The crystal structures of two hydrogen-bonded compounds, namely 4-meth-oxy-benzoic acid-1,3-bis-(pyridin-4-yl)propane (2/1), C13H14.59N2·C8H7.67O3·C8H7.74O3, (I), and biphenyl-4,4'-di-carb-oxy-lic acid-4-meth-oxy-pyridine (1/2), C14H9.43O4·C6H7.32NO·C6H7.25NO, (II), have been determined at 93 K. In (I), the asymmetric unit consists of two crystallographically independent 4-meth-oxy-benzoic acid...