(Terpyridine)manganese(II) Coordination Polymers with Thio‐ and Selenidoarsenate(III) Ligands: Coligand Influence on the Chalcogenidoarsenate(III) Species and Coordination Mode

Hydrothermal reaction of [MnCl 2 (terpy)] with elemental As and Se at 150 °C in 1:2:4 and 1:4:8 molar ratios in the presence of Cs 2 CO 3 affords the complexes [{Mn(terpy)} 2 (As 2 Se 5 )] 2 ( 1 ) and [{Mn(terpy)} 2 (As 4 Se 8 )] ( 2 ), respectively. 1 contains dipyramidal [As 2 Se 5 ] 4− ligands that bridge three Mn II atoms in a tetradentate μ 3 ‐1κ 2 Se 1 , Se 2 :2κ Se 4 :3κ Se 5 manner. The tetranuclear complex is centrosymmetric and exhibits a central 8‐membered (MnSeAsSe) 2 ring. Cyclic [As 4 Se 8 ] 4− ligands are present in the centrosymmetric dinuclear complex 2 and chelate the Mn(II) atoms through adjacent terminal Se atoms. Both 1 and 2 are linked into infinite chains through weak Mn···Se interactions. [{Mn(terpy)} 2 (As 4 S 8 )] ( 3 ) and $_{\infty}^{1}\rm [{Mn(terpy)}(As_{2}S_{4})]$ ( 4 ) can be obtained by hydrothermal reaction of [MnCl 2 (terpy)] with As 2 S 3 at respectively 150 °C and 190 °C. Whereas 3 exhibits an identical connectivity pattern to that of 2 , the coordination polymer 4 contains vierer $_{\infty}^{1}\rm [AsS_{2}^{-}]$ chains that coordinate {(terpy)Mn} 2+ fragments in a bidentate manner through terminal S atoms. The complex $_{\infty}^{1}\rm [{Mn(tren)}\textrm{ } (As_{4}S_{7})]$ ( 5 ) contains $_{\infty}^{1}\rm [As_{4}S_{7}^{2-}]$ double chains and results from the analogous hydrothermal reaction of [MnCl 2 (tren)] with As 2 S 3 at 150 °C.