2-(6-Methyl-2-pyridyl)-1,1-diphenylethanol

The title compound, C20H19NO, was prepared from 2,6-lutidine and benzophenone. There are two symmetry-independent molecules in the asymmetric unit. Each molecule is involved in one intramolecular O—H⋯N hydrogen bond. In the crystal structure, helical chains are formed along the b axis by weak π–π interactions between neighbouring molecules [centroid–centroid distances between the pyridyl rings of the two independent molecules = 4.041 (3) and 4.051 (3) Å].

The title compound, C 20 H 19 NO, was prepared from 2,6lutidine and benzophenone. There are two symmetry-independent molecules in the asymmetric unit. Each molecule is involved in one intramolecular O-HÁ Á ÁN hydrogen bond. In the crystal structure, helical chains are formed along the b axis by weakinteractions between neighbouring molecules [centroid-centroid distances between the pyridyl rings of the two independent molecules = 4.041 (3) and 4.051 (3) Å ]. H atoms treated by a mixture of independent and constrained refinement Á max = 0.12 e Å À3 Á min = À0.12 e Å À3 Table 1 Hydrogen-bond geometry (Å , ). Data collection: SMART (Bruker, 2000); cell refinement: SMART; data reduction: SAINT (Bruker, 2000); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

2-
There is a growing interest in the chemistry of metal-nitrido complexes, particularly those of late transition metals (Dehnicke et al., 2001). 2-(6-Methyl-pyridin-2-yl)-1,1-diphenyl-ethanol has been used as a multianionic chelating (N, O) ligand and coordinated with transition metals and main group elements, such as Ru, Os, Mo, B, Si etc. (Yip et al., 2003;Gibson et al., 2007). It can be prepared from 2,6-lutidine in moderate yield (Koning et al., 2000). During our studies, we obtained single crystals of the title compound report its crystal structure herein.
The crystal structure of title compound, C 20 H 19 NO, shows that all the bond lengths and angles have normal values. In an asymmetric unit there are two symmetry independent molecules I and II. Each molecule has one intramolecular O-H···N hydrogen bond (O1-H1A···N1, O2-H2A···N2) (Fig. 1).
Molecule I exhibits two benzene rings A (C2-C7) and B (C8-C13) as well as a pyridine ring C (N1/C15-C19) that are not coplanar with respect to each other. The dihedral angles between rings A and B, B and C, and C and A measure to 82.02 (6)°, 47.06 (6)°, and 85.87 (5)°, respectively.
In the crystal packing weak π-π interactions between neighbouring molecules I and II are observed, the distance of g1-g2 being 4.041 (3) and 4.051 (3) Å (g1 is center of mass of N1/C15-C19, g2 is center of mass of N2/C35-C39). Helical chains along the b axis are formed by these interactions (Fig. 2).
Experimental 2-(6-Methyl-pyridin-2-yl)-1,1-diphenyl-ethanol was prepared from 2,6-lutidine and benzophenone according to a procedure described in the literature (Berg & Holm, 1985, yield: 60%). Colorless crystals were obtained by recrystallization from light petroleum-ethyl acetate(vol. ratio: 5:1) at room temperature.  The H atoms were placed in calculated positions except O-H atoms and included as part of a riding model, with C-H = 0.93-0.97 Å, and with U equiv values set at 1.2-1.5 U equiv of the parent atoms. The O-H atoms were located in the Fourier difference map and refined with a given isotropic thermal parameters 1.2 times the U equiv for the parent atom.    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 Rfactors(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.