Assembly and Autochirogenesis of a Chiral Inorganic Polythioanion Möbius Strip via Symmetry Breaking

Using [Mo2S2O2(H2O)6]2+ and squarate dianion, we synthesized
the thiometalate
ring compounds [(Mo2S2O2)x(OH)y(C4O4)z(Mo2O8)o(H2O)p]n−, where [x,y,z,o,p,n] = [7,14,2,0,2,4] for 1, [6,8,2,2,4,8] for 2, and [4,6,1,1,0,4] for both 3a and 3b, which are chiral and nonchiral isomers,
respectively. Not only do the four thiometalate clusters show decreasing
symmetry at the molecular level across the series, but the incorporation
of the “addendum” {Mo2O8}o unit also allows the thiometalate ring to
twist. The reaction initially yields the chiral molecule 3a with a twisted ring, which undergoes spontaneous resolution upon
crystallization; the reaction mixture later yields the intrinsically
nonchiral isomer 3b with a nontwisted ring. In addition,
the compounds are able to promote the electrocatalytic evolution of
hydrogen.