Crystal structures of five (2-chloroquinolin-3-yl)methyl ethers: supramolecular assembly in one and two dimensions mediated by hydrogen bonding and π–π stacking

Abstract

In the molecules of the title compounds, methyl 5-bromo-2-[(2-chloroquinolin-3-yl)methoxy]benzoate, C18H13BrClNO3, (I), methyl 5-bromo-2-[(2-chloro-6-methylquinolin-3-yl)methoxy]benzoate, C19H15BrClNO3, (II), methyl 2-[(2-chloro-6-methylquinolin-3-yl)methoxy]benzoate, C19H16ClNO3, (III), which crystallizes with Z′ = 4 in space group P212121, and 2-chloro-3-[(naphthalen-1-yloxy)methyl]quinoline, C20H14ClNO, (IV), the non-H atoms are nearly coplanar, but in {5-[(2-chloroquinolin-3-yl)methoxy]-4-(hydroxymethyl)-6-methylpyridin-3-yl}methanol, C18H17ClN2O3, (V), the planes of the quinoline unit and of the unfused pyridine ring are almost parallel, although not coplanar. The molecules of (I) are linked by two independent π–π stacking interactions to form chains, but there are no hydrogen bonds present in the structure. In (II), the molecules are weakly linked into chains by a single type of π–π stacking interaction. In (III), three of the four independent molecules are linked by π–π stacking interactions but the other molecule does not participate in such interactions. Weak C—H...O hydrogen bonds link the molecules into three types of chains, two of which contain just one type of independent molecule while the third type of chain contains two types of molecule. The molecules of (IV) are linked into chains by a C—H...π(arene) hydrogen bond, but π–π stacking interactions are absent. In (V), there is an intramolecular O—H...O hydrogen bond, and molecules are linked into sheets by a combination of O—H...N hydrogen bonds and π–π stacking interactions.

Keywords

• crystal structure
• 2-chloroquinolines
• molecular conformation
• hydrogen bonding
• π–π stacking interactions