The structure of malaria pigment beta-haematin
Article Abstract:
It has been possible to describe the crystal structure of beta-haematin, a synthetic analogue of haemozoin. The molecules are connected into dimers through reciprocal iron-carboxylate bonds to one of the propionic side chains of each porphyrin, with the dimers forming chains linked by hydrogen bonds in the crystal. On the basis of this structure, the difference in solubilities in coordinating solvents such as pyridine could be the result of a chelate effect in which the kinetics of iron-carboxylate bond substitution are retarded because of the dimeric nature of beta-haematin.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 2000
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Back to the drawing board
Article Abstract:
Two research groups produced new doped C60 fullerenes that lack the usual relation between size of the crystal-line unit cell and the superconducting transition temperature. AT & T Bell Laboratories researchers detected no superconductivity after doping fullerene with alkali, while Japan's NEC Fundamental Research Laboratories tested the ability of various materials to superconduct. The development of new varieties of C60 should encourage further research into its unusual properties.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1992
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The mean free path for electron conduction in metallic fullerenes
Article Abstract:
Research concerning the increase in the electrical resistivity of metals with increases in temperature is presented. The exceptions to this observation which have been found among superconductors and alkali-doped fullerenes are discussed.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 2000
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