Synthesis of the (N2)3- radical from Y2+ and its protonolysis reactivity to form (N2H2)2- via the Y[N(SiMe3)2]3/KC8 reduction system.

Examination of the Y[N(SiMe(3))(2)](3)/KC(8) reduction system that allowed isolation of the (N(2))(3-) radical has led to the first evidence of Y(2+) in solution. The deep-blue solutions obtained from Y[N(SiMe(3))(2)](3) and KC(8) in THF at -35 °C under argon have EPR spectra containing a doublet at g(iso) = 1.976 with a 110 G hyperfine coupling constant. The solutions react with N(2) to generate (N(2))(2-) and (N(2))(3-) complexes {[(Me(3)Si)(2)N](2)(THF)Y}(2)(µ-η(2):η(2)-N(2)) (1) and {[(Me(3)Si)(2)N](2)(THF)Y}(2)(µ-η(2):η(2)-N(2))[K(THF)(6)] (2), respectively, and demonstrate that the Y[N(SiMe(3))(2)](3)/KC(8) reaction can proceed through an Y(2+) intermediate. The reactivity of (N(2))(3-) radical with proton sources was probed for the first time for comparison with the (N(2))(2-) and (N(2))(4-) chemistry. Complex 2 reacts with [Et(3)NH][BPh(4)] to form {[(Me(3)Si)(2)N](2)(THF)Y}(2)(µ-N(2)H(2)), the first lanthanide (N(2)H(2))(2-) complex derived from dinitrogen, as well as 1 as a byproduct, consistent with radical disproportionation reactivity.

Synthesis and characterization of a polyoxovanadate cluster representing a new topology.

A new type of mixed-valence polyoxoanionic cluster, [V(V)13V(IV)3O42(Cl)]8-, composed of 14 {VO5} square pyramids and 2 {VO4} tetrahedral units, hosting a chloride ion has been synthesized and characterized.

Synthesis and characterization of materials containing arrays of decavanadate clusters.

The synthesis and characterization by single crystal x-ray structure analysis, manganometric titration, valence sum calculations, thermogravimetric analysis, and IR spectroscopic studies of (HN(CH2CH2)3NH)2(Na(H2O)2)(HV10O28)*2H2O (1) and (H3N-4-C5H4N)2(NH4)4(V10O28)*xH2O (2) has been described. The structure of 1 consists of alternating layers composed of two-dimensional arrays of decavanadate clusters (HV10O28)5- interlinked by the [Na(H2O)2O4] moieties, separated by the doubly protonated DABCO cations-- (HN(CH2CH2)3NH)2+. The structure exhibits a fascinating network of hydrogen bonds between cations, solvate water molecules and anion clusters. The crystal structure of 2 contains three-dimensional arrays of (V10O28)6- cluster anions, protonated 4-aminopyridinium groups, ammonium ions, and water molecules. Crystal data for 1: C12H37N4Na2O32V10, Monoclinic space group C2/m, a = 20.4242(8), b = 8.4550(3), c = 11.9255(5)A , beta = 122.0500(10) degrees, Volume = 1745.49(12)(A3), Z = 2, Dcalc = 2.439 Mg/m3. Crystal data for 2: Triclinic space group Pi, a =14.911(2), b = 16.928(2), c = 39.714(5)A, a = 84.454(2), (beta = 84.895(2), ?= 79.603(2) degrees, Volume = 9787.4(13) A3, Z = 8.

A novel cationic heteropolyoxovanadium(IV) cluster functionalized with organic ligands: synthesis and characterization of the fully reduced species [Mn(II)V(IV)6O6[(OCH2CH2)2N(CH2CH2OH)]6]Cl2.

The solvothermal reaction of (HOCH2CH2)3N with [(n-C4H9)4N]3[H3V10O28] and MnCl2 x 4H2O in CH3CN and CH3OH yields a novel cationic heteropolyoxovanadium(IV) cluster, [Mn(II)V(IV)6O6[(OCH2CH2)2N(CH2CH2OH)]6]2+, containing a fully reduced new cyclic [MnV6N6O18] core with the Anderson structure.

Novel water clusters in the crystalline state: structures of a symmetrical, cyclic hexamer and an 'opened-cube' octamer.

Six- and eight-membered hydrogen-bonded water clusters of novel structure types have been found in crystalline hydrates.

[M3 V18 O42 (H2 O)12 (XO4 )]⋠24 H2 O (M=Fe, Co; X=V, S): Metal Oxide Based Framework Materials Composed of Polyoxovanadate Clusters.

New framework materials composed of well-defined vanadium oxide clusters were prepared by low-temperature reactions and characterized by X-ray crystal structure analysis. The structures of these solids contain {V18 O42 } cages linked into two interpenetrating three-dimensional networks by bridging {M(H2 O)4 } groups (M=FeII , CoII ; see picture).

The Trivalent Neodymium Complex [(C5 Me5 )3 Nd] Is a One-Electron Reductant!

A Se22- complex, Ph3 P, and (C5 Me5 )2 are formed in the reduction of Se=PPh3 by the NdIII complex [(C5 Me5 )3 Nd] [Eq. (a)]. The latter is thus reminiscent of [(C5 Me5 )3 Sm], which, however, appears to be a stronger reductant than [(C5 Me5 )3 Nd]. This suggests that the reductive reactivity of [(C5 Me5 )3 Ln] complexes can be tuned by varying the size of the metal atom.

A novel series of materials composed of arrays of vanadium oxide container molecules, [V18O42(X)] (X = H2O, Cl-, Br-): synthesis and characterization of [M2(H2N(CH2)2NH2)5][(M(H2N(CH2)2NH2)2]2V18O42(X)]. 9H2O (M = Zn, Cd).

The synthesis and characterization of the novel systems [Zn(2)(H(2)N(CH(2))(2)NH(2))(5)][(Zn(H(2)N(CH(2))(2)NH(2))(2))(2)V(18)O(42)(H(2)O)].9H(2)O (1), [Cd(2)(H(2)N(CH(2))(2)NH(2))(5)][(Cd(H(2)N(CH(2))(2)NH(2))(2))(2)V(18)O(42)(Br)].9H(2)O (2), and [Zn(2)(H(2)N(CH(2))(2)NH(2))(5)][(Zn(H(2)N(CH(2))(2)NH(2))(2))(2)V(18)O(42)(Cl)].9H(2)O (3) have been described. These materials represent a new class of solids that have been prepared by combining conventional coordination compounds with spherical polyoxovanadate clusters. The isomorphous structures of these hybrid solids consist of two-dimensional arrays of container cluster molecules [V(18)O(42)(X)] (X = H(2)O, Br-, Cl-) interlinked by the transition metal complex moieties [M(H(2)N(CH(2))(2)NH(2))(2)] (M = Zn, Cd). These compounds contain an unprecedented complex cation, [M(2)(H(2)N(CH(2))(2)NH(2))(5)](4+). Crystal data for 1: C(9)H(46)N(9)O(26)V(9)Zn(2), monoclinic space group P2(1)/m (No. 11), a = 12.3723(7) A, b = 20.9837(11) A, c = 15.8379(8) A, beta = 97.3320(10) degrees, Z = 4.

Functionalized metal oxide clusters: synthesis, characterization, crystal structures, and magnetic properties of a novel series of fully reduced heteropolyoxovanadium cationic clusters decorated with organic ligands--[MVIV6O6[(OCH2CH2)2N(CH2CH2OH)]6]X (M = Li, X = Cl x LiCl; M = Na, X = Cl x H2O; M = Mg, X = 2Br x H2O; M = Mn, Fe, X = 2Cl; M = Co, Ni, X = 2Cl x H2O).

A novel series of fully reduced heteropolyoxovanadium(IV) compounds, [MVIV6O6[(OCH2CH2)2N(CH2CH2OH)]6]X (1, M = Li, X = Cl x LiCl; 2, M = Na, X = Cl x H2O; 3, M = Mg, X = 2Br x H2O; 4, M = Mn, X = 2Cl; 5, M = Fe, X = 2Cl; 6, M = Co, X = 2Cl x H2O; 7, M = Ni, X = 2Cl x H2O), have been synthesized and characterized by FT-IR and UV-vis spectroscopies, thermogravimetric analysis, elemental analysis, manganometric titration, temperature-dependent magnetic susceptibility measurements, bond valence sum calculations, X-ray powder diffraction, and single-crystal X-ray diffraction analyses. The structures of the crystals are comprised of discrete units of fully reduced cluster cations, [MVIV6O6[(OCH2CH2)2N(CH2CH2OH)]6]n+, counterions (chloride or bromide), and water of crystallization (in the case of 2, 3, 6, 7). In each case the cluster ion is composed of a fully reduced cyclic [MV6N6O18] (M = Li, Na, Mg, Mn, Fe, Co, Ni) framework decorated with six triethanolamine ligands. Two arms of each triethanolamine ligand are coordinated to the metallacycle, and the third arm projects outward from the hexagonal ring. The [MV6N6O18] core adopts the Anderson-type structure. The cyclic core is comprised of a ring of six edge-sharing [VO5N] octahedra linked to a central [MO6] unit. The hexametalate ring contains six d1 ions [VIV] and shows remarkable flexibility to encapsulate a variety of metal centers Mn+ (Mn+ = Li+, Na+, Mg2+, Mn2+, Fe2+, Co2+, Ni2+) with different (dn) spins. The compounds show good thermal stability and exhibit interesting magnetic properties that make these magnetic clusters promising building blocks for constructing supramolecular structures and extended structure magnetic solids. Crystal data for 1; C36H78Cl2N6Li2O24V6, trigonal space group R, a = 13.7185(3) angstroms, c = 24.8899(8) angstroms, Z = 3. Crystal data for 2: C36H80ClN6NaO25V6, triclinic space group P, a = 11.1817(5) angstroms, b = 12.1612(5) angstroms, c = 21.5979(10) angstroms, alpha = 75.8210(10), beta = 78.8270(10), gamma = 71.1400(10), Z = 2. Crystal data for 4: C36H78Cl2N6MnO24V6, monoclinic, space group P2(1), a =11.2208(5) angstroms, b = 21.5041(9) angstroms, c = 11.8126(5), beta = 111.2680, Z= 2. Crystal data for 5: C36H78Cl2N6FeO24V6, monoclinic, space group P2(1), a = 11.3057(7) angstroms, b = 21.4372(13) angstroms, c = 11.8167(7) angstroms, beta = 111.4170, Z = 2.