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The ultrafast photoinduced ring-closing dynamics of a furan-based difurylethene (YnPhT) has been investigated by femtosecond transient absorption spectroscopy. We performed time-dependent density functional theory (TD-DFT) calculations to explain the experimental results in detail. The sub-picosecond time scale of the ring-closing reaction is comparable with thiophene-based analogues, but oxygen atoms at the photochromic core can avoid adverse interaction between switches and metal contacts in further applications. This observation proves that furan-based diarylethenes are potential optoelectronic elements with an ultrafast optical response.

Picosecond cyclization reaction dynamics of furan-based photochromic diarylethenes with thiosemicarbazone side-chains were studied by femtosecond transient absorption spectroscopy. The monitored ring-closing reaction in the time range of 0+1100 ps is characterized by two main stages. First stage proceeds during the first 1.1 ps and is associated mainly with redistribution of rr -rr molecular orbitals of excited open-ring molecules which consequently leads to the formation of excited closed-ring molecules. During the next 300 ps, a long-term relaxation via vibrational cooling of closed-ring form occurs. The obtained relaxation dynamics curve was fitted by an exponential decay function with 68 ps time constant.

The photochromic properties of furan-based diarylethenes and their interaction with citrate-capped gold nanoparticles were investigated by ultraviolet/visible absorption spectroscopy and transmission electron microscopy. We identified the optimal concentration of diarylethenes in water-ethanol mixture required for stability of colloidal systems. Nanoparticles coupled with diarylethene derivatives exhibit a new surface plasmon resonance band coming from their aggregation. We analyzed the effects of functional side-chain groups on aggregation process. These results can be considered as a basis for further designing of novel hybrid nanomaterials and optoelectronic elements.Electronic supplementary materialThe online version of this article (doi:10.1186/s11671-017-2044-6) contains supplementary material, which is available to authorized users.