Two novel 3D borates: porous-layer and layer-pillar frameworks.

Two new borates, NaK[B{BO(OH)}{BO(OH)}] (1) and Na[Al{BO(OH)}{BO}{BO(OH)}] (2), have been made by a solvothermal method. Structure 1 is made of two types of oxoboron clusters ([BO(OH)] and [BO(OH)]) and BO tetrahedra to form a 3D porous layer, in which the [BO(OH)] clusters are bridged by BO groups to produce a 2D B-O layer with 11-membered ring (MR) windows, while the [BO(OH)] clusters as 2-connected pillars join the adjacent B-O layers to make a 3-D porous layer. Structure 2 is built from two types of oxoboron clusters ([BO(OH)] and [BO]), AlO units and BO(OH) triangles to produce 3D pillar-layered aluminoborate (ABO), in which the [BO] clusters are linked together to form a 2-D B-O layer; the [BO(OH)] clusters and AlO groups join each other to form 1D tubular ABO; and the BO(OH) triangles act as linkers to connect the adjacent B-O layer and the ABO tubes, resulting in 3D pillar-layered ABO.

Characterization of a trinuclear ruthenium species in catalytic water oxidation by Ru(bda)(pic)2 in neutral media.

A Ru(III)-O-Ru(IV)-O-Ru(III) type trinuclear species was crystallographically characterized in water oxidation by Ru(bda)(pic)2 (H2bda = 2,2'-bipyridine-6,6'-dicarboxylic acid; pic = 4-picoline) under neutral conditions. The formation of a ruthenium trimer due to the reaction of Ru(IV)[double bond, length as m-dash]O with Ru(II)-OH2 was fully confirmed by chemical, electrochemical and photochemical methods. Since the oxidation of the trimer was proposed to lead to catalyst decomposition, the photocatalytic water oxidation activity was rationally improved by the suppression of the formation of the trimer.

Dodenuclear [Mn(III)(8)Ln(III)(4)] clusters with 2-(hydroxymethyl)pyridine: syntheses, structures, and magnetic properties.

A new family of isostructural Mn/Ln dodenuclear clusters: [Mn8Ln4(O)8(hmp)4(O2CPh)12(NO3)4(PhCO2H)(C2H5OH)] [Ln = La (1), Pr (2), Nd (3), Gd (4), Dy(5), hmpH = 2-(hydroxymethyl)pyridine] have been synthesized by the reaction of Mn(NO3)2 and Ln(NO3)3·6H2O with hmpH and benzoic acid as co-ligands. Compounds 1-5 possess a spindle-shaped core of [MnLn(μ4-O)4(μ3-O)4(μ3-OR)2(μ2-OR)8](10+), which is composed of six face-sharing defected cubane units and two square-pyramidal units. The compounds represent the highest nuclearity Mn/Ln clusters with the use of hmpH to date.

A family of novel Mn₃Ln₄ clusters displaying single-molecule magnet behavior.

Using 3-methyloxysalicylaldoxime (mosaoH2) and N-methyl diethanolamine (N-mdeaH2) as coligands, a family of heptanuclear Mn/Ln heterometallic compounds [Mn(II)Mn(III)2Ln(III)4(mosao)2(mosaoH)4(piv)4(N-mdea)4]·xMeCN [Ln = Dy(1), Tb(2) and Y(3), pivH = pivalic acid] have been prepared. The crystal structures of 1-3 were obtained, and their core consists of two Mn(III)Ln2(μ3-OR)2 (RO(2-) = N-mdea(2-)) triangles linked to a central Mn(II) atom. A dc magnetic susceptibility study reveals that single-ion effects of the Ln ions are dominant in compounds 1 and 2.

Intramolecular iron-mediated C-H bond heterolysis with an assist of pendant base in a [FeFe]-hydrogenase model.

Although many metalloenzymes containing iron play a prominent role in biological C-H activation processes, to date iron-mediated C(sp(3))-H heterolysis has not been reported for synthetic models of Fe/S-metalloenzymes. In contrast, ample precedent has established that nature's design for reversible hydrogen activation by the diiron hydrogenase ([FeFe]-H2ase) active site involves multiple irons, sulfur bridges, a redox switch, and a pendant amine base, in an intricate arrangement to perform H-H heterolytic cleavage. In response to whether this strategy might be extended to C-H activation, we report that a [FeFe]-H2ase model demonstrates iron-mediated intramolecular C-H heterolytic cleavage via an agostic C-H interaction, with proton removal by a nearby pendant amine, affording Fe(II)-[Fe'(II)-CH-S] three-membered-ring products, which can be reduced back to 1 by Cp2Co in the presence of HBF4.

Hepta-carbonyl-bis-(μ-propane-1,3-di-thiol-ato)triiron(I,II)(2 Fe-Fe).

The trinuclear title compound, [Fe3(C3H6S2)2(CO)7], is a mixed-valent Fe(I)/Fe(II) complex and crystallizes with two mol-ecules of similar configuration in the asymmetric unit. The three Fe atoms in each mol-ecule display a bent arrangement [Fe-Fe-Fe = 156.22 (4) and 157.

Efficient photo-driven hydrogen evolution by binuclear nickel catalysts of different coordination in noble-metal-free systems.

Exploration of the complex Ni2(MBD)4 (MBD = 2-mercaptobenzimidazole) (C1) having different coordinated Ni atoms as a photocatalyst for hydrogen evolution is made. For comparison, the bimetallic Ni2(MBT)4 (MBT = 2-mercaptobenthiazole) (C2) complex with the same coordinated Ni atoms was synthesized. Both of the complexes have been successfully constructed for photo-induced hydrogen production using organic dyes as photosensitizers and triethanolamine (TEOA) as the effective electron donor by visible light (>400 nm) in acetonitrile-water solution.

The first heterometallic examples of 3d-4f heptanuclear [Mn(II)3Ln(III)4] complexes with planar disc-like cores and diverse magnetic properties.

A family of heptanuclear [Mn(II)(3)Ln(III)(4)] clusters with planar disc-like cores have been synthesized by a solvothermal route, where Ln = La, Pr, Nd, and Gd, and such fascinating topology is unprecedented in 3d-4f complexes. Dc magnetic susceptibility data show different magnetic behaviors derived from the difference in Ln ions.

Octanuclear Mn(III)6Mn(II)Ln (Ln = Gd, Dy and Er) clusters with a novel core topology: syntheses, structures, and magnetic properties.

Reactions of [Mn6O2(piv)10(py)2.5(piv)1.5], Ln(NO3)3·6H2O and N-mdeaH2 in MeCN in the presence of Me3SiCl generated a family of octanuclear Mn/Ln complexes [Mn6(III)Mn(II)Ln(N-mdea)3(N-mdeaH)(piv)8O2(OH)3(NO3)(H2O)]·xCH3CN·xH2O [Ln = Gd (1), Dy (2), Er (3), pivH = pivalic acid, N-mdeaH2 = N-methyl diethanolamine].

Syntheses, structures and magnetic properties of a family of heterometallic [Mn(II)2Mn(III)2Ln(III)2] clusters.

A new family of isostructural Mn-Ln heterometallic clusters, [Mn(II)(2)Mn(III)(2)Ln(III)(2)(Piv)(8)(thme)(2)(H(2)tea)(2)] (H(3)thme = 1,1,1-tris(hydroxymethyl)ethane, Hpiv = pivalic acid, H(3)tea = triethanolamine, and Ln = Pr, Nd, Sm, Eu, Gd, Tb, and Dy) have been prepared by reaction of the hexanuclear manganese precursor, [Mn(6)O(2)(Piv)(10)(4-Me-Py)(2.5)(Hpiv)(1.5)], with H(3)thme, H(3)tea, and Ln(NO(3))(3)·6H(2)O under the solvothermal conditions.

Efficient [FeFe] hydrogenase mimic dyads covalently linking to iridium photosensitizer for photocatalytic hydrogen evolution.

Two [FeFe] hydrogenase mimics, [Fe(2)(μ-pdt)(CO)(5)L1] (L1 = PPh(2)SPhNH(2)) (Ph = phenyl) (2) and [Fe(2)(μ-pdt)(CO)(5)L2] (L2 = PPh(2)PhNH(2)) (3), and two molecular photocatalysts, [(CO)(5)(μ-pdt)Fe(2)PPh(2)SPhNHCO(bpy)(ppy)(2)Ir]PF(6) (bpy = bipyridine, ppy = 2-phenylpyridine) (2a) and [(CO)(5)(μ-pdt)Fe(2)PPh(2)PhNHCO(bpy)(ppy)(2)Ir](PF(6)) (3a), have been designed and synthesized, anchoring Ir(ppy)(2)(mbpy)PF(6) (mbpy = 4-methyl-4'-carbonyl-2,2'-bipyridine) (PS) to one of the iron centers of complexes 2 and 3 by forming amide bonds. Molecular dyads 2a, 3a and the intermolecular systems 2, 3 with PS have also been successfully constructed for photoinduced H(2) production using triethylamine (TEA) as a sacrificial electron donor by visible light (>400 nm) in CH(3)CN-H(2)O solution. The time-dependence of H(2) generation and spectroscopic studies suggest that the activity of H(2) evolution can be tuned by addition of a S atom to the phosphane ligand.

Syntheses, structures, and magnetic properties of a family of tetra-, hexa-, and nonanuclear Mn/Ni heterometallic clusters.

A family of Mn(III)/Ni(II) heterometallic clusters, [Mn(III)(4)Ni(II)(5)(OH)(4)(hmcH)(4)(pao)(8)Cl(2)]·5DMF (1·5DMF), [Mn(III)(3)Ni(II)(6)(N(3))(2)(pao)(10)(hmcH)(2)(OH)(4)]Br·2MeOH·9H(2)O (2·2MeOH·9H(2)O), [Mn(III)Ni(II)(5)(N(3))(4)(pao)(6)(paoH)(2)(OH)(2)](ClO(4))·MeOH·3H(2)O (3·MeOH·3H(2)O), and [Mn(III)(2)Ni(II)(2)(hmcH)(2)(pao)(4)(OMe)(2)(MeOH)(2)]·2H(2)O·6MeOH (4·2H(2)O·6MeOH) [paoH = pyridine-2-aldoxime, hmcH(3) = 2, 6-Bis(hydroxymethyl)-p-cresol], has been prepared by reactions of Mn(II) salts with [Ni(paoH)(2)Cl(2)], hmcH(3), and NEt(3) in the presence or absence of NaN(3) and characterized. Complex 1 has a Mn(III)(4)Ni(II)(5) topology which can be described as two corner-sharing [Mn(2)Ni(2)O(2)] butterfly units bridged to an outer Mn atom and a Ni atom through alkoxide groups. Complex 2 has a Mn(III)(3)Ni(II)(6) topology that is similar to that of 1 but with two corner-sharing [Mn(2)Ni(2)O(2)] units of 1 replaced with [Mn(3)NiO(2)] and [MnNi(3)O(2)] units as well as the outer Mn atom of 1 substituted by a Ni atom.

(6-Oxido-2-oxo-1,2-dihydropyrimidine-5-carboxylato-κ2O5,O6)bis[2-(2-pyridyl)-1H-benzimidazole-κ2N2,N3]manganese(II) monohydrate.

In the title compound, [Mn(C(5)H(2)N(2)O(4))(C(12)H(9)N(3))(2)]·H(2)O, the Mn(II) centre is surrounded by three bidentate chelating ligands, namely, one 6-oxido-2-oxo-1,2-dihydropyrimidine-5-carboxylate (or uracil-5-carboxylate, Huca(2-)) ligand [Mn-O = 2.136 (2) and 2.156 (3) Å] and two 2-(2-pyridyl)-1H-benzimidazole (Hpybim) ligands [Mn-N = 2.

Synthesis, structures and electrochemistry studies of 2Fe2S-Fe(ii)(S-2N)(2) models for H-cluster of [FeFe]-hydrogenase.

A series of model complexes [(μ-pdt)Fe(2)(CO)(5)](2)M(sip)(2) (M = Fe, Ni) were synthesized as H-cluster analogues of [FeFe]-hydrogenase. Their electrochemical behaviours were investigated and it is proposed that the bridging metal bis(tris-chelate) groups act as electron transfer sites in theses mimics.

The use of phosphonates for constructing 3d-4f clusters at high oxidation states: synthesis and characterization of two unusual heterometallic CeMn complexes.

The use of phosphonic acids in the synthesis of mixed-metal CeMn complexes has led to the formation of two phosphonate complexes with unusual topologies: [Ce(2)Mn(6)O(6)(OH)(5)(t-BuPO(3))(6)(O(2)CMe)(3)] x 53 H(2)O (1 x 53 H(2)O) and [Ce(22)Mn(12)O(34)(MePO(3))(12)(O(2)CMe)(33)(OMe)(6)(NO(3))(H(2)O)(12)](n) (2). The two mixed-metal CeMn complexes were both prepared from a reaction system containing Mn(O(2)CMe)(2) and (NH(4))(2)[Ce(NO(3))(6)] with similar procedures except for using different phosphonic acids (tert-butylphosphonic acid and methylphosphonic acid, respectively) as coligands. Both complexes possess rare topology of triangular type, with compound 1 being a 0D discrete cluster, whereas, compound 2 is a 1D polymer.

Synthesis and characterization of a series of manganese phosphonate complexes with various valences and nuclearity.

A series of new manganese phosphonate clusters with unprecedented topologies, [Mn(20)Na(4)O(12)(t-BuPO(3))(12)(O(2)CMe)(16)(H(2)O)(12)].5H(2)O (), [Mn(15)O(6)(MePO(3))(2)(MeCOO)(18)(H(2)O)(12)][MePO(3)H](2).12H(2)O (), and [Mn(t-BuPO(3)H)(2)(phen)(2)].

Synthesis and characterization of nona- and trideca-nuclear manganese phosphonate clusters.

Two new Mn(III) complexes with unprecedented topologies containing the tert-butylphosphonate ligand (t-BuPO3(2-)), [Mn9O6(t-BuPO3)2(O2CMe)11 (MeCOOH)(H2O)].8H2O(1), and [NBu(n)4][Mn13O6(t-BuPO3)10(OH)2(N3)6(MeCOOH)2(H2O)2].6H2O(2) have been prepared by treatment of Mn(O2CMe)2 and NBu(n)4MnO4 with tert-butylphosphonic acid in the presence of different bases.

Synthesis and characterization of a family of penta- and tetra-manganese(III) complexes derived from an assembly system containing tert-butylphosphonic acid.

A family of manganese complexes, [Mn 5O 3( t-BuPO 3) 2(MeCOO) 5(H 2O)(phen) 2] ( 1), [Mn 5O 3( t-BuPO 3) 2(PhCOO) 5(phen) 2] ( 2), [Mn 4O 2( t-BuPO 3) 2(RCOO) 4(bpy) 2] (R = Me, ( 3); R = Ph, ( 4)), NBu (n) 4[Mn 4O 2(EtCOO) 3(MeCOO) 4(pic) 2] ( 5), NR' 4[Mn 4O 2( i-PrCOO) 7(pic) 2] (R' = Bu (n) , ( 6); R' = Et, ( 7)), were synthesized and characterized. The seven manganese clusters were all prepared from a reaction system containing tert-butylphosphonic acid, Mn(O 2CR) 2 (R = Me, Ph) and NR' 4MnO 4 (R' = Bu (n) , Et) with similar procedures except for using different N-containing ligands (1,10-phenanthroline (phen), 2,2'-bipyridine (bpy) and picolinic acid (picH)) as coligands. The structures of these complexes vary with the N-containing donors.

[2-(2-Pyridyl)-1H-benzimidazole-kappa2N2,N3]bis(p-toluato-kappa2O,O')manganese(II).

In the title compound, [Mn(C8H7O2)2(C12H9N3)], the manganese(II) centre is surrounded by three bidentate chelating ligands, namely, one 2-(2-pyridyl)benzimidazole ligand [Mn-N = 2.1954 (13) and 2.2595 (14) A] and two p-toluate ligands [Mn-O = 2.

Diiron models for the active site of Fe-only hydrogenase with terminal organosulfur ligation: synthesis, structures and electrochemistry.

Diiron model complexes (micro-SCH(2)CH(2)CH(2)S)Fe(2)(CO)(5)L with thioether-substitution, L=S(CH(2)CH(3))(2) (2), S(CH(2)CH(3))(CH(2)CH(2)Cl) (3), S(CH(2)CH(3))(C(6)H(5)) (4), or sulfoxide-substitution, L=SO(CH(2)CH(2)CH(3))(2) (5), SO(CH(3))(2) (6), were synthesized as active site analogues of Fe-only hydrogenase. The organosulfur ligands were introduced into the diiron centers via moderately stable intermediates following two routes. The X-ray crystallographic structures of complexes 2-6 show the apical positions of terminal organosulfur ligands.

Aggregation of tetranuclear Mn building blocks with alkali ion. Syntheses, crystal structures and chemical behaviors of monomer, dimer and polymer containing [Mn4(mu3-O)2]8+ units.

Aggregation of tetranuclear Mn(4)O(2) building blocks with alkali ion was studied. Several Mn(iii) complexes containing [Mn(4)O(2)(AcO)(7)(pyz)(2)](-) (pyz = pyrazinate) anion(s) were obtained from an assembly system containing Mn(ii), MnO(4)(-), HOAc and Hpyz (Napyz or Kpyz). These [Mn(4)O(2)](8+) complexes have monomeric (1 and 2), dimeric (4 and 5) and one-dimensional chain () structures of which alkali metal ion connects the Mn ions of adjacent [Mn(4)O(2)](8+) units through mu(1,1)- and mu(1,3)-carboxylate bridges.

Syntheses and structural characterizations of 24-membered dimetal (Mn, Ni, Fe) macrocyclic complexes and the C-S bond formation between acetylacetone and a mercapto N-heterocycle.

An organic ligand 2,5-di(3-pentanedionylthio)-1,3,4-thiadiazole (H2L) reacts with metal (Mn, Ni, Fe) salts, resulting in 24-membered dimetal macrocyclic complexes [MnL(H2O)(dmso)](2).2dmso, [NiL(H2O)(dmf)](2).2dmf, [MnL(dmf)2]2 and [Fe2L2(solvent)2(SO4)] (solvent=dmso; H2O ; dmf).

Mono- and binuclear complexes of iron(II) and iron(III) with an N4O ligand: synthesis, structures and catalytic properties in alkane oxidation.

Three mononuclear iron complexes and one binuclear iron complex, [Fe(tpoen)Cl].0.5(Fe2OCl6) (1), [Fe(tpoen)Cl]PF6 (2), Fe(tpoen)Cl3 (3) and [[Fe(tpoen)]2(mu-O)](ClO4)4 (4) (tpoen = N-(2-pyridylmethoxyethyl)-N,N-bis(2-pyridylmethyl)amine), were synthesized as functional models of non-heme iron oxygenases.

catena-Poly[[aqua(2,2'-bipyridine-kappa2N,N')manganese(II)]-mu-terephthalato-kappa3O,O':O"].

The title complex, [Mn(C(8)H(4)O(4))(C(10)H(8)N(2))(H(2)O)](n), takes the form of a zigzag chain, with the terephthalate dianion (tp) acting as a tridentate ligand. The Mn(II) center is surrounded by two tp ligands, one water molecule and one 2,2'-bipyridine (bipy) ligand and exhibits a severely distorted octahedral coordination environment, with cis angles ranging from 57.31 (8) to 123.

Poly[[[aquamanganese(II)]-mu2-4,4'-bipyridine-mu3-succinato] 4,4'-bipyridine hemisolvate].

The polymeric title complex, [[Mn(C(4)H(4)O(4))(C(10)H(8)N(2))(H(2)O)].0.5C(10)H(8)N(2)](n), possesses a three-dimensional open-framework structure, with the solvate 4,4'-bipyridine (bipy) molecules, which lie around centers of inversion, clathrated in the channels of the framework.