Influence of the Synthesis Parameters onto Nucleation and Crystallization of Five New Tin–Sulfur Containing Compounds

The
distinct control of the synthesis parameters achieved crystallization
of five new inorganic–organic hybrid tin sulfides with 1,10-phenanthroline
(phen) as the organic component: {[Mn­(phen)2]2(μ2-Sn2S6)} (1, 3), {[Mn­(phen)2]2(μ2-Sn2S6)}·phen (2),
{[Mn­(phen)2]2(μ2-Sn2S6)}·phen·H2O (4), and
{[Mn­(phen)2]2[μ-η2-η2-SnS4]2[Mn­(phen)]2}·H2O (5). Compounds 1, 3, and 4 occur successively under static conditions by
increasing the reaction time up to 8 weeks. Stirring the reaction
mixtures and keeping the educt ratio constant allow preparation of
distinct phase pure samples within very short reaction times. At higher
autogenous pressure, crystallization and conversion of several compounds
are suppressed, and only 1 crystallized. Compound 2 could only be obtained in glass tubes at low pH value of
the reaction mixture or at low amine concentration. Adjusting the
pH value of the solution, the concentration, and the volume of the
solvent, compounds 1–4 crystallize
sequentially and were successively converted into each other. Results
of thermal stability experiments and solubility studies suggest that
compounds 1 and 3 are polymorphs following
the density rule. Compounds 2 and 4 may
be viewed as pseudopolymorphs of 1 and 3.