A combinatorial chemistry approach to new materials for non-linear optics. I. Five Schiff bases

Abstract

A combinatorial chemistry approach has been used to synthesize an array of Schiff bases, five of which, namely N-[(E, 2E)-3-(4-methoxyphenyl)-2-propenylidene]-3-nitroaniline, C(16)H(14)N(2)O(3), (1a), N-[(E, 2E)-3-(4-methoxyphenyl)-2-propenylidene]-4-nitroaniline, C(16)H(14)N(2)O(3), (2a), N-(E, 2E)-3-[4-(dimethylamino)phenyl]-2-propenylidene-3-nitroaniline, C(17)H(17)N(3)O(2), (1b), N-(E, 2E)-3-[4-(dimethylamino)phenyl]-2-propenylidene-4-nitroaniline, C(17)H(17)N(3)O(2), (2b), and N-(E, 2E)-3-[4-(dimethylamino)phenyl]-2-propenylidene-2-methyl-4-nitroanil ine, C(18)H(19)N(3)O(2), (3b), have been structurally characterized. A stack structure is observed for (1a) and (1b) in the crystal phase. Experimental and calculated molecular structures are discussed for these compounds which belong to a chemical class having potential applications as non-linear optical materials.

Structure Elucidation of Dyes That Are Formed in the Colorimetric Detection of the Improvised Explosive Urea Nitrate

“…p‐DMAC 2 was proposed for forensic detection of urine stains on fabrics (10) and for the visualization of latent fingerprints on paper (11–13). The assumed structural characteristics of both products—electron donor and acceptor groups connected to a π‐conjugated chain—make these compounds potential materials for nonlinear optics (14). To date, however, there has been no unequivocal evidence to confirm the structure of these compounds.…”

Thermally Stable Heterocyclic Imines as New Potential Nonlinear Optical Materials

“…General Method of Synthesis. Heterocyclic imines 7 − 12 were obtained by the reaction of heterocyclic aldehydes (Scheme ) with diaminomaleonitrile on heating in an ethyl alcohol solution in the presence of catalytic amounts of acetic acid. , Heterocyclic aldehydes HAa − f , diaminomaleonitrile (DAM), and all solvents were purchased from Aldrich and used as received. The solution of 0.005 mol of diaminomaleonitrile ( DAM ) and 0.005 mol of the corresponding heterocyclic aldehyde HAa − f with 0.1 mL of acetic acid in 30 mL of ethanol was heated to boiling over 1−3 min.…”