Structures of S-(pyridin-2-yl) 4-nitrobenzothioate, S-(pyridin-2-yl) 4-methylbenzothioate and S-(pyridin-2-yl) 4-methoxybenzothioate: building blocks for low-symmetry multifunctional tetrapyrroles.

The crystal structures of three S-(pyridin-2-yl) benzo­thio­esters with varying para-phenyl substituents are presented, namely, S-(pyridin-2-yl) 4-nitro­benzo­thio­ate (1, C12H8N2O3S), S-(pyridin-2-yl) 4-methyl­benzo­thio­ate (2, C13H11NO2S) and S-(pyridin-2-yl) 4-meth­oxy­benzo­thio­ate (3, C13H11NO2S). This class of compounds are used in the mono-acyl­ation of pyrrolic species to yield multifunctional tetra­pyrroles. The structures presented herein are the first of their compound class. The dominant inter­actions present in this series are π-π stacking and C--H⋯O inter­actions, and as the para-phenyl motif changes from electron withdrawing (NO2, 1) to electron donating (OCH3, 3), changes are observed in the inter­actions present in the crystal packing, from predominant π-π stacking in 1 to exclusively C--H⋯O/N inter­actions (Car­yl--H⋯Ocarbonyl, C--H⋯Ometh­oxy and Caryl--H⋯Npyridine) in 3. [ABSTRACT FROM AUTHOR]