2-[(2-Chloro-quinolin-3-yl)(hy-droxy)meth-yl]acrylo-nitrile

Crystal structures of five (2-chloro-quinolin-3-yl)methyl ethers: supra-molecular assembly in one and two dimensions mediated by hydrogen bonding and π-π stacking

In the mol-ecules of the title compounds, methyl 5-bromo-2-[(2-chloro-quinolin-3-yl)meth-oxy]benzoate, C18H13BrClNO3, (I), methyl 5-bromo-2-[(2-chloro-6-methyl-quinolin-3-yl)meth-oxy]benzoate, C19H15BrClNO3, (II), methyl 2-[(2-chloro-6-methyl-quinolin-3-yl)meth-oxy]benzoate, C19H16ClNO3, (III), which crystallizes with Z' = 4 in space group P212121, and 2-chloro-3-[(naphthalen-1-yl-oxy)meth-yl]quinoline, C20H14ClNO, (IV), the non-H atoms are nearly coplanar, but in {5-[(2-chloro-quinolin-3-yl)meth-oxy]-4-(hy-droxy-meth-yl)-6-methyl-pyridin-3-yl}methanol, C18H17ClN2O3, (V), the planes of the quinoline unit and of the unfused pyridine ring are almost parallel, although not coplanar. The mol-ecules of (I) are linked by two independent π-π stacking inter-actions to form chains, but there are no hydrogen bonds present in the structure. In (II), the mol-ecules are weakly linked into chains by a single type of π-π stacking inter-action. In (III), three of the four independent mol-ecules are linked by π-π stacking inter-actions but the other mol-ecule does not participate in such inter-actions. Weak C-H⋯O hydrogen bonds link the mol-ecules into three types of chains, two of which contain just one type of independent mol-ecule while the third type of chain contains two types of mol-ecule. The mol-ecules of (IV) are linked into chains by a C-H⋯π(arene) hydrogen bond, but π-π stacking inter-actions are absent. In (V), there is an intra-molecular O-H⋯O hydrogen bond, and mol-ecules are linked into sheets by a combination of O-H⋯N hydrogen bonds and π-π stacking inter-actions.

Crystal structure of 2-chloro-3-(di-meth-oxy-meth-yl)-6-meth-oxy-quinoline

The title compound, C13H14ClNO3, crystallizes with Z' = 2 in the space group Pca21, but a search for possible additional crystallographic symmetry found none. However, the crystal structure exhibits pseudosymmetry as the two independent mol-ecules are related by an approximate but non-crystallographic inversion located close to (0.38, 0.26, 1/2) in the selected asymmetric unit, and the structure exhibits partial inversion twinning. The approximate inversion relationship between the two mol-ecules in the selected asymmetric unit is clearly shown by comparison of the relevant torsion angle in the two mol-ecules; the corresponding torsion angles have similar, although not identical magnitudes but with opposite signs. The mean planes of the quinoline rings in the two independent mol-ecules are almost parallel, with a dihedral angle of only 0.16 (3)° between them, and the mutual orientation of these rings permits significant π-π stacking inter-actions between them [centroid-centroid distances = 3.7579 (15) and 3.7923 (15) Å]. In addition, the bimolecular aggregates which are related by translation along [010] are linked by a further π-π stacking inter-action [centroid-centroid distance = 3.7898 (15) Å], so forming a π-stacked chain running parallel to [010]. However, there are no C-H⋯N hydrogen bonds in the structure nor, despite the number of independent aromatic rings, are there any C-H⋯π hydrogen bonds; hence there are no direction-specific inter-actions between adjacent π-stacked chains.