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Extraction in ethylenediamine (en) of AsSe4, TlAsSe4 and InAsSe4, followed by reaction with cation sources or 2.2.2-cryptand was found to result into several complexes. These are (NEt4)2(As2Se6) (1), (enH)(AsSe6)*2.2.2-cryptand (2), (NEt4)(As2Se8) (3), and ((en)2In(SeAs(Se)Se2))*en (4). These compounds were found to contain AsSe+ units coordinated to Se2(super 2-), Se5(super 2-) and Se7(super 2-) ligands in 1 and 4, 2 and 3, respectively.

The [Sb2Se4]2- chalcogenometalate anion is composed two edge-sharing pyramidal SbSe3 units with a four-membered ring that contains two terminal Se atoms in cis configuration. Furthermore, the bridging Sb-Set bond distances of the chalcogenometalate anion contains Sb2Se4 fragments. The Sb2Se4 fragments produces [PPh4]2[Sb4Se6]6 after electrochemical reduction. The [K(2.2.2-cryptand)]2[As4Se6] chalcogenometalate contains four cations and two anions that are crystallographically independent from each other.

Tellumerates (MTe7)n- where n = 2,3 are achieved upon the reaction of appropriate metal substrates with polytelluride solutions in anhydrous N,N-dimethylformamide. The (HgTe7)2- anion, in both the NEt4+ and PPH4+, exhibits a similar structure with only a small discrepancy in the arrangement of the ligand. Anions (AgTe7)3- and (HgTe7)2- incorporate metal atoms that are in trigonal planar coordination to n(super 3)-Te(sub 7)(super4-). The central Te atom of such ligand forms a T-shaped assembly with two Te atoms and the metal atom.

The reactions between Fe(CO)5 and polysulfides or polyselenides are performed under optimum conditions of chain lengths, countercations and stoichiometry. In the presence of excess Fe(CO)5, Fe3(CO)9(mu3-E)(super 2-) is formed. With the rise in the ratio and chain length of polychalcogenide, the oxidation of the iron centers elevates, resulting in the clusters Fe(CO) 12E6(super 2-) and Fe5(CO 14) mu (sub 3) -e 2 (super 2-) (E = S, Se).

A reaction between polytelluride solutions and metal salts' DMF results in compounds of type (PPh4)2(M(Te4)2), where M is Cd, Zn or Hg and x-ray crystallographic studies reveal a complex, tetragonal crystal structure for these compounds. Two Te(sub 4)(super 2-) chelates link the metal atoms in the disordered anions and the chemical shifts of 125Te are identical to those of 77Se.

Synthesis of (Fe3(CO)9(mu 3-Te))2- involves a reaction of Te2- with 3 equiv of Fe(CO)5. Examination of the reactivities of the complex with various hard and soft electrophiles reveals that the apical telluride is not attacked by any of these electrophiles. Reaction of the cluster with various oxidants leads to fragmentation of the cluster.

The formation of {K(2.2.2-cryptand)}2{(mu-O){mu-O2Si(CH3)2}2(GeSe)2} via the adventitious reaction of silicone grease with the residue from the reduction of GeSe2 by K in NH3 in the presence of 2.2.2-cryptand was described. On the other hand, the isolation of {K(2.2.2-cryptand)}2{SbSe6} resulted from the reduction of SbSe under similar conditions. The crystal structures of the resulting compounds were studied using an Enraf-Nonius CAD4 diffractometer.

The electrochemical reduction of HgSe2 by K in NH3 in 2.2.2-cryptand led to the formation of [K(2.2.2-cryptand)]2[HgSe2] while the electrochemical reduction of HgSe2 cathode led to the synthesis of [PPh4]2[Hg(Se4)2].en. Analysis of the [PPh4]2[Hg(Se4)2].en and [K(2.2.2-cryptand)]2[HgSe2] products by nuclear magnetic resonance spectroscopy indicated the absence of the [HgSe2]2- anions. Furthermore, the formation of an electrode with high electrical conductivity was mediated by excess Se.

Studies the different products from the chemical and electrochemical reduction of `HgSe2.' Synthesis of the compound [K(2.2.2-cryptand)]2[HgSe2]; Characterization of the compound by mercury and selenium nuclear magnetic resonance spectroscopy; Observation of the selenium chemical shift of the [HgSe2]2- anion.