In the hydrogen-bonded structure of the title complex, O2S(C6H4OH)(2).C10H8
N2 or C12H10O4S.C10OH8N2, the bis-phenol molecules are linked into C(8) cha
ins by means of O-H ... O=S hydrogen bonds, and the 2,2'- bipyridyl units,
which act as single accepters only, are pendent from these chains by means
of O-H ... N hydrogen bonds. Pairs of these chains, related by centres of i
nversion, are mutually interlocked via their pendent arms.