The synthesis, structural characterization and biocidal properties of some triorganotin(IV) esters of N-arylidene-ω-amino acids

The methods of synthesis, elemental analysis, IR and NMR spectroscopic data and fungicidal activity against Ceratocystis ulmi are reported for a series of triorganotin esters of N‐arylidene‐ω‐amino acids of general formula R3SnOCO(CH2)nN = CHAr (R = Ph, n‐Bu; Ar = 2‐HOC6H4, 2‐HOC10H6; n = 1, 2, 3 and 5). The crystal structures for two of the compounds, tributyltin N‐2‐hydroxynaphthalidene glycinate (1) and tributyltin N‐2‐hydroxynaphthalidene‐β‐alaninate (2), have been determined. Although both of these compounds have a trans‐R3SnO2 structure, in compound 1 the carboxylate group is monodentate and the fifth coordination position around the tin atom is taken up by a coordinated phenolic group, whereas in 2 the carboxylate group is bridging. These two examples thus correspond to the two different structures reported for trans‐R3SnO2 complexes. Both compounds were found to be active against Ceratocystis ulmi, but there was no significant difference in their levels of biological activity against this particular fungus. Apart from compound 1, the other tributyltin compounds reported are believed to adopt the carboxylate bridging mode shown by compound (2). Crystal data: for 1, crystals monoclinic, space group P21/c, a = 12.9435(11) Å, b = 13.5769(10) Å, c = 15.7715(12) Å, β = 108.919(6)°, Z = 4, Rf = 0.046 and Rw = 0.058 for 1448 significant reflections; for 2, crystals monoclinic, space group C 2/c,a = 24.588(14) Å, b = 9.733(3) Å, c = 27.611(12) Å, β = 113.49(4)°, Z = 8, Rf = 0.053 and Rw = 0.069 for 3822 significant reflections. © 1998 John Wiley & Sons, Ltd.