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Initially, a novel series of mixed ligand Pd(II) complexes of 2H[1,4]benzothiazin-3(4H)-one (Hbto) and diamine or phosphine ligands were successfully prepared with yields of 61 to 92%. The treatment of Na2PdCl4 with Hbto in acetone with 1:2 Pd to Hbto ratio affords cis-[PdCl2(Hbto)2] (1) that delivers an appropriate entry into mixed-ligand Hbto complexes. The complex (1) was used as a precursor for preparation the complexes of the type [Pd(Hbto)2(κ2-diamine)]Cl2; (diamine = en (2a), bipy (2b), phen (2c)) and [Pd(Hbto)2(κ2-diphosphine)]Cl2; (diphosphine = dppm (3a), dppe (3b), dppp (3c), dppf (3d)). Likewise, the mono phosphine (PPh3) was used to prepare the contrast complex with complex (1), however, to dissipate the suspicion that define complex [Pd(Hbto)2(PPh3)2]Cl2 is present in the cis or trans structure, two methods were used to prepare this complex, both of which demonstrated that the cis is the preferred structure for the complex [Pd(Hbto)2(PPh3)2]Cl2 (4). For all as-prepared complexes, the characterization techniques (molar conductivity, IR, 1H-, 13C-{1H}, 31P-{1H}NMR and elemental analyses) prove that the Hbto links to Pd(II) in a mono-dentate fashion through the exocyclic oxygen atom. To benefit from the complexes prepared, some as-prepared complexes (1), (2b) and (4) have been evaluated for their H2 storage at 77 K after measuring the N2 adsorption/desorption isotherms in order to get some information about BET surface areas of the samples. The results demonstrate that the selected prepared complexes were all able of storing the H2 and among the complexes (1), (2b) and (4), (2b) was the best one and was able to store 5.4 wt% of H2 under 70 bar and 77 K.

With an aim to obtain a new supramolecular compound based on Keggin-type polyoxometalates with mixed-ligand: [Cu(I)(phen)2]2{[Cu(II)]2(phen)4PTA}[H3PMoV4MoVI8O40] (phen = 1,10-phenanthroline, PTA = terephthalic acid) has been synthesized under hydrothermal conditions and structurally characterized by elemental analyses, IR, X-ray single crystal diffraction, TG analyses and XPS. In the title compound, the Keggin-type phosphomolybates anions, butterfly-shaped [Cu(I)(phen)2]+ subunits and dumbbell-shaped {[Cu(II)]2(phen)4PTA}2+ subunits are alternately connected to form chiral helical chains via hydrogen bonds along b axis, and the adjacent chiral helical chains are connected in the way of sharing butterfly-shaped [Cu(I)(phen)2]+ subunits and dumbbell-shaped {[Cu(II)]2(phen)4PTA}2+ subunits to form 3D supramolecular reticular framework. As expected, the title compound with mixed-ligands (phen and PTA) has been successfully synthesized, inconceivably, the title compound also contains mixed-valence Cu (Cu(I) in butterfly-shaped [Cu(I)(phen)2]+ subunits; Cu(II) in dumbbell-shaped {[Cu(II)]2(phen)4PTA}2+ subunits). The preliminary analyses show that mixed-valence Cu(I/II) may be due to the reduction of Cu(II) (from CuCl2) to Cu(I) (in butterfly-shaped [Cu(I)(phen)2]+ subunits) by N-containing compound. The successful results of this work provide a new idea that supramolecular materials with attractive structures and novel properties, which could be designed and synthesized by introducing of mixed-ligands into the supramolecular materials. Additionally, the electrocatalytic property of the title compound to H2O2 has been studied.

A novel 3D NbO metal-organic framework, [Cd2(pam)2(bpt)2(H2O)]n·0.68nH2O (1) (H2pam = pamoic acid and bpt = 2,5-bis(4-pyridyl)-1,3,4-thiadiazole), has been synthesized by the structural cooperation of well-chosen flexible aromatic acid and rigid bipyridyl ligand. The rare severely distorted mixed-ligand mesomeric networks accommodate two individual heterochiral frameworks interpenetrating with each other. The bulk materials of 1 display excellent fluorescent properties.

Two novel polyrotaxane-like coordination polymers, [Ni4(L)4(H2O)3(bpp)4]·3H2O (1) and [Cd4(L)4(bpp)3]·3H2O (2) (H2L = Me2Si(p-C6H4COOH)2, bpp = 1,3-bis(4-pyridyl)propane), have been synthesized and structurally characterized. Compound 1 features a 2D → 3D polyrotaxane array by the interlock of bilayer networks. Compound 2 exhibits an unusual 3D polyrotaxane-like self-threading framework. In addition, compound 2 shows an emission at 485 nm when it was excitated at 400 nm.

A new stable cobalt-organic framework, namely [Co2(oba)2(H2Me4bpz)]n (1) (H2oba = 4.4′-oxydibenzoic acid, H2Me4bpz = 3.3′,5,5′-tetramethyl-4,4′-bipyrazole), has been synthesized by combining the mixed H2oba and H2Me4bpz with Co(CH3COO)2·4H2O under solvothermal conditions, which was characterized by infrared spectroscopy, single-crystal X-ray diffraction, powder X-ray diffraction, and thermogravimetric analyses. Single-crystal X-ray diffraction analysis reveals that 1 features a three-dimensional framework, which is built from interesting tetrahedral cages. The thermal stability of the complex has also been investigated.

Photo-irradiation of the cis-[Pd(L1-4-κS,O)2] complexes with visible light leads to formation of trans-[Pd(L1-4-κS,O)2] isomers in acetonitrile, as determined by reverse-phase HPLC (RP-HPLC). In the absence of light, the trans-[Pd(L1-4-κS,O)2] isomers spontaneously revert to cis-[Pd(L1-4-κS,O)2]. The trans-[Pd(L1-4-κS,O)2] → cis-[Pd(L1-4-κS,O)2] reversion was found to be catalyzed by the presence of free HL ligands, and results in the formation of mixed-ligand complexes of the type cis-[Pd(L1-κS,O)(L2-κS,O)] as confirmed by RP-HPLC with ESI-MS detection. The mixed-ligand cis-[Pd(L1-κS,O)(L2-κS,O)] complex also undergoes photo-induced isomerism to form trans-[Pd(L1-κS,O)(L2-κS,O)] isomers in solution with visible light irradiation.

A novel three-dimensional cobalt-organic framework [(Me2NH2)Co3(μ3-OH)(tpt)(btb)2]·guest (1) (tpt = 2.4.6-tri(4-pyridinyl)-1,3,5-triazine, H3btb = 4.4ʹ,4″-benzene-1,3,5-triyl-tribenzoate) has been obtained by employing mixed tripodal ligands tpt and H3btb under solvothermal reaction condition. Topological analysis reveals that the whole framework structure of 1 possesses a two-fold interpenetrated 3,6-connected sit topology. Remarkably, the desolvated sample 1a shows a high CO2 uptake of 89.5 cm3 g− 1 (17.6 wt%) at 273 K and 1.0 bar, which is attributed to open metal sites and rich N donors of 1a.

A novel reduced molybdophosphate-based metal–organic framework (MOF) Zn[(MoO2)6(HPO4)2(PO4)2(OH)3]2[Zn2(L1)][Zn(HL2)2]2·10H2O (1) (L1 = 1,6-bis(1,2,4-triazol-1-yl)hexane, L2 = 1,2,4-triazol) has been hydrothermally synthesized and structurally characterized. Compound 1 is constructed from the [Zn(P4Mo6)2]-based 2D layer and μ2-bridging L1 ligands, which shows a (2,3,8)-connected three-dimensional framework with {{4·62}2{44·62·818·124}{4}2} topology. 1 represents the first 3D P4Mo6-based MOF constructed by mixed N-donor ligands. The electrocatalytic and photocatalytic activities of compound 1 have been investigated.

Reactions of Zn(II) salts, presynthesized 5-(4-(1H-imidazol-1-yl)phenyl)-1H-tetrazolate (HIPT) and various carboxylate ligands result to three new coordination polymers (CPs), namely, [Zn2[(IPT)2(ox)]}n (H2ox = oxalic acid, 1), [Zn2(IPT)2(mNBDC)]n (H2mNBDC = 5-nitroisophthalic acid, 2), and [Zn2(IPT)(CA)(H2O)]n (H3CA = citric acid, 3). Compound 1 can be seen as constructed from 2D [Zn(IPT)]n layers with (6,3) topology and pillared by ox2 −. It is a 3D (3,4)-connected framework with InS topology. Compound 2 has 2D bilayer structure based on 2D [Zn(IPT)]n single layer and mNBDC2 − linkers. Compound 3 is a 3D pillar-layer framework built by Zn–CA bilayers and IPT− pillars. The results showed that the coordination modes, configurations of IPT−, and the structure of carboxylate co-ligands have great influence on the structures of the final network. The choice of carboxylate can decide the result of CPs in Zn–IPT chains/net subunits plus carboxyl linkers or Zn–carboxylate chains/net subunits plus IPT− linkers. The thermal stabilities and luminescent properties of selected compounds have also been studied.

Two types of ruthenium(II) complexes cis -[Ru(bpy) 2 ClL] + and cis -[Ru(bpy) 2 L 2 ] 2 + (L = 1,6-diaminohexane (1,6-dahx), 1-aminohexane (1-ahx)) were synthesized, and the interactions of these complexes with DNA were investigated. Importantly, cis -[Ru(bpy) 2 (1,6-dahx) 2 ] 2 + possessed hydrogen-bonding to DNA, preferentially binds at adenine and/or thymine residues, and exhibits more efficient nuclease activity.

A new three-dimensional (3D) POMOF based on α-metatungstate and mixed-ligand, [Cu4(pzta)2(bipy)4(H2O)6][H2W12O40]·2H2O (1) (pzta = 5-(2-pyrazinyl) tetrazole, bipy = 4,4′-bipyridine), has been synthesized and characterized by routine methods. In 1, there is a 2D inorganic layer constructed by W12 clusters and copper cations, which is reinforced by the incorporation of the dinuclear copper complexes to form a poly-pendant layer. Furthermore, the dicoordinated bipy ligands as pillars link parallel neighboring poly-pendant layers to generate a novel 3D framework with a (65 · 81)2(67 · 87 · 121) topology. To the best of our knowledge, it represents the first 3D POMOF constructed by α-metatungstate and mixed-ligand. In addition, the electrochemical studies show that 1 has a good electrocatalytic activity toward reduction of nitrite.

Reported here is a novel Cd(II) coordination polymer (namely [Cd(L1)0.5(ntd)]n (1), L1 = N,N′-di(4-pyridyl)adipoamide, H2ntd2 = 1,4-naphthalenedicarboxylic acid). Single-crystal X-ray diffraction reveals that the framework can be represented as metal/organic-binodal 4-connected Moganite net with three-fold interpenetration. Importantly, for the first time, an unusual coordination mode is observed for the acylamide ligand in such manner that every L1 ligand links four Cd(II) ions through two nitrogen atoms from two pyridine groups and two oxygen atoms from two acylamide groups.

Reaction of the potassium salt of the N-thiophosphorylated thiourea Et 2NC(S)NHP(S)(OiPr) 2 (HL) with a mixture of AgNO 3 and PPh 3 in aqueous EtOH/CH 2Cl 2 leads to the mixed-ligand silver(I) complex [Ag(PPh 3) 2{Et 2NC(S)NP(S)(OiPr) 2}] ([Ag(PPh 3) 2L]). Recrystallization of [Ag(PPh 3) 2L] from an acetone/n-hexane mixture leads to the decomposition of the starting complex with the formation of [Ag(PPh 3){Et 2NC(S)NP(S)(OiPr) 2}] ([Ag(PPh 3)L]), [Ag(PPh 3) 3NCS]·(CH 3) 2C=O and Et 2NP(S)(OiPr) 2. The structures of [Ag(PPh 3) 2L], [Ag(PPh 3)L], [Ag(PPh 3) 3NCS]·(CH 3) 2C=O and Et 2NP(S)(OiPr) 2 were all investigated by IR, 31P{ 1H} and 1H NMR spectroscopy, and their compositions were established by elemental analysis. The crystal structure of the complex [Ag(PPh 3) 3NCS]·(CH 3) 2C=O obtained from single crystal X-ray diffraction is presented. © 2011 Elsevier B.V. All rights reserved.

Reported here is a novel acylamide MOF, Zn(L) (tdca)·1.5 DMF(1), obtained by a mixed ligand approach, where N4,N4′-di(pyridin-4-yl)-[1,1′-biphenyl]-4,4′- dicarboxamide(L) and thiophene-2,5-dicarboxylic acid (tdca) are used. The 3D framework can be represented as a rare 4-connected self-catenated hxg-d-4-Fddd net with a 65.8 topological symbol. Notably, the MOF shows high CO2 adsorption selectivity over CH4, CO, and N2 gases.

Three new nickel(II) complexes [Ni2(btec)(azopy)2(H2O)8]·2H2O (1), {[Ni(H2btec)(azopy)(H2O)2]·(azopy)}n (2) and {[Ni4(btec)2(azopy)3(H2O)10]·8H2O}n (3) (H4btec = 1,2,4,5-benzenetetracarboxylic acid; azopy = 4,4′-azobispyridine) have been synthesized by tuning the reaction temperature and the metal–ligand ratio. They were characterized by single-crystal X-ray diffraction and elemental analysis. 1 shows a binuclear structure, 2 exhibits a 2D grid, and 3 features an interesting 3D framework with (63)(4.62)(42.62.82) topology formed by two types of interlocked 2D layers.

A novel 3D nickel twofold-interpenetrating framework with mixed ligand, [Ni3(H2O)6(4,4′-bipy)4(SIPA)2] · 8H2O (1), has been hydrothermally prepared. X-ray diffraction shows the 3D framework contains Ni-4,4′-bipy 1D chain and 2D bilayer motifs and carboxylate spacers, and the connection of 1D chain and 2D bilayer motifs by carboxylate ligand results in the formation of the final framework with twofold-interpenetration net.

A series of mixed-ligand heterobimetallic complexes of the form MM′(C7H4NS2)4(py)2 and MM′(C7H4NS2)4(N–N) and complex heterobimetallic salts [M(N–N)3][M′(C7H4NS2)4] [M=Co(II) or Ni(II); M′=Zn(II) or Hg(II); N–N=ethylenediamine(en) or 1,10-phenanthroline(phen)] has been prepared and characterized by IR and UV–visible spectroscopy, microanalysis and conductivity techniques. Except with NiZn(C7H4NS2)4(py)2 which is insulator all of the compounds exhibit σrt in the 10 −12 –10 −5 S cm −1 range and semiconduct over 303–393 K.

Cationic [RuIII(app)(pic)(H2O)]+ (1) complex (Happ=N-(hydroxyphenyl)pyridine-2-carboxaldimine; Hpic=picolinic acid) has been synthesized and characterized by physico-chemical methods and employed as catalyst in the oxidation of both saturated and unsaturated hydrocarbons using tert-butylhydroperoxide (t-BuOOH). A mechanism involving formation of and transfer from a reactive high valent Ru(V)-oxo species as catalytic intermediate is proposed for the catalytic processes.

The reaction of [{WBr(CO)4}2(μ-Br)2]2 1 with 1,4,6-trimethylpyrimidine-2-thione (tmpymt) affords the air-sensitive complex [WBr2(CO)3(tmpymt)] 2. The X-ray structure of 2·C3H6O reveals that the geometry surrounding the tungsten(II) atom is best described as a distorted capped trigonal prism with a bromine atom Br(1) in the unique capping position. The other bromine atom Br(2), the (N,S)-chelate and one carbonyl C(41) occupy the capped quadrilateral face. The complex has been additionally characterized by IR and NMR spectroscopy. The optimized molecular structure (RHF/LanL2DZ) supports the experimental data.

The complexes Ir(III)(nbd22 −)(L-L)(acetylacetonate) with nbd22 − = bis-norbornadienyl dianion and L-L = norbornadiene and 2,2′-bipyridyl and Pd(II)[C4(COOMe)4](2,2′-bipyridyl) contain metallacycles and a diolefin or bipyridyl as additional ligand. These complexes are characterized by low-energy LLCT excited states. The CT donor site is associated with the metallacycle while the CT acceptor function is provided by a diolefin or bipy. The LLCT triplets are emissive in solution under ambient conditions.

For the first time, density functional theory (DFT) calculation was performed on the titled complexes and the calculated geometries are in good agreement with the available experimental data. The decrease in the bond distances (Ln–X) as well as the increase in the Hirshfeld charges and the chemical hardness from La to Lu indicates an increase in ionic character on going from La to Lu. The lanthanide contraction and ionic character of metal–ligand bond are found to follow the order: Ln–X > Ln–Cp > Ln–O.