Synthesis and structural characterization of Zintl anions containing the tris(ethylenediamine)-zinc cation: [Zn(N 2C 2H 8) 3][Te 3]·(0.5en) and [Zn(N 2C 2H 8) 3] 2[Sn 2Te 6]·(en)

Abstract

Two Zintl anions which contain the [tris(ethylenediamine)-zinc] 2+ cation have been synthesized and structurally characterized by single-crystal X-ray diffraction. When a constant current of 1 mA is applied between a ZnTe 10 alloy cathode and a Ni plate anode, in a saturated solulion of tetrapropylammonium bromide in ethylenediamine, a deep red-purple solution is generated around the cathode as polyanions are generated. After a few days, small, black crystals formed, which were identified by single crystal X-ray diffraction as [Zn(N 2C 2H 8) 3][Te 3]·0.5(N 2C 2H 8) ( 1). The 1:1:1 stoichiometric reaction of the Zintl phase K 4SnTe 4 with ZnCl 2 in the presence of (C 2H 5) 4NBr in ethylenediamine at 100°C for 1 day in a sealed evacuated quartz tube gave crystals of [Zn(N 2C 2H 8) 3] 2[Sn 2Te 6]·(en) ( 2). The structures of 1 adn 2 consist of discrete anions which are surrounded in the solid state by the tris(ethylenediamine)-zinc cations.