Archive for March, 2018

The dark satanic mills (of the industrial revolution?)

Sunday, March 18th, 2018
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Around the time of the 2012 olympic games, the main site for which was Stratford in east London, I heard a fascinating talk about the “remediation” of the site from the pollution caused by its industrial chemical heritage. Here I visit another, arguably much more famous and indeed older industrial site.

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Never mind main group “hypervalency”, what about transition metal “hypervalency”?

Sunday, March 18th, 2018
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I have posted often on the chemical phenomenon known as hypervalency, being careful to state that as defined it applies just to “octet excess” in main group elements. But what about the next valence shell, occurring in transition metals and known as the “18-electron rule”? You rarely hear the term hypervalency being applied to such molecules, defined presumably by the 18-electron valence shell count being exceeded. So the following molecule (drawn in three possible valence bond representations) first made in 1992 intrigues.[1]

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References

  1. R. Ahlrichs, D. Fenske, H. Oesen, and U. Schneider, "Synthesis and Structure of[Ni(PtBu6)] and[Ni5(PtBu)6(CO)5] and Calculations on the Electronic Structure of[Ni(PtBu)6] and(PR)6, R=tBu,Me", Angewandte Chemie International Edition in English, vol. 31, pp. 323-326, 1992. http://dx.doi.org/10.1002/anie.199203231

How FAIR are the data associated with the 2017 Molecules-of-the-Year?

Wednesday, March 7th, 2018
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C&EN has again run a vote for the 2017 Molecules of the year. Here I take a look not just at these molecules, but at how FAIR (Findable, Accessible, Interoperable and Reusable) the data associated with these molecules actually is.

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What are the highest bond indices for main group and transition group elements?

Sunday, March 4th, 2018
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A bond index (BI) approximately measures the totals of the bond orders at any given atom in a molecule. Here I ponder what the maximum values might be for elements with filled valence shells.

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