•A new (3,4,5)-connected 2D MOF based on the tetranuclear Cu4 units has been obtained.•Magnetic studies reveal magnetic interactions associated with the hydroxo bridges arising from different Cu-OH-Cu angles.•No magnetic ordering is observed for 1.Based on an asymmetric imidazole-1-acetic acid (Hima), a new polynuclear complex [Cu2(ima−)(SO42 −)(H2O)(OH−)]n 1 has been synthesized and characterized structurally and magnetically. Polymer a two-dimensional (2D) structure based on the tetranuclear Cu4 units, which displays a (3,4,5)-connected topology. The magnetic susceptibility data is dominated by magnetic interactions associated with the hydroxo bridges arising from different Cu-OH-Cu angles, which is in agreement with magneto-structural correlations found in the literature relative to such bridges in Cu(II) complexes.Complex 1 shows (3,4,5)-connected 2D structure based on the tetranuclear Cu4 units. Magnetic studies reveal magnetic interactions associated with the hydroxo bridges arising from different Cu-OH-Cu angles.Download high-res image (206KB)Download full-size image

A new facile strategy has been reported for the synthesis of homovalent diruthenium(III,III) phosphates. On assembling the homovalent Ru2 units and Cu2+ in the presence of K+, new trimetallic phosphates, K2[{Cu(H2O)}2Ru2(PO4)4(H2O)2] (1), were formed. In compound 1, the Ru2 dimer showed a Ru–Ru double bond distance of 2.3400 Å with a high spin ground state S = 2, and neighboring [Ru2(PO4)4(H2O)2]6− units were linked via distorted tetragonal pyramid Cu(H2O)2+ ions, forming the negative layer [{Cu(H2O)}2Ru2(PO4)4(H2O)2]n2n−. Antiferromagnetic coupling was mediated between Ru26+ and Cu2+via O–P–O bridges. Detailed magnetism measurements demonstrated that compound 1 exhibited a two-step relaxation in oscillation susceptibilities, and an order below 14 K with a large coercive field of Hc = 24.9 kOe at 1.8 K. It is the highest Tc and Hc for the non-carboxylate diruthenium compounds reported to date.

We reported a facile and scalable salt-templated approach to produce monodisperse Rh nanoparticles (NPs) on ultrathin carbon nanosheets with the assistance of calcination under inert gas. More importantly, in spite of the essentially poor ORR activity of Rh/C, the acquired Rh/C hybrid nanosheets display a comparable ORR activity to the optimal commercial Pt/C catalyst, which may be due to the extra-small size of Rh NPs and the 2D defect-rich amorphous carbon nanosheets that can facilitate the charge transfer and reactive surface exposure. Moreover, Rh/C nanosheets present the optimal current density and best durability with the minimum decline during the entire test, so that ∼93% activity after 20 000 s is achieved, indicating a good lifetime for ORR. In contrast, commercial Pt/C and commercial Rh/C exhibited worse durability, so that ∼74% and ∼85% activities after 20 000 s are maintained. What's more, in the model system of reduction of 4-nitrophenol (4-NP), the kinetic constant k for Rh/C nanosheets is 3.1 × 10−3, which is 4.5 times than that of the commercial Rh/C catalyst, revealing that our Rh/C hybrid nanosheets can be potentially applied in industrial catalytic hydrogenation. This work opens a novel and facile way for the rest of the precious metal NPs to be supported on ultrathin carbon nanosheets for heterogeneous catalysis.

A series of heterometallic magnesium diruthenium(II,III) carbonates, namely K{Mg(H2O)6}2[Ru2(CO3)4Cl2]·4H2O (1), K2[{Mg(H2O)4}2Ru2(CO3)4(H2O)Cl]Cl2·2H2O (2), K[Mg(H2O)5Ru2(CO3)4]·5H2O (3) and K[Mg(H2O)4Ru2(CO3)4]·H2O (4), were synthesized from the reaction of Ru2(CO3)43− and Mg2+ in aqueous solution. Compound 1 is composed of ionic crystals with the Ru2(CO3)4Cl25−:Mg(H2O)62+:K+ ratio of 1:2:1. Compound 2 consists of two dimensional layer structures, in which each octahedral environment Mg(H2O)42+ bonds to two [Ru2(CO3)4(H2O)Cl]4− units in a cis manner forming a neutral square-grid layer {Mg(H2O)4Ru2(CO3)4(H2O)Cl}n. For compound 3, one water molecule of each Mg(H2O)62+ is substituted by an oxygen atom of Ru2(CO3)43− forming [Mg(H2O)5Ru2(CO3)4]−, and then the neighboring Ru2 dimers are linked together by the rest of the two oxygen atoms of carbonates to form a layer structure {Mg(H2O)5Ru2(CO3)4}nn−. In compound 4, the neighboring squared-grid layers {Ru2(CO3)4}n3n−, similar to those in compound 3, are linked by each octahedral environment Mg(H2O)42+ in a cis manner forming the three-dimensional network {Mg(H2O)4Ru2(CO3)4}nn−. Compound 3 shows ferromagnetic coupling between Ru2 dimers, and a long-range ordering is observed below 3.8 K. Compound 4 displays a magnetic ordering below 3.5 K, and a systematic study of the size-dependent magnetic properties of compound 4 reveals that the coercivity of 4 has been improved with reduced sample particle size from the micrometer to the nanometer scale.

A new diruthenium compound, Ru2(η2-DmAniF)2(μ-DmAniF)2(OAc)(O) (1), where DmAniF is N,N′-di(m-methoxyphenyl)formamidinate, was isolated as a secondary product from the reaction between Ru2(DmAniF)3(OAc)Cl and K2CO3, and its formulation was established using both single crystal X-ray diffraction and high resolution mass-spectrometry techniques. Compound 1 has an S = 3/2 ground state, and exhibits an unusually large zero-field splitting (D = 308 cm−1) as revealed by the measurement of temperature dependent magnetism.A new diruthenium compound Ru2(η2-DmAniF)2(μ-DmAniF)2(OAc)(O) was isolated and interesting structural and magnetic properties were revealed.

By introducing different surfactants into a reaction system, two previous mixed-phase Ni(II)–MOFs constructed from an undeveloped pyridyl-tetracarboxylate and Ni(II) salts were successfully isolated to obtain two pure products. Compound 1 exhibits a 3D H-bonded network with (3,8)-connected {4.52}2{42.56.614.72.84} topology, while 2 features a 3D 2-fold interpenetrating framework with a self-penetrating (3,4,4)-connected {62.103.12}{63}2{64.8.10}2 topological net.

•Solvents, temperature and reactants ratio play key roles in the self-assembling.•{Ru2(CO3)4}n3n− layers linked by Mn2+ in a trans manner form pillared layer structure.•Ferromagnetic coupling results in glassy behavior ordering below 4.5 K.The self-assembly of Ru2(CO3)43− and Mn2+ ions in aqueous solution yields a new heterometallic carbonate complex K4[Mn(H2O)4{Ru2(CO3)4}2]·4H2O (1). X-ray diffraction studies on molecular structure reveal that complex 1 is consisted of undulate square-grid layers {Ru2(CO3)4}n3n−, and half of Ru2 dimers between the neighboring layers are linked by Mn(H2O)42+ in a trans manner forming a pillared layer structure of {Mn(H2O)4[Ru2(CO3)4]2}n4n−. Magnetism measurement indicates that complex 1 shows a spin glass behavior ordering below 4.5 K.Half of Ru2 dimers between the neighboring layers {Ru2(CO3)4}n3n− are linked by Mn(H2O)42+ in a trans manner forming a pillared layer structure of {Mn(H2O)4[Ru2(CO3)4]2}n4n−. Magnetism measurement indicates that it shows a spin-glass behavior ordering below 4.5 K.

The self-assembly of Ru2(CO3)43− paddle-wheel precursors and Mn2+ ions in aqueous solution yields various carbonate complexes. With appropriate selection of the synthetic conditions, we are able to intentionally tune the composition and structure of Mn–Ru2-carbonate assemblies to form infinite chain structural complexes, e.g., K[{Mn(H2O)4}2Ru2(CO3)4Br2]·H2O (1) and H[{Mn(H2O)4}2Ru2(CO3)4Br2]·6H2O (2). Complexes 1 and 2 are obtained at different temperatures (25 °C for 1 and 5 °C for 2, respectively), and their crystal structures consist of brick-wall stacked chains, in which neighboring Ru2(CO3)4Br25− units are linked by two disubstituted octahedral Mn(H2O)42+ in a cis manner, resulting in two isomeric (twisted and zigzag) negative double-chain α- and β-{[Mn(H2O)4]2Ru2(CO3)4Br2}nn−. The magnetic properties of complexes 1 and 2 were highly characterized. The alternating current (AC) susceptibility analysis of complex 1 reveals a two-step magnetism transition at T1 = 5.0 K and T2 = 2.6 K, respectively. Complex 2 exhibits metamagnetism behavior, with a transition field HC = ∼1.2 kOe at 2.0 K.

•Ru2(hedp)23 − units are linked by SCN− forms zigzag chain {Ru2(hedp)2(SCN)}n4n−.•Antiferromagnetic exchanges are mediated between Ru2 dimers through SCN−.•The RuRu bond weakening ability is H2O < Br− < Cl− < μ-NCS− < μ-NC− < μ-SCN−.This paper reports the crystal structure and magnetism properties of a novel mixed-valent diruthenium(II,III) complex, [C(NH2)3]4[Ru2(hedp)2(SCN)]·4H2O (1), where hedp represents 1-hydroxyethylidenediphosphonate. It shows a zigzag chain structure in which the paddlewheel diruthenium(II,III) dimers of Ru2(hedp)23 − linked by SCN− bridges. The chains are stacked along the [011] direction with strong intra- and interchain hydrogen bonds. Magnetic studies show that significant antiferromagnetic exchanges are mediated between the [Ru2(hedp)2]3 − (S = 3/2) units through thiocyanate ion bridges. Structural analysis proves that the RuRu bond weakening ability is H2O < Br− < Cl− < μ-NCS− < μ-NC− < μ-SCN−.High stable lantern-type geometry unit Ru2(hedp)23 − linked by SCN− forms zigzag chain structure {Ru2(hedp)2(SCN)}n4n−. Antiferromagnetic exchanges are mediated between the Ru2 units through SCN bridges, and the RuRu bond weakening ability is H2O < Br− < Cl− < μ-NCS− < μ-NC− < μ-SCN−.

Noble metal nano/microstructures have attracted considerable attention because of their unique properties and their various applications. Controlling the shape of noble metal nano/microstructures is a promising strategy to tailor their physical and chemical properties for various applications in fields such as biological labeling and imaging, catalysis, and sensing. Among various specific structures, flower-like and hierarchical silver nano/microstructures have attracted increasing interest because exploration of these novel nano/microstructures with unusual optical properties can provide new perspectives into the rational design of novel materials. It is significantly more challenging to develop facile and effective solution approaches for systematic manipulation of the shape of Ag nano/microstructures. In this article, we revisited the ascorbic acid reduction method to prepare flower-like silver microcrystal with plate petals and hierarchical Ag microcrystal on a large scale and in high purity. Ascorbic acid plays two roles of a reducing agent and a crystal growth regulator. Therefore, the molar ratio of ascorbic acid and silver nitrate is critical to the formation of Ag microcrystal. The controlling of the two different Ag microstructures can be achieved by adjusting the molar ratio of the reactants in aqueous medium at room temperature. The as-prepared Ag microcrystals were characterized by transmission electron microscopy, scanning electron microscopy, and X-ray diffraction. The flower-like Ag microcrystal with plate petals and hierarchical Ag microcrystal with nanoscale sharp tips and gaps could exhibit high catalytic activity and strong surface-enhanced Raman spectroscopy (SERS) activity due to the high surface area and the local electromagnetic field intensity enhancement, respectively. The potential application of the as-prepared Ag microcrystals in catalysis and SERS was investigated, which revealed that these two kinds of Ag microcrystals exhibit high catalytic activities to the NaBH4-catalyzed reduction of 4-nitrophenol and significant SERS effect to 4-aminothiophenol molecular due to their nanoscale sharp tips and gaps. Therefore, the flower-like Ag microcrystal and hierarchical Ag microcrystal investigated here could be promising candidates for single particle catalyst and SERS.

Two novel Co(II)-cluster-based coordination polymers—namely, [Co5(μ3–OH)2(1,4-ndc)4(bix)2]n (1) and {[Co8(μ3–OH)4(1,4-ndc)6(btp)(H2O)6]·H2O}n (2)—were prepared by hydrothermal reactions of Co(II) perchlorate with 1,4-naphthalenedicarboxylic acid (1,4-H2ndc) and different N-donor coligands (bix = 1,4-bis(imidazol-1-ylmethyl)benzene and btp = 4,4′-bis(triazol-1-ylmethyl)biphenyl). In 1, 10-connected [Co5(μ3–OH)2(COO)8] clusters are extended by the μ4-1,4-ndc2– and trans-bix ligands to construct a rare, self-penetrating ile framework that can interestingly be regarded as the cross-link of two interpenetrating 6-connected pcu networks. While for 2, [Co8(μ3–OH)4(COO)12] clusters serve as the 8-connected nodes, which are bridged by the μ4/μ5-1,4-ndc2- and trans-btp ligands to afford the highest-connected uninodal self-penetrating (420.68) network based on octacobalt clusters. A synthetic and structural comparison of 1 and 2 demonstrates that the features of auxiliary N-donor ligands play a key role in governing the in situ formed clusters and the final 3-D coordination frameworks. Magnetic susceptibility measurements indicate that complex 1 shows an antiferromagnetic interaction between the adjacent Co(II) ions, whereas 2 displays the dominant antiferromagnetic exchanges in 300–50 K and a ferrimagnetic-like behavior at lower temperatures.

Isostructural heterometallic diruthenium carbonates KM(H2O)6[M(H2O)2Ru2(CO3)4Cl2]·4H2O [M = Zn (1) and Mn (2)] were synthesized from the reaction of the precursors [Ru2(CO3)4Cl2]5− and transitional metal ions in aqueous solution. Complexes 1 and 2 show layered structures in which Ru2(II,III) units are linked by four octahedral environment M(H2O)22+ ions in a cross fashion and vice versa giving a negative bimetallic square grid layer {M(H2O)2Ru2(CO3)4Cl2}n3n−. M(H2O)62+ ions, linked by K+ forming zigzag chain {KM(H2O)6}n3+, are located in the void spaces between the layers. The adjacent bimetallic carbonate layers are connected with K–O and K–Cl bonds, and hydrogen bonding, forming a supramolecular 3D framework structure. Their magnetic properties were characterized in detail, and intralayer ferromagnetic coupling between the Ru2 dimer and Mn2+ ion, as well as long-range ordering (Tc = 5.2 K) coexistence of domain movement behavior were observed for complex 2.

Two hetero-metallic carbonates, namely KCd(H2O)3Ru2(CO3)4·4H2O (1) and KCd(H2O)3Ru2(CO3)4·3.5H2O (2), have been synthesized in a neutral aqueous solution. Both of the 3D dimensional structured complexes contain mixed-valent diruthenium(II,III) carbonate paddlewheel cores of Ru2II,III(CO3)43− that are connected to each other in trans- or cis-modes by carbonate oxygen atoms, forming rectangular square-grid and isomeric parallelogram layers [Ru2(CO3)4]n3n− in 1 and 2, respectively. The reaction temperature is found to play an important role in directing the final products with particular topologies and their layered structural diversity is due to the various linking modes between the Ru2(CO3)43− units. The magnetic studies show that ferromagnetic interactions are propagated between the diruthenium units in both complexes 1 and 2 but their magnetic properties differ at low temperatures, in which the trans linking mode parallelogram layer [Ru2(CO3)4]n3n− in complex 2 leads to long-range magnetic ordering below 4.0 K. However, no Curie ordering down to 1.8 K is detected for complex 1 containing the isomeric rectangle square-grid layer linking in the cis mode.

Self-assembly of Ru2(CO3)43− units and Cu2+ ions in the presence of halogen (Cl− or Br−) has resulted in two novel isomeric layered structural heterometallic carbonates, K2Li[Cu(H2O)2Ru2(CO3)4X2]·5H2O [X = Cl (1), Br (2)]. X-ray structural analysis reveals that complexes 1 and 2 contain a similar square-grid negative layer [Cu(H2O)2Ru2(CO3)4X2]n5n−, in which each Ru2(CO3)4X25− unit is linked by four Jahn–Teller distorted Cu(H2O)22+ ions in a cross mode and vice versa. The adjacent negative layers are connected by K–O, Li–O bonds, and hydrogen bonding, which led to the formation of a supramolecular 3D network structure. The two complexes show ferromagnetic coupling between the Ru2 dimer and the Cu2+ ion. Detailed magnetism measurement demonstrates that complex 1 exhibits soft magnetic ordering below 2.9 K coexistent with domain movement, and complex 2 shows long-range ferromagnetic ordering below 3.8 K.

An investigation of the reaction conditions influence on the self-assembling of Ru2(CO3)43− paddle wheel precursors and Co2+ ions in aqueous solution has resulted in a series of Co–Ru2 hetero-metallic complexes with different composition and dimensionality, namely [K1/3{Co(H2O)6}4/3{Ru2(CO3)4(H2O)2}]·2H2O (1), [KCo(H2O)5Ru2(CO3)4]·5H2O (2), and [KCo(H2O)4Ru2(CO3)4]·H2O (3). These complexes exhibit dimensional diversity due to the various linking modes of Co2+ ions. X-Ray structural analysis reveals that complex 1 is composed of ionic crystals with the Ru2(CO3)43−:Co(H2O)62+:K+ ratio of 3:4:1. For complex 2, one water of each Co(H2O)62+ is substituted by one oxygen of Ru2(CO3)43− forming [Co(H2O)5Ru2(CO3)4]−, then the neighboring Ru2(CO3)43− units are connected to each other through the remaining two carbonate oxygen atoms forming a negative square-grid layer [Co(H2O)5Ru2(CO3)4]nn−. In complex 3, two water molecules of each Co(H2O)62+ are substituted by the oxygen atoms of Ru2(CO3)43− units, which are connected to each other forming the square-grid layer [Ru2(CO3)4]n3n− similar to that in 2, then Co(H2O)42+ ions bond to neighboring [Ru2(CO3)4]n3n− layers in a cis mode forming the three-dimensional network [Co(H2O)4Ru2(CO3)4]nn−. Complex 2 exhibits ferromagnetic coupling between Ru25+ and Co2+, and long-range ordering is observed below 5.0 K. In contrast, complex 3 with a 3-D sublattice displays spin-glass behavior with the coexistence of spin-canting with magnetic ordering at 4.7 K.

An investigation of halogen (Cl− and Br−) influence on the self-assembling Ru2(CO3)43− paddle-wheel precursors and Co2+ ions in aqueous solution has resulted in two novel layer structural bimetallic carbonate complexes, [{Co(H2O)4}2Ru2(CO3)4(H2O)Cl]n·7.5nH2O (1), and [{Co(H2O)4}2Ru2(CO3)4(H2O)2]n·[{Co(H2O)4}2Ru2(CO3)4Br2]n·10.5nH2O (2). X-ray structural analysis reveals that complexes 1 and 2 contain similar square-grid layer structures, in which each Co(H2O)42+ bonds to two Ru2(CO3)43− units in a trans manner forming square-grid layer [{Co(H2O)4}2Ru2(CO3)4]nn+, and X− (Cl− and Br−) ions influence the packing diagram between neighboring layers. For complex 1, two axial positions of each Ru2(CO3)43− paddlewheel are terminated by H2O and Cl−, respectively, forming a neutral layer [{Co(H2O)4}2Ru2(CO3)4(H2O)Cl]n. Meanwhile in complex 2, the axial positions of each Ru2(CO3)43− in the layer [{Co(H2O)4}2Ru2(CO3)4]nn+ are terminated by two H2O or two Br−, forming two oppositely charge layers packing alternatively, namely, the positive layer [{Co(H2O)4}2Ru2(CO3)4(H2O)2]nn+ and negative layer [{Co(H2O)4}2Ru2(CO3)4Br2]nn−. These two complexes are metamagnets, showing magnetic ordering Tc = 5.1 K, TN = 2.6 K for 1, and Tc = 2.7 K, TN = 2.3 K for 2, and the metamagnetism transition fields are ~1.2 kOe and ~0.5 kOe K for 1 and 2, respectively.

[{MnIII(OH)(H2O)}3SiW9O34]4 −1a, has been isolated from the reaction of Na9[β-SiW9O34H]·23H2O and [Mn3O(O2CMe)6(HIm)3](O2CMe) (Im = imidazole C3H4N2) in aqueous solution. The trimetal-substituted polyoxometalate (TMSP) 1 has been fully characterized by single-crystal X-ray diffraction, elemental analysis, thermogravimetric analysis, and infrared spectroscopy. This monomeric anion is composed of one trilacunary Keggin fragment A-α-SiW9O34 and three manganese ions encapsulated resulting in a triangular {Mn(OH)}36 + ring core. Experimental structural and magnetism aspects of the material are reported and discussed.A new complex displays trilacunary Keggin ligand [A-α-SiW9O34]10 − encapsulating triangular {Mn(OH)}36 + fragment, in which hydroxo bridges connect the high-spin Jahn–Teller (JT) distorted MnIII centers with antiferromagnetic coupling predominates throughout the cluster.Highlights► {Mn(OH)}36+ encapsulated in trivacant Keggin anion SiW9O3410− was obtained ► Magnetism measurement convinced spin frustration in the Mn3 core ► Mn ions in complex 1 show evident Jahn–Teller (JT) distortion

A series of novel one-dimensional (1-D) lanthanide coordination polymers (CPs), with the general formula {[Ln(bptcH)(H2O)2]·H2O}n (Ln = NdIII (1), EuIII (2), GdIII (3), TbIII (4), DyIII (5), HoIII (6), or ErIII (7)) have been synthesized by the solvothermal reactions of the corresponding lanthanide(III) picrates and 2,2′-bipyridine-3,3′,6,6′-tetracarboxylic acid (bptcH4). These polymers have been structurally characterized by single-crystal X-ray diffraction, IR, PXRD, thermogravimetric (TGA), and elemental analysis. Coordination polymers 1–7 are isostructural; they possess the same 3D supramolecular architectures and crystallize in triclinic space group P1̅. The frameworks constructed from dinuclear lanthanide building blocks exhibit one-dimensional double-stranded looplike chain architectures, in which the bptcH3– ions adopted hexadentate coordination modes. The EuIII (2) and TbIII (4) polymers exhibit characteristic photoluminescence in the visible region. The magnetic properties of polymers 2, 3, and 5 have been investigated through the measurement of their magnetic susceptibilities over the temperature range of 1.8–300 K.

A three-dimensional CO32−-bridged Mn(II)–Ru2(II,III) complex, Mn4(H2O)16H[Ru2(CO3)4]2[Ru2(CO3)4(H2O)2]·11H2O (1), was synthesized by self-assembling Ru2(CO3)43− paddle-wheel precursors and Mn2+ cations. It contains an unprecedented layer [Ru2(CO3)4]n3n− with (4,4) network. The ferromagnetic coupling between spin centers results in ordering below 3.0 K.

By auxiliary N-donor ligand-directed assembled, two entangled CoII-coordination nets have been constructed from 3,3′,5,5′-azobenzenetetracarboxylic acid (H4abtc), which present a rare 2D→3D polythreading motif constructed from 2-fold (6,3) polymeric layers with thickness being 10.2 Å and a 3-fold interpenetrating pillar-layered framework based on linear trinuclear CoII-SBUs. In addition, two CoII-complexes both show an antiferromagnetic coupling by long organic spacers and H2O bridges, respectively.

Three new ionic crystals based on Keggin anion and mixed-valent diruthenium tetracetate, [Ru2(CH3CO2)4(H2O)2]2[HnXW12O40]·[Ru2(CH3CO2)4(H2O)Cl]·12H2O {X = B, n = 3 (1); X = Si, n = 2 (2); X = Ge, n = 2 (3)}, have been prepared in acidic aqueous solution at about pH 3.0 by reaction of K4BW12O40·mH2O, K8SiW11O39·mH2O and K8GeW11O39·mH2O with diruthenium tetracetate Ru2(CH3COO)4Cl, respectively, and their structures were determined by X-Ray diffraction analysis. They are isostructural structure with the ratio of heteropolytungstate anion, Ru2(CH3CO2)4+ cation and neutral molecular Ru2(CH3CO2)4Cl of 1:2:1. The cyclic voltammetry in 0.5 M KNO3 aqueous solution at pH 3.0 show the respective electrochemical behaviors of the W-centers and Ru2-centers for these three complexes. Magnetic data analysis shows that diruthenium units display the ground state electronic configuration π*2δ* with large positive D value..Highlights► New ionic crystals incorporation of Keggin anion and mix-valent diruthenium tetracetates. ► Cyclic voltammetry redox couples of the W-centers and Ru2-centers could be separated clearly. ► Diruthenium units in ionic crystals show mix-valent Ru2(II,III) ground state S = 3/2.

Six transition metal coordination polymers, [Cu3(nbta)2(bipy)2(H2O)2]·2H2O (1), [Cu3(nbta)2(bpp)2(H2O)2]·2H2O (2), [Co3(nbta)2(bipy)3(H2O)2]·2H2O (3), [Co3(nbta)2(bpp)2(H2O)2] (4), [Ni2(Hnbta)2(bipy)2(H2O)2] (5) and [Ni3(nbta)2(bpa)3(H2O)2]·2H2O (6) (H3nbta = 5-nitro-1,2,3-benzenetricarboxylic acid, bipy = 4,4′-bipyridine, bpa = 1,2-bis(4-pyridyl)ethane, bpp = 1,3-bis(4-pyridyl)propane), have been hydrothermally synthesized by the reactions of CuII, CoII and NiII salts with H3nbta in the presence of dipyridyl-type co-ligands, respectively. Their structures were determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, and TG analyses. Compounds 1–4 and 6 exhibit 3D pillared-layer structures while compound 5 has a 2D layer. The nbta3− ligands in the 2D carboxylate layer motifs of 1–4 and 6 connect transition metal ions in different coordination modes, and the dipyridyl-type co-ligands in compounds 1–4 and 6 serve as the pillar between the 2D layers, creating 3D open frameworks. From a topologic point of view, complex 1, 2 and 4 present 4-connected 3D coordination frameworks with the topologies of (42·62·82) (62·72·82) (42·62·7·8), (64·82) (42·64) (42·64) and (4·64·8)(44·62)(43·63) respectively. Complex 3 shows a (4,5)-connected 3D network with (42·67·8)(64·82)(42·64) topology. Whereas the structure of 5 is a 2D (4,4) net due to the partially deprotonated H3nbta ligand existed. Complex 6 features a 3D (4,5)-connected framework with (4·68·8) (65·8) (4·65) topology, also exhibiting the intriguing helical motif. The variable-temperature magnetic susceptibility studies reveal antiferromagnetic interactions between CuII or CoII ions in 1, 2, 3, 4 and ferromagnetic interactions between NiII ions for 5 and 6, respectively.

The coordination polymer {[Cu3(hbpdc)(OH)2(H2O)]·2H2O}n (1, hbpdc = 3,3′-dihydroxy-2,2′-bipyridine-6,6′-dicarboxylic anion) was prepared under hydrothermal conditions. Single-crystal X-ray diffraction revealed that complex 1 features a highly ordered 3D nanoporous structure encapsulating a zigzag water chain. Variable-temperature magnetic studies indicated the presence of strong antiferromagnetic coupling.

By introducing different surfactants into a reaction system, two previous mixed-phase Ni(II)–MOFs constructed from an undeveloped pyridyl-tetracarboxylate and Ni(II) salts were successfully isolated to obtain two pure products. Compound 1 exhibits a 3D H-bonded network with (3,8)-connected {4.52}2{42.56.614.72.84} topology, while 2 features a 3D 2-fold interpenetrating framework with a self-penetrating (3,4,4)-connected {62.103.12}{63}2{64.8.10}2 topological net.

Two hetero-metallic carbonates, namely KCd(H2O)3Ru2(CO3)4·4H2O (1) and KCd(H2O)3Ru2(CO3)4·3.5H2O (2), have been synthesized in a neutral aqueous solution. Both of the 3D dimensional structured complexes contain mixed-valent diruthenium(II,III) carbonate paddlewheel cores of Ru2II,III(CO3)43− that are connected to each other in trans- or cis-modes by carbonate oxygen atoms, forming rectangular square-grid and isomeric parallelogram layers [Ru2(CO3)4]n3n− in 1 and 2, respectively. The reaction temperature is found to play an important role in directing the final products with particular topologies and their layered structural diversity is due to the various linking modes between the Ru2(CO3)43− units. The magnetic studies show that ferromagnetic interactions are propagated between the diruthenium units in both complexes 1 and 2 but their magnetic properties differ at low temperatures, in which the trans linking mode parallelogram layer [Ru2(CO3)4]n3n− in complex 2 leads to long-range magnetic ordering below 4.0 K. However, no Curie ordering down to 1.8 K is detected for complex 1 containing the isomeric rectangle square-grid layer linking in the cis mode.

Six transition metal coordination polymers, [Cu3(nbta)2(bipy)2(H2O)2]·2H2O (1), [Cu3(nbta)2(bpp)2(H2O)2]·2H2O (2), [Co3(nbta)2(bipy)3(H2O)2]·2H2O (3), [Co3(nbta)2(bpp)2(H2O)2] (4), [Ni2(Hnbta)2(bipy)2(H2O)2] (5) and [Ni3(nbta)2(bpa)3(H2O)2]·2H2O (6) (H3nbta = 5-nitro-1,2,3-benzenetricarboxylic acid, bipy = 4,4′-bipyridine, bpa = 1,2-bis(4-pyridyl)ethane, bpp = 1,3-bis(4-pyridyl)propane), have been hydrothermally synthesized by the reactions of CuII, CoII and NiII salts with H3nbta in the presence of dipyridyl-type co-ligands, respectively. Their structures were determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, and TG analyses. Compounds 1–4 and 6 exhibit 3D pillared-layer structures while compound 5 has a 2D layer. The nbta3− ligands in the 2D carboxylate layer motifs of 1–4 and 6 connect transition metal ions in different coordination modes, and the dipyridyl-type co-ligands in compounds 1–4 and 6 serve as the pillar between the 2D layers, creating 3D open frameworks. From a topologic point of view, complex 1, 2 and 4 present 4-connected 3D coordination frameworks with the topologies of (42·62·82) (62·72·82) (42·62·7·8), (64·82) (42·64) (42·64) and (4·64·8)(44·62)(43·63) respectively. Complex 3 shows a (4,5)-connected 3D network with (42·67·8)(64·82)(42·64) topology. Whereas the structure of 5 is a 2D (4,4) net due to the partially deprotonated H3nbta ligand existed. Complex 6 features a 3D (4,5)-connected framework with (4·68·8) (65·8) (4·65) topology, also exhibiting the intriguing helical motif. The variable-temperature magnetic susceptibility studies reveal antiferromagnetic interactions between CuII or CoII ions in 1, 2, 3, 4 and ferromagnetic interactions between NiII ions for 5 and 6, respectively.

By auxiliary N-donor ligand-directed assembled, two entangled CoII-coordination nets have been constructed from 3,3′,5,5′-azobenzenetetracarboxylic acid (H4abtc), which present a rare 2D→3D polythreading motif constructed from 2-fold (6,3) polymeric layers with thickness being 10.2 Å and a 3-fold interpenetrating pillar-layered framework based on linear trinuclear CoII-SBUs. In addition, two CoII-complexes both show an antiferromagnetic coupling by long organic spacers and H2O bridges, respectively.

Isostructural heterometallic diruthenium carbonates KM(H2O)6[M(H2O)2Ru2(CO3)4Cl2]·4H2O [M = Zn (1) and Mn (2)] were synthesized from the reaction of the precursors [Ru2(CO3)4Cl2]5− and transitional metal ions in aqueous solution. Complexes 1 and 2 show layered structures in which Ru2(II,III) units are linked by four octahedral environment M(H2O)22+ ions in a cross fashion and vice versa giving a negative bimetallic square grid layer {M(H2O)2Ru2(CO3)4Cl2}n3n−. M(H2O)62+ ions, linked by K+ forming zigzag chain {KM(H2O)6}n3+, are located in the void spaces between the layers. The adjacent bimetallic carbonate layers are connected with K–O and K–Cl bonds, and hydrogen bonding, forming a supramolecular 3D framework structure. Their magnetic properties were characterized in detail, and intralayer ferromagnetic coupling between the Ru2 dimer and Mn2+ ion, as well as long-range ordering (Tc = 5.2 K) coexistence of domain movement behavior were observed for complex 2.

A three-dimensional CO32−-bridged Mn(II)–Ru2(II,III) complex, Mn4(H2O)16H[Ru2(CO3)4]2[Ru2(CO3)4(H2O)2]·11H2O (1), was synthesized by self-assembling Ru2(CO3)43− paddle-wheel precursors and Mn2+ cations. It contains an unprecedented layer [Ru2(CO3)4]n3n− with (4,4) network. The ferromagnetic coupling between spin centers results in ordering below 3.0 K.

The self-assembly of Ru2(CO3)43− paddle-wheel precursors and Mn2+ ions in aqueous solution yields various carbonate complexes. With appropriate selection of the synthetic conditions, we are able to intentionally tune the composition and structure of Mn–Ru2-carbonate assemblies to form infinite chain structural complexes, e.g., K[{Mn(H2O)4}2Ru2(CO3)4Br2]·H2O (1) and H[{Mn(H2O)4}2Ru2(CO3)4Br2]·6H2O (2). Complexes 1 and 2 are obtained at different temperatures (25 °C for 1 and 5 °C for 2, respectively), and their crystal structures consist of brick-wall stacked chains, in which neighboring Ru2(CO3)4Br25− units are linked by two disubstituted octahedral Mn(H2O)42+ in a cis manner, resulting in two isomeric (twisted and zigzag) negative double-chain α- and β-{[Mn(H2O)4]2Ru2(CO3)4Br2}nn−. The magnetic properties of complexes 1 and 2 were highly characterized. The alternating current (AC) susceptibility analysis of complex 1 reveals a two-step magnetism transition at T1 = 5.0 K and T2 = 2.6 K, respectively. Complex 2 exhibits metamagnetism behavior, with a transition field HC = ∼1.2 kOe at 2.0 K.

A series of heterometallic magnesium diruthenium(II,III) carbonates, namely K{Mg(H2O)6}2[Ru2(CO3)4Cl2]·4H2O (1), K2[{Mg(H2O)4}2Ru2(CO3)4(H2O)Cl]Cl2·2H2O (2), K[Mg(H2O)5Ru2(CO3)4]·5H2O (3) and K[Mg(H2O)4Ru2(CO3)4]·H2O (4), were synthesized from the reaction of Ru2(CO3)43− and Mg2+ in aqueous solution. Compound 1 is composed of ionic crystals with the Ru2(CO3)4Cl25−:Mg(H2O)62+:K+ ratio of 1:2:1. Compound 2 consists of two dimensional layer structures, in which each octahedral environment Mg(H2O)42+ bonds to two [Ru2(CO3)4(H2O)Cl]4− units in a cis manner forming a neutral square-grid layer {Mg(H2O)4Ru2(CO3)4(H2O)Cl}n. For compound 3, one water molecule of each Mg(H2O)62+ is substituted by an oxygen atom of Ru2(CO3)43− forming [Mg(H2O)5Ru2(CO3)4]−, and then the neighboring Ru2 dimers are linked together by the rest of the two oxygen atoms of carbonates to form a layer structure {Mg(H2O)5Ru2(CO3)4}nn−. In compound 4, the neighboring squared-grid layers {Ru2(CO3)4}n3n−, similar to those in compound 3, are linked by each octahedral environment Mg(H2O)42+ in a cis manner forming the three-dimensional network {Mg(H2O)4Ru2(CO3)4}nn−. Compound 3 shows ferromagnetic coupling between Ru2 dimers, and a long-range ordering is observed below 3.8 K. Compound 4 displays a magnetic ordering below 3.5 K, and a systematic study of the size-dependent magnetic properties of compound 4 reveals that the coercivity of 4 has been improved with reduced sample particle size from the micrometer to the nanometer scale.

A new facile strategy has been reported for the synthesis of homovalent diruthenium(III,III) phosphates. On assembling the homovalent Ru2 units and Cu2+ in the presence of K+, new trimetallic phosphates, K2[{Cu(H2O)}2Ru2(PO4)4(H2O)2] (1), were formed. In compound 1, the Ru2 dimer showed a Ru–Ru double bond distance of 2.3400 Å with a high spin ground state S = 2, and neighboring [Ru2(PO4)4(H2O)2]6− units were linked via distorted tetragonal pyramid Cu(H2O)2+ ions, forming the negative layer [{Cu(H2O)}2Ru2(PO4)4(H2O)2]n2n−. Antiferromagnetic coupling was mediated between Ru26+ and Cu2+via O–P–O bridges. Detailed magnetism measurements demonstrated that compound 1 exhibited a two-step relaxation in oscillation susceptibilities, and an order below 14 K with a large coercive field of Hc = 24.9 kOe at 1.8 K. It is the highest Tc and Hc for the non-carboxylate diruthenium compounds reported to date.