene varied with density of supercritical carbon dioxide, from around 3:1 at low densities, rising to a maximum of 4:1 before falling back to 3:1 as density was increased further.
		This change could be rationalised on the basis of a solvent potential tuning phenomenon, where the number of solvent molecules per molecule of substrate is optimised to favour one particular transition state.
	www.chem.leeds.ac.uk /People/CMR/da.html (329 words)

Try your search on: Qwika (all wikis)