The structure of [Os([eta][sup 2]-H[sub 2])en[sub 2]CH[sub 3]CO[sub 2]]PF[sub 6] (1) has been stu... more The structure of [Os([eta][sup 2]-H[sub 2])en[sub 2]CH[sub 3]CO[sub 2]]PF[sub 6] (1) has been studied by X-ray diffraction at 120 K and neutron diffraction at 165 K. Compound 1 belongs to a series of dihydrogen complexes of osmium(II) amines, exhibiting an extensive range in the strength of the H-H interaction as judged by the wide variation in observed J[sub H-D] coupling constants. The ethylenediamine ligands in I have a trans arrangement. The H[sub 2] and the acetate ligands occupy positions on opposite sides of the OsN[sub 4] plane, giving overall approximately octahedral coordination. Consistent with the relatively low J[sub H-D] value (9.0 Hz), the H-H distance in 1.134(2) [angstrom] as determined by neutron diffraction, is unusually long and approaches that of 1.357(7) [angstrom] found in the polyhydride ReH[sub 7][P(p-tolyl)[sub 3]][sub 2]. It is presumed that I may represent an intermediate stage in the oxidative addition of dihydrogen at transition-metal centers. The Os-H ...
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Journal of the Chemical Society, Perkin Transactions 2, 2000
ABSTRACT 2-Hydroxy-3,4,5-trichlorothiophene (4), 3-hydroxy-4-bromo-2,5-dichlorothiophene (5) and ... more ABSTRACT 2-Hydroxy-3,4,5-trichlorothiophene (4), 3-hydroxy-4-bromo-2,5-dichlorothiophene (5) and 3-hydroxy-2,4,5-trichlorothiophene (6) have been synthesised. It was found that 4 exists in a carbonyl form, whereas in 5 and 6 the hydroxy forms were the major tautomers. Several derivatives of the trihalogenated hydroxythiophenes were prepared. O-Methylation was carried out with diazomethane and O-acetylation with acetyl chloride. Silylation of 4 was performed using N,O-bis(trimethylsilyl)acetamide. Compound 4 reacted with methylmagnesium iodide in an unexpected way by exchanging chlorine with magnesium iodide, giving 3,4-dichloro-2,5-dihydrothiophen-2-one (16) after hydrolysis. In an unsuccessful attempt to try to prepare thiophene isosteres of the infamous 2,3,7,8-tetrachlorodibenzo-p-dioxine, the new dimer 2,2′,3,3′,4,4′-hexachloro-2,2′,5,5′-tetrahydro-2,2′-bithiophen-5-one (15) was discovered, the crystal structure of which is reported.
Magnetic susceptibilities of a number of the rare earth (R) phosphomolybdates, RPO4(MoO3)12 × 30H... more Magnetic susceptibilities of a number of the rare earth (R) phosphomolybdates, RPO4(MoO3)12 × 30H2O, have been measured from 300 K down to ∼ 10 mK. These materials are cubic, with space group Fd3, and are characterized by weak crystalline field splittings. Most can be explained in terms of a lowest order theory for a crystal field with Td (43 m)
Three new neo-clerodane diterpenoids, deoxyajugarin-I, ajugarin-I chlorohydrin, and 3β-acetoxy-cl... more Three new neo-clerodane diterpenoids, deoxyajugarin-I, ajugarin-I chlorohydrin, and 3β-acetoxy-clerodinin C, have been isolated from Ajuga parviflora collected near Nainital, India. Also isolated were ajugarin-I and II, ajugamarin F4, dihydroclerodin-I, clerodinins C and D ...
[2R-(2α,4aβ,5aβ,7α,9aβ,10aβ)]-Octahydro-2,7-bis(1-methylethenyl)5aH, 10aH-4a, 9a-ethanodibenzo[b,... more [2R-(2α,4aβ,5aβ,7α,9aβ,10aβ)]-Octahydro-2,7-bis(1-methylethenyl)5aH, 10aH-4a, 9a-ethanodibenzo[b, e] [1,4]dioxin-5a,10a-diol (cymbodiacetal), isolated from the essential oil ofCymbopogon martinii, was identified by means of X-ray diffraction of its 1:1 solvate with ...
The structure of [Os([eta][sup 2]-H[sub 2])en[sub 2]CH[sub 3]CO[sub 2]]PF[sub 6] (1) has been stu... more The structure of [Os([eta][sup 2]-H[sub 2])en[sub 2]CH[sub 3]CO[sub 2]]PF[sub 6] (1) has been studied by X-ray diffraction at 120 K and neutron diffraction at 165 K. Compound 1 belongs to a series of dihydrogen complexes of osmium(II) amines, exhibiting an extensive range in the strength of the H-H interaction as judged by the wide variation in observed J[sub H-D] coupling constants. The ethylenediamine ligands in I have a trans arrangement. The H[sub 2] and the acetate ligands occupy positions on opposite sides of the OsN[sub 4] plane, giving overall approximately octahedral coordination. Consistent with the relatively low J[sub H-D] value (9.0 Hz), the H-H distance in 1.134(2) [angstrom] as determined by neutron diffraction, is unusually long and approaches that of 1.357(7) [angstrom] found in the polyhydride ReH[sub 7][P(p-tolyl)[sub 3]][sub 2]. It is presumed that I may represent an intermediate stage in the oxidative addition of dihydrogen at transition-metal centers. The Os-H ...
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Journal of the Chemical Society, Perkin Transactions 2, 2000
ABSTRACT 2-Hydroxy-3,4,5-trichlorothiophene (4), 3-hydroxy-4-bromo-2,5-dichlorothiophene (5) and ... more ABSTRACT 2-Hydroxy-3,4,5-trichlorothiophene (4), 3-hydroxy-4-bromo-2,5-dichlorothiophene (5) and 3-hydroxy-2,4,5-trichlorothiophene (6) have been synthesised. It was found that 4 exists in a carbonyl form, whereas in 5 and 6 the hydroxy forms were the major tautomers. Several derivatives of the trihalogenated hydroxythiophenes were prepared. O-Methylation was carried out with diazomethane and O-acetylation with acetyl chloride. Silylation of 4 was performed using N,O-bis(trimethylsilyl)acetamide. Compound 4 reacted with methylmagnesium iodide in an unexpected way by exchanging chlorine with magnesium iodide, giving 3,4-dichloro-2,5-dihydrothiophen-2-one (16) after hydrolysis. In an unsuccessful attempt to try to prepare thiophene isosteres of the infamous 2,3,7,8-tetrachlorodibenzo-p-dioxine, the new dimer 2,2′,3,3′,4,4′-hexachloro-2,2′,5,5′-tetrahydro-2,2′-bithiophen-5-one (15) was discovered, the crystal structure of which is reported.
Magnetic susceptibilities of a number of the rare earth (R) phosphomolybdates, RPO4(MoO3)12 × 30H... more Magnetic susceptibilities of a number of the rare earth (R) phosphomolybdates, RPO4(MoO3)12 × 30H2O, have been measured from 300 K down to ∼ 10 mK. These materials are cubic, with space group Fd3, and are characterized by weak crystalline field splittings. Most can be explained in terms of a lowest order theory for a crystal field with Td (43 m)
Three new neo-clerodane diterpenoids, deoxyajugarin-I, ajugarin-I chlorohydrin, and 3β-acetoxy-cl... more Three new neo-clerodane diterpenoids, deoxyajugarin-I, ajugarin-I chlorohydrin, and 3β-acetoxy-clerodinin C, have been isolated from Ajuga parviflora collected near Nainital, India. Also isolated were ajugarin-I and II, ajugamarin F4, dihydroclerodin-I, clerodinins C and D ...
[2R-(2α,4aβ,5aβ,7α,9aβ,10aβ)]-Octahydro-2,7-bis(1-methylethenyl)5aH, 10aH-4a, 9a-ethanodibenzo[b,... more [2R-(2α,4aβ,5aβ,7α,9aβ,10aβ)]-Octahydro-2,7-bis(1-methylethenyl)5aH, 10aH-4a, 9a-ethanodibenzo[b, e] [1,4]dioxin-5a,10a-diol (cymbodiacetal), isolated from the essential oil ofCymbopogon martinii, was identified by means of X-ray diffraction of its 1:1 solvate with ...
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