Tomislav Balić

Triclinic polymorph of 4-[4-(4-formyl­phen­oxy)but­oxy]benzaldehyde

The title compound, C18H18O4, is a triclinic polymorph of the previously reported monoclinic polymorph [Han & Zhen (2005 ▶). Acta Cryst. E61, o4358–o4359]. In the crystal of the triclinic polymorph, molecules are linked by two pairs of C—H⋯O hydrogen bonds, forming a two-dimensional network parallel to (102), and enclosing loops with graph set motifs of R 2 2(8) and R 2 2(6).

4-[5-(4-Formyl­phen­oxy)pent­oxy]benzaldehyde

In the title compound, C20H19O4, the benzene rings, linked via five methylene C atoms, form a dihedral angle of 77.28 (6)°. In the crystal, molecules are linked via pairs of weak C—H⋯O interactions [graph set R 2 2(6)] into dimers that are further connected by additional weak C—H⋯O interactions [graph sets R 2 2(14), R 2 2(26) and R 2 2(6)].