Reactivity of 2,2-dimethylaziridine towards d10 transition metal halides

The reaction of zinc(II)bromide and zinc(II)-, cadmium(II)-, and mercury(II)iodide with 2,2-dimethylaziridine (az) yields tetrahedral mononuclear complexes of the type (az)₂MX₂ (M = Zn, X = Br, I; M = Hg, X = I). The reaction of CdI₂, however, with az yields the formal dimerized ligand N-(2-aminoisobutyl)-2,2-dimethylaziridine (aiaz) forming the ionic complex [(aiaz)₂CdI]₂[CdI₄]. This dimerization of two az ligands into the new bidentate aiaz ligand occurs in the coordination sphere of the metal via a metal-mediated template reaction. This may be favored by the formation of a five-membered N,N′-chelating ring. While the zinc(II) and mercury(II) complexes show tetrahedral geometries of the type (az)₂MX₂, the cadmium aiaz complex consists of two mono cationic trigonal bipyramidal coordinated cadmium(II) centers and one tetrahedral [CdI₄]^2? dianion.     

Synthesis,structures, and characterization of cadmium(II), cobalt(II), and copper(II) metal polymers with tetrazole-1-acetate

Three new coordination polymers {[Cd(tza)(2,2′-bpy)(H₂O)](ClO₄)} _n 1, {[Co(tza)(2,2′-bpy)(H₂O)](ClO₄)} _n 2, and {[Cu(tza)(phen)](ClO₄)} _n 3 (Htza = tetrazole-1-acetic acid, 2,2′-bpy = 2,2′-bipyridyl, phen = 1,10-phenanthroline) were synthesized and characterized by X-ray single-crystal diffraction, elemental analysis, and IR spectra. Complexes 1 and 2 exhibit 3-D architectures formed by π–π interaction of 2,2′-bpy ligands interlinking to the adjacent 2-D layers. Complex 3 is a 1-D zigzag double chain and the 3-D structure is formed by π–π stacking interaction of phen and nonclassical hydrogen bonding.     

Synthesis and structures of three 1-aminoethylidenediphosphonate compounds with transition-metal ions

Three new aminodiphosphonates, namely M(phen)(AEDPH₃)₂·4H₂O (M = Zn, (1); Ni, (2)) and Cu(phen)(AEDPH₃)₂·H₂O (4), in addition to the previously reported Co(phen)(AEDPH₃)₂·4H₂O (3), Cu(2,2′-bipy)(H₂O)(HEDPH₂)·2H₂O (5), and Cu(phen)(H₂O)(HEDPH₂)·2H₂O (6) (AEDPH₄ = 1-aminoethylidenediphosphonic acid, HEDPH₄ = 1-hydroxyethylidenediphosphonic acid, phen = 1,10-phenanthroline and 2,2′-bipy = 2,2′-bipyridyl), have been synthesized and characterized. These compounds are all synthesized at the similar condition (80 °C), whereas they illustrate different frameworks. Compounds 1, 2 and 3 are isomorphous, which contain two same chelate and one six-coordinated metal ion, and display a three-dimensional (3D) supramolecular structure through hydrogen bonds and π–π stacking interactions. Compound 4 contains a chelate and a monodentate , while the Cu ion is five-coordinated. The coordination model of Cu²⁺ in 4 is similar to that of 5 and 6. Comparing with four aminoethylidenediphosphonates, the difference of their structures is directed to the coordination model of the metal ions, while the three copper(II) diphosphonates illustrate different structures based on the deprotonized degree of the corresponding diphosphonic acids.     

Synthesis,crystal structures,and properties of two novel compounds containing triphosphonate groups

Two novel phosphonate compounds (H₂L)·Hphen (1) and [Ca(HL)(H₂O)]_n·3.5nH₂O (2) (L = N(CH₂PO₃H)₃^3?) were synthesized under hydrothermal conditions. Compound 1 features a chain structure in the ac plane, where HL^2? anions are interconnected through sharing hydrogen ions to form a 1D zigzag type. Compound 2 features a layered structure in the ab plane, which has inorganic calcium cores with the organic part of the phosphonate anions being encircling the cores through coordination actions. The free water molecules can form hydrogen bonds with the coordinated water molecules and phosphonate oxygen atoms, which are able to link the adjacent layers to generate a 3D network structure. In addition, the thermal stability and photoluminescence properties were also studied.     

Syntheses and structures of Cd(II) and Co(II) compounds of 4-[(3-pyridyl)methylamino]benzoate anion

Three coordination polymers containing Cd(II) and Co(II), connected via 4-[(3-pyridyl)methylamino]benzoate (L^?), have been synthesized in hydrothermal conditions. In [Cd(L)Cl] _n (1), adjacent Cd(II) cations are linked by carboxylates to give a dinuclear cluster. Pairs of L^? bridge the dinuclear cluster to form double helical chains, and these chains are further linked by Cl^? to produce a 4-connected net with (4²?·?6³?·?8) topology. [CdL₂] _n (2) contains 1-D ladder-like chains. The packing structure displays a 3-D supramolecular structure, with π?···?π interactions stabilizing the framework. [CoL₂] _n (3) has a 2-D extended supramolecular structure via π?···?π interactions of 1-D coordination polymers of 3. The crystal structures of 1–3 have been determined by single-crystal X-ray diffraction. Luminescent properties for 1 and 2 are discussed.     

Synthesis,structure and nonlinear optical properties of three dimensional compounds

The combination of metal ions with H₃tbba has resulted in the formation of two three dimensional coordination compounds {[Zn(H₂tbba)₂(H₂O)] · 2(OC₃H₆)} _n (1) and {[Mn(H₂tbba)₂(H₂O)] · 2(OC₃H₆)} _n (2) (H₂tbba = 2-thiobarbituric acid anion). Compounds 1 and 2 are isostructural with metal ions bridged by four hydroxyl oxygens from four different H₂tbba ligands to form a 3D network. H₂tbba exhibits bidentate coordination with both hydroxyl oxygens participating in coordination, a new coordination mode. Nonlinear absorption and refraction of 1 and 2 in DMF are studied by using Z-scan measurement technique at 532 nm. 1 and 2 possess nonlinear optical absorption and self-focusing.     

Bottom-up synthesis of three heterometallic coordination polymers with layered structures constructed from presynthesized [Sb2(tart)2] metalloligands

Self-assembly of presynthesized [Sb₂(tart)₂]²⁻ metalloligand as molecular building block with metal salts affords three unique heterometallic coordination polymers, namely, {[Ln(H₂O)₆][Sb₂(tart)₂]}Cl·5H₂O (Ln = La (1), Pr (2)) and {[Ba₂(H₂O)₇][Sb₂(tart)₂]₂}·4H₂O (3), (tart = tartaric acid). Their structures were determined by single crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, and TG analyses. Compounds 1 and 2 are isostructural and represent the first examples of lanthanide-organic open frameworks containing [Sb₂(tart)₂]²⁻ metalloligands. The structures of 1 and 2 contain left-handed and right-handed layer, each built up from the same-handed helical chains. Compound 3 consists of two kinds of arm-shaped chiral layers, which alternately stack in a heterochiral fashion to yield a racemic 3D hydrogen-bonded network with 1D channels along the a axis. To the best of our knowledge, compounds 1-3 are the first 2D chiral layer frameworks constructed from [Sb₂(tart)₂]²⁻ metalloligands and rare-earth or alkaline-earth metal ions.     

Syntheses and Structural Characterization of 1D Chain and 1D Ladder Coordination Polymers Assembled from Exo‐bidentate Imidazolyl Ligands

Five novel coordination polymers, [(Cu(L¹)₂OH) · Cl · 3H₂O] ( 1 ) [L¹ = bis(N‐imidazolyl)methane], [Cd(L¹)₂(NCS)₂] ( 2 ), [Zn(L¹)₂(NCS)₂] ( 3 ), [Cu(L¹)₂(NO₃)₂] ( 4 ), and [Cu(L²)_1.5(NCS)₂] ( 5 ) [L² = 1,4‐bis(N‐imidazolyl)butane] were obtained from self‐assembly of the corresponding metal salts with flexible ligands and their structures were fully characterized by X‐ray diffraction (XRD) analysis, Fourier Transform Infrared (FT‐IR) spectroscopy, elemental analysis and thermogravimetric (TGA) measurements. X‐ray diffraction analyses revealed that complexes 1 , 2 , 3 , and 4 exhibit 1D double‐stranded chain structures, which result from doubly bridged [CuOH], [M(NCS)₂] (M = Cd, Zn), and [Cu(NO₃)₂] units, respectively. The polymeric copper complex 5 displays 1D ladder structure., These complexes, with the exception of complex 1 , are stable up to 300 °C.     

Cyclodiphosphazanes with functionalities: Synthesis, reactivity and transition metal chemistry

The saturated, four-membered rings of the type [XP(μ-NR)]₂ containing alternating phosphorus(III) and nitrogen atoms are known as cyclodiphosphazanes or diazadiphosphetidines. The current interest in these well-known heterocycles is due to their catalytic and biological applications besides their excellent synthetic utility as scaffolds to design interesting macrocycles with or without involving main group or transition metals. Although the rigid and nearly-planar neutral P₂N₂ rings resemble [Cu(μ-X)]₂ (X = Cl, Br or I) rhombic units ([Cu(μ-X)]₂ are known for giving a variety of structures with suitable ligands), their utility in designing the high-nuclearity clusters, cages or coordination polymers is scarce. In this context, we fine tuned the coordinating ability of these ligands by incorporating pendant hemi-labile functionalities on phosphorus centers which resulted in the isolation of several interesting molecules. The details are described.     

Two transition metal supramolecular compounds based on 2-(4-isopropylbenzoyl)benzoic acid: syntheses,crystal structures,and luminescent properties

Two new supramolecular compounds, [Zn₂(L)₃(4,4′-bpy)(OH)]_n (1) and [Cd(L)₂(2,2′-bpy)(H₂O)]·2H₂O (2) (HL?=?2-(4-isopropylbenzoyl)benzoic acid, 4,4′-bpy?=?4,4′-bipyridine, 2,2′-bpy?=?2,2′-bipyridine), have been hydrothermally synthesized and characterized by elemental analysis, infra-red spectroscopy, thermal gravimetric analyzes, and single-crystal X-ray diffraction. 1 exhibits 1-D chain and 2 is 0-D mononuclear. They are both linked into 2-D supramolecular layers by non-covalent interactions. Luminescence properties were also investigated.     

Synthesis,Structures, and Photoluminescence Properties of Five Novel Zinc(II) and Cadmium(II) Coordination Polymers based on Different Zwitterionic Pyridine Ligands

A series of five new Zn^II and Cd^II mixed‐ligand coordination polymers, namely, {[Zn(L₁)(4,4′‐bpy)] · (ClO₄) · 2H₂O} ( 1 ), {[Zn(L₂)(4,4′‐bpy)_0.5] · (ClO₄)} ( 2 ), {[Zn(L₃)(4,4′‐bpy)] · (NO₃) · 2H₂O} ( 3 ), {[Cd(L₄)(4,4′‐bpy)_0.5(NO₃)] · 5H₂O} ( 4 ), and {[Zn(L₄)(4,4′‐bpy)] · Cl · H₂O} ( 5 ) [4,4′‐bpy = 4,4′‐bipyridine, L₁ = 4‐carboxy‐1‐(4‐carboxybenzyl)pyridin‐1‐ium chloride, L₂ = 3‐carboxy‐1‐(4‐carboxybenzyl)pyridin‐1‐ium chloride, L₃ = 4‐carboxy‐1‐(3‐carboxybenzyl)pyridin‐1‐ium chloride, and L₄ = 3‐carboxy‐1‐(3‐carboxybenzyl)pyridin‐1‐ium chloride], were obtained by the reactions of the 4,4′‐bipyridine with four dicarboxylate zwitterionic pyridine ligands. Single‐crystal X‐ray structural analyses reveal that the five complexes demonstrate different molecular frameworks coming from various coordination modes and flexibilities of different dicarboxylate zwitterionic pyridine ligands and central metal atoms. Mononuclear twofold dinuclear 2D twofold interpenetrating net for 2 , four‐coordinate mononuclear twofold interpenetrating 2D layer for 3 , mononuclear 2D layer arranged in parallel and with large grids for 4 , and twofold trans interpenetrating 2D network for compound 5 . The structural diversities in 1 – 5 indicate that the nature of the ligands and the presence of different metal atoms have a great influence on central metal coordination modes and the structural topologies of the metal‐organic molecular architectures. In addition, π ··· π stacking interactions also play important roles in the final crystal packing and supramolecular frameworks. The powder X‐ray diffraction, elemental analysis, and photoluminescence properties of 1 – 5 were studied, which show that architectures play an important role in emission bands and intensities.     

Three d10 coordination polymers assembled from 3,5-bis(imidazole-1-yl)pyridine and different polycarboxylates: Syntheses,structures and luminescence properties

Three novel Zn(II)/Cd(II) coordination polymers, [Cd₂(bip)₂(m-bdc)₂(H₂O)₂·3H₂O]_n (1), [Zn₂(bip)₂(p-bdc)₂·2.5H₂O]_n (2) and [Zn(bip) (p-bdc)·3H₂O]_n (3), where bip = 3,5-bis(imidazole-1-yl)pyridine, m-H₂bdc = 1,3-benzenedicarboxylic acid, p-H₂bdc = 1,4-benzenedicarboxylic acid, have been successfully synthesized under solvothermal conditions. The linkage of different ligands with Cd(II) ions in compound 1 affords a (3,5)-connected layer. Furthermore, 2D→3D parallel polycatenation occurs wherein the layers are polycatenated with the adjacent two parallel layers to form a 3D framework. In 2 and 3, the polycarboxylates act as pillars to combine the metal-bip chains, yielding the layered structures. These 2D networks are extended to the final 3D supramolecular architectures by π-π stacking interactions. The results show that bip can act as a versatile building block for the construction of various coordination polymers. Moreover, the fluorescent properties of 1–3 in the solid state at room temperature have been investigated.     

Syntheses,structures, and properties of transition metal coordination polymers based on a long semirigid tetracarboxylic acid and multidentate N-donor ligands

Six transition metal coordination polymers based on a semirigid tetracarboxylic acid and the multidentate N-donor ligands have been synthesized by the hydrothermal method, namely, {[Co(H₂obda) (μ₂-H₂O) (H₂O)₂]·2H₂O}_n (1), {[Co(obda)_0.5(bpe) (H₂O)₂]·3H₂O}_n (2), {[Zn(H₂obda) (H₂O)₄]·H₄obda·6H₂O}_n (3), {[Zn(bpy) (H₂O)₄]·H₂obda}_n (4), {[Ni(bpy) (H₂O)₄]·H₂obda}_n (5) and {[Cu(H₂obda) (bpy)₂]}_n (6) (H₄obda = 1,4-bis(4-oxy-1,2-benzene dicarboxylic acid)benzene, bpe = 1,2-Bis(4-pyridyl)ethylene), bpy = 4,4′-bipyridine). Compounds 1–6 were structurally characterized by the elemental analyses, infrared spectra, and single crystal X-ray diffractions. Compounds 1–2 exhibit the 2D quadrilateral and polygonal layered grid structures, respectively; a 3D supramolecular structure of 2 has been build via π···π and hydrogen bonds interactions. Compounds 3–6 reveal the 1D zigzag and linear chains structures, respectively; furthermore, 3–5 display the diverse 3D supramolecular structures via hydrogen bonds, respectively. The 1-D infinite water chain in 3 has been found between the lattice water molecules. In addition, the thermogravimetric analyses of 1–6, magnetic property of 1, and photoluminescence of 3–4 have been investigated, respectively.     

Synthesis, structure, and fluorescence of two cadmium(II)-citrate coordination polymers with different coordination architectures

Two novel Cd(II)-citrate complexes were obtained with different metal/ligand ratios through hydrothermal method. Their structures were determined by single-crystal X-ray diffraction analysis. Although their topological structures are both 2-D layer network assemblies, both central Cd(II) ions and Hcit³⁻ ligands display completely different coordination modes. In polymeric complex 1, Hcit³⁻ serves as a μ₁₀-bridged and central Cd(II) ions adopt 6- and 8-coordinated configurations. In contrast, a μ₉-bridged and 6- and 7-coordinated environments between Cd(II) and Hcit³⁻ are established in the polymeric complex 2. Two Complexes remain stable up to approximately 300 °C. The complex 1 exhibits strong fluorescent emission band at 450 nm (λ=346 nm) as well as complex 2 exhibits strong fluorescent emission band at 430 (λ=346 nm).     

Syntheses,structures, and luminescence of coordination compounds based on N-containing polycarboxylates

Six coordination compounds constructed by two structurally related flexible nitrogen-containing polycarboxylate ligands 2,2′-(2,2′-(ethane-1,2-diylbis(oxy))bis(2,1-phenylene))bis(methylene)bis(azanediyl)dibenzoic acid (H₂L1) and 5,5′-(2,2′-(ethane-1,2-diylbis(oxy))bis(2,1-phenylene))bis(methylene)bis(azanediyl)diisophthalic acid (H₄L2) have been synthesized: [Ni(H₂O)₆]?·?L1?·?(C₂H₅OH)_0.5?·?H₂O (1), [Co(L1)(L3)]?·?CH₃OH (2), [Ni(L1)(L3)]?·?CH₃OH (3), [Zn(L1)(L3)]?·?CH₃OH (4), [Cd(L1)(L3)]?·?CH₃OH (5), and [Zn(L2)_0.5(phen)]?·?C₂H₅OH (6), where L3?=?3,4?:?9,10?:?17,18?:?23,24-tetrabenzo-1,12,15,26-tetraaza-5,8,19,22-tetraoxacyclooctacosan and phen?=?1,10-phenanthroline. The crystal structures have been determined by single-crystal X-ray diffraction. Compound 1 displays a discrete structure, which is further linked by hydrogen bonds to form a 2-D supramolecular layer. Compounds 2–5 display similar structures. These compounds possess 1-D meso-chain structures linked by L1 and metals. The C–H?···?π interactions from neighboring chains extend the chains in different directions, giving a 3-D plywood network. Compound 6 possesses 2-D layers, which are further linked by hydrogen-bonding interactions to generate a 3-D supramolecular architecture.     

Syntheses,crystal structures,and properties of four new coordination compounds of transition metals and imidazoledicarboxylic acid derivatives

Four new transition metal coordination complexes, [Cd(H₂pimdc)₂(H₂O)₂]?·?4H₂O (1), [Zn(H₂pimdc)₂(H₂O)₂]₂?·?7H₂O (2), and [M(H₂pimdc)₂] (M?=?Cu (3) or Ni (4), H₂pimdc^??=?2-propyl-4,5-imidazoledicarboxylate), have been prepared by conventional synthesis and characterized by elemental analyses, IR, TG, and single-crystal X-ray diffraction. H₂pimdc^? is a bidentate chelating ligand in 1 and 2, leading to 3-D supramolecular structures through hydrogen bonds. However, H₂pimdc^? is a tridentate chelating-bridge ligand in 3 and 4, which exhibit 2-D layer structures. Thermal properties and photoluminescence spectra of 1–4 were measured.     

Synthesis, characterisation and thermal behaviour of solid state compounds of 4-methylbenzylidenepyruvate with some bivalent metal ions

Solid state M-4-Me-BP compounds, where M stands for bivalent Mn, Fe, Co, Ni, Cu, Zn, Pb and 4-Me-BP is 4-methylbenzylidenepyruvate, have been synthesized. Simultaneous thermogravimetry-differential thermal analysis (TG-DTA), differential scanning calorimetry (DSC), X-ray powder diffractometry, infrared spectroscopy, elemental analysis, and complexometry were used to characterise and to study the thermal behaviour of these compounds. The results led to information about the composition, dehydration, thermal stability and thermal decomposition of the isolated complexes.     

Syntheses,Structures, and Luminescent Properties of d10 Coordination Polymers with 2‐(4‐Carboxyphenyl)‐imidazo[4, 5‐f]‐1, 10‐phenanthroline and 1, 3‐Benzenedicarboxylate Derivatives

Four Zn^II/Cd^II coordination polymers (CPs) based on 2‐(4‐carboxy‐phenyl)imidazo[4, 5‐f]‐1, 10‐phenanthroline (HNCP) and different derivatives of 5‐R‐1, 3‐benzenedicarboxylate (5‐R‐1, 3‐BDC) (R = NO₂, H, OH), [Zn(HNCP)(5‐NO₂‐1, 3‐BDC)]_n ( 1 ), [Cd(HNCP)(5‐NO₂‐1, 3‐BDC)]_n ( 2 ), [Zn(HNCP)(1, 3‐BDC)(H₂O)₂]_n ( 3 ), and {[Zn(HNCP)(5‐OH‐1, 3‐BDC)(H₂O) · H₂O}_n ( 4 ) were synthesized under hydrothermal conditions. Compounds 1 – 4 were determined by elemental analyses, IR spectroscopy, and single‐crystal and powder X‐ray diffraction. Compounds 1 and 2 are isomorphous, presenting a 4‐connected uninodal (4, 4)‐sql 2D framework with threefold interpenetration, which are further extended into the three‐dimensional (3D) supramolecular architecture through π ··· π stacking interactions between the aryl rings of 5‐NO₂‐1, 3‐BDC. Compared to compound 1 , 3 is obtained by using different reaction temperatures and metal‐ligand ratios, generating a 3D framework with –ABAB– fashion via π ··· π stacking interactions. Compound 4 is a 1D chain, which is further extended into a 3D supramolecular net by hydrogen bonds and π ··· π stacking interactions. The thermogravimetric and fluorescence properties of 1 – 4 were also explored.     

Synthesis,Crystal Structures,and Fluorescent Properties of Two ZnII/CdII Coordination Polymers Constructed from Isomeric Ligands

The d¹⁰ coordination polymers (CPs), [Zn(L₁)(OH)]_n ( 1 ) and [Cd(L₂)₂]_n ( 2 ) were obtained from isomeric ligands 3‐(6‐aminpyridinium‐3‐yl) benzoic acid (L₁) and 4‐(6‐aminpyridinium‐3‐yl) benzoic acid (L₂), and characterized by elemental analyses, IR spectroscopy, single‐crystal and powder X‐ray diffraction. In compound 1 , a spiral chain structure connected by μ₂‐OH^– and the Zn^II ions, which are further linked by the L₁ ligands to give atwo‐dimensional layered structure. Classical hydrogen‐bonding interactions (O ··· H–N) between adjacent layers result in three‐dimensional supramolecular structure. Compound 2 features a three‐dimensional framework formed by linking [Cd₂(COO)₂] clusters in a bcu net. Thermal stabilities and fluorescent properties of 1 and 2 were also investigated.