Hydrazine-Assisted Synthesis, Structures, Photoelectricity, and Photocatalysis of Ternary Mercury-Tellurostannate Hybrids with Transition-Metal Complexes.

Tellurostannates are traditionally prepared by multistep reactions using the tellurides SnTe, SnTe2, K4SnTe4, or A6SnTe6 (A = K, Rb, or Cs) as precursors, which are usually prepared by the molten reaction of alkali metals Sn and Te under harsh synthetic conditions. Differently, ternary Hg-tellurostannate hybrids [Mn(en)3]HgSnTe3(Te2) (1) (en = ethylenediamine), [Mn(dien)2]HgSnTe3(Te2) (2), and [Fe(dien)2]HgSnTe3(Te2) (3) (dien = diethylenetriamine) were synthesized by one-pot reactions using Sn and Te powders as starting materials in the presence of hydrazine under mild solvothermal conditions. In 1, HgTe3 and SnTe4 units are joined via Te-sharing to form a 1-D polymeric chain [HgSnTe3(Te2)]n2n-, while the [HgSnTe3(Te2)]n2n- chains in 2 and 3 are composed of HgTe4 and SnTe4 units. The common feature of the [HgSnTe3(Te2)2-]n chains in 1-3 is that they are constructed by both the telluride anion Te2- and the polytelluride anion Te22-. 1-3 exhibited strong photocurrent responses with current densities of 5.26, 3.38, and 3.94 µA cm-2, respectively. They showed effective photocatalytic activities for methylene blue degradation with degradation ratios in the range of 85.3-94.6% after light irradiation for 80 min. Investigation of the photocatalytic mechanism showed that •O2- radicals and h+ holes were the main active substances in the photodegradation.

Syntheses, structures, photoelectric properties and photocatalysis of iodobismuthate hybrids with lanthanide complex cations.

New iodobismuthate hybrids with lanthanide complex counter cations, [Ln(DMF)8][Bi2I9] (Ln = La (1), Eu (2)) and [Tb(DMF)8]2[Bi2I9]2 (3) (DMF = N,N-dimethylformamide), were prepared using solvated Ln(III) complexes formed in situ as structure-directing agents. The dimeric [Bi2I9]3- anion moieties of compounds 1-3 are aggregated by two slightly twisted BiI6 octahedra through face-sharing mode. The different crystal structures of 1-3 are due to the different I⋯I and C-H⋯I hydrogen bond interactions. Compounds 1-3 have narrow semiconducting band gaps at 2.23, 1.91 and 1.94 eV, respectively. Under Xe light irradiation, they exhibit steady photocurrent densities that are 1.81, 2.10 and 2.18 times higher than that of pure BiI3, respectively. Compounds 2 and 3 exhibited higher catalytic activities than 1 in the photodegradation of organic dyes CV and RhB, which are attributed to the stronger photocurrent response derived from the redox cycles of Eu3+/Eu2+ and Tb4+/Tb3+.

2-D Heterometallic Pb-Iodoargentate Framework [PbAg2I6]n with a Diskoid [Pb(18-crown-6)]2+ Linker and Cocatalyst for Synergistically Enhanced Photocatalytic Properties via g-C3N4 Doping.

The heterometallic Pb-iodoargentate hybrid [Pb(18-crown-6)(PbAg2I6)]n (1; 18-crown-6 = 1,4,7,10,13,16-hexaoxacyclooctadecane) was prepared via self-assembly of the tetrahedal AgI4 and octahedral PbI6 primary units using crown ether 18-crown-6 as an organic ligand in DMF solvent. The hybrid heterocomposite cocatalyst based on 1 and graphitic carbon nitride (g-C3N4) was prepared by a facile solvothermal method. In 1, the dimeric units Ag2I6 and Pb2I10 are joined via face sharing, leading to a ternary heterometallic 1-D [PbAg2I62-]n chain containing novel Ag2Pb2I4 cubes. The 1-D chains are joined by the discoid [Pb(18-crown-6)]2+ complex cations, forming the 2-D [Pb(18-crown-6)(PbAg2I6)]n hybrid with the skeleton of [Pb2Ag2I6]n. Compound 1 shows photocatalytic activity in the degradation of MB at room temperature under visible-light irradiation. The photoelectric response measurement showed that the photocurrent of 1 increased from 1.41 to 2.43 µA/cm-2 when g-C3N4 was loaded, indicating that the introduction of a certain amount of g-C3N4 on the surface of 1 improves the separation and migration rate of photoinduced electrons and holes. The 1/g-C3N4 composite showed much higher photocatalytic efficiency in comparison to pristine 1 and g-C3N4 for MB degradation, which suggests the synergistic effect between 1 and g-C3N4 toward visible-light-driven photocatalytic performance. Meanwhile, the 1/g-C3N4 composite exhibited good reusability and stability in the photocatalytic reaction. Free radical quenching experiments showed that the •O2- radical is the main reactive substance over catalyst 1, while h+, •OH, and •O2- species have synergistic effects over the 1/g-C3N4 composite catalyst in the process of photodegradation.

Polymeric Iodoargentate Hybrids Incorporating Octakis- or Heptakis-Solvated Lanthanide Complexes: Syntheses, Crystal Structures, and Photocatalysis.

New iodoargentate hybrids containing lanthanide complexes, [La(DMA)8]Ag9I12·2H2O (1) and [Ln(DMA)7]2Ag16I22 (Ln = Pr (2), Sm(3); DMA = N,N-dimethylacetamide), were prepared by diffusion methods using DMA-solvated lanthanide complexes as structure-directing agents. The octakis-solvated La3+ cation leads to formation of the 1-D nonanuclear [Ag9I12]n3n- polymeric anion constructed by AgI4 tetrahedral units through edge sharing, while the heptakis-solvated Ln3+ (Ln = Pr, Sm) cation affords the new 1-D hexadecanuclear [Ag16I22]n6n- polymeric anion built up from AgI4 units by both corner and edge sharing. Compounds 1-3 possess band gaps of 2.58, 2.77, and 2.74 eV, respectively, and show steady photocurrents in the range 14.2-18.0 µA under Xe light irradiation. They are photocatalytic active in the degradation of organic pollutants of crystal violet (CV) and rhodamine B (RhB) in water at room temperature. 2 and 3 perform higher photocatalytic activities than 1 in the CV degradation, which is attributed to the different photocurrent intensities. Photocatalytic mechanism investigations on compounds 2 and 3 show that h+ hole and ·O2- radical play major roles in the CV degradation, respectively.

Hydrazine-solvothermal methods to synthesize polymeric thioarsenates from one-dimensional chains to a three-dimensional framework.

A series of polymeric Mn(ii)-thioarsenates [Mn(en)3] n [(N2H4)2Mn6(µ6-S)(µ-N2H4)2(µ3-AsS3)4] n (1), [N2H5] n [{Mn(µ-N2H4)2(µ-AsS4)}·0.5en] n (2), [Mn(µ-trien){Mn(µ-N2H4)(µ-AsS3)}2] n (3), [{Mn(N2H4)}2(µ-N2H4)2{Mn(µ-N2H4)2(µ-AsS3)2}] n (4), [Mn3(µ-N2H4)6(µ3-AsS4)(µ2-AsS4)] n (5), and [Mn(NH3)6] n [{Mn(NH3)(µ-AsS4)}2] n (6) were synthesized using a hydrazine-solvothermal method. The thioarsenate units AsS3 and AsS4 coordinate to Mn(ii) ions with variable coordination modes, forming a Mn-As-S ternary cluster (1), chains (2, 4-6), and layers (3), respectively. The hydrazine molecules act as inter-cluster, intra-chain and intra-layer bridging ligands to join the Mn(ii) ions, resulting in hydrazine hybrid 1-D, 2-D, and 3-D Mn(ii)-thioarsenate moieties in 1-5. Compounds 1-6 exhibit tunable semiconducting band gaps varying in the range of 2.19-2.47 eV. Compound 1 displays stronger antiferromagnetic coupling interactions than that of compound 2.

Hydrazine-Assisted Syntheses and Properties of Mercury Tellurides Containing Transition-Metal Complexes.

With assistance of reactive and coordinative hydrazine, transition-metal telluromercurates [Mn(trien)(N2H4)2]2[Hg2Te4]2 (A), [Zn(trien)(N2H4)2]Hg2Te4 (B), [Mn(tepa)(N2H4)]2Hg4Te12 (C), [TM(trien)(Hg2Te4)] (TM = Mn (D), Zn (E)), and [Zn(atep)]2Hg5Te12 (atep = 4-(2-aminoethyl)triethylenetetramine) (F) were solvothermally prepared in triethylenetetramine (trien) or tetraethylenepentamine (tepa) solvents using elemental Te as precursor in lower temperature range. Compounds A and B consist of mixed coordination cations [TM(trien)(N2H4)2]2+ (TM = Mn, Zn) and one-dimensional polyanion [Hg2Te4]2- with the five-membered Hg2Te3 rings being coplanar. Compound C is composed of two [Mn(tepa)(N2H4)]2+ cations and a [Hg4Te12]4- cluster with a centrosymmetric structure. Compounds D and E consist of coordination polymer [TM(trien) (Hg2Te4)] containing novel doubled [Hg2Te4]n chain with tetrahedrally coordinated Hg(II) centers, which is quite different from the common single chain with the same composition of [Hg2Te4]n. D and E are the first examples of telluromercurates incorporated with TM complex units via TM-Te bonds. Compound F contains fivefold coordinated [Zn(atep)]2+ cations and zigzag [Hg5Te124-]n polymeric anion. The [Hg5Te124-]n anion is a new species of the binary telluromercurates. It is built from [Hg4Te6] and [HgTe2(Te4)] subunits via interconnectivity, which generates Hg3Te3 and Hg4Te4 rings in the structure. Compounds A-F are potential semiconductors with narrow band gaps in the range of 0.96-1.09 eV. Photocatalytic investigation of Mn(II) complexes show that they are photocatalytically active in the degradation of CV under visible-light irradiation with the highest catalytic effective of cluster compound C.

Novel one-, two-, and three-dimensional selenidostannates templated by iron(II) complex cation.

The novel iron selenidostannates [Fe(bipy)3]Sn4Se9·2H2O (1) and [Fe(bipy)3]2[Sn3Se7]2·bipy·2H2O (2) (bipy = bipyridine) were prepared by the reactions of Sn, Se, FeCl2·4H2O, bipy, and dien with/without KSCN under hydrothermal conditions (dien = diethylenetriamine). In 1, four SnSe5 units condense via edge sharing to form the novel 3-D framework selenidostannate (∞)³[Sn4Se9²â»] containing an interpenetrating channel system. The [Fe(bipy)3]²âº cations are accommodated in the different channels according to the conformation of the [Fe(bipy)3]²âº cation. In 2, three SnSe5 units share edges to form a 2-D (∞)²[Sn3Se7²â»] layered anion, while two SnSe5 units and one SnSe4 unit are connected via edge sharing, forming a 1-D (∞)¹[Sn3Se7²â»] chainlike anion. The (∞)¹[Sn3Se7²â»], [Fe(bipy)3]²âº, bipy, and H2O species are embedded between the (∞)²[Sn3Se7²â»] layers. 2 is the first example of a selenidostannate constructed by both (∞)²[Sn3Se7²â»]and (∞)¹[Sn3Se7²â»] anions. The coexistence of 1-D (∞)¹[Sn3Se7²â»] and 2-D (∞)²[Sn3Se7²â»] anions in 2 might support the possible reaction mechanism that the (∞)²[Sn3Se7²â»] anions are formed by condensation of the (∞)¹[Sn3Se7²â»] chains. 1 and 2 exhibit band gaps at 1.43 and 2.01 eV, respectively.

Syntheses and properties of 2-D and 3-D Pb-Ag heterometallic iodides decorated with ethylene polyamines at the Pb(II) center.

Hybrid organic-inorganic Pb-Ag heterometallic iodides [(en)2(PbAgI3)]2n·nH2O (1), [(pda)2(PbAgI3)]n (2), [(tmeda)(PbAgI3)]n (3), [(trien)(PbAgI3)]n (4), [(tepa)(PbAg2I4)]n (5), and [{(dien)3(CO3)}2(Pb6Ag8I15)]nIn (6) were prepared by the reactions of PbI2, AgI (or Ag2CO3) and KI with different polyamines in N,N'-dimethylformamide (DMF) solution. In 1-4, two AgI4 tetrahedra share a common edge to form the bimeric Ag2I6 unit. It coordinates to the Pb(II) ion of [PbL2](2+) or [PbL'](2+) (L = en, pda; L' = tmeda, trien) via iodine atoms to form hybrid organic-inorganic heterometallic iodides 1, 2, 3 and 4, respectively. Compounds 1, 3, 4 and contain 2-D layered backbones of [PbAgI3]n, whereas 2 contains a backbone of [PbAgI3]n with a 3-D structure. Steric hindrance and denticity of the ethylene polyamines influence the coordination modes and connection strength between the iodoargentate aggregates and Pb(II) ions. In 5 the AgI4 units are joined via sharing common edges to form a 1-D polymeric [Ag2I4]n(2n-) anion. It is connected with [Pb(tepa)](2+)via iodine atoms to form a 3-D network of [(tepa)(PbAg2I4)]n. In 6, the CO3(2-) ion binds three [Pb(dien)](2+) units to form the novel trinuclear [{Pb(dien)}3(µ3-CO3)](4+) complex ion. Eight AgI4 tetrahedra are connected via sharing common edges to give a novel Ag8I15 cluster with C3 symmetry. The Ag8I15 cluster and the [{Pb(dien)}3(CO3)](4+) unit are connected to form a novel layered heterometallic iodometallate cation [{(dien)3(CO3)}2(Pb6Ag8I15)]n(n+)via sharing iodine atoms. Compounds 1-6 represent a new type of hybrid organic-inorganic heterometallic iodide containing coordinative organic components. Optical absorption spectra show a blue shift of the absorption edges for 1-6 compared with those of the bulk PbI2 and AgI solids.

Clusters [Co(As3S3)2]2-, [Ni(As3S3)2]2-, and [{Co(en)}6(µ3-S)4(AsS3)4]2- with Co-As or Ni-As bonds: solvothermal syntheses and characterizations of thioarsenates containing transition-metal complexes.

Solvothermal reactions of As2O3 and S with CoCl2·6H2O or NiCl2·6H2O in an aqueous solution of dien produced novel thioarsenates [Co(dien)2][Co(As3S3)2] (1) and [Ni(dien)2][Ni(As3S3)2] (2) (dien = diethylenetriamine), and the reaction with CoCl2·6H2O in an aqueous solution of en afforded complex [Hen]2[{Co(en)}6(µ3-S)4(AsS3)4] (3) (en = ethylenediamine). In 1 and 2, one transition-metal ion is coordinated by two dien ligands to form [TM(dien)2](2+) (TM = Co, Ni) complex cations. The As3S3 unit coordinates to the other TM(II) ion with both As- and S-donor atoms to form the [TM(As3S3)2](2-) anionic cluster, in which TMAs2, TMAs2S2, and TMAs3S2 rings are formed. In 3, each Co(3+) ion is coordinated by an en ligand. Six Co(en) units are interlinked by four µ3-S and four AsS3 ligands to form a [{Co(en)}6(µ3-S)4(AsS3)4](2-) cluster containing an adamantane-like Co6S4 core. The AsS3 unit coordinates to Co atom in the η(1)-As1,η(2)-S coordination mode with As binding Co(1) and S(1) binding Co(1) and Co(2). The As3S3 and AsS3 ligands with both As- and S-donor atoms in 1-3 have never been obtained in amine solution before. The same reactions in pure dien and en solvents afforded compounds [Co(dien)2]3[As3S6]2 (4) and [Co(en)3]2As2S5 (5) containing discrete anions [As3S6](3-) and [As2S5](4-), respectively. The band gaps of 1-3 are in the range of 1.37-1.55 eV, and the band gaps of 4 and 5 are 2.24 and 2.26 eV, which show the influence of the coordination mode of thioarsenate ligands on the electronic transitions in the TM-thioarsenates.

Polymeric heterometallic Pb-Ag iodometallates, iodoplumbates and iodoargentates with lanthanide complex cations as templates.

Heterometallic Pb-Ag iodometallates [Ln(DMF)8]2Pb3Ag10I22 [Ln = Ce(1), Pr(2)] were prepared by the reactions of PbI2, AgNO3 and KI in dimethylformamide (DMF) templated by [Ln(DMF)8](3+) complexes formed in situ by stirring LnCl3 in DMF. The same reactions in the absence of AgNO3 or PbI2 afforded iodoplumbate [Pr(DMF)9]2[Pr(DMF)8]Pb11I31 (3), and iodoargentates [Ln(DMF)8]Ag6I9 [Ln = Ce(4), Pr(5)], respectively. Compounds 1 and 2 contain a ternary one-dimensional polymeric [Pb3Ag10I22](6-) anion self-assembled from five AgI4, one PbI6 and one PbI4 primary units via edge- and face-sharing. Twelve PbI6 octahedra are interlinked via sharing of common faces to generate a 1D zigzag [Pb11I31(9-)]n chain in 3, which represents a new member of iodoplumbate aggregates. In 4 and 5, three AgI4 tetrahedra connect through common edges to form the [Ag6I12](6-) building block. The [Ag6I12](6-) blocks are further interlinked by sharing common edges, resulting in the 1D [Ag6I9(3-)]n chain. Optical absorption spectra showed that the synthesized Ag-iodoplumbate and iodoplumbate have potential for being used as semiconductors. Our results show that heterometallic halometallate properties can be tuned by combining structural units with different symmetries, enabling the synthesis of specific functional materials.

Heterometallic clusters [CuSn3S9]5⁻ and [Cu6Sn6S20]¹°â»: solvothermal synthesis and characterization of 4f-3d thiostannates.

Two types of 4f-3d thiostannates with general formula [Hen]2[Ln(en)4(CuSn3S9)]∙0.5 en (Ln1; Ln=La, 1; Ce, 2) and [Hen]4[Ln(en)4]2[Cu6Sn6S20]∙3 en (Ln2; Ln=Nd, 3; Gd, 4; Er, 5) were prepared by reactions of Ln2O3, Cu, Sn, and S in ethylenediamine (en) under solvothermal conditions between 160 and 190 °C. However, reactions performed in the range from 120 to 140 °C resulted in crystallization of [Sn2S6]4⁻) compounds and CuS powder. In 1 and 2, three SnS4 tetrahedra and one CuS3 triangle are joined by sharing sulfur atoms to form a novel [CuSn3S9]5⁻ cluster that coordinates to the Ln(3+) ion of [Ln(en)4]³âº (Ln=La, Ce) as a monodentate ligand. The [CuSn3S9]5⁻ unit is the first thio-based heterometallic adamantane-like cluster coordinating to a lanthanide center. In 3-5, six SnS4 tetrahedra and six CuS3 triangles are connected by sharing common sulfur atoms to form the ternary [Cu6Sn6S20 ]¹°â» cluster, in which a Cu6 core is enclosed by two Sn3S10 fragments. The topological structure of the novel Cu6 core can be regarded as two Cu4 tetrahedra joined by a common edge. The Ln³âº ions in Ln1 and Ln2 are in nine- and eightfold coordination, respectively, which leads to the formation of the [CuSn3S9]5⁻ and [Cu6Sn6S20]¹°â» clusters under identical synthetic conditions. The syntheses of Ln1 and Ln2 show the influence of the lanthanide contraction on the quaternary Ln/Cu/Sn/S system in ethylenediamine. Compounds 1-5 exhibit bandgaps in the range of 2.09-2.48 eV depending on the two different types of clusters in the compounds. Compounds 1, 3, and 4 lost their organic components in the temperature range of 110-350 °C by multistep processes.

The first µ-Ge2Se8 ligand to lanthanide(III) centers: solvothermal syntheses and characterizations of lanthanide selenidogermanate complexes with a pentadentate polyamine as a co-ligand.

Solvothermal reactions of elements Ge and Se with Ln(2)O(3) in a pentadentate polyamine, tetraethylenepentamine (tepa), produced novel neutral lanthanide-selenidogermanate polymers [{Ln(tepa)(µ-OH)}(2)(µ-Ge(2)Se(8))](n) (Ln = Eu 1, Gd 2, Dy 3). The reaction with Dy(2)O(3) in ethylenediamine (en) afforded an ionic selenidogermanate [{Dy(en)(3)}(2)(µ-OH)(2)]Ge(2)Se(6) (4). In compounds 1-3, the Ln(3+) ions are coordinated by a tepa and two OH(-) ligands to form binuclear [{Ln(tepa)}(2)(µ-OH)(2)](4+) fragments. Two GeSe(4) tetrahedra are linked through two Se-Se bonds to form a novel [Ge(2)Se(8)](4-) unit containing a six-membered Ge(2)Se(4) ring in the chair conformation. The [Ge(2)Se(8)](4-) unit acts as a bridging ligand via the trans terminal Se atoms to interlink the [{Ln(tepa)}(2)(µ-OH)(2)](4+) fragments into one-dimensional polymers [{Ln(tepa)(µ-OH)}(2)(µ-Ge(2)Se(8))](n). Compounds 1-3 are the first examples of solvothermally prepared lanthanide complexes with a selenidogermanate anion as a ligand. The [Ge(2)Se(6)](4-) anion in 4 is composed of two GeSe(4) tetrahedra sharing a common edge, and is charge compensated by a [{Dy(en)(5)}(2)(µ-OH)(2)](4+) complex cation. The formation of the [Ge(2)Se(8)](4-) and [Ge(2)Se(6)](4-) anions and their behavior towards lanthanide ions in 1-4 show the significant influence of ethylene polyamines on the solvothermal synthesis of Ln selenidogermanates.

Solvothermal synthesis and characterization of polyselenidoarsenate salts of transition metal complex cations.

The polyselenidoarsenates [Fe(phen)(3)][As(2)Se(6)] (1), [Zn(phen)(dien)][As(2)Se(6)]·2phen (2), [{Mn(phen)(2)}(2)(µ-η(2),η(2)-AsSe(4))](2)[As(2)Se(6)]·H(2)O (3), and [Ni(phen)(3)][As(2)Se(2)(µ-Se(3))(µ-Se(5))] (4) (dien = diethylenetriamine and phen = 1,10-phenanthroline) were prepared by the reaction of As(2)O(3), Se, dien, and phen in the presence of transition metals in a methanol solvent under solvothermal conditions. Compounds 1-3 consist of [As(2)Se(6)](2-) anions with [Fe(phen)(3)](2+), [Zn(phen)(dien)](2+), and [{Mn(phen)(2)}(2)(µ-η(2),η(2)-AsSe(4))](+) complex counter cations, respectively. The [As(2)Se(6)](2-) anion is formed from two As(III)Se(3) trigonal pyramids linked through two Se-Se bonds. Compound 3 is the first example of a mixed-valent selenidoarsenate(III,V) and exhibits the coexistence of As(III)Se(3) trigonal pyramidal and As(V)Se(4) tetrahedral units. Compound 4 is composed of a helical chain of [As(2)Se(2)(µ-Se(3))(µ-Se(5))(2-)](∞) and octahedral [Ni(phen)(3)](2+) cations. The [As(2)Se(2)(µ-Se(3))(µ-Se(5))(2-)](∞) chain is constructed from AsSe(+) units alternatively linked by µ-Se(3)(2-) and µ-Se(5)(2-) bridging ligands. When the structures of compounds 1-4 are compared, the transition metal ions show different structural directing effects during the synthesis of arsenic polyselenides in methanol. Compounds 1, 2, 3, and 4 exhibit semiconducting properties with band gaps of 1.88, 2.29, 1.82, and 2.01 eV, respectively.

Novel polyselenidoarsenate and selenidoarsenate: solvothermal synthesis and characterization of [Co(phen)3][As2Se2(µ-Se3)(µ-Se5)] and [Co(phen)3]2[As8Se14].

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.

Effects of lanthanide metal size and amino ligand denticity on the solvothermal systems Ln/Sn/Se/en and Ln/Sn/Se/dien (Ln = lanthanide).

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.

Investigating metal size effects in the Ln/As/Se/amine (Ln = lanthanide excluding Pm, amine = en, dien, en+trien) systems: solvothermal syntheses and characterizations of lanthanide selenidoarsenates.

Three solvothermal systems Ln/As/Se/en, Ln/As/Se/dien and Ln/As/Se/(en+trien) (Ln = lanthanide excluding Pm, en = ethylenediamine, dien = diethylenetriamine, trien = triethylenetetramine) were investigated in detail across the lanthanide series, and ternary lanthanide selenidoarsenates [Ln(en)(3)(H(2)O)(mu-eta(1),eta(1)-AsSe(4))] (Ln = La(1a), Ce(1b), Nd(1c)), [Ln(en)(4)]AsSe(4) x 0.5 en (Ln = Sm(1d), Gd(1e), Dy(1f)), [Ln(dien)(2)(mu-eta(1),eta(2)-AsSe(4))] (Ln = La(2a), Ce(2b), Pr(2c)), [Ln(en)(trien)(mu-eta(1),eta(2)-AsSe(4))] (Ln = La(3a), Nd(3b)) and [Sm(en)(trien)(eta(2)-AsSe(4))] (3c) were prepared. Systematic investigations of the three systems clarify the relationship between the molecular structures of the synthetic lanthanide selenidoarsenates and the metal size evolution of the lanthanide series. Meanwhile, the coordination modes of the [AsSe(4)](3-) tetrahedral anion to the same lanthanide ion are dependent on the denticity of ethylene polyamine as the second ligand. The lanthanide selenidoarsenates exhibit semiconducting properties with E(g) between 2.15 and 2.31 eV.

An unprecedented mu4-Sn2Se9 ligand: solvothermal syntheses and characterizations of novel lanthanum selenidostannates [{La(dien)2}4(mu4-Sn2Se9)(mu-Sn2Se6)]infinity and [La2(en)8(mu-Se2)]Sn2Se6.

Solvothermal reaction of La2O3, Sn and Se in dien yields a novel lanthanide selenidostannate [{La(dien)2}4(mu4-Sn2Se9)(mu-Sn2Se6)]infinity, the first example of the coordination of Sn2Se9 and Sn2Se6 ligands to hard Lewis acidic lanthanide metals, while the reaction in en yields an ionic compound [La2(en)8(mu-Se2)]Sn2Se6 containing a ten-coordinated binuclear lanthanum complex [La2(en)8(Se2)]4+ with the diselenide Se(2)(2-) group as a bridging ligand.

The coordination of the tetraselenidoantimonate [SbSe4]3- anion with trivalent lanthanide ions tuned by ethylene polyamines.

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.

Hydrothermal syntheses and characterizations of thioarsenates [Fe(phen)3][As3S6] x dien x 7 H2O and [Mn2(phen)4(As2S5)] x phen x 2 H2O: a new coordination mode of the As2S5(4-) anion.

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.

Direct solvothermal growth, crystal structures, and optical properties of one-dimensional lanthanide selenidoarsenate(v) polymers [Ln(dien)2(micro3-AsSe4)] (Ln = Nd, Sm): the first example of an AsSe4(3-) anion acting as a ligand to a lanthanide complex.

Two novel lanthanide selenidoarsenates(v) [Ln(dien)2(micro(3)-AsSe(4))] (Ln = Nd 1, Sm 2, dien = diethylenetriamine) were synthesized by the reactions of As(2)O(3) and Se with Nd(2)O(3) or Sm(2)O(3) in dien under solvothermal conditions. 1 and 2 are in the orthorhombic crystal system with Iba2 and Pbca space groups, respectively. The [AsSe(4)](3-) anion acts as a tridentate micro(3)-AsSe(4) ligand to bridge the lanthanide [Ln(dien)2](3+) complexes leading to one-dimensional neutral [Ln(dien)(2)(micro(3)-AsSe(4))](infinity) chains. The chains contact through hydrogen bonding to form network structures. The lanthanide center lies within a nine-coordinated environment involving six N atoms of two dien ligands and three Se atoms of two different tetrahedral [AsSe(4)](3-) anions forming a distorted monocapped square antiprism. The novel coordination polymers [Nd(dien)2(micro(3)-AsSe(4))](infinity) and [Sm(dien)2(micro(3)-AsSe(4))](infinity) are the first examples of solvothermally synthesized selenidoarsenates with [AsSe(4)](3-) anion acting as a ligand in lanthanide complexes. The band gaps of 2.11 eV for 1, and 2.18 eV for 2 have been derived from optical absorption spectra. TG-DSC curves show that two compounds remove coordinated dien ligands in a single step.