RESUMEN
A CuII coordination polymer, catena-poly[[[aqua-copper(II)]-bis-(µ-4-amino-benz-o-ato)-κ2 N:O;κ2 O:N] monohydrate], {[Cu(pABA)2(H2O)]·H2O}n (pABA = p-amino-benzoate, C7H4NO2 -), was synthesized and characterized. It exhibits a one-dimensional chain structure extended into a three-dimensional supra-molecular assembly through hydrogen bonds and π-π inter-actions. While the twinned crystal shows a metrically ortho-rhom-bic lattice and an apparent space group Pbcm, the true symmetry is monoclinic (space group P2/c), with disordered Cu atoms and mixed roles of water mol-ecules (aqua ligand/crystallization water). The luminescence spectrum of the complex shows an emission at 345â nm, cf. 349â nm for pABAH.
RESUMEN
Two novel 1D heterobimetallic compounds {[MnIII(SB2+)MIII(CN)6]·4H2O}n (SB2+ = N,N'-ethylenebis(5-trimethylammoniomethylsalicylideneiminate) based on orbitally degenerate cyanidometallates [OsIII(CN)6]3- (1) and [RuIII(CN)6]3- (2) and MnIII Schiff base complex were synthesized and characterized structurally and magnetically. Their crystal structures consist of electrically neutral, well-isolated chains composed of alternating [MIII(CN)6]3- anions and square planar [MnIII(SB2+)]3+ cations bridged by cyanide groups. These -ion magnetic anisotropy of MnIII centers. These results indicate that the presence of compounds exhibit single-chain magnet (SCM) behavior with the energy barriers of Δτ1/kB = 73 K, Δτ2/kB = 41.5 K (1) and Δτ1/kB = 51 K, Δτ2 = 27 K (2). Blocking temperatures of TB = 2.8, 2.1 K and magnetic hysteresis with coercive fields (at 1.8 K) of 8000, 1600 Oe were found for 1 and 2, respectively. Theoretical analysis of the magnetic data reveals that their single-chain magnet behavior is a product of a complicated interplay of extremely anisotropic triaxial exchange interactions in MIII(4d/5d)-CN-MnIII fragments: -JxSMxSMnx-JySMySMny-JzSMzSMnz, with opposite sign of exchange parameters Jx = -22, Jy = +28, Jz = -26 cm-1 and Jx = -18, Jy = +20, Jz = -18 cm-1 in 1 and 2, respectively) and single orbitally degenerate [OsIII(CN)6]3- and [RuIII(CN)6]3- spin units with unquenched orbital angular momentum in the chain compounds 1 and 2 leads to a peculiar regime of slow magnetic relaxation, which is beyond the scope of the conventional Glaubers's 1D Ising model and anisotropic Heisenberg model.
RESUMEN
The reaction of [Cu(CH3CN)4](BF4) with 1-methyl-1,3-imidazolidine-2-thione {SC3H4(NMe)NH}, under aerobic conditions at room temperature, yielded an unusual one-dimensional coordination polymer, namely, catena-poly[[[(1-meth-yl-1,3-imidazolidine-2-thione-κS)copper(I)]-µ-(1-methyl-1,3-imidazolidine-2-thione)-κ2 S:S-copper(I)-µ-[3,3'-(sulfanedi-yl)bis-(1-methyl-1,3-imidazolidine-2-thione)]-κ5 S,S',S'':S,S''] bis-(tetra-fluorido-borate)], {[Cu2(C4H8N2S)2(C8H14N4S3)](BF4)2} n or [Cu4(κ5:L 1-N-S-N-L 1)2(κ1:L 1-NH)2(κ2:L 1-NH)2] n (BF4)4n 1 [L 1 = SC3 H4(NMe)NH] with sulfur-bridged {CuI 4S10} n central cores. The in situ generated bis-(1-methyl-1,3-imidazolidinyl-2-thione) sulfide [{SC3H4(NMe)NSN(NMe)C3H4S; abbrev. L 1-N-S-N-L 1] ligand, in combin-ation with 1-methyl-1,3-imidazolidine-2-thione (L 1-NH) ligands, construct this coordination polymer. Each CuI ion is bonded to four sulfur donor atoms in a distorted tetra-hedral geometry and the formation of this polymer solely by sulfur donor atoms with {CuI 4S10} n central cores, is the first such example in copper-heterocyclic-2-thione chemistry.
RESUMEN
Two kinds of silver(I) coordination polymers consisting of the same chemical composition, [Ag(CF3SO3)(L)] [L is 2-methylidene-1,3-bis(nicotinoyloxy)propane], were synthesized and characterized by infrared (IR) and photoluminescence (PL) spectroscopy, elemental and thermal analyses, and single-crystal X-ray diffractometry; these are catena-poly[[(trifluoromethanesulfonato-κO)silver(I)]-µ-2-methylenepropane-1,3-diyl dinicotinate-κ2N:N'], [Ag(CF3SO3)(C16H14N2O4)]n, and its chloroform monosolvate, {[Ag(CF3SO3)(C16H14N2O4)]·CHCl3}n. The X-ray crystallographic measurements revealed that the silver(I) compounds exhibit one-dimensional sinusoidal or helical molecular structures depending on the solvent used for crystallization. Self-assembly in a methanol/chloroform mixture produces the sinusoidal molecular strand, whereas recrystallization from acetonitrile medium affords a racemic mixture of the helical strands. These compounds display a fluorescence emission arising from both the ligand-centred transition and the ligand-to-metal charge transfer (LMCT) in the solid state under ambient conditions.
RESUMEN
Pyrimidine-2-thione (HSpym) reacts with lead(II) thiocyanate and lead(II) bromide in N,N-dimethylformamide (DMF) to form poly[(µ-isothiocyanato-κ2N:S)(µ4-pyrimidine-2-thiolato-κ6N1,S:S:S:S,N3)lead(II)], [Pb(C4H3N2S)(NCS)]n or [Pb(Spym)(NCS)]n, (I), and the polymeric one-dimensional (1D) compound catena-poly[[µ4-bromido-di-µ-bromido-(µ-pyrimidine-2-thiolato-κ3N1,S:S)(µ-pyrimidine-2-thione-κ3N1,S:S)dilead(II)] N,N-dimethylformamide monosolvate], {[Pb2Br3(C4H3N2S)(C4H4N2S)]·C3H7NO}n or {[Pb2Br3(Spym)(HSpym)]·DMF}n, (IIa), respectively. Poly[µ4-bromido-di-µ3-bromido-(µ-pyrimidine-2-thiolato-κ3N1,S:S)(µ-pyrimidine-2-thione-κ3N1,S:S)dilead(II)], [Pb2Br3(C4H3N2S)(C4H4N2S)]n or [Pb2Br3(Spym)(HSpym)]n, (IIb), could be obtained as a mixture with (IIa) when using a lesser amount of solvent. In the crystal structures of the pseudohalide/halide PbII stable compounds, coordination of anionic and neutral HSpym has been observed. Both Spym- (in the thiolate tautomeric form) and NCS- ligands were responsible for the two-dimensional (2D) arrangement in (I). The Br- ligands establish the 1D polymeric arrangement in (IIa). Eight-coordinated metal centres have been observed in both compounds, when considering the Pb...S and Pb...Br interactions. Both compounds were characterized by FT-IR and diffuse reflectance spectroscopies, as well as by powder X-ray diffraction. Compound (IIa) and its desolvated version (IIb) represent the first structurally characterized PbII compounds containing neutral HSpym and anionic Spym- ligands. After a prolonged time in solution, (IIa) is converted to another compound due to complete deprotonation of HSpym. The structural characterization of (I) and (II) suggests HSpym as a good candidate for the removal of PbII ions from solutions containing thiocyanate or bromide ions.
RESUMEN
A novel manganese(III)-porphyrin complex, namely, catena-poly[[chloridomanganese(III)]-µ2-5,10,15,20-tetrakis(pyridin-3-yl)-21H,23H-porphinato(2-)-κ5N21,N22,N23,N24:N5], [MnCl(C40H24N8)]n, 1, was prepared by the hydrothermal reaction of manganese chloride with 5,10,15,20-tetrakis(pyridin-3-yl)-21H,23H-porphine. The crystal structure was determined by single-crystal X-ray diffraction. The porphyrin macrocycle exhibits a saddle-like distortion geometry. The MnIII atom has a six-coordination geometry. Each porphyrin unit links to two neighbouring units to yield a one-dimensional coordination polymer. These chains are further interlinked by hydrogen bonds to form a two-dimensional network. The complex shows red photoluminescence emission bands in ethanol solution, which can be attributed to ligand-to-ligand charge transfer (LLCT) accompanied by partial metal-to-ligand charge transfer (MLCT), as revealed by TDDFT calculations.
RESUMEN
Employment of the organic 2-(pyridin-4-yl)quinoline-4-carboxylic acid ligand with extended coordination capabilities leads to the formation of the one-dimensional copper(II) coordination polymer catena-poly[[diaquacopper(II)]-bis[µ-2-(pyridin-4-yl)quinoline-4-carboxylato]-κ2N2:O;κ2O:N], {[Cu(C15H9N2O2)2(H2O)2]·2H2O}n, under hydrothermal conditions. The ligand, isolated as its hydrochloride salt, namely, 4-(4-carboxyquinolin-2-yl)pyridinium chloride monohydrate, C15H11N2O2+·Cl-·H2O, reveals a pseudosymmetry element (translation a/2) in its crystal structure. The additional pyridyl N atom, in comparison with the previously reported analogues with an arene ring instead of the pyridyl ring in the present ligand molecule, promotes the formation of a one-dimensional coordination polymer, rather than discrete molecules. This polymer shows photoluminescent properties with bathochromic/hypsochromic shifts of the ligand absorption bands, leading to a single band at 479â nm. The CuII ions are involved in weak antiferromagnetic interactions within dimeric units, as evidenced by SQUID magnetometry.
RESUMEN
Three novel complexes, namely, penta-µ-acetato-bis(µ2-2-{[2-(6-chloropyridin-2-yl)hydrazinylidene]methyl}-6-methoxyphenolato)-µ-formato-tetramanganese(II), [Mn4(C13H11ClN3O2)2(C2H3O2)5.168(CHO2)0.832], 1, hexa-µ2-acetato-bis(µ2-2-{[2-(6-bromopyridin-2-yl)hydrazinylidene]methyl}-6-methoxyphenolato)tetramanganese(II), [Mn4(C13H11BrN3O2)2(C2H3O2)6], 2, and catena-poly[[µ2-acetato-acetatoaqua(µ2-2-{[2-(6-chloropyridin-2-yl)hydrazinylidene]methyl}-6-methoxyphenolato)dimanganese(II)]-µ2-acetato], [Mn2(C13H11ClN3O2)(C2H3O2)3(H2O)]n, 3, have been synthesized using solvothermal methods. Complexes 1-3 were characterized by IR spectroscopy, elemental analysis and single-crystal X-ray diffraction. Complexes 1 and 2 are tetranuclear manganese clusters, while complex 3 has a one-dimensional network based on tetranuclear Mn4(L1)2(CH3COO)6(H2O)2 building units (L1 is 2-{[2-(6-chloropyridin-2-yl)hydrazinylidene]methyl}-6-methoxyphenolate). Magnetic studies reveal that complexes 1-3 display dominant antiferromagnetic interactions between MnII ions through µ2-O bridges. In addition, 1-3 also display favourable electrochemiluminescence (ECL) properties.
RESUMEN
By employing the conjugated bithiophene ligand 5,5'-bis(1H-imidazol-1-yl)-2,2'-bithiophene (bibp), which can exhibit trans and cis conformations, two different CuII coordination polymers, namely, poly[[µ-5,5'-bis(1H-imidazol-1-yl)-2,2'-bithiophene-κ2N:N'](µ2-4,4'-oxydibenzoato-κ2O:O')copper(II)], [Cu(C14H8O5)(C14H10N4S2)]n or [Cu(bibp)(oba)]n, (I), and catena-poly[µ-aqua-bis[µ-5,5'-bis(1H-imidazol-1-yl)-2,2'-bithiophene-κ2N:N']bis(µ3-4,4'-oxydibenzoato)-κ3O:O':O'';κ4O:O',O'':O'-dicopper(II)], [Cu2(C14H8O5)2(C14H10N4S2)(H2O)]n or [Cu2(bibp)(oba)2(H2O)]n, (II), have been prepared through one-pot concomitant crystallization and characterized by single-crystal X-ray diffraction, IR spectroscopy, elemental analysis, powder X-ray diffraction (PXRD) and thermogravimetric (TG) analysis. Single-crystal X-ray diffraction indicates that the most interesting aspect of the structure is the existence of sole trans and cis conformations of the bibp ligand in a single net of (I) and (II), respectively. Compound (I) displays a threefold interpenetrating three-dimensional framework with a 4-connected {65.8} cds topology, whereas (II) features a one-dimensional chain structure. In the crystal of (II), the polymeric chains are further extended through C-H...O hydrogen bonds and C-H...π interactions into a three-dimensional supramolecular architecture. In addition, strong intramolecular O-H...O hydrogen bonds formed between the bridging water molecules and the carboxylate O atoms improve the stability of the framework of (II). Furthermore, solid-state UV-Vis spectroscopy experiments show that compounds (I) and (II) exhibit optical band gaps which are characteristic for optical semiconductors, with values of 2.70 and 2.26â eV, respectively.
RESUMEN
The asymmetric unit of the title barium coordination polymer, [Ba(C6H2N3O7)2(C2H6OS)] n , consists of a barium cation (site symmetry m) and a dimethyl sulfoxide (DMSO) ligand (point group symmetry m) and a 2,4,6-tri-nitro-phenolate anion located in general positions. The S atom and the methyl group of DMSO are disordered over two sets of sites. The DMSO ligand bridges a pair of BaII atoms resulting in a chain extending parallel to the a axis. The unique 2,4,6-tri-nitro-phenolate anion also bridges a pair of BaII ions via the phenolic oxygen atom, with each BaII being additionally bonded to an oxygen atom of an adjacent nitro group. The µ 2-monoatomic bridging binding mode of both types of ligands results in the formation of an infinite chain of face-sharing {BaO10} polyhedra flanked by the remaining parts of the 2,4,6-tri-nitro-phenolato and DMSO ligands. In the one-dimensional coordination polymer, parallel chains are inter-linked with the aid of C-Hâ¯O hydrogen bonds.
RESUMEN
A new cyanide-bridged FeIII-MnII heterobimetallic coordination polymer (CP), namely catena-poly[[[N,N'-(1,2-phenylene)bis(pyridine-2-carboxamidato)-κ4N,N',N'',N''']iron(III)]-µ-cyanido-κ2C:N-[bis(4,4'-bipyridine-κN)bis(methanol-κO)manganese(II)]-µ-cyanido-κ2N:C], {[FeMn(C18H12N4O2)(CN)2(C10H8N2)2(CH3OH)2]ClO4}n, (1), was prepared by the self-assembly of the trans-dicyanidoiron(III)-containing building block [Fe(bpb)(CN)2]- [bpb2- = N,N'-(1,2-phenylene)bis(pyridine-2-carboxamidate)], [Mn(ClO4)2]·6H2O and 4,4'-bipyridine, and was structurally characterized by elemental analysis, IR spectroscopy, single-crystal X-ray crystallography and powder X-ray diffraction (PXRD). Single-crystal X-ray diffraction analysis shows that CP 1 possesses a cationic linear chain structure consisting of alternating cyanide-bridged Fe-Mn units, with free perchlorate as the charge-balancing anion, which can be further extended into a two-dimensional supramolecular sheet structure via inter-chain π-π interactions between the 4,4'-bipyridine ligands. Within the chain, each MnII ion is six-coordinated by an N6 unit and is involved in a slightly distorted octahedral coordination geometry. Investigation of the magnetic properties of 1 reveals an antiferromagnetic coupling between the cyanide-bridged FeIII and MnII ions. A best fit of the magnetic susceptibility based on the one-dimensional alternating chain model leads to the magnetic coupling constants J1 = -1.35 and J2 = -1.05â cm-1, and the antiferromagnetic coupling was further confirmed by spin Hamiltonian-based density functional theoretical (DFT) calculations.
RESUMEN
Single crystals of two new bimetallic oxalate compounds with the formula [ACr(C2O4)2(H2O)4]n (A = Li or Na), namely catena-poly[[diaqualithium(I)]-µ-oxalato-κ4O1,O2:O1',O2'-[diaquachromium(III)]-µ-oxalato-κ4O1,O2:O1',O2'], (I), and catena-poly[[diaquasodium(I)]-µ-oxalato-κ4O1,O2:O1',O2'-[di-aquachromium(III)]-µ-oxalato-κ4O1,O2:O1',O2'], (II), have been synthesized, characterized and their crystal structures elucidated by X-ray diffraction analysis and compared. The compounds crystallize in the monoclinic space group C2/m for (I) and in the triclinic space group P-1 for (II); however, they have somewhat similar features. In the asymmetric unit of (I), the Li and Cr atoms both have space-group-imposed 2/m site symmetry, while only half of the oxalate ligand is present and two independent water molecules lie on the mirror plane. The water O atoms around the Li atom are disordered over two equivalent positions separated by 0.54â (4)â Å. In the asymmetric unit of (II), the atoms of one C2O42- ligand and two independent water molecules are in general positions, and the Na and Cr atoms lie on an inversion centre. Taking into account the symmetry sites of both metallic elements, the unit cells may be described as pseudo-face-centred monoclinic for (I) and as pseudo-centred triclinic for (II). Both crystal structures are comprised of one-dimensional chains of alternating trans-Cr(CO)4(H2O)2 and trans-A(CO)4(H2O)2 units µ2-bridged by bis-chelating oxalate ligands. The resulting linear chains are parallel to the [101] direction for (I) and to the [11-1] direction for (II). Within the two coordination polymers, strong hydrogen bonds result in tetrameric R44(12) synthons which link the metal chains, thus leading to two-dimensaional supramolecular architectures. The two structures differ from each other with respect to the symmetry relations inside the ligand, the role of electrostatic forces in the crystal structure and the molecular interactions of the hydrogen-bonded networks. Moreover, they exhibit the same UV-Vis pattern typical of a CrIII centrosymmetric geometry, while the IR absorption shows some differences due to the oxalate-ligand conformation. Polymers (I) and (II) are also distinguished by a different behaviours during the decomposition process, the precursor (I) leading to the oxide LiCrO2, while the residues of (II) consist of a mixture of sodium carbonate and CrIII oxide.
RESUMEN
The new title one-dimensional CdII coordination polymer, [Cd(C10H10N2)2(µ1,3-N3)2] n , has been synthesized and structurally characterized by single-crystal X-ray diffraction. The asymmetric unit consists of a CdII ion, one azide and one 1-benzyl-imidazole (bzi) ligand. The CdII ion is located on an inversion centre and is surrounded in a distorted octa-hedral coordination sphere by six N atoms from four symmetry-related azide ligands and two symmetry-related bzi ligands. The CdII ions are linked by double azide bridging ligands within a µ1,3-N3 end-to-end (EE) coordination mode, leading to a one-dimensional linear structure extending parallel to [100]. The supra-molecular framework is stabilized by the presence of weak C-Hâ¯N inter-actions, π-π stacking [centroid-to-centroid distance of 3.832â (2)â Å] and C-Hâ¯π inter-actions between neighbouring chains.
RESUMEN
The sulfur coordination polymer catena-poly[zinc(II)-µ2-bis[5-(methylsulfanyl)-2-sulfanylidene-2,3-dihydro-1,3,4-thiadiazol-3-ido-κ2N3:S]], [Zn(C3H3N2S3)2]n or [Zn2MTT4]n, constructed from Zn2+ ions and 5-methylsulfanyl-1,3,4-thiadiazole-2-thione (HMTT), was synthesized successfully and structurally characterized. [Zn2MTT4]n crystallizes in the tetragonal space group I-4 (No. 82). Each MTT- ligand (systematic name: 5-methylsulfanyl-2-sulfanylidene-2,3-dihydro-1,3,4-thiadiazol-3-ide) coordinates to two different ZnII ions, one via the thione group and the other via a ring N atom, with one ZnII atom being in a tetrahedral ZnS4 and the other in a tetrahedral ZnN4 coordination environment. These tetrahedral ZnS4 and ZnN4 units are alternately linked by the organic ligands, forming a one-dimensional chain structure along the c axis. The one-dimensional chains are further linked via C-H...N and C-H...S hydrogen bonds to form a three-dimensional network adopting an ABAB-style arrangement that lies along both the a and b axes. The three-dimensional Hirshfeld surface analysis and two-dimensional (2D) fingerprint plots confirm the major interactions as C-H...S hydrogen bonds with a total of 35.1%, while 7.4% are C-H...N hydrogen-bond interactions. [Zn2MTT4]n possesses high thermal and chemical stability and a linear temperature dependence of the bandgap from room temperature to 270â °C. Further investigation revealed that the bandgap changes sharply in ammonia, but only fluctuates slightly in other solvents, indicating its promising application as a selective sensor.
RESUMEN
The structures of a new hybrid terpyridine-pyrazine ligand, namely 4'-[4-(pyrazin-2-yl)phenyl]-4,2':6',4''-terpyridine (L2), C25H17N5, and its one-dimensional coordination polymer catena-poly[[bis(acetylacetonato-κ2O,O')zinc]-µ-4'-[4-(pyrazin-2-yl-κN4)phenyl]-4,2':6',4''-terpyridine-κN1], [Zn(C5H7O2)2(C25H17N5)]n or [Zn(acac)2(L2)]n (Hacac is acetylacetone), are reported. Packing interactions in both crystal structures are analyzed using Hirshfeld surface and enrichment ratio techniques. For the simpler structure of the monomeric ligand, further studies on the interaction hierarchy using the energy framework approach were made. The result was a complete picture of the intermolecular interaction landscape, which revealed some subtle details, for example, that some weak (at first sight negligible) C-H...N interactions in the structure of free L2 play a relevant role in the crystal stabilization.
RESUMEN
Changing the pH value of a reaction system can result in polymers with very different compositions and architectures. Two new coordination polymers based on 1,1'-[1,4-phenylenebis(methylene)]bis(3,5-dicarboxylatopyridinium) (L2-), namely catena-poly[[[tetraaquacadmium(II)]-µ2-1,1'-[1,4-phenylenebis(methylene)]bis(3,5-dicarboxylatopyridinium)] 1.66-hydrate], {[Cd(C22H14N2O8)(H2O)4]·1.66H2O}n, (I), and poly[{µ6-1,1'-[1,4-phenylenebis(methylene)]bis(3,5-dicarboxylatopyridinium)}cadmium(II)], [Cd(C22H14N2O8)]n, (II), have been prepared in the presence of NaOH or HNO3 and structurally characterized by single-crystal X-ray diffraction. In polymer (I), each CdII ion is coordinated by two halves of independent L2- ligands, forming a one-dimensional chain structure. In the crystal, these chains are further connected through O-H...O hydrogen bonds, leading to a three-dimensional hydrogen-bonded network. In polymer (II), each hexadentate L2- ligand coordinates to six CdII ions, resulting in a three-dimensional network structure, in which all of the CdII ions and L2- ligands are equivalent, respectively. The IR spectra, thermogravimetric analyses and fluorescence properties of both reported compounds were investigated.
RESUMEN
The croconate dianion is a highly versatile ligand with two tautomeric forms making it useful for building large superstructures in the solid state. The single-crystal X-ray structures of PbII- and CdII-croconate coordination polymers, namely catena-poly[[[diaqualead(II)]-µ-croconato-κ4O1,O2:O3,O4] monohydrate], {[Pb(C5O5)(H2O)2]·H2O}n, 1, and catena-poly[[triaquacadmium(II)]-µ-croconato-κ4O1,O2:O3,O4], [Cd(C5O5)(H2O)3]n, 2, have been determined. Both polymers form one-dimensional (1D) structures; 1 is a nonplanar 1D zigzag coordination polymer extended along the crystallographic b axis, whereas 2 is a planar 1D ribbon parallel to the [101] direction. In 2, three H2O molecules are coordinated directly to the metal atom, while in 1, only two H2O molecules are directly coordinated to the metal atom. A third interstitial H2O molecule is involved in hydrogen bonding with O atoms of the croconate ligands of an adjacent layer and other H2O molecules, resulting in stacked double layers parallel to the [105] plane. Solid-state FT-IR and solution UV-Vis spectra also substantiate the croconate coordination.
RESUMEN
Compared with the monomorphic type of ligand, combining mixed ligands in one coordination polymer offers greater tunability of the structural framework. Employment of N-heterocyclic ligands and aromatic polycarboxylates is an effective approach for the construction of metal-organic frameworks (MOFs). Two new coordination polymers incorporating both 2-[(1H-imidazol-1-yl)methyl]-1H-benzimidazole (imb) and benzenedicarboxylic acid isomers, namely, catena-poly[[[di-µ-chlorido-bis[(2-carboxybenzoato-κ2O1,O1')cadmium(II)]]-bis{µ-2-[(1H-imidazol-1-yl)methyl]-1H-benzimidazole-κ2N:N'}] dihydrate], {[Cd(C8H5O4)Cl(C11H10N4)]·H2O}n, (I), and poly[[aqua(µ2-benzene-1,3-dicarboxylato-κ3O1,O1':O3){µ2-2-[(1H-imidazol-1-yl)methyl]-1H-benzimidazole-κ2N:N'}cadmium(II)] dihydrate], {[Cd(C8H4O4)(C11H10N4)(H2O)]·2H2O}n, (II), have been prepared and structurally characterized by single-crystal X-ray diffraction. In polymer (I), imb ligands bridge CdII ions, forming a one-dimensional chain, and 2-carboxybenzoate anions coordinate to the CdII ions in a terminal fashion. Polymer (II) exhibits a two-dimensional network structure in which imb ligands and the benzene-1,3-dicarboxylate anions join CdII ions co-operatively. This indicates that changing of the aromatic dicarboxylic acids can result in polymers with different compositions and architectures. Moreover, their IR spectra, PXRD (powder X-ray diffraction) patterns, thermogravimetric analyses and fluorescence properties were also investigated.
RESUMEN
Two one-dimensional (1D) coordination polymers (CPs), namely catena-poly[[[aqua(2,2'-bipyridine-κ2N,N')(nitrato-κO)copper(II)]-µ-1,3-bis(pyridin-4-yl)propane-κ2N:N'] nitrate], {[Cu(NO3)(C10H8N2)(C13H14N2)(H2O)]·NO3}n (1), and catena-poly[[[aqua(nitrato-κO)(1,10-phenanthroline-κ2N,N')copper(II)]-µ-1,3-bis(pyridin-4-yl)propane-κ2N:N'] nitrate], {[Cu(NO3)(C12H8N2)(C13H14N2)(H2O)]·NO3}n (2), have been synthesized using [Cu(NO3)(NN)(H2O)2]NO3, where NN = 2,2'-bipyridine (bpy) or 1,10-phenanthroline (phen), as a linker in a 1:1 molar ratio. The CPs were characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis and single-crystal X-ray structure determination. The 1,3-bis(pyridin-4-yl)propane (dpp) ligand acts as a bridging ligand, leading to the formation of a 1D polymer. The octahedral coordination sphere around copper consists of two N atoms from bpy for 1 or phen for 2, two N atoms from dpp, one O atom from water and one O atom from a coordinated nitrate anion. Each structure contains two crystallographically independent chains in the asymmetric unit and the chains are linked via hydrogen bonds into a three-dimensional network.
RESUMEN
Seven crystal structures of five first-row (Fe, Co, Ni, Cu, and Zn) and one second-row (Cd) transition metal-4-picoline (pic)-sulfate complexes of the form [M(pic)x]SO4 are reported. These complexes are catena-poly[[tetrakis(4-methylpyridine-κN)metal(II)]-µ-sulfato-κ2O:O'], [M(SO4)(C6H7N)4]n, where the metal/M is iron, cobalt, nickel, and cadmium, di-µ-sulfato-κ4O:O-bis[tris(4-methylpyridine-κN)copper(II)], [Cu2(SO4)2(C6H7N)6], catena-poly[[bis(4-methylpyridine-κN)zinc(II)]-µ-sulfato-κ2O:O'], [Zn(SO4)(C6H7N)2]n, and catena-poly[[tris(4-methylpyridine-κN)zinc(II)]-µ-sulfato-κ2O:O'], [Zn(SO4)(C6H7N)3]n. The Fe, Co, Ni, and Cd compounds are isomorphous, displaying polymeric crystal structures with infinite chains of MII ions adopting an octahedral N4O2 coordination environment that involves four picoline ligands and two bridging sulfate anions. The Cu compound features a dimeric crystal structure, with the CuII ions possessing square-pyramidal N3O2 coordination environments that contain three picoline ligands and two bridging sulfate anions. Zinc crystallizes in two forms, one exhibiting a polymeric crystal structure with infinite chains of ZnII ions adopting a tetrahedral N2O2 coordination containing two picoline ligands and two bridging sulfate anions, and the other exhibiting a polymeric crystal structure with infinite chains of ZnII ions adopting a trigonal bipyramidal N3O2 coordination containing three picoline ligands and two bridging sulfate anions. The structures are compared with the analogous pyridine complexes, and the observed coordination environments are examined in relation to crystal field theory.