24- and 26-membered macrocyclic diorganotin(IV) bis-dithiocarbamate complexes with N,N'-disubstituted 1,3- and 1,4-bis(aminomethyl)benzene and 1,1'-bis(aminomethyl)ferrocene as spacer groups.

The potassium bis-dithiocarbamate (bis-dtc) salts of 1,3-bis(benzylaminomethyl)benzene (1,3-Bn-ambdtc), 1,3-bis(iso-butylaminomethyl)benzene (1,3-(i)Bu-ambdtc), 1,4-bis(benzylaminomethyl)benzene (1,4-Bn-ambdtc), and 1,4-bis(iso-butylaminomethyl)benzene (1,4-(i)Bu-ambdtc) were reacted with three different diorganotin dichlorides (R2SnCl2 with R = Me, (n)Bu, and Ph) in 1:1 stoichiometric ratios to give the corresponding diorganotin bis-dithiocarbamates. Additionally, the dimethyltin bis-dithiocarbamate of 1,1'-bis(benzylaminomethyl)ferrocene (1,1'-Bn-amfdtc) was prepared. The resulting complexes have been characterized as far as possible by elemental analysis, FAB(+) mass spectrometry, IR and NMR ((1)H, (13)C, and (119)Sn) spectroscopy, and single-crystal X-ray diffraction, showing that the tin complexes are dinuclear 24- and 26-membered macrocyclic species of composition [{R2Sn(bis-dtc)}2]. As shown by (119)Sn NMR spectroscopy, the tin centers are hexa-coordinated in all cases; however, two different coordination environments are possible, as detected by single-crystal X-ray diffraction. In the dimethyltin derivatives of 1,3-Bn-ambdtc, 1,3-(i)Bu-ambdtc, 1,4-Bn-ambdtc, and 1,1'-Bn-amfdtc and the di-n-butyltin derivative of 1,3-(i)Bu-ambdtc, the metal atoms are embedded in skewed-trapezoidal-bipyramidal coordination polyhedra with asymmetrically coordinating trans-oriented dtc groups. In contrast, in the diphenyltin derivative 1,3-(i)Bu-ambdtc, the metal centers have distorted octahedral coordination with symmetrically coordinating cis-oriented dtc functions. Thus, for the complexes derived from 1,3-Bn/(i)Bu-ambdtc, two different macrocyclic structures were observed. In the dimethyl- and di-n-butyltin derivatives, the bridging bis-dtc ligands adopt U-shaped conformations, while in the case of the diphenyltin derivative, the conformation is L-shaped. Furthermore, two different macrocyclic ring conformations can occur, which differ in the spatial orientation of the substituents attached to the nitrogen atoms (Bn or (i)Bu). The dimethyltin derivatives of 1,4-Bn-ambdtc and 1,1'-Bn-amfdtc have cavities, in which aromatic rings are accommodated in the solid state.