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A cobalt(II) complex and manganese(II) coordination polymer, formulated as [Co2(H2btca)(mbpy)4][H2btca]·4H2O (1) and {Mn2(btca)(mbpy)2(H2O)2}n (2) (H4btca = 1,2,4,5-benzenetetracarboxylic acid; mbpy = 4,4′-dimethyl-2,2′-bipyridyl), constructed by mixed bipyridine-tetracarboxylic ligands were synthesized and characterized. Single-crystal structural analyses reveal that compound 1 is a discrete neutral binuclear molecule, while compound 2 is a two-dimensional (2D) coordination polymer. The metal ions in these compounds are well isolated, with an intramolecular Co2+⋯Co2+ distance of 9.170 Å for 1 and Mn2+⋯Mn2+ separation of 10.984 and 11.164 Å for 2 due to the bulk tetracarboxylic linker. This isolation gives rise to a single-ion magnetism origin of the compounds. Magnetic studies reveal a large zero-field splitting parameter D of 82.6 cm−1 for 1, while a very small D of 0.42 cm−1 was observed for 2. Interestingly, dynamic ac magnetic measurements exhibited slow magnetic relaxation under the external dc field of the two compounds, revealing the field-supported single-ion magnet (SIM) of 1 and 2. The detailed theoretical calculations were further applied to understand the electronic structures, magnetic anisotropy, and relaxation dynamics in 1 and 2. Combined with our recently reported compound (Eur. J. Inorg. Chem., 2022, e202200354), the foregoing results provide not only a rare binuclear cobalt(II) SIM and the first 2D manganese(II) SIM coordination polymer but also a bipyridine-tetracarboxylic ligand approach toward novel SIMs. [ABSTRACT FROM AUTHOR]

Two new metal–organic frameworks [Mn 3 (MMA) 2 (INA) 2 ] n ( 1 ) and [Cu 2 (FA)(INA) 3 (H 2 O)] n ( 2 , FA = formate) were prepared solvothermally by using mixed methylmalonic acid (H 2 MMA) and isonicotinic acid (HINA) as the initial reactants. Single-crystal X-ray diffraction analyses reveal that complex 1 has a 3D framework structure consisting of 2D [Mn 3 ] layer units and INA connector, and 2 owns a 2D pillar-layered structure constituted of mononuclear-Cu(II)-based 2D layer unit and paddle-wheel dinuclear Cu(II) cluster-based pillared linker, which further interspersed with each other to form a 3-fold interpenetrated framework with a (4 8 .6 2 )- SP topology. The magnetic studies show that 1 displays antiferromagnetic ordering at low temperature, and a strong antiferromagnetic interaction exists in 2 . [ABSTRACT FROM AUTHOR]

In this work, a versatile multi-dentate 1,2-bis(pyridin-4-ylmethylene)hydrazine (L) ligand has been employed to construct three novel iron(II) coordination complexes, [Fe(L) 2 (NCS) 2 (H 2 O) 2 ]·2H 2 O ( 1 ), [Fe(L)(NCS) 2 (H 2 O) 2 ] ( 2 ) and {[Fe(L) 2 (NCS) 2 ]·2CH 3 OH} n ( 3 ) (NH 4 NCS = ammonium thiocyanate), which can be isolated under similar synthetic conditions, only different molar ratio of metal/ligand or different solvent systems are used. 1 is a mono-nuclear iron(II) coordination complex, and 2 is a one-dimensional (1D) iron(II) coordination complex, while 3 is a 2D micro-porous iron(II) framework with the channel dimensionality of 13.936(3) Å × 13.936(3) Å. PXRD patterns also confirm the purity of the bulky samples of 1 – 3 . For 1 – 3 , it represents the first example of solvent-induced drastic reversible dynamic conformation between different dimensional iron(II) coordination complexes 1 (0D), 2 (1D) and 3 (2D) (for 1 : water; for 2 : benzene; for 3 : methanol/acetone/acetonitrile), which are unambiguously confirmed by PXRD characterizations. Variable-temperature magnetic susceptibility data of 2 – 3 have been recorded in the 2–300 K temperature range, indicating weak antiferromagnetic interactions. [ABSTRACT FROM AUTHOR]

A novel three-dimensional europium metal-organic framework (Eu-MOF), [Eu(L)(OAc)(DMA)] n ( 1 ), has been successfully obtained based on a newly designed ligand 4′-(3,5-dicarboxyphenyl)-4,2′:6′,4″-terpyridine (H 2 L). The structure of 1 was established by single crystal X-ray diffraction technique, and structure analysis shows that two Eu 3 + in 1 are 4-fold bridged by two η 1 :η 1 :μ 2 carboxylates from L 2 − and the other two η 1 :η 2 :μ 2 carboxylates from acetic acid, respectively. The binuclear [Eu 2 ] were further linked by L 2 − to form a 3D framework. The investigations on luminescent properties reveal that 1 can detect Al 3 + quickly with relatively high sensitivity and selectivity. More importantly, it displays high thermal and solvent stability. Additionally, a self-made fluorescence test paper fabricated based on 1 was used to detect Al 3 + in practice. [ABSTRACT FROM AUTHOR]

Two nickel(II) complexes were synthesized and structurally as well as magnetically characterized by using two positional isomeric nitronyl nitroxide radical ligands and H3cda as co-ligand: [Ni(NIToPy)(cda)]H2O ·CH3OH ( 1) and [Ni(IM4Py)2(cda)H2O] ( 2) [NIToPy = 2-(3′-pyridinyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazolyl-1-oxyl-3-oxide; IM4Py = 2-(4′-pyridinyl)-4,4,5,5-tetramethylimidazoline-l-oxyl; H3cda = 4-hydroxypyridine-2,6-dicarboxylic acid]. Single-crystal structures analyses show that both complexes have similar mononuclear structures, in which the central NiII ions are hexacoordinated with a distorted octahedral arrangement. The magnetic properties of 1 and 2 were studied, and antiferromagnetic interactions between NiII ion and radicals are observed. [ABSTRACT FROM AUTHOR]

Eu(III)–Sr(II)–K(I) and Tb(III)–Sr(II)–K(I) heterotrimetallic metal-organic frameworks with 2,4,6-pyridinetricarboxylic acid have been synthesized under hydrothermal conditions. The complexes are isomorphic and both in triclinic space groupP-1. The ligands bond with three metal ions with two coordination modes. One connects seven metal ions and the other connects eight metal ions. IR spectra, thermal analysis, and photoluminescent properties have been studied. The results display strong characteristic emissions of Eu(III) or Tb(III) ions with excitation of ultraviolet radiation. [ABSTRACT FROM PUBLISHER]

Abstract: 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. [Copyright &y& Elsevier]

Abstract: Under hydrothermal conditions using cis-butenedioic acid (H2L) and corresponding lead(II) salts, a three-dimensional (3D) lead(II) complex {[Pb2(L)(μ2-Cl)(μ3-Cl)]} n (1) containing 3D Pb–X–Pb (X=O and Cl) linkage has been isolated. 1 also represents a truly 3D hybrid luminescent lead(II) framework with I 3 O 0 type connectivity. Further analysis reveals that cis- and trans-conformations of butenedioic acid ligand greatly affect the lead(II) framework structure. Solid-state fluorescence spectrum of 1 exhibits the maximum emission peak at 379nm. [Copyright &y& Elsevier]

The reaction of the decadentate ligand tpmen (H4tpmen = N,N,N'N'-tetrakis[(6-carboxypyridin-2-yl)methyl]ethylenediamine) with MnCl2·4H2O in aqueous solution gives a homodinuclear complex [Mn2(H2O)2(tpmen)]·16H2O, which has been characterized by elemental analysis, thermal gravimetric and single-crystal X-ray diffraction analysis. The complex crystallizes in the orthorhombic system, space group Cmca, a = 28.786(5) Å, b = 11.5033(19) Å, c = 14.437(2) Å, Z = 8, R1 = 0.0432, wR2 = 0.0786. The tpmen ligand contains four picolinate groups, two of which bind each Mn(II) to form a dinuclear complex. The geometry around the Mn(II) is distorted octahedral with two nitrogen and two oxygen atoms from the picolinate groups and two oxygen atoms from coordinated water. The variable-temperature (2-300 K) magnetic susceptibilities shows an antiferromagnetic interaction between Mn(II) ions. [ABSTRACT FROM AUTHOR]

Abstract: Two copper(II)–poly(pyrazolyl)methane complexes [Cu2(bpm)4(ta)](ClO4) 2 ·2H2O 1 and {[Cu2(tpm)2(ta)2]·H2O} n 2 (bpm=bis(3,5-dimethylpyrazolyl)methane, tpm=tris(pyrazolyl)methane, H2ta=terephthalic acid) were synthesized and characterized by elemental analysis, FT-IR and UV–vis spectra. 1 is a binuclear complex, while 2 exhibits as a 1D zigzag coordination polymer. [Copyright &y& Elsevier]

Utilizing 1,3,4-oxadiazole amide that possesses outstanding electron mobility to serve as auxiliary ligands, four novel iridium (III) complexes of Ir1 – Ir4 were prepared. Their structure, photophysical, and electrochemical characteristics were examined in detail, and quantum chemical calculations were used to interpret their photophysical behaviors. At room temperature, complexes Ir1 and Ir2 exhibit almost coincident green phosphorescence with peaks at 506 nm. Ir3 and Ir4 complexes produce greenish blue and greenish yellow light with a double-peak structure located at 496 and 531 nm. Organic light-emitting diodes utilizing Ir1 – Ir4 as emitters exert extremely moderate efficiency roll-off, which is caused by the emitters bearing CF 3 -substituted 1,3,4-oxadiazole amide possessing excellent electron mobility. [Display omitted] • Iridium complexes Ir1–Ir4 with CF 3 -substituted 1,3,4-oxadiazole amide ancillary ligands are synthesized. • Both Ir1 and Ir2 exhibit green phosphorescence, Ir3 and Ir4 produce greenish blue and greenish yellow light, respectively. • Complexes Ir1–Ir4 have excellent thermal and electrochemical stability. • The OLEDs based on Ir1–Ir4 exhibit very mild efficiency roll-off. [ABSTRACT FROM AUTHOR]

One new three-dimensional Cd(II) polymer [Cd 3 (MMA) 2 (INA) 2 ] n ( 1 ) was synthesized hydrothermally based on mixed flexible methylmalonic acid (H 2 MMA) and rigid isonicotinic acid (HINA) ligands. Single-crystal X-ray diffraction analysis reveals that compound 1 has a 3D framework structure consisting of 2D {Cd 3 } layer unit and INA − connector, which bears a (3,8)-connected tfz-d topology with Schläfli symbol of {4 3 } 2 {4 6 .6 18 .8 4 }. The solid-state luminescent property was studied and 1 exhibits strong emission centered at 429 nm. [ABSTRACT FROM AUTHOR]

A cationic iridium complex [Ir(dfpmpy) 2 (pzpy)](PF 6 ) with 2-(1H-pyrazol-1-yl)pyridine as ancillary ligand has been prepared, and its crystal structure, photophysical and electrochemical properties have been investigated. In degassed CH 3 CN solution, this complex exhibits blue emission with a peak wavelength of 451 nm. Photophysical property indicates that photoluminescence of complex [Ir(dfpmpy) 2 (pzpy)](PF 6 ) originates mainly from ligand-centered 3 π → π ∗ states. In addition, solution-processed organic light-emitting diodes based on [Ir(dfpmpy) 2 (pzpy)](PF 6 ) have been fabricated. A blue light electroluminescence (484 nm) was observed and a maximum current efficiency of 1.56 cd A −1 corresponding to a maximum power efficiency of 0.33 lm W −1 , has been achieved. This demonstrates that this complex is a promising phosphor for achieving efficient electrophosphorescence in the blue light region. [ABSTRACT FROM AUTHOR]

Two new cationic iridium complexes bearing cyclometalated carbene ligands have been prepared, and the photophysical and electrochemical properties have been investigated. In degassed acetonitrile solutions, these complexes exhibit yellow light emission with peaks at 591 and 579 nm, respectively. Both photophysical properties and quantum chemical calculations indicate that photoluminescence of these complexes are mainly from triplet charge-transfer excited states. Solution-processed organic light-emitting diodes based on these complexes exhibit yellow electroluminescences with the maximum current efficiencies of 17.42 and 6.36 cd A −1 and Commission Internationale d’Énclairage(x, y) coordinates (CIE x,y ) of (0.47, 0.51) and (0.51, 0.47), respectively. [ABSTRACT FROM AUTHOR]

In this work, we report three deep-blue emitting cationic iridium complexes Ir1–Ir3 with 2ʹ,6ʹ-difluoro-2,3ʹ-bipyridine cyclometalated ligand and pyrazole-type ancillary ligands. Synthesis, crystal structure, photophysical and electrochemical properties of Ir1–Ir3 are studied in detail. Ir1–Ir3 exhibit efficient phosphorescence emissions at 439, 438 and 437 nm with CIE 1931 coordinates of (0.14, 0.12), (0.14, 0.12) and (0.14, 0.13), and luminescence quantum yields of 0.35, 0.27 and 0.50 in CH 2 Cl 2 solutions, respectively, which are among the highest levels of ever reported cationic iridium(III) complexes emitting deep-blue light. High luminescence quantum yields, excellent color purity and short lifetimes demonstrates the great potential of Ir1–Ir3 for light-emitting electrochemical cells (LECs) and solution-processable organic light-emitting diodes (OLEDs) as efficient blue emitters. Image 1 • Deep-blue emitting cationic iridium complexes. • Ir1−Ir3 are synthesized. • Ir1−Ir3 exhibit high photoluminescence quantum yields in CH 2 Cl 2 solutions. [ABSTRACT FROM AUTHOR]