2-Methyl-4-nitroaniline crystal structure

ABSTRACT. Second harmonic generation(S.H.G.) in inclusion complexes between dimethyl-cyclodextrin(dimethyl -CD) and nitroaniline derivatives occurs. This is due to the destruction of the centrosyimntric crystal structure in nitroaniline derivatives caused by forming inclusion complexes. S.H.G. intensity of dimethyl /-CD complex with N-methyl-nitroaniline is 5 5 times as large as that of urea. 

For these classes of conjugated molecular and polymer structures, the principal property is that their nonreson-ant, nonlinear optical responses are dominated by ultrafast, virtual excitations of the ir-electron states. This was directly demonstrated by MNA (2-methyl-4-nitroaniline) single crystal measurements of macroscopic second order susceptibilities at do (j 3) and optical frequencies (13-1 ) and combined second harmonic measurements and theo-... 

Hexakis(2,6-di-0-methyl)-a-CyD complexes with a small guest molecule, such as iodine and 1-propanol, crystallize with the cage-type packing structure [185]. Compared with the structure of the corresponding -CyD complex, the guest molecules in the both complexes are shifted to the secondary hydroxyl side from the center of the cavity. 3-Iodopropionic acid [186], m-nitroaniline [187], and acetonitrile [188] are also fully accommodated in the host cage . A 3-0 acetylated host, hexakis(2,6-di-0-methyl-3-0-acetyl)-a-CyD, was crystallized from butylacetate [189]. In spite of the disruption of intramolecular hydrogen bonds, the host molecule is in a round shape because of the inclusion of butylacetate. 

Phase-matched second harmonic generation in single crystal polymers was first observed in 2-methyl-4-nitroaniline substituted diacetylene polymers. Subsequently, a number of other diacetylene structures... 

Sugihara, O., and Sasaki, K., Phase-matched second-harmonic generation in a 2-methyl-4-nitroaniline single-crystal waveguide combined structure of grating couplers and four-layer waveguide, J. Opt. Soc. Am. B, 9, 104-107 (1992). 

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