Naslov
Structure and spectroscopic characteristics of Schiff bases of salicylaldehyde with 2, 3-diaminopyridine

Autori
Cimerman, Zvjezdana ; Galešić, Nikola ; Bosner, Branka

Izvornik
Journal of molecular structure (0022-2860) 274 (1992); 131-144

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Schiff bases ; salicylaldehyde ; 2 ; 3-diaminopyridine

Sažetak
The Schiff bases 2-amino-3-salicylideneaminopyridine (1) and 2, 3-bis(salicylideneamino)pyridine (bimorphous, 2a and 2b) were prepared and characterized by X-ray crystallography and by IR and NMR spectrometry. (1) C12H11N3O, Mr = 213.240, monoclinic, space group P21/c, a = 12.00(2), b = 6.594(3), c = 14.06(2) Å ; , = 104.90(8)°, V = 1075(2) Å ; 3, Z = 4, Dx = 1.317 g cm -3, (Mo K ) = 0.71073 Å ; , = 0.82 cm -1, F(000) = 448, T = 295 K, R = 0.047, Rw = 0.028 for 886 reflections with I -(I). (2a) C19H15N3O2, Mr = 317.348 monoclinic, space group P21, a = 6.202(3), b = 17.622(7), c = 14.724(8) Å ; , = 91.85(3)°, V = 1608(1) Å ; 3, Z = 4 (two crystallographically independent molecules A and B), Dx = 1.311 g cm -3, (Mo K ) = 0.71073 Å ; , = 0.816 cm -1, F(000) = 664, T = 295 K, R = 0.058, Rw = 0.034 for 972 reflections with I > 3 (I). The angle between the benzene and the pyridine ring is 51.5(2)° in 1, whereas in 2a the corresponding angles are 51.1(4)° in molecule A and 51.8(4)° in molecule B. Molecules of 1 are connected in pairs by two centrosymmetric hydrogen bonds N---H• • • NPy of 3.024(5)Å ; . Intermolecular bonding of 1 does not take place in CHCl3 solution. No evidence was found in the IR and NMR spectra for tautomeric interconversion of 1 and 2 into the ketoamine or for cyclization of 2 into the cyclic diamine.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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