Norbornadiene

About: Norbornadiene is a research topic. Over the lifetime, 2389 publications have been published within this topic receiving 38603 citations.

Molecular and electronic structures of two 16-electron complexes of tungsten(II): WBr2(CO)2(C7H8) (C7H8 = norbornadiene) and WBr2(CO)2(PPh3)2

Abstract: Le compose WBr 2 (CO) 2 (C 7 H 8 ) cristallise dans le systeme monoclinique, groupe P2 1 /n et le compose WBr 2 (CO) 2 (PPh 3 ) 2 dans le systeme triclinique, groupe P1. Affinement des structures jusqu'a R=0,032 et 0,064 respectivement. Le premier compose est diamagnetique a geometrie pseudo-octaedrique. Le second possede une geometrie octaedrique tres deformee

Helix formation of poly(phenylacetylene) derivatives bearing amino groups at the meta position induced by optically active carboxylic acids

Abstract: Two novel phenylacetylene derivatives bearing diethylaminomethyl groups at the meta position on phenyl groups [3-(N,N-diethylaminomethyl)phenyl]acetylene (1) and [3,5-bis(N,N-diethylaminomethyl)phenyl]acetylene (2) were synthesized and polymerized with [Rh(nbd)Cl]2 (nbd: norbornadiene). Both monomers gave highly cis–transoidal stereoregular polymers that exhibited an induced circular dichroism (ICD) in the UV–visible region, probably because of a prevailing one-handed helical conformation upon complexation with optically active carboxylic acids such as mandelic acid and lactic acid. The sign of the Cotton effects reflected the absolute configuration of the chiral acids. Therefore, these polymers can be used as a novel probe for determining the configuration of chiral acids. The polymers were stable in the presence of chiral acids in solution. The poly-1 complexed with chiral acids exhibited a split-type ICD, whereas the poly-2 complexed with chiral acids showed a different, non-split-type ICD. The ICD pattern of the poly-1/chiral acids complexes dramatically changed with an increase in the concentration of the chiral acids, thus showing a non-split-type ICD similar to those of the poly-2/chiral acid complexes. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3180–3189, 2001

Synthesis of Polyesters Carrying Norbornadiene (NBD) Moieties by the Ring-Opening Copolymerization of Glycidyl Esters Containing NBD Moieties with Carboxylic Anhydrides and Their Photochemical Reactions

Abstract: Various epoxy monomers containing norbornadiene (NBD) moieties were prepared by reactions of potassium salts of NBD derivatives with excess epichlorohydrin using tetrabutylammonium bromide (TBAB) as a phase transfer catalyst. The copolymerization of glycidyl (3-phenyl-2,5-norbornadien-2-yl)carboxylate (GPNC) with phthalic anhydride (PAn) proceeded smoothly using TBAB as a catalyst in sulfolane at 100 °C for 24 h to give polyester P-1 containing pendant NBD moieties. Copolymerizations of various epoxy monomers containing certain NBD moieties with carboxylic anhydrides gave the corresponding NBD polyesters in good yields. The photochemical valence isomerizations of the NBD moieties in the polymers were carried out in the film state or in the solution. Rates of the isomerizations of some NBD moieties in the polymers were strongly enhanced by the addition of photosensitizers such as 4-(N,N-dimethylamino)benzophenone (DABP). The Tgs of the polyesters having NBD residues and stored thermal energy in the corresp...

Hydrogenation reactions on heterogenized Wilkinson complexes

Abstract: A novel clay catalyst containing a heterogenized Rh(I) triphenylphosphine complex (Rh-bentonite) has been prepared via ion exchange of a Hungarian Na+-bentonite with Wilkinson complex [RhCl(PPh3)3]. It was established that the active species [Rh(PPh3)]+ was situated on the external surface of the catalyst, which was found to be efficient in the liquid-phase hydrogenation of 1-octene, cyclohexene, norbornadiene, 1,5-cyclooctadiene, phenylacetylene and cyclohexene-3-one.