Syntheses,crystal structures,and properties of four transition metal complexes based on 5-nitro-8-hydroxyquinoline

Four new complexes, [M(C₉H₅N₂O₃)₂(H₂O)₂]·CH₃OH (M?=?Zn(II), Cd(II) and Mn(II)) (1–3) and [Cu(C₉H₅N₂O₃)₂] (4), have been synthesized by reactions of 5-nitro-quinoline-8-yl acetate (NQA) and corresponding metal salts at room temperature and characterized by elemental analysis, IR, thermal gravimetric analysis (TGA), fluorescence measurement and single crystal X-ray diffraction. 1–3 are mononuclear, further extended to 2-D layers by hydrogen bonds. For 4, Cu²⁺ is coordinated by two N atoms and two O atoms from two NQ ligands. TGA indicates that 1–4 have good thermal stabilities. Furthermore, 1 and 2 show excellent luminescence in the solid state at room temperature.     

catena‐Poly­[[bis­(quinoxaline‐κN)cobalt(II)]‐di‐μ‐dicyan­amido‐κ2N1:N5] and catena‐poly­[[bis(quinoxaline‐κN)copper(II)]‐di‐μ‐dicyan­amido‐κ2N1:N5]

Two new complexes, [Co(C₂N₃)₂(C₈H₆N₂)₂], (I), and [Cu(C₂N₃)₂(C₈H₆N₂)₂], (II), are reported. They are essentially isomorphous. Complex (I) displays distorted octahedral geometry, with the Co atom coordinated by four dicyan­amide nitrile N atoms [Co—N = 2.098 (3) and 2.104 (3) Å] in the basal plane, along with two monodentate quinoxaline N atoms [Co—N = 2.257 (2) Å] in the apical positions. In complex (II), the Cu atom is surrounded by four dicyan­amide nitrile N atoms [Cu—N = 2.003 (3) and 2.005 (3) Å] in the equatorial plane and two monodentate quinoxaline N atoms [Cu—N = 2.479 (3) Å] in the axial sites, to form a distorted tetragonal–bipyramidal geometry. The metal atoms reside on twofold axes of rotation. Neighbouring metal atoms are connected via double dicyan­amide bridges to form one‐dimensional infinite chains. Adjacent chains are then linked by π–π stacking interactions of the quinoxaline mol­ecules, resulting in the formation of a three‐dimensional structure.     

Trinuclear and dinuclear Ni(II) complexes constructed by bridging oxygen: crystal structures,magnetic, and thermal properties

The reaction of H₂L (N,N ′-bis(5-ethyl-1,3,4-thiadiazol-2-yl)-2,6-pyridinedicarboxamide) with Ni(II) salts gave crystals of two new complexes, [Ni₃(µ₃-O)(H₂L)(L)₂] · 2DMF (1) and [Ni₂(µ-H₂O)(CH₃OH)(DMF)(L)₂] · H₂O · CH₃OH (2). The complexes were characterized by elemental analysis, IR, thermal analysis, and X-ray single crystal diffraction. Complex 1 is a trinuclear complex containing a triangle frame in the center formed by three Ni(II) atoms with a bridging µ₃-O. Complex 2 is dinuclear formed by two Ni(II) atoms with a bridging H₂O. H₂L coordinates to metal centers as a pentadentate ligand in 1 and tetradentate in 2. Thermal analysis shows that the thermal stability of 1 is higher than that of 2. In addition, the magnetic properties of 2 are also reported.     

Construction of three metal-organic frameworks based on multifunctional T-shaped tripodal ligands (4,5-dicarboxy-1H-imidazol-2-yl)pyridine-1-oxide

Three metal-organic frameworks, [Eu(C₁₀H₆N₃O₅)₃(H₂O)₂]?·?H₂O (1), [Tb(C₁₀H₆N₃O₅)₃(H₂O)₂]?·?H₂O (2), and [Cd(C₁₀H₆N₃O₅)₂Cl₂] (3) based on T-shaped tripodal ligands 3-(4,5-dicarboxy-1H-imidazol-2-yl)pyridine-1-oxide and 4-(4,5-dicarboxy-1H-imidazol-2-yl)pyridine-1-oxide (H₃DCImPyO), have been synthesized by the hydrothermal method and characterized by elemental analysis, IR, and single-crystal X-ray structure analysis. The diverse coordination modes of H₃DCImPyO ligands have afforded the three compounds. Complexes 1 and 2 are isomers and the Ln (Ln?=?Eu or Tb) atoms have coordination number eight with a distorted square prism geometry. The partly deprotonated H₂DCImPyO^? ligands display three different coordination modes to link Ln (Ln?=?Tb or Eu) into 1-D double chains. In 3, Cd(II) lies on an inversion center and displays a slightly distorted octahedral coordination. All three compounds exhibit strong fluorescent emissions in the solid state at room temperature.     

A novel cadmium(II) coordination polymer with a four‐connected (4,4)‐net based on a trinuclear cadmium(II) node

In the title cadmium(II) coordination polymer, poly[tri‐μ₄‐adipato‐bis(2‐phenyl‐1H‐1,3,7,8‐tetraazacyclopenta[l]phenanthrene‐κ²N⁷,N⁸)tricadmium(II)], [Cd₃(C₆H₈O₄)₃(C₁₉H₁₂N₄)₂]_n, one of the Cd atoms is in a distorted pentagonal bipyramidal coordination environment, surrounded by five O atoms from three adipate (adip) ligands and two N atoms from one 2‐phenyl‐1H‐1,3,7,8‐tetraazacyclopenta[l]phenanthrene (L) ligand. A second Cd atom occupies an inversion center and is coordinated by six O atoms from six adip ligands in a distorted octahedral geometry. The carboxylate ends of the adip ligands link Cd^II atoms to form unique trinuclear Cd^II clusters, which are further bridged by the adip linkers to produce a two‐dimensional layer structure. Topologically, each trinuclear Cd^II cluster is connected to four others through six adip ligands, thus resulting in a unique two‐dimensional four‐connected framework of (4,4)‐topology. This work may help the development of the coordination chemistry of 1,10‐phenanthroline derivatives.     

Syntheses,crystal structures and characterization of divalent transition metal sulfonate complexes with O-phenanthroline

Two new complexes, [Zn(phen)₂(H₂O)₂]2L·H₂O (1) and [Cu(phen)(L)(H₂O)₂]L·3H₂O (2), where HL?= 4-aminobenzenesulfonic acid and phen = o-phenanthroline, have been synthesized and their crystal structures determined by X-ray diffraction. In the complexes the Cu(II) and Zn(II) atoms revealed two different coordination environments. Complex 1 consists of a cation [Zn(phen)₂(H₂O)₂]²⁺, in which Zn(II) is six-coordinated by four nitrogen atoms from two o-phenanthroline molecules and by two water molecules. Complex 2 has two crystallographically unique Cu(II) ions, where Cu(II) ion is five-coordinate with two nitrogen atoms of o-phenanthroline, two water molecules and one sulfonate oxygen atom. The electrochemical behavior and FT-IR of the two compounds have also been studied in detail.     

Hydrogen-bond networks of 1,3-imidazolidine-2-thione: synthesis and structures of complexes of silver(I), copper(I), cadmium(II) and zinc(II)

Solution reactions of silver(I), copper(I), cadmium(II) and zinc(II) salts with 1,3-imidazolidine-2-thione (imdt) under diverse conditions yielded four complexes: [Cd(SC₃H₆N₂)₂(Ac)₂] (1), [Zn(SC₃H₆N₂)₂(Ac)₂] (2), [Cu₂(SC₃H₆N₂)₆]SO₄ (3) and [Ag₂(SC₃H₆N₂)₆]SO₄ (4). Complexes 1 and 2 are 1D and 2D hydrogen-bond aggregations. Complexes 3 and 4 are isostructural 3D hydrogen-bond networks. The diverse coordination modes of imdt and different anions are the major factors for three distinct hydrogen-bond structures.     

Syntheses and crystal structures of two Cd(II) coordination polymers: one-dimensional chain [Cd(C4H6N2)2(C4H2O4)(H2O)2] n and two-dimensional sheet [Cd(C4H6N2)(H2O)(C4H4O4)] n · n H2O

Two new Cd(II) coordination polymers, [Cd(C₄H₆N₂)₂(C₄H₂O₄)(H₂O)₂] _n (1) (where C₄H₆N₂?=?2-methylimidazole, C₄H₂O₄?=?fumarate), and [Cd(C₄H₆N₂)(H₂O)(C₄H₄O₄)] _n ?·?nH₂O (2), (where C₄H₄O₄?=?succinates), have been prepared and structurally characterized by single crystal X-ray diffraction. Complex 1 crystallizes in the triclinic space group P 1 in a one-dimensional chain structure, in which carboxy is monodentate; a three-dimensional supermolecular network structure was formed through hydrogen bonding. In complex 2, the coordination geometry of the Cd atoms is a pentagonal bipyramid, and a two-dimensional sheet is formed though carboxyl group bridging. In 1 and 2, IR spectra indicate the presence of bridging carboxyl groups, confirmed by structure analyses.     

Synthesis,crystal structures and luminescence properties of seven mononuclear zinc(II), cadmium(II), cobalt(II) and nickel(II) complexes with 5‐(4‐methylphenyl)‐3‐(pyridin‐2‐yl)‐1H‐1,2,4‐triazole

Due to their versatile coordination modes and metal‐binding conformations, triazolyl ligands can provide a wide range of possibilities for the construction of supramolecular structures. Seven mononuclear transition metal complexes with different structural forms, namely aquabis[3‐(4‐methylphenyl)‐5‐(pyridin‐2‐yl)‐1H‐1,2,4‐triazolato‐κ²N ¹,N ⁵]zinc(II), [Zn(C₁₄H₁₁N₄)₂(H₂O)], (I), bis[5‐(4‐methylphenyl)‐3‐(pyridin‐2‐yl)‐1H‐1,2,4‐triazole‐κ²N ³,N ⁴]bis(nitrato‐κO )zinc(II), [Zn(NO₃)₂(C₁₄H₁₂N₄)₂], (II), bis(methanol‐κO )bis[3‐(4‐methylphenyl)‐5‐(pyridin‐2‐yl)‐1H‐1,2,4‐triazolato‐κ²N ¹,N ⁵]zinc(II), [Zn(C₁₄H₁₁N₄)₂(CH₄O)₂], (III), diiodidobis[5‐(4‐methylphenyl)‐3‐(pyridin‐2‐yl)‐1H‐1,2,4‐triazole‐κ²N ³,N ⁴]cadmium(II), [CdI₂(C₁₄H₁₂N₄)₂], (IV), bis[5‐(4‐methylphenyl)‐3‐(pyridin‐2‐yl)‐1H‐1,2,4‐triazole‐κ²N ³,N ⁴]bis(nitrato‐κO )cadmium(II), [Cd(NO₃)₂(C₁₄H₁₂N₄)₂], (V), aquabis[3‐(4‐methylphenyl)‐5‐(pyridin‐2‐yl)‐1H‐1,2,4‐triazolato‐κ²N ¹,N ⁵]cobalt(II), [Co(C₁₄H₁₁N₄)₂(H₂O)], (VI), and diaquabis[3‐(4‐methylphenyl)‐5‐(pyridin‐2‐yl)‐1H‐1,2,4‐triazolato‐κ²N ¹,N ⁵]nickel(II), [Ni(C₁₄H₁₁N₄)₂(H₂O)₂], (VII), have been prepared by the reaction of transition metal salts (Zn^II, Cd^II, Co^II and Ni^II) with 3‐(4‐methylphenyl)‐5‐(pyridin‐2‐yl)‐1H‐1,2,4‐triazole (pymphtzH) under either ambient or hydrothermal conditions. These compounds have been characterized by elemental analysis, IR spectroscopy and single‐crystal X‐ray diffraction. All the complexes form three‐dimensional supramolecular structures through hydrogen bonds or through π–π stacking interactions between the centroids of the pyridyl or arene rings. The pymphtzH and pymphtz⁻ entities act as bidentate coordinating ligands in each structure. Moreover, all the pyridyl N atoms are coordinated to metal atoms (Zn, Cd, Co or Ni). The N atom in the 4‐position of the triazole group is coordinated to the Zn and Cd atoms in the crystal structures of (II), (IV) and (V), while the N atom in the 1‐position of the triazolate group is coordinated to the Zn, Co and Ni atoms in (I), (III), (VI) and (VII).     

Structural diversity in pseudohalide complexes of cadmium(II) with N-methylthiourea (Metu): Polymeric [Cd(Metu)2(NCS)2]n versus monomeric [Cd(Metu)2(CN)2]

Cadmium(II) complexes, catena-poly[bis(thiocyanato-κN)bis(N-methylthiourea)cadmium(II)], [Cd(Metu)₂(NCS)₂]_n (1) and dicyanidobis(N-methylthiourea)cadmium(II), [Cd(Metu)₂(CN)₂] (2) were prepared and their structures were determined by single crystal X-ray analysis. In 1, the cadmium(II) ion is bound to four sulfur atoms of bridging Metu ligands and two nitrogen atoms of thiocyanate adopting a distorted octahedral environment. In 2, the geometry around cadmium is distorted tetrahedral attained by two cyanide ions and two methylthiourea molecules bound through the sulfur atoms. The crystal structures of both complexes show intra and intermolecular hydrogen bonding interactions. The complexes were also characterized by IR and NMR spectroscopy and the spectroscopic data were discussed in terms of the nature of bonding.     

Two lanthanum(III) complexes containing η2‐pyrazolate and η2‐1,2,4‐triazolate ligands: intramolecular C—H...N/O interactions and coordination geometries

The lanthanum(III) complexes tris(3,5‐diphenylpyrazolato‐κ²N,N′)tris(tetrahydrofuran‐κO)lanthanum(III) tetrahydrofuran monosolvate, [La(C₁₅H₁₁N₂)₃(C₄H₈O)₃]·C₄H₈O, (I), and tris(3,5‐diphenyl‐1,2,4‐triazolato‐κ²N¹,N²)tris(tetrahydrofuran‐κO)lanthanum(III), [La(C₁₄H₁₀N₃)₃(C₄H₈O)₃], (II), both contain La^III atoms coordinated by three heterocyclic ligands and three tetrahydrofuran ligands, but their coordination geometries differ. Complex (I) has a mer‐distorted octahedral geometry, while complex (II) has a fac‐distorted configuration. The difference in the coordination geometries and the existence of asymmetric La—N bonding in the two complexes is associated with intramolecular C—H...N/O interactions between the ligands.     

Bis(μ‐3,5‐di‐tert‐butylcatecholato‐O1:O1,O2)bis[tris(pyridine‐N)cadmium(II)] dipyridine solvate

X‐ray diffraction shows that the title cadmium(II) complex, [Cd₂(C₁₄H₂₀O₂)₂(C₅H₅N)₆]·2C₅H₅N, has a dimeric structure in which two (py)₃Cd(3,5‐di‐tert‐butylcatecholate) units (py is pyridine) are connected by two bridging O atoms, the coordination of the Cd atoms being distorted octahedral. There are two symmetrically independent dimers in the crystal structure; one is in a general position and the other lies about an inversion centre. In both cases, the bridging Cd—O distances between the Cd–catecholate units [2.224 (2)–2.237 (2) Å] are shorter than the bridging Cd—O distances within the catecholate cycle [2.273 (2)–2.281 (2) Å]. The Cd—N_py distances are 2.354 (2)–2.471 (2) Å. Besides the main mol­ecules, the crystal also contains pyridine solvate mol­ecules.     

Synthesis,X‐ray characterization and density functional theory studies of N6‐benzyl‐N6‐methyladenine–M(II) complexes (M = Zn,Cd): The prominent role of π–π, C–H···π and anion–π interactions

We report the synthesis and X‐ray characterization of the N⁶‐benzyl‐N⁶‐methyladenine ligand (L) and three metal complexes, namely [Zn(HL)Cl₃]·H₂O ( 1 ), [Cd(HL)₂Cl₄] ( 2 ) and [H₂L]₂[Cd₃(μ‐L)₂(μ‐Cl)₄Cl₆]·3H₂O ( 3 ). Complex 1 consists of the 7H‐adenine tautomer protonated at N3 and coordinated to a tetrahedral Zn(II) metal centre through N9. The octahedral Cd(II) in complex 2 is N⁹‐coordinated to two N⁶‐benzyl‐N⁶‐methyladeninium ligands (7H‐tautomer protonated at N3) that occupy apical positions and four chlorido ligands form the basal plane. Compound 3 corresponds to a trinuclear Cd(II) complex, where the central Cd atom is six‐coordinated to two bridging μ‐L and four bridging μ‐Cl ligands. The other two Cd atoms are six‐coordinated to three terminal chlorido ligands, to two bridging μ‐Cl ligands and to the bridging μ‐L through N3. Essentially, the coordination patterns, degree of protonation and tautomeric forms of the nucleobase dominate the solid‐state architectures of 1 – 3 . Additionally, the hydrogen‐bonding interactions produced by the endocyclic N atoms and NH groups stabilize high‐dimensional‐order supramolecular assemblies. Moreover, energetically strong anion–π and lone pair (lp)–π interactions are important in constructing the final solid‐state architectures in 1 – 3 . We have studied the non‐covalent interactions energetically using density functional theory calculations and rationalized the interactions using molecular electrostatic potential surfaces and Bader's theory of atoms in molecules. We have particularly analysed cooperative lp–π and anion–π interactions in 1 and π⁺–π⁺ interactions in 3 .     

Syntheses,Structures, and Magnetic Behavior of New Azide Linked Compounds with One‐ and Two‐Dimensional Structures

Three azide based compounds were synthesized employing aliphatic amines as site blocking agents: [Ni(N₃)(C₆H₁₆N₂)₂]ClO₄ ( I ) [C₆H₁₆N₂ = N,N′‐diethylethylenediamine (DEDA)], [Cu₈(N₃)₁₆(C₆H₁₈N₄)₂] ( II ) [C₆H₁₈N₄ = tris(2‐aminoethyl) amine (TREN)], and [Cu₇(N₃)₁₄(C₇H₁₉N₃)₂] · 2H₂O ( III ) [C₇H₁₉N₃ = 3,3′‐diamino‐N‐methyldipropylamine (DMDA)]. The compounds I and II have one‐dimensional structure and III has a two‐dimensional structure. Compound I is a simple linear cationic Ni–azide chain and compound II has Cu₆ azide units forming a column terminated by the copper‐metalloligand generated in‐situ during the course of the reaction. The charge compensation perchlorate anions occupy spaces in between the chains in I . Compound II packs in a herringbone arrangement, which is not commonly observed in low‐dimensional structures. Compound III has one‐dimensional copper‐azide chains connected through copper‐metalloligand forming the two‐dimensional structure. All the three compounds exhibit anti‐ferromagnetic behavior.     

Cobalt(II) and cadmium(II) square grids supported with 4,4′‐bipyrazole and accommodating 3‐carboxyadamantane‐1‐carboxylate

In poly[[bis(μ‐4,4′‐bi‐1H‐pyrazole‐κ²N²:N^2′)bis(3‐carboxyadamantane‐1‐carboxylato‐κO¹)cobalt(II)] dihydrate], {[Co(C₁₂H₁₅O₄)₂(C₆H₆N₄)₂]·2H₂O}_n, (I), the Co²⁺ cation lies on an inversion centre and the 4,4′‐bipyrazole (4,4′‐bpz) ligands are also situated across centres of inversion. In its non‐isomorphous cadmium analogue, {[Cd(C₁₂H₁₅O₄)₂(C₆H₆N₄)₂]·2H₂O}_n, (II), the Cd²⁺ cation lies on a twofold axis. In both compounds, the metal cations adopt an octahedral coordination, with four pyrazole N atoms in the equatorial plane [Co—N = 2.156 (2) and 2.162 (2) Å; Cd—N = 2.298 (2) and 2.321 (2) Å] and two axial carboxylate O atoms [Co—O = 2.1547 (18) Å and Cd—O = 2.347 (2) Å]. In both structures, interligand hydrogen bonding [N...O = 2.682 (3)–2.819 (3) Å] is essential for stabilization of the MN₄O₂ environment with its unusually high (for bulky adamantanecarboxylates) number of coordinated N‐donor co‐ligands. The compounds adopt two‐dimensional coordination connectivities and exist as square‐grid [M(4,4′‐bpz)₂]_n networks accommodating monodentate carboxylate ligands. The interlayer linkage is provided by hydrogen bonds from the carboxylic acid groups via the solvent water molecules [O...O = 2.565 (3) and 2.616 (3) Å] to the carboxylate groups in the next layer [O...O = 2.717 (3)–2.841 (3) Å], thereby extending the structures in the third dimension.     

Two New Octahedral Cd(II) Complexes [Cd(L)2] and {[Cd(LH)2(SCN)2]H2O} [L = C6H5C(OH)NN = C(CH3)C5H4N]: Synthesis and Structural Studies

Two new octahedral Cd(II) complexes [Cd(L)₂] (1) and {[Cd(LH)₂(SCN)₂]H₂O} (2) [where LH = C₁₄H₁₃N₃O] are synthesized using a tridentate hydrazone ligand (LH) and they are characterized by elemental analysis, IR spectra, NMR spectra, thermal studies and finally the structures have been determined by single crystal X-ray diffraction. Complex 1 crystallizes in monoclinic system, space group C2/c with a = 22.565(6) ?, b = 10.252(3) ?, c = 12.187(4) ?, β = 118.851(2)^∘, and Z = 4. Complex 2 also crystallizes in the monoclinic system, space group P2₁/c with a = 9.257(9)?, b = 17.809(2)?, c = 9.548(9)?, β = 107.439(4)^∘, and Z = 2. In 1 the ligand binds the Cd(II) ion in tridentate fashion, whereas in 2 it acts as a bidentate ligand.     

Mononuclear and three‐dimensional metal complexes based on a multidentate hydrazone ligand

A potentially pentadentate hydrazone ligand, N′‐[1‐(pyrazin‐2‐yl)ethylidene]nicotinohydrazide (HL), was prepared from the condensation reaction of nicotinohydrazide and acetylpyrazine. Reactions of HL with MnCl₂, Mn(CH₃COO)₂ and Cd(CH₃COO)₂ afforded three metal complexes, namely dichlorido{N′‐[1‐(pyrazin‐2‐yl‐κN¹)ethylidene]nicotinohydrazide‐κ²N′,O}manganese(II), [MnCl₂(C₁₂H₁₁N₅O)], (I), bis{N′‐[1‐(pyrazin‐2‐yl‐κN¹)ethylidene]nicotinohydrazidato‐κ²N′,O]manganese(II), [Mn(C₁₂H₁₀N₅O)₂], (II), and poly[[(acetato‐κ²O,O′){μ₃‐N′‐[1‐(pyrazin‐2‐yl‐κ²N¹:N⁴)ethylidene]nicotinohydrazidato‐κ³N′,O:N¹}cadmium(II)] chloroform disolvate], {[Cd(C₁₂H₁₀N₅O)(CH₃COO)]·2CHCl₃}_n, (III), respectively. Complex (I) has a mononuclear structure, the Mn^II centre adopting a distorted square‐pyramidal coordination. Complex (II) also has a mononuclear structure, with the Mn^II centre occupying a special position (C₂ symmetry) and adopting a distorted octahedral coordination environment, which is defined by two O atoms and four N atoms from two N′‐[1‐(pyrazin‐2‐yl)ethylidene]nicotinohydrazidate (L⁻) ligands related via a crystallographic twofold axis. Complex (III) features a unique three‐dimensional network with rectangular channels, and the L⁻ ligand also serves as a counter‐anion. The coordination geometry of the Cd^II centre is pentagonal bipyramidal. This study demonstrates that HL, which can act as either a neutral or a mono‐anionic ligand, is useful in the construction of interesting metal–organic compounds.     

Formation of mononuclear and polynuclear d-block metal complexes from 1,4,7-tris(3-hydroxypropyl)-1,4,7-triazacyclononane: crystal structures,spectroscopic studies,and magnetic properties

Four new d-block metal complexes formulated as [Ni^II(H3thptacn)]Cl₂·H₂O (1), [Mn^IV(thptacn)]ClO₄ (2), [Cu^II₃(Hthptacn)₂](ClO₄)₂ (3), and [Cd^II₂(H3thptacn)₂Cl₂][B(C₆H₅)₄]₂ (4) were obtained from the macrocyclic ligand 1,4,7-tris(3-hydroxypropyl)-1,4,7-triazacyclononane (H3thptacn) either through solvent diffusion or by evaporation of their solutions. These complexes were characterized by single crystal X-ray structural determination, elemental analysis, and routine spectroscopic methods. Complexes 1 and 2 exhibit similar mononuclear structures with the metal centers being surrounded by both the backbone nitrogen atoms and the pendant coordinating alcohol/alkoxide groups. Complex 3 is a linear trinuclear cluster, where three Cu(II) centers are combined together by the bridging alkoxide groups in a centro-symmetric pattern. Two chloride groups join two Cd(II) atoms each chelated by one triply protonated ligand H3thptacn to afford dinuclear compound 4 with a symmetry center. When coordinating to different d-block metals, the macrocyclic ligand exhibits four types of binding modes with various dissociation status on its pendant alcohol groups and different numbers of these pendant groups participating in coordination. The magnetic measurements revealed significant zero-field splitting for mononuclear Ni(II) and Mn(IV) complexes. A moderate antiferromagnetic interaction between the neighboring Cu(II) centers governs the magnetic properties of 3 with J = ?166(3) cm^?1.     

Cadmium nitrate coordination polymers with substituted pyridazino[4,5‐d]pyridazines

catena‐Poly[[aquabis(nitrato‐κ²O,O′)cadmium(II)]‐μ‐1,2,3,6,7,8‐hexa­hydro­cinnolino[5,4,3‐cde]cinnoline‐κN¹:κN⁶], [Cd(NO₃)₂(C₁₂H₁₂N₄)(H₂O)]_n, (I), and catena‐poly[[[bis(nitrato‐κ²O,O′)cadmium(II)]‐μ‐2,2,7,7‐tetra­methyl‐1,2,3,6,7,8‐hexahydro­cinnolino[5,4,3‐cde]cinnoline‐κN¹:κN⁶] chloro­form solvate], {[Cd(NO₃)₂(C₁₂H₁₂N₄)]·CHCl₃}_n, (II), are the first structurally examined cadmium–pyridazine coordination compounds. They possess one‐dimensional polymeric structures supported by the bidentate bridging function of the cinnolino[5,4,3‐cde]cinnoline ligands, which lie about inversion centres. The Cd atoms are seven‐coordinated in (I) and six‐coordinated in (II), involving two bidentate nitrate groups [Cd—O = 2.229 (2)–2.657 (2) Å], two N atoms of the cinnoline ligands [Cd—N = 2.252 (2)–2.425 (2) Å], and, additionally, a water O atom in (I) [Cd—O = 2.284 (2) Å]. In (I), the coordinated organic and aqua ligands form an intra­molecular O—H⋯N hydrogen bond [O⋯N = 2.730 (3) Å].     

Containing‐PMBP N2O2‐donors transition metal(II) complexes: Synthesis,crystal structure,Hirshfeld surface analyses and fluorescence properties

Three newly designed containing‐PMBP N₂O₂‐donors complexes, [Co(L¹)(CH₃OH)₂] ( 1 ), [{Zn(L²)(CH₃OH)(H₂O)}₃] ( 2 ) and [Cu₄(L²)₄]?2CHCl₃ ( 3 ), have been synthesized and structurally characterized using elemental analyses, infrared and UV–visible spectroscopies and single‐crystal X‐ray diffraction. X‐ray crystal structure determinations revealed that 1 consists of one Co(II) atom, one completely deprotonated (L¹)^2? unit and two coordinated methanol molecules. Complex 2 consists of three Zn(II) atoms, three completely deprotonated (L²)^2? units, three coordinated methanol molecules and three coordinated water molecules. However, 3 includes four Cu(II) atoms, four completely deprotonated (L²)^2? units and two crystallization chloroform molecules. The Co(II) and Zn(II) atoms in the structures of 1 and 2 adopt slightly distorted octahedral geometries. While, Cu(II) atoms in 3 can be best described as adopting slightly distorted square planar geometries. Complex 2 is a novel structure, and the ratio of H₂L² to Zn(II) atom is 3:3. In addition, two‐, three‐ and three‐dimensional supramolecular structures were constructed for 1 , 2 and 3 . Most importantly, Hirshfeld surface analysis of 1 , 2 and 3 was conducted and fluorescence properties were investigated.