Synthesis, spectroscopic characterization and in vitro antitumour activity of di‐n‐butyltin and diethyltin trimethoxybenzoates: X‐ray structure analysis of bis[di‐n‐butyl(3,4,5‐trimethoxybenzoato)tin] oxide

Di‐n‐butyltin(IV) and diethyltin(IV) 2,3,4‐, 2,4,5‐ and 3,4,5‐trimethoxybenzoates [(CH 3 O) 3 C 6 H 2 COO] 2 SnR [Type a] and {[(CH 3 O) 3 C 6 H 2 COO]R 2 Sn} 2 O [Type b] have been synthesized and characterized spectroscopically. The crystal structure of bis[di‐n‐butyl(3,4,5‐ trimethoxybenzoato)tin] oxide has been determined. The triclinic unit cell contains one centrosymmetric dimer; a = 15.919(2) Å, b = 11.711(3) Å, c = 13.475(1) Å, and α = 63.63(2)°, β = 67.49(1)°, γ = 76.61(2)°. The geometry of the dimer is very similar to that of bis[di‐n‐butyl(5‐methoxysalicylatotin] oxide), with two different types of five‐coordinate tin atoms and one central planar Sn 2 O 2 ring.