Crystal Structure of N,N’-Bis-

(********)**************

******** ******* ******,a ***** ******,b

******* *********,a **** *. *********,b

and ******* *****b

a	Department of Chemistry, University of *******, *******, 12345–12345, ****

b	School of Science, ********* *******,*** ***, ****

Correspondence: A. B. C***** (E-mail: ******@****.**.**)

The structure of N,N-bis(******)********** was determine by X-ray crystallography. The symmetry operation (–x + 2, –y + 1, –z) generates the whole molecule. The compound crystallizes in a monoclinic system and was characterized thus: P21/c, a = **.***(5), b = **.***(7), c = **.***(8)Å,  = **.**(*)˚, Z = 2, V = ****.*(8)Å3. The crystal structure was solved by direct methods and refined by full-matrix least-squares on F2 to final values of R1 = 0.0*** and wR2 = 0.****.

Received November **, 2008; Accepted Februray **, 2009

Published on web  , 

Schiff-bases are well-know chelating ligands in coordination chemistry.1 During the last decade, Schiff-base complexes have been applied to catalytic reactions and biological systems.2 Schiff bases can be used to obtain optical materials and conducting polymers.3,4 Thus, new optical and organic conducting materials can be produced by using these compounds. These compounds, containing Schiff bases, seem to be suitable candidates for further chemical modifications, and may be used to produce optical communication and optical devices.5 Recently, three Schiff-base compounds were reported with nitrobenzaldehyde, and have been structurally characterized.6–8

In this research ********** was prepared by the reaction of ******** (0.* mmol, ** mg) and ************* (0.* mmol, ** mg), which were dissolved in chloroform (10 ml). The mixture was stirred at room temperature for 5 h (Fig. 1). Single crystals suitable for X-ray structure analysis could be obtained by crystallisation from an ethanol and dichloromethane (1:1) solution, which afforded yellow crystals. The crystal and structure-refinement data are summarized in Tables 1‑–‑3. H atoms were placed at calculated positions, with C–H distances of 0.95‑–‑0.99 Å, and treated as riding atoms, with Uiso(H) = 1.3 Ueq(C). In Fig. 1, two 3-nitrobenzaldehyde groups are bridged by butane-1,4-diamine via two C=N double bonds in a roughly linear geometry. This molecule is on the crystallographic center of symmetry. The C7=N2 bond length of 1.267(3)Å conforms to the value for a double bond, while the C8–N2 bond length of 1.466(3)Å conforms to the value for a single bond. The C7=N2 bond distance is 1.267(3)Å, which is longer than the corresponding bond length in N,N-bis********************* [1.250(2)Å].7 The torsion angles, C8–C9–C9(A)–C8(A) and C9(A)–C9–C8–N2, are 180 and –68.9(3)˚, respectively. The benzene rings of the two 3-nitrobenzaldehyde groups are parallel by symmetry. In the crystal packing, the molecules are linked via weak intermolecular C–H…O hydrogen bonds (Table 4).

Fig.1 Chemical diagram of the title compound.

Fig.2 ORTEP structure of N,N’-bis************, showing 50% probability ellipsoids.

References

1.	A. D. Garnovski, A. L. Nivorozhkin, and V. I. Minki, Coord. Chem. Rev., 1993, 1, 126.

2.	O. P. Anderson, A. L. Cour, M. Findeisen, L. Hennig, O. Simonsen, L. Taylor, and H. Toflund, J. Chem. Soc. Dalton Trans., 1997, 111.

3.	B. J. Palys, J. Bukowska, and K. Jackowska, J. Electroanal. Chem., 1997, 19, 428.

4.	A. A. Aly and K. M. El-Shaieb, Tetrahedron, 2004, 60, 3797.

Crystal Structure of N,N‘-Bis-

Hidehiro Uekusa

2008-06-30