Beyaz

Taha Toros Arşivi, Dosya No: 3-Ziya Osman SabaUnutma İstanbul projesi İstanbul Kalkınma Ajansı'nın 2016 yılı "Yenilikçi ve Yaratıcı İstanbul Mali Destek Programı" kapsamında desteklenmiştir. Proje No: TR10/16/YNY/010

Effects of Photochromic Furan-Based Diarylethenes on Gold Nanoparticles Aggregation

Abstract 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

Optical properties of gold nanoparticles decorated with furan-based diarylethene photochromic molecules

The optical properties of the photochromic 1,2-bis(2-methyl-5-((4-mercaptophenyl)ethynyl)-furan-3-yl)perfluorocyclopentene (YnPhT) covalently attached to gold nanoparticles (AuNP) (d = 17 ± 1 nm) were studied in air at ambient conditions. The reversible ring-opening/closing photochromic reactions of molecules attached on AuNP surface can occur under similar light irradiation conditions as observed for free molecules in ethanolic solution. An unexpected blue shift of the local surface plasmon resonance band (LSPR) of AuNP covered by photochromic molecules was observed after UV light irradiation. A reverse red shift of LSPR was observed when the AuNP are illuminated by visible light. Moreover, increased amplitude of the LSPR was observed for AuNP covered with molecules in the closed-ring state. These observations are discussed in view of molecule – AuNP interactions. These interactions decelerate the kinetics of the ring-closing reaction of YnPhT on AuNP surfaces under UV light irradiation.publishe

Additional file 4: Figure S4. of Effects of Photochromic Furan-Based Diarylethenes on Gold Nanoparticles Aggregation

The spatial structures of C5F-MTSC (top) and C5F-TSC (bottom) in open-ring (left) and closed-ring (right) states obtained with ChemDraw MM2 energy minimization. (PPT 219 kb

Additional file 1: Figure S1. of Effects of Photochromic Furan-Based Diarylethenes on Gold Nanoparticles Aggregation

The color changes that represents the interection of DAEs with AuNPs: (a) C5F-MTSC and (b) C5F-TSC. The volume ratio water to ethanol is equal to 4:1, C DAE = 1 × 10−6, 5 × 10−6, 1 × 10−5 mol·L−1. The concentration of gold C Au = 2 × 10−4 mol·L−1 was constant for all series. The spectra of the corresponding solutions are presented in Fig. 3. (PPT 128 kb

Picosecond cyclization reaction dynamics of furan-based diarylethene with thiosemicarbazone side-chain groups

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 π-π 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.publishe

Ultrafast ring-closing reaction dynamics of a photochromic furan-based difurylethene

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.publishe