The eight organotin compounds bis｛oxo-bis[(heteroaromatic carboxylato)di-n-butyltin(IV)]｝ were synthesized by the reaction of (n-Bu)₂SnO with heteroaromatic carboxylic acidin 1∶1 molar ratio. The crystal structure of bis｛oxo-bis[(2-thiophenylcarboxylato)di-n-butyltin(IV]｝ was determined by single-crystal X-raydiffraction. This compound belongs to centrosymmetric dimer structure mode witha four-membered central endo-cyclic Sn₂O₂ unit in which the bridging oxygen atoms are tri-coordinated. Each bridging oxygen atom also connects with an exo-cyclic tin atom. The endo-cyclic and exo-cyclic tin atoms all are six-coordinated and have coordination geometry of distorted octahedron. The crystal belongs to monoclinic system with space group P2(1)/n, a=1.3721(10) nm,b=1.7297(13) nm, c=1.3721(10) nm, β=93.709(8)°, Z=2, V=3.249(4) nm³, D_c=1.505 g/cm³, μ=1.695 mm^－1, F(000)=1480, R=0.0480, wR=0.0978.

Key words: organotin, heteroaromatic carboxylic acid, synthesis, crystal structure