Molbank 2006, M488

http://www.mdpi.org/molbank/

 

Synthesis of 4-[4-(4-nitrobenzylideneiminophenylene)phenyleneimino methylidene] phenol

 

L. Marin*, V. Cozan

 

Romanian Academy, ¡°Petru Poni¡± Institute of Macromolecular Chemistry, Aleea Gr. Ghica Voda 41A, Iasi 700487, Romania,

Phone: 0232-260332, Fax: 0232-211299, E-mail: [email protected]

*Author to whom correspondence should be addressed;

 

Received: 26 October 2006 / Accepted: 13 January 2006 / Published: 1 September 2006

 

Keywords: azomethine, liquid crystal, phenolic intermediate, thermotropic, nematic

 

The azomethine 1 was prepared as described elsewhere [1].  The 4-[4-(4-nitrobenzylidene- iminophenylene)phenyleneimino methylidene] phenol (2) was obtained in a similar manner [2] by reacting the azomethine 1 with 4-nitrobenzaldehyde in stoichiometric ratio:

 

 

A mixture of 0.8 g (2.88 mmol) 1 and 0.42 g (2.77 mmol) 4-nitrobenzaldehyde was dissolved in 10 mL DMSO. The mixture was stirred under heating at 90 oC for 30 min. The reaction product was isolated by pouring the reaction mixture into water, washing with water and then with methanol. The purity was tested by the thin layer chromatography. IR spectra and elemental analysis confirmed that synthesised compound had the correct structure with a good degree of purity. The azomethine 2 has an orange-ochre powder aspect , yield 80 %.  

Mp. 213 oC (by polarization light microscopy), 212 oC (by thermooptical analysis), 215 oC (by DSC method). In the melting state the product exhibit liquid crystalline behavior displaying a typical schlieren texture (see Figure 1). The isotropisation temperature could not be measured, because the decomposition started before (decomposition temperature To = 256oC)

 

Figure 1. The schlieren texture of azomethine 2 at 246 oC, between crossed polarizers

 

UV (DMF) 286, 382 nm

 

Anal. calc. for C26 H19 N3 O3 (421.45): N % 9.97; found: N % 9.52

 

IR (KBr, cm-1):  3450 (O-H), 1625 (CH=N), 1600, 1580 (C=C), 1520 (NO2 asym.), 1450 (C=C), 1350 (NO2  sym.), 1240 (C-O, asym.), 1160 (C-O, sym.), 855, 840 (1,4-phenylene ring).

 

References:

1. V. Cozan, E. Avram  Eur. Polym. J. 2003, 39, 107-114.

2. C. Racles, V. Cozan, High Performance Polymers  2002, 14, 169-181.

 

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