Hydrogen Bonding in 2,3‐Dithiolatoterephthaldiamide Complexes of Cobalt(III), Nickel(II), and Iron(III)

The synthesis and characterization of the novel 2,3‐dithiolatoterephthaldiamide ligands C 6 H 2 {C(O)NHBn} 2 (SH) 2 (H 2 ‐ 1a )and C 6 H 2 {C(O)NH‐ i Pr} 2 (SH) 2 (H 2 ‐ 1b ) as well as their complexes with Ni II , Co III , and Fe III is described. The molecular structures of the complexes (NEt 4 )[Co( 1a ) 2 ], (AsPh 4 ) 2 [Ni( 1b ) 2 ] · dmf, and (AsPh 4 )[Fe( 1a ) 2 ] · CH 2 Cl 2 were determined by single‐crystal X‐ray diffraction. Electronic absorption spectroscopy and cyclic voltammetry were applied to investigate the electronic properties of the complex anions [M(L) 2 ] n – (M = Ni, Co; L = 1a , 1b ; n = 1, 2). Comparison of the structural and electronic characteristics of the complexes with ligands 1a 2– and 1b 2– to those of the corresponding complexes with related benzene‐ o ‐dithiolato ligands indicates a notable influence of intramolecular N–H ··· S hydrogen bonding between amide protons and coordinated sulfur atoms in 2,3‐dithiolatoterephthalamide complexes.