Henry Rzepa's Blog Chemistry with a twist

March 9, 2011

From the colour blue to molecular wires

Filed under: Interesting chemistry — Tags: , , — Henry Rzepa @ 1:54 pm

In the previous post I pondered the colour of Monastral blue (copper phthalocyanine). Something did not quite fit, and so I speculated that perhaps some oxidation of the pigment might give a new species. This species (Cambridge code FEGJOQ) comprises two parts of copper phthalocyanine, 1 part of the corresponding cation, and 1 part of triodide anion. Looking at the packing of this system, I spotted something I had seen some time ago in NaI2.Acetone, namely an infinitely long and absolutely straight chain of iodine atoms, a molecular wire if you like.


March 8, 2011

Monastral: the colour of blue

The story of Monastral is not about a character in the Magic flute, but is a classic of chemical serendipity, collaboration between industry and university, theoretical influence, and of much else. Fortunately, much of that story is actually recorded on film (itself a unique archive dating from 1933 and being one of the  very first colour films in existence!). Patrick Linstead, a young chemist then (he eventually rose to become rector of Imperial College) tells the story himself here. It is well worth watching, if only for its innocent social commentary on the English class system (and an attitude to laboratory safety that should not be copied nowadays). Here I will comment only on its colour and its aromaticity.

Copper phthalocyanine


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