Novel hydrogen-bonded supramolecular thioarsenates [Fe(phen)(3)][As(3)S(6)] x dien x 7 H(2)O (1) and [Mn(2)(phen)(4)(As(2)S(5))] x phen x 2 H(2)O (2) (dien = diethylenetriamine, phen = 1,10-phenanthroline) were hydrothermally synthesized and characterized. The structure of 1 consists of [As(3)S(6)](3-)-H(2)O anionic layers and [Fe(phen)(3)](3+)-dien cationic layers assembled via O-H...S and O-H...N hydrogen-bonding interactions. The layers stack alternately and are parallel to each other to give a 3D network structure with channels accommodating unique branched water chains, which are anchored on the anionic and cationic layers via hydrogen bonds. In 2, the [As(2)S(5)](4-) anion acts as a tetradentate brigding ligand via four terminal S atoms to link two [Mn(phen)(2)](2+) cations, forming the neutral complex [Mn(2)(phen)(4)(As(2)S(5))]. This is a new coordination mode for the [As(2)S(5)](4-) ion. [Mn(2)(phen)(4)(As(2)S(5))], phen, and H(2)O form a 3D network structure via O-H...S, O-H...O, and pi-pi stacking interactions.

The solvothermal synthetic system Ln/Sb/Se (Ln = La, Eu) was investigated in different ethylene polyamines, and a series of lanthanum and europium selenidoantimonates [La(en)(2)(dien)(eta(2)-SbSe(4))] (Ia), [La(dien)(2)(mu-eta(1),eta(2)-SbSe(4))] (Ib), [La(trien)(2)(H(2)O)]SbSe(4) (Ic), [La(en)(trien)(mu-eta(1),eta(2)-SbSe(4))] (Id), [Eu(en)(2)(dien)(SbSe(4))] (IIa), [Eu(en)(trien)(eta(2)-SbSe(4))] (IIb), and [Eu(dien)(2)(eta(2)-SbSe(4))] (IIc) (en = ethylenediamine, dien = diethylenetriamine, trien = triethylenetetramine) were prepared. A systematic investigation of the crystal structures showed that the soft Lewis basic ligand [SbSe(4)](3-) can be tuned to coordinate to the hard Lewis acidic lanthanide ions as a monodentate ligand, mono-SbSe(4); a bidentate chelating ligand, eta(2)-SbSe(4); or a tridentate bridging ligand, mu-eta(1),eta(2)-SbSe(4), by the ethylene polyamines or mixed ethylene polyamines used in the syntheses. The [SbSe(4)](3-) anion exhibited different coordination modes for La(3+) and Eu(3+) ions in the presence of the same ethylene polyamine because of the different coordination numbers of La(3+) and Eu(3+) ions.

The compounds [Ni(en)3]2Sn2Se6 (1), [Ni(en)(trien)]2Sn2Se6 (2), [Co(en)(trien)]2Sn2Se6 (3), and [Ni2(trien)2(μ‐trien)]Cl4·2H2O (4) (en = ethylenediamine, trien = triethylenetetramine) were solvothermally synthesized by the reactions of NiCl2·6H2O (or CoCl2·6H2O), tin and selenium in en, mixed en/trien and trien solvents, respectively. The selenidostannates 1–3 are composed of the [Sn2Se6]4– anion and [Ni(en)3]2+ or [M(en)(trien)]2+ (M = Co, Ni) complex cations. The large dinuclear complex cation [Ni2(trien)2(μ‐trien)]4+ seems to prevent the formation of the [Sn2Se6]4– anion in the tien solvent, which indicates the different structural directing effects of the complex cations on the formation of the [Sn2Se6]4– anion. As far as we know, compounds 2 and 3 are the first examples of [Sn2Se6]4– compounds containing transition metal complexes with mixed ammine ligands. In the crystal structures of 1–4, the cations and anions are connected to three‐dimensional supramolecular networks by N–H···Se or N–H···Cl, N–H···O, and O–H···Cl hydrogen bonds.

Two systems, Ln/Sn/Se/en and Ln/Sn/Se/dien, were investigated under solvothermal conditions, and novel lanthanide selenidostannates [{Ce(en)(4)}(2)(μ-Se(2))]Sn(2)Se(6) (1a), [{Ln(en)(3)}(2)(μ-OH)(2)]Sn(2)Se(6) (Ln = Pr(1b), Nd(1c), Gd(1d); en = ethylenediamine), [{Ln(dien)(2)}(4)(μ(4)-Sn(2)Se(9))(μ-Sn(2)Se(6))](∞) (Ln = Ce(2a), Nd(2b)), and [Hdien][Gd(dien)(2)(μ-SnSe(4))] (2c) (dien = diethylenetriamine) were prepared and characterized. Two structural types of lanthanide selenidostannates were obtained across the lanthanide series in both systems. In the Ln/Sn/Se/en system, two types of binuclear lanthanide complex cations [Ce(2)(en)(8)(μ-Se(2))](4+) and [{Ln(en)(3)}(2)(μ-OH)(2)](4+) (Ln = Pr, Nd, Gd) were formed depending on the Ln(3+) ions. The complex cations are compensated by the [Sn(2)Se(6)](4-) anions. In the Ln/Sn/Se/dien system, coordination polymer [{Ln(dien)(2)}(4)(μ(4)-Sn(2)Se(9))(μ-Sn(2)Se(6))](∞) and ionic complex [Hdien][Gd(dien)(2)(μ-SnSe(4))] are obtained along the lanthanide series, among which the μ(4)-Sn(2)Se(9), μ-Sn(2)Se(6) and μ-SnSe(4) ligands to the Ln(3+) ions were observed. The formation of title complexes shows the effects of lanthanide metal size and amino ligand denticity on the lanthanide selenidostannates. Complexes 1a-2c exhibit semiconducting properties with band gaps between 2.08 and 2.48 eV.

Novel cobalt polyselenidoarsenate [Co(phen)(3)][As(2)Se(2)(μ-Se(3))(μ-Se(5))] (1; phen = 1,10-phenanthroline) was methanolothermally synthesized by the reaction of CoCl(2), As(2)O(3), and Se templated by phen in a CH(3)OH solvent at 130 °C. The same reaction in a H(2)O solvent yielded cobalt selenidoarsenate [Co(phen)(3)](2)[As(8)Se(14)] (2). In 1, the AsSe(+) units are alternately joined by the μ-Se(3)(2-) and μ-Se(5)(2-) bridging ligands to form a novel helical polyselenidoarsenate chain [As(2)Se(2)(μ-Se(3))(μ-Se(5))(2-)](∞). In 2, eight pyramidal AsSe(3) units are connected via corner sharing into the new member of the selenidoarsenate aggregate [As(8)Se(14)](4-) with a condensation grade of 0.571, which represents the first discrete selenidoarsenate(III) with a condensation grade of above 0.50. The octahedral complex [Co(phen)(3)](2+) is formed in situ to act as a countercation in compounds 1 and 2. 1 and 2 exhibit steep absorption band gaps at 2.09 and 2.16 eV, respectively.