Hydrothermal crystallisation of metal (II) orotates (M=nickel, cobalt, manganese or zinc). Effect of 2,2-bipyridyl, 2,2-dipyridyl amine, 1-methyl-3-(2-pyridyl)pyrazole, phenanthroline and 2,9-dimethyl-1,10-phenanthroline upon structure

Hydrothermal synthesis of orotic acid (H3L) with Ni(OAc)2·4H2O gives a green 1D co-ordinative network of composition [Ni(HL)(H2O)3] (3). The kinetic product [Ni(HL)·(H2O)4]H2O (4) can be prepared by conventional crystallisation. When boiled in water it is transformed into the thermodynamically favoured trihydrate 3. An unstable blue phase 5 that could not be characterised was also observed. Hydrothermal synthesis of orotic acid and M(OAc)2·4H2O (M=Ni, Co, Mn or Zn) and either 2,2-bipyridyl (bipy), 2,2-dipyridylamine (dpa), phenanthroline (phen), methyl-3-(2-pyridyl)pyrazole (pypz) or 2,9-dimethyl-1,10-phenanthroline (dmphen) gave infinite 1D co-ordinative networks of composition [M(HL)bipy(H2O)] (M=Co or Mn) (6–7) and complexes of composition [Ni(HL)bipy (H2O)2]2H2O (8); [Ni(HL)(dpa)(H2O)2]H2O (9); [Ni(HL)(phen)(H2O)2]·2H2O (10); [Ni(HL)(C9H9N3)(H2O)2]·2H2O (11); [Ni(HL)(dmphen)(H2O)] (12); [Zn(HL)bipy(H2O)] (13) and [Ni(HL)(dpa)2]·0.5H2O (14).