Diradical hexacoordinated tin(IV) bis-o-iminobenzosemiquinonates: synthesis, structure and magnetic properties

Abstract

By the metal salt metathesis reaction between tin(IV) bis-o-iminobenzosemiquinonates imSQi−Pr2SnCl2 (1) or imSQMe2SnCl2 (2) (where imSQi-Pr – radical-anion of N-2,6-di-iso-propylphenylsubstituted o-iminobenzoquinone, imSQMe - radical-anion of N-2,6-dimethylphenylsubstituted o-iminobenzoquinone) and an excess of sodium azide, potassium isocyanate or potassium thiocyanate new hexacoordinated tin(IV) bis-o-iminobenzosemiquinonates imSQi−Pr2SnX2 (3, 5 and 7) and imSQMe2SnX2 (4, 6 and 8) (where X - azide, isocyanate or thioisocyanate group) were synthesized and characterized including X-ray diffraction analysis. The magnetic susceptibility measurements for new compounds 2–8 and related previously known complexes imSQi−Pr2SnX2 (X = Me (9), Br (11), I (12)) were performed. All tin(IV) bis-o-iminobenzosemiquinonates were found to be characterized by antiferromagnetic exchange interaction between unpaired electrons of two imSQ ligands independently on the X substituent nature. However known tin(IV) complexes imSQi−Pr2Sn(Me)2 (9) and imSQi−Pr2Sn(Ph)2 (10) containing organic ligands bonded to the metal atom demonstrate quite strong magnetic interaction compared with complexes including halide or pseudohalide substituents. Due to their great kinetic stability the diradical tin(IV) derivatives obtained have a possible application as potential components for molecular electronics and spintronics, lithium batteries, nonlinear optics and magnetic materials.