scispace - formally typeset
Search or ask a question

Showing papers on "Norbornadiene published in 1982"


Journal ArticleDOI
TL;DR: In this article, the catalytic capacity of the (Pd(CH/sub 3/CN)/sub 4/)(BF/ sub 4/)/sub 2/n-triphenylphosphine n = (1-3) was demonstrated for copolymerization of CO with ethylene and other alkenes under very mild conditions.
Abstract: The catalyst, (Pd(CH/sub 3/CN)/sub 4/)(BF/sub 4/)/sub 2/.n-triphenylphosphine n = (1-3), demonstrated the capacity to mediate the copolymerization of CO with ethylene and other alkenes under very mild conditions. The reaction of ethylene (350 psi), dissolved in acetonitrile, and CO(350 psi) was performed at 25/sup 0/C for 1 d. The copolymerizations of CO(800 psi) with norbornadiene and norbornylene were performed at 60/sup 0/C. The structures of the copolymers were studied by NMR. 9 references, 1 figure.

195 citations


Journal ArticleDOI
TL;DR: The cationic Pd(II) compound was found to catalyze the polymerization of H-C identical with C-R (R = Ph, COOMe), styrene,..cap alpha..-methyl-styrene, 1,3-cyclohexadiene, norbornylene, and norbornadiene under very mild conditions.

114 citations



Journal ArticleDOI
Iwao Omae1
TL;DR: Etude des complexes contenant cyclooctadiene, dicyclopentadiene (DCP), norbornadiene and cycloctatetraene as discussed by the authors.

52 citations




Journal ArticleDOI
TL;DR: In this article, chemical induced dynamic nuclear polarization (CIDNP) has been observed on irradiation of dimethylbicyclolhepta 2,5-diene-2,3-dicarboxylate (3) in the presence of aromatic electron-donor sensitizers in acetonitrile.
Abstract: Chemically induced dynamic nuclear polarization (CIDNP) has been observed on irradiation of dimethylbicyclolhepta-2,5-diene-2,3-dicarboxylate (3) in the presence of aromatic electron-donor sensitizers in acetonitrile. Nuclear polarization is detected for selected protons of 3 (emission) and its quadricyclene valence isomer 4 (enhanced absorption). The complementary CIDNP effects are rationalized in terms of the quenching of hydrocarbon singlets via electron transfer, intersystem crossing between resultant singlet and triplet radical-ion pairs, and competition between singlet and triplet ion recombination. The energetics of recombination allow that triplet level is above or below that of 3. The CIDNP effects are discussed in terms of other photochemical results regarding the electron-transfer photosensitized isomerization, 3 ..-->.. 4.

24 citations


Journal ArticleDOI
TL;DR: In this article, the electron transfer from the sensitizer, intersystem crossing of resultant radical-ion pairs, and ion recombination were used to give norbornadiene triplets followed by rearrangement to the valence isomer.
Abstract: Quenching of the fluorescence of a series of electron donor aromatic hydrocarbons in acetonitrile by dimethyl bicyclo(2.2.1)hepta-2,5-diene-2,3-dicarboxylate results in isomerization of the norbornadiene with varying efficiency. Quantum yield, CIDNP, and flash photolysis results are consistent with a rearrangement mechanism involving electron transfer from the sensitizer, intersystem crossing of resultant radical-ion pairs, and ion recombination to give norbornadiene triplets followed by rearrangement to the valence isomer. Where energetic factors are favorable, the isomerization quantum yield is as high as 0.39 and the efficiency of formation of norbornadiene triplets via ion recombination as high as 65%.

18 citations


Journal ArticleDOI
TL;DR: In this article, the bridging formamidino ligand was added to the formamidine ligand of the cycloocta-1,5-diene (C8H12)-formamidine (C5-Diene) complex to obtain a polymeric structure.

17 citations


Journal ArticleDOI
TL;DR: In this paper, the 13NMR signals of α-pinene and camphene were reassigned unequivocally. And the J(CH) values of 1, 2, bornene, norbornene and norbornadiene were reported.
Abstract: The 13NMR signals of camphene (1) and α-pinene (2) are reassigned unequivocally. J(CH) values of 1, 2, bornene, norbornene and norbornadiene are reported.

17 citations


Journal ArticleDOI
Dennis P. Riley1
TL;DR: In this article, a solution 31 P NMR study of the asymmetric hydrogenation catalyst derived from the [rhodium(1,2-bis(diphenylphosphino)-1-cyclohexylethane)] system was initiated to gain further insight into the solution chemistry of this catalyst.

Journal ArticleDOI
TL;DR: In this article, it was shown that the mechanism of sensitization by Cu(I) can be controlled by the judicious addition of ligands to the system, and the latter species functions as an effective sensitizer for quadricyclene (Q) production.
Abstract: Formation of a ground-state complex between CuBr(py)(PPh/sub 3/) (py is pyridine) and norbornadiene (NBD) occurs upon mixing the compounds in benzene. Irradiation of the complex with 313-nm light generates the valence isomer quadricyclene (Q) with moderate observed quantum efficiency. This efficiency varies with the nature and concentration of excess ligands present in solution. Spectral studies reveal that this behavior arises fom the creation of new Cu(I) species whose sensitization properties differ from those of CuBr(py)(PPh/sub 3/). Thus a sufficient excess of triphenylphosphine converts the parent compound to CuBr(PPh/sub 3/)/sub 3/. The latter species functions as an effective sensitizer for Q production but by a pathway involving bimolecular interaction of photoexcited CuBr(PPh/sub 3/)/sub 3/ with ground-state NBD. These results demonstrate that the mechanism of sensitization by Cu(I) can be controlled by the judicious addition of ligands to the system.

Journal ArticleDOI
TL;DR: In this paper, standard synthetic steps have been used to convert 7-methylene quadricyclane into the spiro-cyclopropene 1 and the allene 2.
Abstract: Standard synthetic steps have been used to convert 7-methylenequadricyclane into the spiro-cyclopropene 1 and the allene 2. These (and other) quadricyclanes are cleanly isomerized on alumina to the respective bicyclo[2.2.1]hepta-2,5-dienes 3 and 4.

Journal ArticleDOI
TL;DR: The photochemical hydrogenation of norbornadiene (NBD) in the presence of Cr(CO)6 or Cr( CO)4NBD at normal pressure yields nortricyclene and norbornene in a ratio of 3/1.

Journal ArticleDOI
TL;DR: In this paper, it was shown that the homologous catalyst supported on a phosphinated polystyrene is not active, and that the [RhCl(nbd)]2 (nbd = norbornadiene) is an efficient catalysts for the hydrogenation of arenes under mild conditions.
Abstract: Immobilized complexes prepared from [RhCl(nbd)]2 (nbd = norbornadiene) and phosphinated polydiacetylene or silica are efficient catalysts for the hydrogenation of arenes under mild conditions. However, the homologous catalyst supported on a phosphinated polystyrene is not active.


Journal ArticleDOI
TL;DR: In this article, the 1H NMR spectra of the complexes were discussed and the stability sequence for variation of the coordinated diene, is: cycloocta-1,5-diene > norbornadiene > cycloxctatetraene.

Journal ArticleDOI
TL;DR: In this paper, the results of ultrahigh vacuum studies of C/sub 4/-C/sub 8/ cyclic olefins and polyene chemisorption on Ni and Pt surfaces are presented.
Abstract: Results of ultrahigh vacuum studies of C/sub 4/-C/sub 8/ cyclic olefins and polyene chemisorption on Ni and Pt surfaces are presented. A mechanism is proposed for the novel surface mediated conversions of cycloheptatriene and norbornadiene to benzene. Studies of adsorption and thermal desorption of norbornadiene-7-d/sub 1/ on Pt(111) and Pt(100) indicated that there is no deuterium in the benzene produced on Pt(111), but that produced on Pt(100) contained approx. 15 to 20% C/sub 6/H/sub 5/D. An exchange process between C/sub 6/H/sub 6/ and D atoms on Pt(100) has been established but not for Pt(111). (BLM)

Journal ArticleDOI
TL;DR: In this article, the authors showed that the triplet energy of the sensitizer is a major limiting factor for rearrangement of dimethyl bicyclo[2.2.1]hepta-2.5-dien-2,3-dicarboxylate.

Journal ArticleDOI
TL;DR: In this article, photochemical valence isomerization of norbornadiene derivative 1 to quadricyclane derivative 2 occurred quantitatively, and reverse isomerisation of 2 to 1 under release of heat was achieved by catalytic action of cobalt hematoporphyrin 3 and analogues.
Abstract: In an alkaline aqueous solution, photochemical valence isomerization of norbornadiene derivative 1 to quadricyclane derivative 2 occurred quantitatively, and reverse isomerization of 2 to 1 under release of heat was achieved by catalytic action of cobalt hematoporphyrin 3 and analogues. This system may be of a great practical use for a solar energy storage.

Journal ArticleDOI
TL;DR: The conversion of quadricyclane (1) to norbornadiene (2 ) is catalyzed by stannous chloride and Stannous 4-phosphine complexes as mentioned in this paper.

Journal ArticleDOI
TL;DR: Adsorption of [Ir(bipy)3OH]2 + bipy = 2,2′-bipyridine onto silica gel does not adversely affect the efficiency with which this transition metal complex photosensitizes the valence isomerization of norbornadiene to quadricyclene as mentioned in this paper.
Abstract: Adsorption of[Ir(bipy)3OH]2+(bipy = 2,2′-bipyridine) onto silica gel does not adversely affect the efficiency with which this transition metal complex photosensitizes the valence isomerization of norbornadiene to quadricyclene.

Journal ArticleDOI
TL;DR: The existence of nonplanar olefinic groups in norbornadiene has been confirmed by an analysis of various model structures based upon proton coordinates, obtained from the partially oriented NMR spectrum in a nematic liquid-crystal solvent, combined with carbon coordinates from electron-diffraction studies as discussed by the authors.

Journal ArticleDOI
TL;DR: Sulphur dioxide adds in acheleotropic way to norbornadiene giving 4ththiatetracyclo[3.3.0.2,8.03,6] octane 4,4-dioxide, while non-cycloaddition products are obtained with other homo-conjugated dienes as discussed by the authors.
Abstract: Sulphur dioxide adds in acheleotropic way to norbornadiene giving 4-thiatetracyclo[3.3.0.0.2,8.03,6]octane 4,4-dioxide, while non-cycloaddition products are obtained with other homo-conjugated dienes.


Journal ArticleDOI
TL;DR: In this paper, a marker inverse kinetic isotope effect for the hydrogenation of bicyclo[2.2.1]hepta-2,5-diene(norbornadiene, nbd) by the [Ir(PPh3)2(OCMe2)2H2]+ Ion (1), and its dideuterio-analogue, and a detailed mechanism is proposed.
Abstract: A stopped-flow kinetic study reveals a marker inverse kinetic isotope effect for the hydrogenation of bicyclo[2.2.1]hepta-2,5-diene(norbornadiene, nbd) by the [Ir(PPh3)2(OCMe2)2H2]+ Ion (1), and its dideuterio-analogue, and a detailed mechanism is proposed.

Journal ArticleDOI
TL;DR: The synthesis and properties of complexes of the [Rh(COD)L 2 ]BPh 4 type (COD = 1,5-cyclooctadiene, L = monodentate N-donor ligand) and of mixed complexes as discussed by the authors were described.

Journal ArticleDOI
TL;DR: In this paper, a new product arising from the reaction of dichlorocarbene with norbornadiene, 6endo-(2,2-dichlorovinyl)-cis-bicyclo[3.1.0]hex-2-ene, is described.
Abstract: A new product arising from the reaction of dichlorocarbene with norbornadiene, 6endo-(2,2-dichlorovinyl)-cis-bicyclo[3.1.0]hex-2-ene, is described. It does not arise from the normal exo-l,2-adduct, but possibly originates by sigmatropic rearrangement of an initially formed zwitterionic intermediate.

Journal ArticleDOI
TL;DR: Cationic rhodium(I) norbornadiene complexes with polystyrene-immobilized imidazole, tetramethylbiimidazoles or phosphine ligands in the presence of potassium hydroxide catalyze hydrogen transfer from isopropanol to acetophenone and 1-hexene as mentioned in this paper.
Abstract: Cationic rhodium(I) norbornadiene complexes with polystyrene-immobilized imidazole, tetramethylbiimidazole or phosphine ligands in the presence of potassium hydroxide catalyze hydrogen transfer from isopropanol to acetophenone and 1-hexene. [Rh(NBD) (poly-PPh2)2] ClO4 complexes are particularly efficient for the reduction of acetophenone, but slow decomposition to rhodium metal is observed.

Journal ArticleDOI
TL;DR: In this article, X-ray diffraction on [RN(PF2)2]nMo2(CO)11 − 2n(n= 3, 4, and 5) indicates the presence of symmetrical and unsymmetrical bridging carbonyl groups, respectively.
Abstract: Thermal reactions of the olefin-molybdenum carbonyls C7H8Mo(CO)n(n= 4, C7H8= norbornadiene; n= 3, C7H8= cycloheptatriene) with RN (PF2)2 ligands (R = Me and Ph) in hydrocarbon solvents at 100–120 °C lead ultimately to binuclear complexes of the type [RN(PF2)2]nMo2(CO)11 – 2n(n= 3, 4, and 5); structure determinations by X-ray diffraction on [PhN(PF2)2]3Mo2(CO)5 and [MeN(PF2)2]4Mo2(CO)3 indicate the presence of symmetrical and unsymmetrical bridging carbonyl groups, respectively.