A low molecular weight OLED material: 2-(4-((2-hydroxyethyl)(methyl)amino)benzylidene)malononitrile. Synthesis, crystal structure, thin film morphology, spectroscopic characterization and DFT calculations

A low molecular weight fluorescent malononitrile derivative showed an efficient solid-state emission and electroluminescence properties.

Regio- and stereoselective 1,3-dipolar cycloaddition reactions of C-aryl (or hetaryl)-N-phenylnitrones to monosubstituted ylidene malononitriles and 4-benzylidene-2-phenyloxazol-5(4H)-one

The first example of 1,3-dipolar cycloaddition reactions of C-aryl (or hetaryl)-N-phenylnitrones to monosubstituted ylidene malononitriles and 4-benzylidene-2-phenyl-oxazol-5(4H)-one is described. The reaction of C-(4-(dimethylamino)phenyl)-N-phenyl-nitrone (1a) with 2-(4-substituted-benzylidene)malononitriles 2a, b in dry toluene, in the absence of catalyst, at reflux temperature furnished the novel cycloadducts 2-(3-aryl-2-phenyl-2,3-dihydro-1,2,4-oxadiazol-5-yl)-3-(4-methoxyphenyl)acrylonitriles 3a, b. Refluxing C-aryl (or hetaryl)-N-phenylnitrones 1b–i with 2-(4-methoxy-benzylidene)malononitrile (2a) in dry toluene, in the absence of catalyst, gave the unexpected 2-cyano-3-(4-methoxyphenyl)-acrylamide (5), as the sole product. On the other hand, refluxing 4-benzylidene-2-phenyloxazol-5(4H)-one (7) with an equimolar amount of C-aryl (or hetaryl)-N-phenyl-nitrones 1a–c, f–i in absolute EtOH afforded the previously unknown 5-anilino-4-benzoyl-2-phenyloxazole (10), as the only isolable product. The resulting products were formed with a high degree of regio- and stereoselectivity. Quantum chemical calculations were performed to verify stereoselectivity of the studied reaction. A mechanistic proposal is presented to rationalize the formation of these products.

Crystal structure of 2-[2-(benzyloxy)benzylidene]malononitrile

In the title benzylidenemalononitrile derivative, C17H12N2O, the dihedral angles between the central benzene ring and the Y-shaped C=C(CN)2group (r.m.s. deviation = 0.006 Å) and the terminal benzene ring are 12.72 (8) and 37.60 (11)°, respectively. The Car—O—Csp3—Cartorsion angle is −174.52 (13)° and the major twist between the aromatic rings occurs about the Csp3—Carbond. Weak aromatic π–π stacking [centroid–centroid separation = 3.7784 (13) Å; slippage = 1.21 Å] between inversion-related pairs of the central benzene rings is observed in the crystal.