ISSN:
1573-4803
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract Two-dimensional charge-transfer molecules based on N,N′-dialkyl-2,4-dinitro-1,5-diaminobenzene have been synthesized. 1H and 13C-NMR spectroscopy, elemental analysis and mass spectroscopy were used to elucidate their chemical structures. The physical and non-linear optical properties of this new family of dyes containing alkyl chain; C3H7, C6H13, C8H17, C10H21, C11H23 and C18H37 are discussed, taking into account the possible role of alkyl chain length. These two-dimensional molecules have a significantly large off-diagonal β component in contrast to one-dimensional molecules. These compounds showed no powder second-harmonic generation (SHG) at 1.064 μm being centrosymmetric, however, their poled guest-host systems with poly(methyl methacrylate) and co-crystals with p-nitroaniline were SHG active. Powder SHG as high as 37 times that of urea was observed from N,N′-dihexyl-2,4-dinitro-1,5-diaminobenzene with its mixture with p-nitroaniline. Second-harmonic generation of N,N′-dioctadecyl-2,4-dinitro-1,5-diaminobenzene (DIODD) was studied as Langmuir–Boldgett monolayers. The Langmiur–Blodgett monolayer of a 1: 1 mixture of DIODD and arachidic acid showed second-order non-linear optical coefficients d11 and d13 of 11 × 10−9 and 3.85 × 10−9 esu, respectively, at a tilt angle of 60°. For the first time, a relationship between the microscopic polarizabilities and the molecular orientation of two-dimensional charge-transfer molecules has been established. In the light of the present experimental and theoretical data analysis, the potential of two-dimensional charge-transfer molecules for second-order non-linear optics is discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1004680001795
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