SYNTHESIS, CHARACTERIZATION AND IN-VITRO ANTITUMOR-ACTIVITY OF DIBUTYLTIN CARBOXYLATES INVOLVING THE PERFLUOROPHENYL MOIETY - CRYSTAL-STRUCTURE OF THE DIMERIC BIS[(4-FLUORO-BENZOATO)DI-N-BUTYLTIN] AND PENTAFLUORO-BENZOATO)DI-N-BUTYLTIN] OXIDES

Crystal structure determinations of {[(F5C6COO)Bu(2)Sn]O-2}(2) and {[( 4-F-C6H4COO)Bu(2)Sn]O-2}(2) show that the structures are similar and f eature central Bu(4)Sn(2)O(2) units with two Bu(2)Sn groups connected by bridging oxygen atoms. Each pair of exo- and endo-cyclic tin atoms is linked by an almost symmetrically bridging carboxylate group, with the two remaining groups attached to the exocyclic tin atom only. Crys tals of {[(F5C6COO)Bu(2)Sn]O-2}(2) are triclinic, space group P (1) ov er bar, with unit cell dimensions a=12.425(3) Angstrom, b=13.090(5) An gstrom, c=11.697(3) Angstrom, alpha=95.31(3)degrees, beta=93.28(2)degr ees, gamma=113.01(2)degrees, V=1734(1) Angstrom(3), Z=1. Crystals of { [(4-F-C6H4COO)Bu(2)Sn]O-2}(2) are also triclinic, space group P (1) ov er bar, a=12.599(6) Angstrom, b=25.359(4) Angstrom, c=11.480(4) Angstr om, alpha=91.44(3)degrees, beta=114.77(3)degrees, gamma=97.43(3)degree s, V=3289(2) Angstrom(3), Z=2. The structures were refined to final R= 0.046, R(w)=0.046 for 4312 reflections with l greater than or equal to 3.0 sigma(l) for {[(F5C6COOO)Bu(2)Sn]O-2}(2) and R=0.061, R(w)=0.068 for 4112 reflections with l greater than or equal to 3.0 sigma(l) for {[(4-F-C6H4COOO)Bu(2)Sn]O-2}(2).