[Bi10{RuPPh3}3]-: Paramagnetic 13-Vertex Polybismuthide Heteroanion.

Ru(PPh3)3Cl2 reacts with Binn- from an ethylenediamine (en) solution of K5Bi4 to yield a new architype of 13-vertex [Bi10{RuPPh3}3]- (1) composed of unprecedented incomplete cuboidal Bi73- and triangular Bi33- held together by {RuPPh3}2+.

Dimeric polybismuth heteroanion of [Rh@Bi10(RhCO)5]2- constructed using Bi10-bowl and square pyramidal Rh@(Rh-CO)5.

Redox reaction of the monovalent Rh2(CO)4Cl2 and Binn- (n = 2, 3) from K5Bi4 in ethylenediamine (en) solution produced the decabismuthide-hexarhodium dianion [Rh@Bi10(RhCO)5]2- (1a) wherein a novel Bi10-bowl was constructed from oxidized 2Bi3/2Bi2 open triangles/dimers, which was stabilized by strong bonding to a reduced Rh@(RhCO)5 square pyramid. Two 1a dianons are held together by weak interactions (van der Waals forces and spatial resistance) to form a dimer [Rh@Bi10(RhCO)5]24- (1). The structure and bonding of the novel polybismuthide heteroanion 1 are discussed.

Metal-metal bonded pentamolybdate hybrids as electron storage materials.

Two electron-rich, metal-metal bonded pentamolybdate hybrids, 2D-[MoIV3MoVI2O10Sr2(H2O)5(C6H4O7)2py3]·3.5H2O (1) and 1D-[MoIV3MoVI2O10Sr(H2O)3(C6H4O7)2py3]·py·2[NH2(CH3)2]·2H2O (2, py = pyridine), were prepared by the partial solvothermal oxidation of [MoIV3O2(O2CCH3)6(H2O)3]ZnCl4·8H2O and citric acid in py/H2O (for 1) or py/H2O/DMF (for 2). Both 1 and 2 feature a triangularly metal-metal bonded incomplete cuboidal [MoIV3O4] unit. Redox-active 6e-[MoIV3O4] units can serve as an "electron sponge" to store/release six electrons reversibly via Δ-bond breakage and re-formation during charging/discharging processes. 1 and 2 further form 3D and 2D supramolecular structures, respectively, through slipped π-π stacking interactions between the pyridine ligands. Both the incorporated 6e-redox active [MoIV3O4] unit and the 3D/2D supramolecular conductive networks in hybrid-POM 1/2 remarkably enhance the electronic conductivity and reversible multi-electron redox ability with the structural integrity retained. Consequently, 1 and 2 exhibited high discharge specific capacities of 236.0 and 277.0 mA h g-1 at 50 mA g-1, respectively, and a good cycling performance at high current density (121.8 mA h g-1, 2 A g-1 for 2), providing a new way for improving POM-based electrode materials.

Electron-Rich MoIV 3 -Polyoxomolybdates Resembling the Paratungstic Archetype.

The first polyoxometalates (POMs) composed of MoIV , MoV 2 , discrete d1 -MoV and MoVI , [MoIV 3 MoV 6 MoVI 4 O32 (µ2 -OH)(µ3 -OH)py9 ] (1), was prepared from the solvothermal partial oxidation of [MoIV 3 O2 (O2 CCH3 )6 (H2 O)3 ]ZnCl4 in a mixture of pyridine and water. The MoV =O adduct-free unit [H2 Mo12 O33 py9 ] presents the 11e-reduced Mo derivative of the paratungtic archetype. The use of methanol, ethanol, n-propyl alcohol and triglycol instead of water produced the isostructural [MoIV 3 MoV 6 MoVI 4 O32 (µ3 -OH)(µ2 -OR)py9 ](R=CH3 , 2; C2 H5 , 3; C3 H7 , 4; C2 H4 OH, 5), providing the first examples of MoIV 3 -POMs containing bridging alkoxyl groups. The addition of [CrIII Mo6 O24 ]9- led to the substitution of {MoV =O}3+ with {CrIII -py}3+ in the allomer [MoIV 3 MoV 5 MoVI 4 CrIII O32 (µ-OH)2 py10 ] (6). Using a mixture of Mo3 and MoW2 precursors afforded WVI -incorporated allomer [MoIV 3 MoV 6 MoVI WVI 3 O32 (µ-OH)2 py9 ] (7). The complete substitution of MoVI with WVI by using a mixture of the Mo2 W, MoW2 and W3 precursors produced the diamagnetic [MoIV 3 MoV 6 WVI 4 O33 (µ3 -OH)py9 ]- (syn-8) resulting from the anti→syn conversion between the top and bottom M3 triads concomitant with MoV -MoV bonding. Both anti-1-7 and syn-8 have been characterized by X-ray single crystal structural analyses. The spin distribution and magnetic interactions have been investigated by temperature-dependent magnetic susceptibility and DFT theoretical calculations. Heterogeneous hydrogen transfer catalysis has been examined by the Lewis catalysis field (LCF) theory.

Mo[O8Mo4]3 Lewis acid-base cluster pairs: highly efficient and stable Lewis catalysis fields frustrated in crystalline nanoclusters.

By using metal compounds or oxide/organic acid and enhanced reaction temperatures in the controlled solvothermal oxidation of [Mo3O2(MeCO2)6(H2O)3]2+, more interstitial metal atoms were introduced to produce the largest nanoscale MoIV-polyoxomolybdates, [M2@(MoIV3py3)4Mo18Ox]q- (M = Al, V, Mo). Each [H4V2@(MoIV3py3)4Mo18O84]12- (2a) nanocluster is surrounded by 12 [V3Mo12O42] to build a Lewis catalysis field (LCF) composed of MoIV3[O8Mo4]3 Lewis acid-base cluster pairs in the crystalline 2, accounting for the excellent and stable catalysis performance in the hydrazine reduction of nitroarenes to arylamines in varied solvents. The proposed new concept LCF provides a new way of thinking for designed synthesis and real applications of highly efficient LCF catalysts.

K11Cd2Sb5 built of an unprecedented planar CdSb3 triangle.

The novel ternary Zintl phase K11Cd2Sb5 (1) with the unusual butterfly-shaped [Cd2Sb5](11-) (1a) cluster anion has been prepared by employing an enhanced stoichiometric proportion of K atoms that act as scissors. 1a is composed of two corner-shared unprecedented planar CdSb3 triangles that represent the first tricoordinated example of Cd unexpected for the octet rule.

[Ge8(Mo(CO)3)2]4⁻: an unprecedented 20-electron empty ten-vertex Zintl cluster.

The unprecedented ten-vertex Zintl anion with the two vertices occupied by transition metal fragments, [Ge8(Mo(CO)3)2](4-), has been synthesized and structurally characterized, representing the first example of 20-electron empty ten-vertex Zintl clusters. The two less cluster-bonding electrons result in a markedly distorted bicapped square antiprismatic structure featuring the up-expanded and down-compressed squares.

Linear triatomic [ZnBi2]4- in K4ZnBi2.

The linear triatomic [ZnBi2](4-) found in the diamagnetic K4ZnBi2 was prepared as the first discrete Zn-Bi Zintl cluster anion in the neat solid state from the unique K-Zn-Bi system. The tetraanionic trimer has sixteen valence electrons isovalent with CO2, accounting for its nearly linear triatomic structure (Zn-Bi-Zn, 177.3(3)°) and multiple Zn[double bond, length as m-dash]Bi bonds revealed by the unprecedentedly short bond length (2.553(3) Å) and DFT π-bonding analyses, on the basis of the established 16-electron counting rule for a linear triatomic species. The VASP theoretical calculations reveal that K4ZnBi2 is a narrow gap direct semiconductor that is expected to present promising optical properties.

[ZnBi4](3-) pentagon in K6ZnBi5: aromatic all-metal heterocycle.

The first aromatic all-metal heterocycle, [ZnBi4](3-), found in the metallic salt, K6ZnBi5, has been synthesized and structurally characterized. The exactly planar [ZnBi4](3-) pentagon with six π electrons coupled with multiply bonded Zn-Bi and Bi-Bi bonds, multicentered π-conjugated bonding, and negative nucleus-independent chemical shift values reveals its aromatic character. The metallic nature of K6ZnBi5 has been established by Pauli-type temperature-independent paramagnetism and theoretical analysis of the band structure and total/partial density of states.

Unprecedented infinite lanthanide hydroxide ribbons [Ln3(µ3-OH)3]n(6n+) in a 3-D metal-organic framework.

Unprecedented infinite lanthanide hydroxide ribbons interconnected by Pra2biim(2-) (H2Pra2biim = 1'-di(propionic acid)-2,2'-biimidazole) into 3-D [Ln3(µ3-OH)3(Pra2biim)3 (H2O)2]n·4nH2O (Ln = Nd, Pr and La) have been achieved by utilizing the unique H2Pra2biim-Ln(3+) hydrolysis system. The Ln···Ln antiferromagnetic coupling with magnetic anisotropy has been observed.

An unprecedented [Mo(IV)3O4]-incorporated polyoxometalate concomitant with MoO2 nucleophilic addition.

An unprecedented [Mo(IV)3O4]-incorporated polyoxometalate (POM), [H4Mo(IV)6Mo(VI)7O36py6](2-) (1a, py = pyridine), has been successfully prepared and structurally characterized by unique, controlled oxidization of the [Mo(IV)3O4] precursor. It has a ß-Keggin structure with two Mo-Mo bonded [Mo(IV)3O4] constitutional units. Unusual MoO2 nucleophilic addition of the ß-Keggin structure has been observed.

An unprecedented 3-D SHG MOF material of silver(I) induced by chiral triple helices.

An unprecedented 3-D SHG-active metal-organic framework (MOF) of silver(I), Ag-Amidn (1) (HAmidn: 2-amino-4,5-imidazoledicarbonitrile), has been successfully prepared by employing the new single ligand. The cooperative coordination of the imidazole and carbonitrile N atoms leads to the chiral triple helices accounting for the noncentrosymmetric space group, which are linked together to form a rare 10(3) topological structure. Ag-Amidn (1) with high thermal stability and insolubility may be considered as a potential second-order NLO material.

Unprecedented Dawson isomerism induced by a central [WO5] and four 45°-rotated belt square pyramids.

The seventh type of Wells-Dawson isomer, δ-[(WO(5))W(17)Cu(H(2)O)O(55)](10-) (1a) was obtained as a consequence of the formation of the first central square-pyramidal [WO(5)] moiety that results in a 45° rotation of the four belt [CuO(5)]/[WO(5)] square pyramids, establishing a new type of WD isomerism involving the rotation of the belt polyhedra, that were previously believed to stay unchanged.

Structure and aromaticity of B6H5(+) cation: a novel borhydride system containing planar pentacoordinated boron.

A novel structural pattern: two-dimensional, five-membered ring-like boron hydride system B(6)H(5)(+), which contains both planar tetra- and pentacoordinated boron (ptB and ppB) was designed and investigated at [B3LYP, MP2(Full) and CCSD(T,FC)]/6-311+G(d,p) theoretical levels. The results indicate that both degenerate ppB B(6)H(5)(+) configurations A (D(5H),(1)A(1)') and B (C(2nu),(1)A(1)) are energetically favorable, sharing the lowest energy comparison with other isomers considered in this work. The computed considerably large smallest vibrational frequencies [197.5 and 197.4 cm(-1), respectively at MP2 (full) level], HOMO-LUMO energy separations [10.99-11.03 eV computed at MP2 (full) level], and fairly large endothermic dissociation reaction energies suggest they are promising candidate molecules for experimental detection. The detailed molecular orbital analysis, natural bond orbital analysis, magnetic susceptibility anisotropy, and NMR chemical shift analyses confirmed that the two low-energy ppB molecules exhibit strong aromaticities.

Unprecedented helix-based microporous metal-organic frameworks constructed from a single ligand.

Unprecedented helix-based MMOFs with a cylindrical channel constructed from a single, newly designed Na(2)Pra(2)biim [Na(2)Pra(2)biim = 1,1'-di(propionic acid)-2,2'-biimidazole disodium salt], [M(Pra(2)biim)(H(2)O)](n) x xnH(2)O (M = Cd, Pb) have been presented, which are built from alternately arranged left- and right-handed helical M-biim tubes interconnected by the carboxyl arms of the ligand, and these findings reveal the promising potential of functionalized helical ligands in the construction of helix-based MMOFs from a single linker.

A series of single, double, and triple Me2biim-bridged dinuclear, trinuclear, and polymeric complexes: syntheses, crystal structures, and luminescent properties.

Reaction of ZnCl(2) and Me(2)biim (Me(2)biim = N,N'-dimethyl-2,2-'-biimidazole) in acidic or neutral aqueous solutions gave the noncoordinated ZnCl(4).H(2)Me(2)biim (1) or the double Me(2)biim bridged [Zn(2)Cl(4)(mu-Me(2)biim)(2)] (2). Use of CdX(2) (X = Cl, Br, I) instead of ZnCl(2) yielded the single Me(2)biim bridged one-dimensional coordination polymer [CdX(2)(mu-Me(2)biim)](n) (X = Cl, 3; Br, 4; I, 5). The stacking of the infinite chains are dominated by C-H...X interactions in 3 and 4 but by I...I interactions in 5, responsible for their different crystal structures. Use of Zn(NO(3))(2) instead of ZnCl(2) produced the novel triple Me(2)biim-bridged [Zn(2)(mu-Me(2)biim)(3)(H(2)O)(2)](NO(3))(4).H(2)O (6). The unprecedented hexa-Me(2)bim bridged trinuclear [Cd(3)(mu-Me(2)biim)(8)](2)(ClO(4))(12)(H(2)O)(6) (7) was obtained by using Cd(CH(3)CO(2))(2) in the presence of NaClO(4). Compounds 1-7 were characterized by X-ray crystallography and IR. Examination of photophysical properties of 1-7 indicates that the fluorescence emission of Me(2)biim has been effectively enhanced, quenched, or shifted in its metal complexes 1-7.