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Post by dosamaniac on Jul 6, 2024 14:38:09 GMT
DDR 1960 National Chemists' Day [5pf] (Mi 800)
The stamp shows molecular structure of 2-benzofuran-1,3-dione [O=C1OC(=O)c2ccccc12/C₆H₄(CO)₂O], an anhydride of benzene-1,2-dicarboxylic acid and the source compound of phthalate esters or plasticizers that are used in the production of plastics.
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Post by dosamaniac on Jul 7, 2024 8:18:46 GMT
Portugal 2009 Science in Portugal [€0.32] [Mundifil (ex-Afinsa) 3810]
The stamp shows the 3D model of the center strings of the enzyme CotA laccase, a member of the multi-copper-dependent oxidase family and a protein laccase, a benzenediol oxygen oxidoreductase that is found in the bacterium Bacillus subtilis (Ehrenberg 1835).
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Post by dosamaniac on Jul 12, 2024 7:35:09 GMT
BRD 1982 Friedrich Wöhler (1800–1882): Wöhler Synthesis [50pf.] (Mi 1148)
The stamp shows 3D ball and socket model of carbonyl diamide/urea [CO(NH₂)₂] and the Wöhler synthesis of urea from ammonium cyanate [NH₄CNO], first described by German chemist Friedrich Wöhler (1800– 1882) in 1828. This reaction was a watershed moment in the field of chemistry which showed the conversion of an inorganic compound to an organic compound.
[O=C=N]⁻NH₄⁺→O=C—(NH₂)₂
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Post by dosamaniac on Jul 14, 2024 9:51:17 GMT
Československo 1966 Centennial of Československé Společnosti Chemické Při, Praha [60h] (Pof 1542)
The stamp shows the molecular structure of tricyclo[3.3.1.1³ ⁷]decane/adamantane [C1C2CC3CC1CC(C2)C3/(CH)₄(CH₂)₆], a polyhedral polymer of cyclohexane and the simplest diamondoid, that is found in petroleum.
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hrdoktorx
Member
Posts: 6,952
What I collect: France (and French territories), Africa, Canada, USA, Germany, Guatemala, stamps about science, flags, maps, stamps on stamps...
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Post by hrdoktorx on Jul 21, 2024 9:44:39 GMT
Gutter pair of stamps issued by Finland in 1991 for the 100 th anniversary of the Finnish chemistry research fund, and showing two isomers of the "same" molecule. Look carefully and you'll find the two atoms that have switched places, a very common occurrence in organic chemistry that can lead to drastically different behaviours:
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hrdoktorx
Member
Posts: 6,952
What I collect: France (and French territories), Africa, Canada, USA, Germany, Guatemala, stamps about science, flags, maps, stamps on stamps...
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Post by hrdoktorx on Jul 22, 2024 5:52:31 GMT
Stamp issued in 1970 by Finland to showcase its chemical industry:
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Post by dosamaniac on Jul 27, 2024 10:51:52 GMT
Nihon 1991 III International Conference on Superconductivity 1981 Kanazawa [62¥] (Sak C1369)
The stamp shows 3D model of the defect perovskite crystal unit cell of lanthanum barium copper oxide [CuBa₀.₁₅La₁.₈₅O₄], the first high temperature superconductor that was discovered in 1986 by Johannes Georg Bednorz and Karl Alexander Müller, for which they got Nobelpriset in 1987.
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