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A new organic fluorescent ionic compound [MOBIP]I (1) (MOBIP+ = 1-methyl-2-oxo-3 -(1H-benzimidazol-2(3H)-ylidene)-2,3-dihydropyridinium) was synthesized and used to prepare seven maleonitriledithiolate metal complexes [MOBIP] n [M(mnt)2] by substitution of the iodide ion with [M(mnt)2] n − (M = Cu2+ (2), Ni2+ (3a), Ni3+ (3b), Zn2+ (4), Cd2+ (5), Pd2+ (6), and Pt2+ (7)). An investigation of fluorescence properties shows that these complexes are a new series of solution luminescent complexes of maleonitriledithiolate derivatives with strong blue light fluorescence in daylight by irradiation with UV light with high quantum yields. They display similar symmetric emissions with λem at the deep blue region of ∼426 nm upon excitation at ∼364 nm in DMF, caused by L–L transition of MOBIP+. Existence of [M(mnt)2] n − anions in the solution prolongs the fluorescent lifetimes. For all these compounds in the solid state, the fluorescent emission is blue-shifted and more narrow than that in solution. Based on their crystal structure analysis, the weak stacking interactions in compounds cause the difference of their fluorescence spectrum. Investigations of variable-temperature magnetic susceptibility indicate that 2 has weak antiferromagnetic coupling, while 3b exhibits stronger antiferromagnetic coupling. [ABSTRACT FROM AUTHOR]

[Ni(hmp)(MeOH)Br]4 ⋅ 2H2O has been prepared by the reaction of 2-hydroxymethylpyridine with NiBr2 ⋅ 3H2O and characterized by IR, elemental analysis, powder X-ray diffraction, thermogravimetric analyses, magnetic measurements, and single crystal X-ray diffraction. The crystal structure shows two independent [Ni(hmp)(MeOH)Br]4 molecules in the asymmetric unit and [Ni4O4]4+ cubane-type cores. Each octahedral Ni(II) is bridged by four μ3-CH2O- fragments from four hmp- ligands. Magnetic studies show that ferromagnetic coupling gives an S = 4 ground state with significant magnetoanisotropy, and the parameters are J1 = 8.56, J2 = 2.28, D = -0.65 cm-1, and g ≈ 2.13. [ABSTRACT FROM AUTHOR]

A new ion-pair complex, [BzTPP]2[Ni(i-mnt)2](1) (i-mnt2- = iso-maleonitriledithiolate, [BzTPP]+ = benzyltriphenylphosphinium) was synthesized and characterized by elemental analysis, IR, UV, EI-MS spectra and single crystal X-ray diffraction. The single-crystal structural analysis shows that 1 crystallizes in the triclinic space group P-1, with a = 9.466(1) Å, b = 10.196(1)Å, c = 29.252(3)Å, α = 99.28(1)ˆ, β = 93.96(1)ˆ, γ = 106.34(1)ˆ, V = 2654.3(4)Å3, Z = 2. The Ni(II) ions of the [Ni(i-mnt)2]2 - anion adopted a square-planar coordination geometry. Four weak C─H...N hydrogen bonds between the anions and the cations observed in the crystal give further rise to a 3D structure. [ABSTRACT FROM AUTHOR]

The synthesis, molecular structure and spectroscopic and magnetic properties of (NH4)2(15-crown-5)3[Ni(mnt)2]2 (mnt  =  maleonitriledithiolate dianion) are reported. The most notable structural feature of (NH4)2(15-crown-5)3[Ni(mnt)2]2 is that the ions form a stacked structure with well-separated columns along the c and a axes. Variable temperature magnetic susceptibility measurements indicate strong antiferromagnetic interactions in the complex. [ABSTRACT FROM AUTHOR]

A new polymer complex of copper(II)-glycylglycine {[Cu(glygly)(H 2 O)][Cu(glygly)(H 2 O) 2 ]} n ·5 n H 2 O ( 1 ) is reported. It crystallizes in the P 2 1 / c space group, with a = 14.669(2), b = 9.8480(10), c = 14.053(2) Å, β = 102.730(10)° and Z = 4. Compound 1 consists of [Cu(glygly)(H 2 O)] n 1D carboxylate-bridged polymeric chains, monomer Cu(glygly)(H 2 O) 2 molecules which form hydrogen-bonded chains and uncoordinated water molecules. In all cases, the geometry around copper(II) is a slightly distorted square pyramid with the water oxygen at the apex of the pyramid. The ESR, UV-Vis and IR spectroscopy of the compound were also studied. [ABSTRACT FROM AUTHOR]

Abstract: A novel molecular solid, [OFBzIQl][Ni(mnt)2] (1), where [OFBzIQl]+ =1-(2′-fluorobenzyl)isoquinolinium and mnt2− =maleonitriledithiolate, forms 1D column of alternating between cations and anions via π⋯π stacking interaction between Ni(mnt)2 plane and isoquinoline ring, and the Ni(mnt)2 anions between the adjacent columns exist short C⋯N interaction. The extensive hydrogen bonds between anions and cations in the crystal generate a 2D network structure. Magnetic susceptibility measurement for 1 in the temperature range 2.0–300K shows that 1 exhibits a magnetic constant transition from ferromagnetic to antiferromagnetic around 35K as the temperature is lowered. [Copyright &y& Elsevier]

Abstract: A new 3d–4f heterometallic coordination polymer [Gd(H2O)3(NO3 −)(CuL)2] H2O (1) (H3L=glycylglycine, N-[1-(2-hydroxy, phenyl)-propylidene]) has been synthesized and characterized by IR, elemental analysis, TGA and X-ray single-crystal diffraction. In the coordination polymer, two metallo-ligand CuLs are connected with Gd3+ ion to form a 1-D chain via carboxylate and carbonyl oxygen. The neighboring Cu–Gd–Cu chains are further connected by hydrogen bonds to form a two-dimensional structure. Magnetic studies for 1 reveal that ferromagnetic interactions (J CuGd =1.30cm−1) between Cu(II) and Gd(III) centers are operating within the CuII–GdIII–CuII systems. [Copyright &y& Elsevier]

Abstract: One new compound, [Ag(p-bix)]3[Ag(Hbtc)2]·2H2O (H3btc=1,2,4-benzenetricarboxylate, p-bix=1,4-bis(imidazol-1-ylmethyl)-benzene), has been synthesized under hydrothermal conditions and characterized by elemental analysis, IR, PXRD, luminescent analysis, and single-crystal X-ray diffraction. X-ray structural analysis revealed that 0-D unit [Ag(Hbtc)2]3− and two kinds of 1-D linear chain [Ag(p-bix)] ∞ +, can be found within the crystal structure. The combination of 0-D [Ag(Hbtc)2]3− unit and 1-D undulated chain [Ag1(p 1-bix)] ∞ + through weak Ag–O bond gave rise to 2-D anionic supramolecular doublelayer. Then the grids of the 2-D layer are threaded by 1-D linear cationic chain [Ag2(p 2-bix)] ∞ + to generate entangled 3-D architecture with unusual poly(pseudo-rotaxane)-type arrangements. Luminescent properties of the title complex were also studied in this paper. [Copyright &y& Elsevier]

Abstract: Two complexes of [Ni(dmit)2]− (dmit2− =2-thioxo-1,3-dithiole-4,5-dithiolate) with nonmagnetic Schiff base cations, 1-(4-bromobenzylideneamino)pyridinium (4-BrBz-1-APy+; 1) and 1-(3-nitrobenzylideneamino)pyridinium (3-NO2Bz-1-APy+; 2), have been characterized structurally. Their striking structural feature is the deviation of the [Ni(dmit)2]− anion from the square-planar environment around the Ni atom with 11.42° and 6.57° dihedral angles (between the mean molecular planes of two dmit2− ligands) in 1 and 2, respectively. These twists arise from the molecular packing interactions between the superimposed anion and cation. In 1, the magnetic [Ni(dmit)2]− anions are arranged into a wave-shaped regular spin chain, whose magnetism was well fitted by one-dimensional (1D) Heisenberg uniform linear antiferromagnetic chain with |J/k B|=66K. In 2, 1D ladder-shape [Ni(dmit)2]− chains are formed through lateral-to-lateral SS contacts between the adjacent anions, which are further aligned into a two-dimensional (2D) anion layer via van der Waals forces. Complex 2 shows Curie–Weiss-type paramagnetic behavior with Curie constant C =0.421emuKmol−1 and Weiss constant θ =−1.279K. The broken-symmetry DFT approach was utilized to evaluate the magnetic coupling nature for 1 and 2, the theoretical analyses performed at ubpw91/lanl2dz level and concerned the so-called “weak bonding” regime approaches qualitatively explained the magnetic behaviors of 1 and 2. [ABSTRACT FROM AUTHOR]

Abstract: Three complexes of [Ni(mnt)2]− (mnt2− =maleonitriledithiolate) with benzylpyridinium derivatives, 1-(2′,6′-dichlorobenzyl)-4-aminopyridinium (abbr. Cl2BzNH2Py+) and 1-(2′,6′-dichlorobenzyl)quinolinium (abbr. Cl2BzQl + ), have been characterized structurally and magnetically. The [Cl2BzNH2Py][Ni(mnt)2] solution in MeCN was slowly evaporated to give the crystals of 2, whilst its solution in i-PrOH/MeCN yields 2·0.5i-PrOH. The [Ni(mnt)2]− anions are arranged in the mixed stacks of anions and cations in 2, and the segregated stacks of anions and cations in 2·0.5i-PrOH and 4. Even though three complexes exhibit different stacking pattern of magnetic anions, their temperature dependences of magnetic susceptibilities in 2–300K range show a common feature, namely, two broad maxima of magnetic susceptibility. Powder X-ray examination for three complexes excluded that the impurity causes such complicated magnetic behaviors. Combined with the single crystal structure analyses, the double broad maxima of magnetic susceptibility is probably attributed to anisotropic magnetic exchange interactions between magnetic anions. [Copyright &y& Elsevier]

Abstract: Two new molecular solids, [1-NaMePid][Ni(mnt)2] (1) and [2-NaMePid][Ni(mnt)2] (2) (mnt2− =maleonitriledithiolate, [1-NaMePid]+ =1-(1′-naphthylmethyl)piperidinium and [2-NaMePid]+ =1-(2′-naphthylmethyl)piperidinium) have been characterized structurally and magnetically. Both [Ni(mnt)2]− anions and the cations of 1 and 2 form segregated column stacks, and the Ni(III) ions form a 1D zigzig alternating magnetic chain within a [Ni(mnt)2]− column through Ni···S, S···S, Ni···Ni, or π···π interactions. Some conformational features in two isomeric cations and the geometry of the individual [Ni(mnt)2]− anion for 1 and 2 remain similar, while the changes of the space filling properties, the packing requirements and the existence of the water molecule in 2 result in the difference of the stacking mode of the [Ni(mnt)2]− anions. Magnetic susceptibility measurements in the temperature range 2–300K show that 1 is diamagnetism, while 2 exhibits a novel and interesting spin–gap transition around 16.8K with antiferromagnetic interaction (J =−4.6cm−1) in the high-temperature phase (HT) and the spin–gap (Δ/k b =68.5K) in the low-temperature phase (LT). [Copyright &y& Elsevier]

Abstract: Employing the tetrapodal compound 1,2,3,4-tetra(4-pyridyl)thiophene (TPT) as a bridging ligand, a new metal–organic framework was obtained and characterized by single crystal X-ray diffraction, [Cd(TPT)(N3)2·(H2O)] (1). This polymer exhibits a 2D layer network and an unprecedented 3,4-connected topology, which is constructed from the three-connector TPT and EE azido bridges. It also displays good thermal stability and strong photoluminescence in the blue regionband thus may serve as a candidate of thermally stable blue-light-emitting electroluminescence material. The nature of electronic transitions in the photoluminescent process has also been investigated by means of time-dependent density functional theory (TDDFT) calculations and molecular orbital analyses, which shows that the luminescent property is ligand-based. [Copyright &y& Elsevier]

Abstract: Syntheses, structural characterizations, magnetic behaviors and theoretical analyses of two new ion-pair complexes, [IFBzIQl][Ni(mnt)2](1) and [IClBzIQl]2[Ni(mnt)2]2 ·MeCN(2) [IFBzIQl][Ni(mnt)2] ([IFBzIQl]+ =1-(2′-fluoro-4′-iodobenzyl)isoquinolinium, [IClBzIQl]+ =1-(2′-chloro-4′-iodobenzyl)isoquinolinium, mnt2− =maleonitriledithiolate), have been investigated. In crystal of 1, the [Ni(mnt)2]− anions and the [IFBzIQl]+ cations stack into an alternating column through π⋯π stacking interactions. The anions of both 1 and 2 form a dimer via π⋯π stacking and S⋯S short interactions between the [Ni(mnt)2]− anions. The overlapping mode of two neighboring [Ni(mnt)2]− anions in the dimer is the Ni-ring fashion with a Ni⋯Ni distance of 4.076Å for 1, and ring–ring fashion with the Ni⋯Ni and S⋯S distances being 4.395 and 3.593Å for 2. Some weak interactions such as π⋯π, C⋯N, C–H⋯F or C–H⋯N in 1 and 2 play a crucial role in stacking and stabilizing the crystal lattice, and give a 3D network structure and exchange pathways of the magnetic interaction for 1 and 2. Magnetic susceptibility measurements for 1 and 2 in the temperature range 1.8–300K show that the overall magnetic behavior indicates the presence of antiferromagnetic interaction, while 2 exhibits an activated magnetic behavior in the high-temperature region (HT) together with a Curie tail in the low-temperature region (LT). [Copyright &y& Elsevier]

Abstract: Two new molecular magnets, based on [Ni(mnt)2]− monoanion, [DiBrBzPy][Ni(mnt)2] (1) and [DiBrBzIQl][Ni(mnt)2] (2) ([DiBrBzPy]+ =1-(3′,5′-dibromobenzyl)pyridinium, [DiBrBzIQl]+ =1-(3′,5′-dibromobenzyl)isoquinolinium and mnt2− =maleonitriledithiolate), were prepared and characterized by elemental analyses, IR, ESI-MS spectra, single crystal X-ray diffraction and magnetic measurements. The [Ni(mnt)2] anions and the cations of 1 and 2 are alternately stacked and form 1D column via π⋯π stacking interactions between the [Ni(mnt)2] anions and the neighboring cations. Some weak Ni⋯N, C⋯N interactions and CBr, CN hydrogen bonds between the adjacent columns further generate a 3D network structure. Magnetic susceptibility measurements show that both 1 and 2 exhibit the typical magnetic behavior of a spin gap system with an energy gap of 1151.9K for 1 and 73.9K for 2. [Copyright &y& Elsevier]

Abstract: Three new ion-pair complexes, consisting of 1-benzyl-4-aminopyridinium with [M(mnt)2]2− where mnt2− =maleonitriledithiolate and M=Ni2+, Pd2+ or Pt2+ for complexes 1–3, have been synthesized and structurally characterized. X-ray single crystal studies revealed that three complexes are isostructural and crystallize in monoclinic space group C2/c, and there exist weak H-bonding interactions between –NH2 groups of cation and –CN group of anion as well as weak M…H-bonding interactions between anions and cations. The calculations of charge density distribution disclosed that the M…H-bonding interaction in crystals of 1–3 is mainly attributed to static electric interactions. Two types of H-bonding interactions lead to the formation of two-dimensional sheet structure which is parallel to the crystallographic bc-plane in the crystals of 1–3. A near-IR absorbance appears in the UV–vis-NIR spectra of 1 and 3, respectively, while does not come out in the spectra of 2. [Copyright &y& Elsevier]

Abstract: A coordination polymer [Ag4(C12H12N6)3](ClO4)4(H2O)4 (1), was achieved via the self-assembly of AgClO4 with ligand 2,5-bis(pyrazinyl)-3,4-diaza-2,4-hexadiene (L1). The structure of compound 1 is a 3D metal–organic framework that consists of the circular helicate Ag3 (L1)3 secondary building blocks (SBUs). Each is capped at its every exo-monodentate pyrazinyl terminal by the unusual hexa-coordinated Ag(I) centers. Being filled within the cavities, the anions could be exchanged reversibly with in the solid state. [Copyright &y& Elsevier]

Abstract: A charge-transfer compound, [NO2BzPz][Ni(mnt)2] (NO2BzPz+ =1-(4′-nitrobenzyl)pyrazinium and mnt2− =maleonitriledithiolate), has been structurally characterized, which shows rare noncovalently intermolecular interactions between lone-pair electron and electron-deficient pyrazine rings (NO2⋯π and CN⋯π), theoretical analysis reveals that such intermolecular interactions can be attributed to Coulomb interaction. The paramagnetic [Ni(mnt)2]− anions in [NO2BzPz][Ni(mnt)2] form a dimerized stack and strong antiferromagnetic coupling interaction is observed in such a spin dimer which lead to weak paramagnetic feature in this compound. [Copyright &y& Elsevier]

Abstract: Two isostructural bimetallic tetranuclear chiral complexes, [K(18-crown-6)]3[Fe(ox)3]·9H2O and [K(18-crown-6)]3[Cr(ox)3]·9H2O, crystallize in rhombohedral R3 space group, the tetranuclear cluster is respectively built from one [Fe(ox)3]3− or [Cr(ox)3]3− species with three K(18-crown-6 ether) supramolecular cations linked by oxalate groups, and lattice water molecules form the double helical chains. Two complexes are second-harmonic-generation (SHG) active with the SHG response about 0.5 times that of urea. [Copyright &y& Elsevier]

A novel heterometallic 2D coordination polymer, {[Ba(H2O)4(CuL)2]}∞ (1) (H3L=N-2-hydroxyacetophenoneglycylglycine), was synthesized by self-assembly between metalloligands [CuL]− and the Ba(II) ions. The structure reveals the polymer contains hexanuclear building blocks, which are connected to form 28-membered decanuclear metallocycles, and are assembled further into 2D network structure. [Copyright &y& Elsevier]

Reaction of the Na[CuL] (where L= Schiff base derived from 5-bromosalicylaldehyde and glycylglycine) with LaCl3 · nH2O leads to the formation of the title complex 1 [La(H2O)5(CuL)2][CuL] · 8H2O which containing ring-like hexa-nuclear [La2(H2O)10(CuL)4]2+ cation. [Copyright &y& Elsevier]