Gold inorganic rings based on polychalcogenide chains

‘The reaction of AuCN with Se_x ^2_ and Te_x ²’ in dimethylformamide in the presence of organic cations forms complexes with ring structures such as (Ph₄P)2[Au2Se5] (I), (Ph₄P)2[Au2Se6l (II), (Ph₃P N P P h3)2 – K2[Au₄Te₄]–2DMF (III). The reaction of AuCI₃ with Te²– yielded (Ph₄P)2[Au2(Te2)2l (IV). (1) crystallizes in the triclinic space group P–1 with a=10.381 (4) A, b=11.002(5) A, c=21.181(9) A, ct = 75.50(4)0, P = 74.74(3)0, y=81.40(4)0, V=2250 A³ (–93 °C). (II) crystallizes in the monoclinic space group C2/c with a=28.409(7) A, b=10.97(1) A, c=19.762(5) A, 0=130.49(1)°, V–4680 A³ (23 °C). (Ill) crystallizes in the orthorhombic space group Pbcn with a=29.90(2)A, b=17.39(2)A, c=17.707(8)A, V=9206A³ (23 °C). (IV) crystallizes in the triclinic space group P–1 with a–10.526(3)A, b=11.237(2)A, c=10.453(4)A, a=103.03(2)0, p=106.95(3)0, y=81.66(2)0, v=1148 A³ (–95 °C). Single–crystal X–ray diffraction studies of (I) and (II) show that both compounds possess the same structural feature. Two linearly–coordinated Au(i) atoms interact with each other at 3.004 A in (I) and 3.132A in (II) with a bridging Se2²’ unit on one side and a bridging triselenide Se₃ ²– ligand (for I) and tetraselenide Se₄ ²– ligand (for II) on the other, forming respectively seven and eight membered rings each containing two gold atoms. The structure of (III) consists of a distorted square where the Te atoms occupy the corners and the Au atoms lie in the center of the square's edges. Ionic interactions between the Au and K atoms result in a one-dimensional structure. The structure of (IV) is similar to those of (I) and (II) except two Te2²” ligands are involved.