[(E)-1-(Naphthalen-2-yl)ethylidene](naphthalen-1-ylmethyl)amine

The title compound, C23H19N, was obtained unexpectedly from the reaction of [Eu(nta)3(PzPy)] {Hnta = 1-(2-naphthoyl)-3,3,3-trifluoroacetone and PzPy = 2-[3(5)-pyrazolyl]pyridine} with 1-naphthylmethylamine. The 1- and 2-naphthyl groups are essentially planar [r.m.s. deviations of 0.007 and 0.011 Å, respectively] and subtend angles of 38.69 (11) and 16.50 (11)°, respectively, with the central CH3—C=N—CH2 unit, which is also almost planar [r.m.s. deviation = 0.002 Å]. In the crystal, the molecules are disposed in zigzag-type fashion, forming layers perpendicular to [100]. Weak supramolecular C—H⋯π interactions contribute to the packing forces.


Experimental
As free ligands, imines have diverse applications: as protecting groups for the C═O double bond or the amine function; as chiral auxiliaries in asymmetric substitution reactions of amino acids; as reagents for the quantitative transformation of aldimines into aza-enolates; the synthesis of primary and secondary amines by reduction of the C═N double bond (Hampe et al., 2004). They can also form complexes with various metals (e.g., Mg, Mn, Co, Cr, Zn Pd, Pt) with application as catalysts of polymerization reactions (e.g., polymerization of lactide; copolymerization of CO 2 and epoxides), epoxidation of alkenes and for the Heck reaction between methyl acrylate and p-iodonitrobenzene (Hampe et al., 2004;Kumar et al., 2008).
The presence of the metal is essential because the non-catalyzed reaction of β-diketonates with amines does not produce monoimines (Filyakova et al., 1996).
The asymmetric unit of the title compound is composed of a whole molecular unit, C 23 H 19 N (see Scheme and Figure 1).
The close packing of the molecules in the triclinic centrosymmetric space group is mediated by the need to fill the space in conjunction with several supramolecular weak interactions, such as C-H···π ( Figure 2; see Table 1 for geometrical details of these supramolecular interactions). Individual molecules are disposed in zigzag-type forming supramolecular layers which are perpendicular to the [100] direction of the unit cell ( Figure 2).

Experimental
All chemicals were purchased from Sigma-Aldrich and used as received. Literature procedures were used to prepare [Eu(nta) 3 (PzPy)] (1.00 g, 0.92 mmol) was dissolved in toluene (45 ml) at ambient temperature. 1-Naphthylmethylamine (0.78 ml, 5.5 mmol) was added leading to the formation of an orange solution, which was refluxed for 3 days. The water formed in the reaction was removed by using a Dean-Stark apparatus. The reaction mixture was filtered off and the

Refinement
Hydrogen atoms bound to carbon were placed at their idealized positions with C-H = 0.93 Å (aromatic and delocalized), 0.97 Å (-CH 2 -) and 0.96 Å (terminal -CH 3 ). These hydrogen atoms were included in the final structural model in riding-motion approximation, with the isotropic thermal displacement parameters fixed at 1.2×U eq (for -CH and the -CH 2 -moieties) or 1.5× U eq (for the -CH 3 group) of the carbon atom to which they are attached.    Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.