8-(Naphthalen-1-yl)quinoline

Godwin Kanu; Roger A Lalancette; Dale E Vitale

doi:10.1107/S1600536811034052

. 2011 Aug 31;67(Pt 9):o2522. doi: 10.1107/S1600536811034052

8-(Naphthalen-1-yl)quinoline

Godwin Kanu ^a, Roger A Lalancette ^b, Dale E Vitale ^c,^*

PMCID: PMC3200913 PMID: 22059059

Abstract

In the title molecule, C₁₉H₁₃N, the angle between the mean planes of the naphthalene and quinoline ring systems is 68.59 (2)°. The compound is of interest with respect to its potential for spontaneous resolution. In the crystal structure, the R and S isomers are arranged in alternating homochiral layers. The molecules of a given layer are oriented with their major axes (i.e. the axis perpendicular to the interannular bond) in the same direction and their naphthalene and quinoline ring systems are arranged parallel. Like the configurations, this orientation alternates in adjacent layers.

Related literature

For spontanteous-resolution experiments, see: Asakura & Plasson (2006 ▶); Kondipudi et al. (1999 ▶); Kranz et al. (1993 ▶); Sainz-Diaz et al. (2005 ▶); Wilson & Pincock (1974 ▶). For related structures, see: Kerr & Robertson (1969 ▶); Kuroda & Manson (1981 ▶). For details of the synthesis, see: Huff et al. (1998 ▶).

Experimental

Crystal data

C₁₉H₁₃N
M _r = 255.30
Triclinic,
a = 6.1778 (1) Å
b = 10.0392 (2) Å
c = 10.8828 (2) Å
α = 104.537 (1)°
β = 106.435 (1)°
γ = 90.002 (1)°
V = 624.80 (2) Å³
Z = 2
Cu Kα radiation
μ = 0.61 mm⁻¹
T = 100 K
0.37 × 0.20 × 0.10 mm

Data collection

Bruker SMART CCD APEXII diffractometer
Absorption correction: numerical (SADABS; Sheldrick, 2008 ▶) T _min = 0.806, T _max = 0.942
5783 measured reflections
2058 independent reflections
1678 reflections with I > 2σ(I)
R _int = 0.011

Refinement

R[F ² > 2σ(F ²)] = 0.044
wR(F ²) = 0.131
S = 1.06
2058 reflections
181 parameters
H-atom parameters constrained
Δρ_max = 0.38 e Å⁻³
Δρ_min = −0.34 e Å⁻³

Data collection: APEX2 (Bruker, 2006 ▶); cell refinement: APEX2; data reduction: SAINT (Bruker, 2005 ▶); program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: Mercury (Macrae et al., 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536811034052/lh5298sup1.cif

e-67-o2522-sup1.cif^{(17.3KB, cif)}

Supplementary material file. DOI: 10.1107/S1600536811034052/lh5298Isup2.mol

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811034052/lh5298Isup3.hkl

e-67-o2522-Isup3.hkl^{(101.2KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811034052/lh5298Isup4.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Acknowledgments

This work was partly supported by the SpF program of Kean University. The authors acknowledge support by NSF-CRIF Grant No. 0443538 for the X-ray diffractometer.

supplementary crystallographic information

Comment

The structural similarities between the title compound (81QNNP) and 1,1'-binaphthalenyl (11BNP) suggest that, like the hydrocarbon, 81QNNP might exhibit spontaneous resolution. The characteristics that afford spontaneous resolution of the racemic compound of 11BNP are its dimorphism and moderate barrier to rotation about the C1—C1' interannular bond (Kranz et al., 1993). The barrier is large enough to prevent racemization of resolved forms below about 351 K, but small enough to afford rapid interconversion of the enantiomers in the melt. The dimorphs consist of an optically inactive racemic compound (Kerr & Robertson, 1969) that is the more stable form at temperatures below 351 K and a conglomerate of single crystals of the R and S isomers (Kuroda & Manson, 1981) that is the more stable above this temperature. Accordingly, heating of the racemic compound above the melting point of the conglomerate (431 K) followed by supercooling to 423 K can produce an optically active solid (Kondipudi et al., 1999).

The molecular structure of the title compound is shown in Fig. 1. The title compound closely resembles 1,1-binaphthalenyl in molecular structure, crystal structure, and thermal behavior (Wilson & Pincock, 1974). On the molecular level, the two compounds differ only in the substitution of a nitrogen in 81QNNP for the C8 carbon in 11BNP. Likewise, the room temperature solid of 81QNNP is an optically inactive racemic compound with the components of an enantiotopic pair of molecules in the unit cell. Moreover, while spontaneous development of optical activity has not been demonstrated in the title compound, preliminary DSC results suggest that it is polymorphic. This means that, in addition to the racemic compound described herein, 81QNNP may also exist as a conglomerate. If so, it has the potential for spontaneous resolution via a mechanism similar to that of 11BNP (Asakura & Plasson, 2006; Sainz-Diaz et al., 2005). In the crystal, the R and S isomers are arranged in alternating homochiral layers. The molecules of a given layer are oriented with their major axes in the same direction and their naphthalene and quinoline ring systems are arranged parallel. Like the configurations this orientation alternates in adjacent layers (Fig. 2).

Experimental

The synthesis was carried out according to a literature procedure (Huff et al., 1998). 8-(Naphthalen-1-yl)quinoline was synthesized in 58% yield from 8-bromoquinoline (Frontier Chemical) and 1-naphthalenylboronic acid (Sigma–Aldrich) using a modification of the Suzuki coupling reaction (Huff et al., 1998) and crystallized from 1-propanol; m.p. 436.0–437.5 K, ¹³C NMR (CDCl₃): DEPT-CH δ 121.3, 125.6, 125.9, 126.0, 126.4, 127.0, 128.1, 128.2, 128.3, 128.6, 131.9, 136.4, 150.9 p.p.m. IR (KBr ν cm^-1): 3041 (CH_ar) 1592 and 1491 (C═C and C═N), 1379, 1310, 1204, 1064, 1015, 944, 828, 797, 782, 772, 677, 617, 517.