The effect of substituents of the 1,10-phenanthroline ligand on the nature of diorgnotin(IV) complexes formation

Abstract

The adduct formation between dimethyl- and dibuthyltin diisothiocyanate and 1,10-phenanthroline and 2,9-dimethyl-1,10-phenanthroline were investigated. It was found that the reaction of R2Sn(NCS)2 (R = Me, n-Bu) with 1,10-phenanthroline in a 1:1 M ratio led to the formation of simple adducts of [Me2Sn(NCS)2(phen)]·CH3CN (1) and [Bu2Sn(NCS)2(phen)] (2), for R = Me and R = n-Bu, respectively. However, the reaction of 2,9-dimethyl-1,10-phenanthroline with R2Sn(NCS)2 (R = Me, n-Bu), instead of adducts, resulted in the formation of an organostannate salt, (C14H13N2)2[Me2Sn(NCS)4] (3), and dimeric stannoxane, [Me2(NCS)SnOSnMe2OCH3]2 (4), for R = Me and (C14H13N2)NCS (5), and [Bu2(NCS)SnOSnR2OBu]2 (6), for R = n-Bu. Single crystal X-ray structural analyses were carried out for complexes 1, 3, 4, and 5. The crystal structures results of 1, 3, 4, and 5 along with the 1H, 13C and 119Sn NMR and IR spectroscopic measurements of all the products are used to discuss the effect of the substituent of 1,10-phenanthroline on complex formation. The results show that the central tin atom of the stannate salt (3) is not bonded to the two N donor atoms of the ligand species, and the moderately bulky substituent at the 2 and 9 positions of 1,10-phenanthroline ligand exerts a profound influence on the nature of the complexes and their formation.