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Chemical reduction of a vertically expanded pentacene, TIPS- peri -pentacenopentacene (TIPS-PPP), with sodium metal in THF readily afforded a doubly-reduced product isolated as [{Na + (THF) 3 } 2 (TIPS-PPP2-)]. Single-crystal X-ray diffraction revealed the formation of a π-complex of TIPS-PPP2- with two {Na + (THF) 3 } moieties. The sodium ion is coordinated to three C-atoms at the most negatively charged edge sites and at the lateral ethynyl group. The delocalisation of the charge on the ethynyl function is accompanied by its notable elongation ( Δ = 0.015 Å) coupled with the contraction of the adjacent single C-C bond ( Δ = 0.033 Å). Bond length analysis supported by Harmonic Aromaticity Oscillator Model (HOMA) shows that the dianion can be written with four aromatic sextets in agreement with the Clar representation. Although TIPS-PPP2- has 36 π-electrons (4 n ), it does not show a global magnetic paratropic response. The rings with the most negative charge density have a very low paratropic response, while the other rings have a low diatropic response. Overall, the dianion is a non-aromatic molecule.

The first photoresponsive cholesteric liquid crystal comprising a photoisomerizable helical naphthopyran derivative dopant and a nematic liquid crystal is reported. An unprecedented helical twisting power switching ratio of over 90% allowed us to demonstrate multi-cycle rotational motion of micro-objects by UV light irradiation.

The synthesis and characterisation of a three-dimensional lithium-organic framework MIL-145 is described, which upon thermal treatment yields a second open framework, MIL-146, that contains four and three-coordinate lithium centres: the coordinatively unsaturated trigonal planar lithium centres are able to reversibly bind water with crystallinity maintained, while the dehydrated phase shows preferential adsorption of CO(2) over N(2).

Bis-spiropryran molecules were grafted onto the surface of upconverting nanoparticles. Fluorescence resonance energy transfer from the upconverting nanoparticles to the surface bis-spiropyran molecules triggered the transformation of the ring-closed bis-spiropyran to the ring-open bis-merocyanine forms.

Photochromic liquid crystals based on [2H]-chromenes functionalised in the 3,3[prime or minute]-positions by phenyl groups linked to 4-cyano-4[prime or minute]-hydroxybiphenyl groups via alkyl and siloxane spacers as chromophore were synthesised and the photochromic and mesomorphic behaviour was investigated., (Copyright 2004 The Royal Society of Chemistry)

A photochromic liquid crystal system based on a diarylethene functionalised in the 2,2'-positions and linked to 4-cyano-4'-hydroxybiphenyl groups via alkyl spacers as chromophores was synthesised and its photochromic and mesomorphic behaviour was investigated.