A Facile Electrochemical Grafting of Poly(3,3′-dioctyl-2,2′-bithiophene) on a Gold Surface Modified with a Chemisorbed Monolayer of a 3-Mercapto-2,2′-bithiophene

✍ Scribed by Siu-Choon Ng; Ping Miao; Zhikuan Chen; Hardy S. O. Chan

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 248 KB
• Volume: 10
• Category: Article
• ISSN: 0935-9648
• DOI: 10.1002/(sici)1521-4095(199807)10:10<782::aid-adma782>3.0.co;2-n

✦ Synopsis

All the physical measurements were performed in 1,4-dioxane. The intrinsic molecular hyperpolarizabilities of all the new compounds were determined by the hyper-Rayleigh scattering (HRS) method as described by Clays et al. [14]. The measurements were performed with a newly developed set-up at 1542 nm. The incident beam was the Stokes line of a methane Raman cell pumped by a Nd:YAG laser operating at 1064 nm. The pump beam was polarized in the Z direction and the second harmonic signal was detected at 90 to the propagation direction of the fundamental with an analyzer in the Z direction. The comparison with the intensity of the reference DR1 then allowed the determination of áb 2 ZZZ ñ 1/2 . The beam was only slightly focused onto the cell with a lens of focal length f = 500 mm in order to have a larger volume of solution contributing to the second harmonic signal and to avoid sparks in the solution due to the high light intensity. For the detection of the signal no concave mirror was used. All solutions, of number densities around 2 ´10 19 cm ±3 , were made in dioxane, whose contribution to the second-harmonic signal is negligible. The precision errors for all the measurements are less than 10 %.