(E)-N-(Ferrocenylmethylidene)(pyridin-3-yl)methanamine

In the title compound, [Fe(C5H5)(C12H11N2)], the cyclopentadienyl rings are present in an eclipsed conformation. The imine is E-configured. In the crystal, C—H⋯N interactions involving both N atoms connect the molecules into two undulating sheets perpendicular to the b axis. The centroid–centroid distance between the two aromatic systems in the ferrocenyl moiety is 3.2928 (18) Å. A C–H⋯π interaction is also present.

In the title compound, [Fe(C 5 H 5 )(C 12 H 11 N 2 )], the cyclopentadienyl rings are present in an eclipsed conformation. The imine is E-configured. In the crystal, C-HÁ Á ÁN interactions involving both N atoms connect the molecules into two undulating sheets perpendicular to the b axis. The centroidcentroid distance between the two aromatic systems in the ferrocenyl moiety is 3.2928 (18) Å . A C-HÁ Á Á interaction is also present.
Cg is the centroid of the C21-C25 ring.

Comment
Chelate ligands are an important class of molecules for complexation reactions. Given a specific set of donor atoms, their chelation ability in terms of Lewis basicity as well as denticity can be fine-tuned. Endowing the "backbone" of a chelate ligand with various substituents, a seemingly endless variety of ligands featuring different steric pretenses, solubility properties and derivatization possibilities is available. Ferrocenyl-substituted chelate ligands seem to be promising candidates with respect to all of the aforementioned features. In a larger study aimed at elucidating the rules guiding the formation and properties of N,N-ligand-supported coordination compounds, we determined the structure of the title compound to enable comparative studies. General background on ferrocenyl compound is amply available in the literature (Nolan et al., 2007;Cheng et al., 2008;Quing et al., 2009;Bildstein et al., 1999).
The cyclopentadienyl rings (Cp) in the ferrocenyl moiety are present in an ecliptic conformation. Both cyclopentadienyl moieties are nearly parallel to each other, the least-squares planes defined by their respective atoms enclose an angle of only 2.20 (14) °. The iron atom is a bit closer to the substituted Cp ring than to the unsubstituted one with the vertical displacements found at 1.6414 (5) Å and 1.6516 (5) Å. The imine is E-configured. The pyridyl system is roughly orientated perpendicular to the aromatic systems of the ferrocenyl moiety, the least-squares plane defined by its atoms intersects with the planes defined by the five-membered carbocycles at an angle of 78.66 (12) ° and 80.31 (11) °, respectively ( Fig. 1).
In the crystal structure, two sets of C-H···N contacts are present whose ranges fall by about 0.1 Å below the sum of van-der-Waals radii of the atoms participating. While the N-atom in the pyridine-system acts as acceptor for one of the H-atoms of the substituted cyclopentadienyl-moiety, the second C-H···N contact is evident between the imine-type N-atom and the H-atom in meta-position to the N-atom in the pyridyl-moiety (Fig. 2). In terms of graph-set analysis (Etter et al., 1990;Bernstein et al., 1995), the descriptor for the first set of contacts is C 1 1 (10) on the unitary level while the second set necessitates a C 1 1 (6) descriptor on the same level. Additionally, a C-H···π interaction stemming from the CH group in ortho position to the nitrogen atom of the pyridine system is present. In total, the molecules are connected to wavy sheets perpendicular to the crystallographic b-axis (Fig. 2). The intercentroid distance between the two aromatic systems in the ferrocenyl moiety was measured at 3.2928 (18) Å.
The packing of the title compound is shown in Figure 3.

Experimental
The title compound was prepared upon condensation of ferrocenyl aldehyde with (pyridin-3-yl)methanamine in an aprotic solvent. Crystals suitable for the X-ray diffraction study were obtained upon recrystallization from dichloromethane-n-hexane.
supplementary materials sup-2 Refinement Carbon-bound H-atoms were placed in calculated positions (C-H 0.99 Å for the methylene group and C-H 0.95 Å for aromatic carbon atoms) and were included in the refinement in the riding model approximation, with U(H) set to 1.2U eq (C). Fig. 1. The molecular structure of the title compound, with atom labels and anisotropic displacement ellipsoids (drawn at 50% probability level).