Synthesis, crystal structures and characterization of four coordination polymers based on 5-amino-2,4,6-triiodoisophthalic acid

One homochiral 1D coordination polymer [Cu(ATIBDC)(2,2′-bipy)]·3H₂O·CH₃OH (1) and three achiral 1D coordination polymers: [Cd(ATIBDC)(2,2′-bipy)(H₂O)]·3H₂O (2), [Cd(ATIBDC)(phen)(H₂O)]·4H₂O (3), and [Mn(ATIBDC)(phen)₂]·5H₂O (4) have been synthesized and characterized (H₂ATIBDC=5-amino-2,4,6-triiodoisophthalic acid, 2,2′-bipy=2,2′-bipyridine, and phen=1,10-phenanthroline). Extended high dimensional network architectures are further constructed with the help of weak secondary interactions, such as hydrogen bonding, aromatic stacking, and halogen bonding (C-I…π and C-I…N/O). Complex 1 crystallizes in the monoclinic system with chiral space group P2(1) and exhibits a right-handed 2₁ helical chain structure. The homochirality of 1 was confirmed by CD spectrum. Interestingly, two new configurations of decameric water cluster are found in 3 and 4. The acyclic tetrameric cluster (H₂O)₃(CH₃OH) in 1 and (H₂O)₄ in 2 array into highly ordered helical infinite chains. Thermal stabilities of all the complexes have been studied. Solid state fluorescent properties of the Cd(II) complexes have been explored.     

Synthesis and characterization of a cadmium(II)–organic supramolecular coordination compound based on the multifunctional 2‐amino‐5‐sulfobenzoic acid ligand

Much attention has been paid by chemists to the construction of supramolecular coordination compounds based on the multifunctional ligand 5‐sulfosalicylic acid (H₃SSA) due to the structural and biological interest of these compounds. However, no coordination compounds have been reported for the multifunctional amino‐substituted sulfobenzoate ligand 2‐amino‐5‐sulfobenzoic acid (H₂asba). We expected that H₂asba could be a suitable building block for the assembly of supramolecular networks due to its interesting structural characteristics. The reaction of cadmium(II) nitrate with H₂asba in the presence of the auxiliary flexible dipyridylamide ligand N,N′‐bis[(pyridin‐4‐yl)methyl]oxamide (4bpme) under ambient conditions formed a new mixed‐ligand coordination compound, namely bis(3‐amino‐4‐carboxybenzenesulfonato‐κO¹)diaquabis{N,N′‐bis[(pyridin‐4‐yl)methyl]oxamide‐κN}cadmium(II)–N,N′‐bis[(pyridin‐4‐yl)methyl]oxamide–water (1/1/4), [Cd(C₇H₆NO₅S)₂(C₁₄H₁₄N₄O₂)₂(H₂O)₂]·C₁₄H₁₄N₄O₂·4H₂O, (1), which was characterized by single‐crystal and powder X‐ray diffraction analysis (PXRD), FT–IR spectroscopy, thermogravimetric analysis (TG), and UV–Vis and photoluminescence spectroscopic analyses in the solid state. The central Cd^II atom in (1) occupies a special position on a centre of inversion and exhibits a slightly distorted octahedral geometry, being coordinated by two N atoms from two monodentate 4bpme ligands, four O atoms from two monodentate 4‐amino‐3‐carboxybenzenesulfonate (Hasba⁻) ligands and two coordinated water molecules. Interestingly, complex (1) further extends into a threefold polycatenated 0D→2D (0D is zero‐dimensional and 2D is two‐dimensional) interpenetrated supramolecular two‐dimensional (4,4) layer through intermolecular hydrogen bonding. The interlayer hydrogen bonding further links adjacent threefold polycatenated two‐dimensional layers into a three‐dimensional network. The optical properties of complex (1) indicate that it may be used as a potential indirect band gap semiconductor material. Complex (1) exhibits an irreversible dehydration–rehydration behaviour. The fluorescence properties have also been investigated in the solid state at room temperature.     

Self assembly of two novel three-dimensional supramolecular networks with blue photoluminescence

Two novel photoluminescent coordination polymers of the formula [Cd(Haip)₂(H₂O)₂] · 2H₂O (1) and [Zn(aip)(atz)] · 3H₂O (2) (H₂aip = 5-aminoisophthalic acid; atz = 3-amino-1,2,4-triazole) have been synthesized through the self-assembly of metal(II) ions with H₂aip and N-containing ligands [2-amino-5-mercapto-1,3,4-thiadiazole for 1 and 3-amino-1,2,4-triazole for 2, respectively] in the presence of NaOH. These complexes were characterized by FT-IR spectroscopy, thermogravimetric analysis (TG), elemental analysis and X-ray analysis. X-ray crystallographic studies of the complexes reveal that 1 is a first example where only one carboxylate group of the H₂aip ligand participates in coordination with the metal(II) ion and it exhibits a two-dimensional framework which further assembles into a three-dimensional supramolecular network via interlayer π–π stacking interactions and strong hydrogen bonds, while 2 exhibits a two-dimensional porous architecture. The extensively strong hydrogen bonds and interlayer π–π stacking interactions in 2 lead to the formation of a three-dimensional supramolecular network. Photoluminescence properties of the compounds 1 and 2 have been examined in the solid state at room temperature. These compounds have been found to exhibit blue photoluminescence and may be good candidates for photoactive materials.     

Syntheses,characterization and luminescent properties of two lead(II) fumarate metal-organic frameworks

It is of interest that the hydrous 3D metal-organic framework (MOF) {[Pb₂(fum)₂(H₂O)₄] · 2H₂O}_n (1) has been synthesized by the reaction of the fum dianion with the lead(II) ion (fum = fumarate) in the presence of pyrazole, while the anhydrous 3D MOF [Pb(fum)]_n (2) is obtained by the reaction of the fum dianion with the lead(II) ion in the presence of pyrazine. These complexes were further characterized by FT-IR spectroscopy, thermogravimetric analysis (TG), X-ray analysis and solid state photoluminescence spectra. The arrangement of the ligands displays a coordination gap around the Pb atom, occupied possibly by a stereoactive lone pair of electrons on lead(II), with the coordination around both the eight-coordinated lead atom in 1 and six-coordinated lead atom in 2 exhibiting a hemidirected geometry. The fum ligand shows different ligation behavior toward the lead(II) ions in these complexes. These compounds exhibit photoluminescence with the maximum emission located in the UV region.     

三核锰配合物[Mn_3O(O_2CCH=CHCH_3)_6(py)_3]ClO_4·py的合成,晶体结构及磁性(英文)

0 Introduction Molecular-based magnetic materials have attractedmuch attention in designing and synthesizing a newclass of magnetic clusters with high spin ground stateand high critical temperature. The synthesis andmagnetic properties of oxo-centered trinuclear man-ganese complexes have been a focus of intense research     

Synthesis,crystal structure and magnetic properties of the first dinuclear copper(II)–iron(II) complex [Cu(L)Fe(CN)5NO] based on nitroprusside

The nitrosyl cyanide [Cu(L)Fe(CN)₅NO] was prepared by the reaction of [Cu(L)]Cl₂ [L = 3, 10-bis(2-hydroxymethyl)-1,3,5,8,10,12-hexaazacyclotetradecane] with Na₂[Fe(CN)₅NO]·2H₂O in aqueous solution. Single-crystal analysis revealed that the title complex is the first structurally characterized dinuclear copper(II)–iron(II) complex based on the nitroprusside. Variable temperature magnetic susceptibility measurements (4.0–180.0 K) show the occurrence of very weak antiferromagnetic interactions between the copper(II) ions with zJ = –0.410 cm^–1.     

Band gap,sorption properties and fluorescence sensing behaviour of a novel 1D→2D cathenane‐like cobalt(II)–organic framework

A novel hydrolytic stable Co^II–organic framework, namely poly[[bis(2‐amino‐4‐sulfonatobenzoato‐κO¹)tetraaquatris{μ‐1,4‐bis[(imidazol‐1‐yl)methyl]benzene‐κ²N³:N^3′}dicobalt(II)] tetrahydrate], {[Co(C₇H₅NO₅S)(C₁₄H₁₄N₄)_1.5(H₂O)₂]·2H₂O}_n, ( 1 ), based on multifunctional 2‐amino‐5‐sulfobenzoic acid (H₂asba) and the auxiliary flexible ligand 1,4‐bis[(imidazol‐1‐yl)methyl]benzene (bix), was prepared using the solution evaporation method. The purity of ( 1 ) was confirmed by elemental analysis and powder X‐ray diffraction (PXRD) analysis. Complex ( 1 ) shows a novel 1D→2D interpenetrating network, which is further extended into a 3D supramolecular framework with channels occupied by the lattice water molecules. The 2‐amino‐4‐sulfonatobenzoate (asba^2?) ligand adopts a monodentate coordination mode. The bix ligands exhibit gauche–gauche (GG) and trans–trans (TT) conformations. A detailed analysis of the solid‐state diffuse‐reflectance UV–Vis spectrum reveals that an indirect band gap exists in the complex. The band structure, the total density of states (TDOS) and the partial density of states (PDOS) were calculated using the CASTEP program. The calculated band gap (E_g) matches well with the experimental one. The complex exhibits a reversible dehydration–rehydration behaviour. Interestingly, gas sorption experiments demonstrate that the new fully anhydrous compound obtained by activating complex ( 1 ) at 400 K shows selective adsorption of CO₂ over N₂. Complex ( 1 ) retains excellent framework stability in a variety of solvents and manifests distinct solvent‐dependent fluorescence properties. Moreover, the complex shows multiresponsive fluorescence sensing for some nitroaromatics in aqueous medium.     

Synthesis, crystal and molecular structure and magnetic properties of [Mn(saloph)(N3)(CH3OH)]

The mononuclear manganese(III) complex of formula [Mn(saloph)(N₃)(CH₃OH)] [saloph=N,N′-o-phenylenebis(salicylidenaminato)] has been synthesized and its crystal structure has been determined by single-crystal X-ray diffraction method. The compound has a 1D hydrogen-bonded extended structure. Both the FT-IR spectrum and the electrospray ionization mass spectrum (ESI-MS) of the title compound have been recorded. The thermogravimetric analysis has also been carried out. Magnetic calculations showed the presence of antiferromagnetic exchange interactions between the manganese(III) ions through hydrogen bonds with J=−4.0 cm⁻¹.     

Preparation and characterization of two three-dimensional metal–organic photoluminescent supramolecular networks

Two novel photoluminescent coordination compounds of the formula [Cd(atpt)phen(H₂O)] · H₂O (1) and [Zn₂(atpt)₂(bipy)₂(H₂O)₂] (2) (H₂atpt = 2-aminoterephthalic acid, bipy = 2,2′-bipyridine and phen = 1,10-phenanthroline) were synthesized through the self-assembly of H₂atpt and N-containing ligands (bipy for 1 and phen for 2) with metal(II) ions in the presence of NaOH, and were characterized by FT-IR spectroscopy, thermogravimetric analysis (TG), X-ray analysis and photoluminescence spectra in the solid state. Compound 1 is the first structurally characterized Cd(II) complex with the atpt ligand. The coordination mode of the atpt ligand in 2 is novel and is first reported in this presentation. X-ray crystallographic studies reveal that compound 1 shows a 1D architecture. Compound 1 further assembles into a 3D supramolecular network via interchain hydrogen bonds and π–π stacking interactions. Compound 2 exhibits a binuclear structure with intramolecular π–π stacking interactions, which is further extended into a 3D supramolecular framework via intermolecular hydrogen bonds and C–H?π interactions. Compounds 1 and 2 exhibit green photoluminescence in the solid state at room temperature.