Superconductivity and Magnetic Properties of YBa2(Cu1-xFex)3O7-y

Arai, Jun; Shimizu, H.; Mita, Masaru

doi:10.1143/jpsj.58.673

Cited by 14 publications

(2 citation statements)

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“…These four-coordination compounds on the square plane include corrinoids (vitamin B 12 group), 68,387 -400 porphyrins, 387,401 -419 phthalocyanines, 387 bisdimethylglyoxims, 387,420 porphycenes, 387 etc. 387,421 -429 The other types of four coordination compounds are bis(salicylaldehyde)ethylenediamine (salen), 387,430 -442 bis(acetylacetone)ethylenediamine (BAE) type compounds, 66,67,387,443 -486 etc.…”

Section: Reactions With Vitamin B 12 -Type Compoundsmentioning

confidence: 99%

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Three characteristic reactions of organocobalt compounds in organic synthesis

Omae

2007

Applied Organom Chemis

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Organocobalt compounds in organic synthesis have three characteristic reactions. The first occurs because cobalt has a high affinity to carbon-carbon π -bonds or carbon-nitrogen π -bonds. The second occurs because cobalt has a high affinity to carbonyl groups. The third is due to cobalt easily tending to form square-planar bipyramidal six-coordination structures with four nitrogen atoms or two nitrogen atoms and two oxygen atoms at the square-planar position, and to bond with one or two carbon atoms at the axial position. The first characteristic reactions are the representative reactions of organocobalt compounds with a mutually bridged bond between the two π -bonds of acetylene and the cobalt-cobalt bond of hexacarbonyldicobalt. These are reactions with a Co 2 (CO) 6 INTRODUCTIONOrganometallic intramolecular coordination compounds, especially five-membered ring compounds of organotin compounds, have been studied since 1965, and many reviews 1 -13 and some books 14 -16 have published on the subject. These compounds are mainly synthesized by cyclometalation reactions with transition metal compounds. The first publication on this subject is generally considered to be the reaction of diazobenzene with nick elocene by Kleiman and Dubeck 17 in 1963 as shown in equation (1).*Correspondence to: Iwao Omae, Nihon Pharmaceutical University, 10281, Komuro, Ina-cho, Saitama, An earlier article on the direct synthesis of 2-phenyl-3-indazolinone by carbonylation of azobenzene with a cobalt Materials, Nanoscience and CatalysisThree characteristic reactions of organocobalt compounds 319 carbonyl catalyst, as shown in equation (2), was published in 1956. 18 It was also synthesized in 1967 through a twostep reaction, that is, (i) cyclopalladation of azobenzene via the five-membered ring product, and (ii) carbonylation, as shown in equation (3). 19From these two reactions, the former reaction [equation (2)] is presumed also to proceed via cyclometallation, that is, cyclocobaltation with the cobalt carbonyl catalyst, as shown in equation (4). Actually, many cyclomatalations with cobalt compounds have been reported. 20 -35 For example, a similar cyclometalated organocobalt compound was prepared by the reaction of azobenzene with methyltetra(trimethylphosphine)cobalt, as shown in equation (5). 20 Further, one year previously, in 1955, the same type of heterocyclic compound was prepared by the same type of carbonylation reaction with an organocobalt compound, as shown in equation (6). 36 This publication by Murahashi 36 may be considered to be the first reaction relating cyclometalation reactions.In the chemical industry, organocobalt is an essential constituent in many important catalysts. Specifically, they are key components in the multimillion-pound technology of hydroformylation; that is, the catalytic transformation of olefins into aldehydes using homogeneous catalysts. This article reports on three characteristic reactions of the organocobalt compounds in organic syntheses on the basis of their structures and reactivities...

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Section: Reactions With Vitamin B 12 -Type Compoundsmentioning

confidence: 99%

“…4. 66,387,405,406,420,487 The salcomine 37 is a cobalt complex [Co(salen)] of salen, a Schiff base of salicylaldehyde with ethylenediamine. This cobalt complex has a square-planar four-coordination structure with two nitrogen and two oxygen atoms.…”

Section: Reactions With Vitamin B 12 -Type Compoundsmentioning

confidence: 99%