Rhombic Grid Research Articles

Two-dimensional rhombus grid coordination polymer showing heterogeneous catalytic activities

A coordination polymer, {[Cd(L) 2(DMF) 2]·(ClO 4) 2·(2DMF)} n ( 1) (L = bis-(4-imidazol-1-yl-phenyl)-diazene) has been synthesized at room temperature. The polymer forms a two-dimensional (2D) rhombus-grid sheet structure. These 2D sheets are stacked in ABAB… mode with an inter-planar spacing of 3.729 Å. Each Cd(II) ion is equatorially bonded to four imidazole N atoms belong to four different ligand units while O atoms from two DMF molecules occupy the axial sites. Two ClO 4 − counter anions as well as two DMF molecules occupy the void space in each rhombus grid. This compound catalyzes cyanosilylation reactions of aromatic aldehydes in dichloromethane under mild conditions in heterogeneous fashion. On heating 1 at 120 °C for 4 h, all DMF molecules are lost and the ClO 4 − anions move out of the void space to occupy the axial sites on the metal to yield, de-solvated {[Cd(L) 2(ClO 4) 2]} n ( 1) without losing crystallinity. De-solvated 1 exhibits heterogeneous catalytic activity in several Knoevenagel condensation reactions at RT.

Syntheses and crystal structures of four 1-D or 2-D coordination polymers based on 1-((benzotriazol-1-yl)methyl)-1 H-1,3-imidazole

In this paper, four coordination polymers, {[Ag(bmi)]·NO 3} n ( 1), [Co(N 3) 2(bmi) 2] n ( 2), [Cu(SCN) 2(bmi) 2] n ( 3), and {[Cu(bmi) 2(CH 3OH)(H 2O)]·(ClO 4) 2} n ( 4) have been synthesized through the reactions of an unsymmetrical ligand 1-((benzotriazol-1-yl)methyl)-1 H-1,3-imidazole (bmi) with Ag(I), Co(II) and Cu(II) salts at room temperature. X-ray diffraction analyses showed that compound 1 exhibits double-stranded helical chain. Compounds 2– 4 display 2-D rhombus grid network structure. The rhombus grid consists of 32-membered rings, and gives the dimensions of ca. 8.9 × 8.9 Å for compound 2, ca. 10.1 × 10.1 Å for compound 3, and ca. 9.7 × 9.5 Å for compound 4. In addition, the 2-D layers of compound 3 are stacked into 3-D structure via π– π interactions, while the 3-D architecture of compound 4 is realized through complicated hydrogen bonds and π– π interactions. The thermal analyses of compounds 1 and 3 indicate that they have high thermal stability and are stable up to 259 °C.

Magnetic and Luminescent Properties of Sm, Eu, Tb, and Dy Coordination Polymers with 2‐Hydroxynicotinic Acid

AbstractBy using multidentate ligand 2‐hydroxynicotinic acid (H2nica), six new lanthanide coordination polymers [Sm(Hnica)(H2O)2SO4]n (1), {[Sm3(Hnica)6(H2O)6(OH)]·3H2O·SO4}n (2), [Eu(Hnica)(H2O)2SO4]n (3), {[Eu3(Hnica)6(H2O)6(OH)]·6H2O·SO4}n (4), {[Tb(Hnica)2(H2O)2]ClO4·H2O}n (5), and {[Dy(Hnica)2(H2O)2]ClO4·H2O}n (6) were synthesized and characterized by elemental analysis, IR spectra, and X‐ray single‐crystal diffraction. Compounds 1 and 3 exhibit a 1D Ln–O–Ln chain structure. Compounds 2 and 4 show a 2D Kagomé lattice structure, whereas 5 and 6 display a 2D rhombic grid structure. The luminescent properties of 1–6 at room temperature were studied. Direct‐current (dc) magnetic susceptibility studies reveal antiferromagnetic interactions between LnIII ions in 1–6, and alternating‐current (ac) magnetic susceptibility data of 6 suggests frequency‐dependent out‐of‐phase signals below 5 K.

LED lighting system based on modules that form uniform irradiance of a hexagonal region

Lighting-system modules have been designed that form a uniformly illuminated region of hexagonal shape for the Luxeon<sup>®</sup> Rebel Cool-White LED. The rms error with which a uniform irradiance distribution having an angular size of 143°is formed at a distance of 15 mm from the radiation source was 3–4% with an energy efficiency greater than 81%. These modelling results show that a large, uniformly illuminated region can be formed by means of a system of the indicated modules, located at the nodes of a rhombic grid.

Flexible and Redox‐Active Coordination Polymer: Control of the Network Structure by Pendant Arms of a Macrocyclic Complex

AbstractThe coordination polymer {[Ni(C20H32N8)]2[TCM]}·5DMF·8H2O (1) has been assembled from a NiII macrocyclic complex that contains two pyridyl pendant arms, [Ni(C20H32N8)](ClO4)2, and sodium tetrakis[4‐(carboxyphenyl)oxamethyl]methane (Na4TCM) in DMF/water. The X‐ray structure of 1 reveals that the pyridyl pendant arms in the macrocyclic complex play a crucial role in determining the network structure through the π–π interactions. Compound 1 forms doubly catenated rhombic grids that generate 1D channels. It exhibits flexible behavior upon desorption/resorption and exchange of organic guest molecules as well as temperature change. Solid 1 is redox active due to the incorporated NiII macrocyclic species, and reacts with Pd(NO3)2 dissolved in acetonitrile at room temperature to produce small Pd nanoparticles [(2.9 ± 0.4) nm in diameter] in the channels in the absence of extra reducing or capping agents.

Anion-directed supramolecular assembly of cobalt(II)-fluconazole coordination polymers: Structural diversity, fluorescent and magnetic properties

Six fluconazole-bridged cobalt(II) coordination polymers, namely [Co(HFlu) 2(H 2O) 2](ClO 4) 2 ( 1), [Co(HFlu) 2(H 2O)(AcO)](AcO)·2C 2H 5OH ( 2), [Co(HFlu) 2Cl 2]·2C 2H 5OH ( 3), [Co 3(Flu) 2(acac) 4]·C 2H 5OH ( 4), [Co(HFlu) 2(malo)(H 2O)]·3H 2O ( 5), and [Co(HFlu) 2(fum)(H 2O) 2]·H 2O ( 6) (HFlu = 2-(2′,4′-difluorophenyl)-1,3-bis(1,2,4-triazol-1-yl)-propan-2-ol, AcOH = acetate acid, Hacac = acetylacetonate, H 2malo = malonate acid, H 2fum = fumaric acid), have been synthesized and structurally characterized, and the thermal, fluorescent and magnetic properties investigated. The crystal structures display the one-dimensional cationic double-bridged chain consisting of 20-membered macrocycles to be parallel in 1 and perpendicular in 2. The structure of 3 consists of two-dimensional neutral rhombic grid in bc plane with (4,4) topology and alternative P/M helices intersecting at the Co sites along b direction. Complex 4 shows one-dimensional polymeric chain, in which binuclear Co 2(Flu) 2(acac) 2 units act as bridging blocks to link Co(acac) 2 nodes through triazolyl nitrogen atoms. The structure of 5 shows dimeric 20-membered macrometallacyclic motif. Complex 6 shows HFlu-bridged one-dimensional chain, which is stabilized by hydrogen-bonding interactions to produce alternative hydrophobic and hydrophilic architecture. Complexes 1– 3 and 5– 6 exhibit the similar electronic absorption and fluorescent spectra as those of HFlu, while complex 4 shows a fluorescent quenching phenomenon. Fluorescence titration of HFlu suggests that the fluorescent intensities at the maximal emission decrease upon the addition of Co(acac) 2. The variable-temperature magnetic measurement of 4 reveals weak ferromagnetic interaction combined with the spin–orbit coupling effect in the 1-D Co(II) chain.

A Novel μ2‐(H2O)‐Bridged Double‐Chain Coordination Polymer [Cd(pc)(phen)(H2O)]n with Rhombic Grids (H2pc = pamoic acid, phen = 1,10‐phenanthroline)

AbstractA novel coordination polymer [Cd(pc)(phen)(H2O)]n (H2pc = pamoic acid, phen = 1,10‐phenanthroline) has been synthesized under hydrothermal conditions. Single crystal X‐ray diffraction analysis reveals that the compound crystallizes in triclinic space group P1. All the CdII atoms in the compound are hexacoordinate and are linked by pamoicate ligands to form a one‐dimensional zigzag chain. Furthermore, two adjacent zigzag chains are connected by the μ2‐(H2O) molecules to form a double‐chain with rhombic grids. There exist intermolecular C–H···π contacts, π–π stacking and hydrogen‐bonding interactions. Compound 1 displays strong fluorescent emission in the solid state at room temperature.

Supramolecular Rhombic Grids Formed from Bimolecular Building Blocks

A programmed assembly process produces rhombic grid networks from compounds L1-L4 in the crystal by pi-pi stacking interactions that generate a bimolecular grid synthon, which undergoes further NH...N hydrogen-bond-mediated assembly.

Anion effect on construction of two Cd(II) coordination polymers with phenylformic acid-imidazole ditopic ligand: Hydrothermal synthesis, crystal structure and antimicrobial activity

Two new coordination polymers, [Cd(L−H)2] ∞ (1) and [Cd(L−H)(NO3)] ∞ (2) (L = C10H8N2O2), have been synthesized by hydrothermal reactions of 4-(imidazole-1-yl)-benzoic acid and CdX2 (X = and ). X-ray single crystal diffraction demonstrates that the counterion has an important effect on the assembly process. Crystals of 1 were orthorhombic, space group Pnna, with a = 13.8052(6), b = 16.5126(10) and c = 8.2158(12). Complex 2 crystals were isolated as orthorhombic, space group Pbca, with a = 7.9988(6), b = 15.8290(11) and c = 17.9580(13). Cd2+ is six-coordinate in a distorted octahedral geometry in both complexes. In 1, L bridges the metal centers with the intramolecular Cd ··· Cd separation of 11.651 Å, resulting in an infinite rhombic grid; is not in the grid. In 2, adjacent Cd(II)'s were linked by L, and further by nitrate and carboxylate, producing an infinite zigzag chain. The toxicity of the two complexes is evaluated by testing antimicrobial activity against bacterial strands using the agar diffusion method.

Microwave-Assisted Solvothermal Synthesis of a Dynamic Porous Metal-Carboxylate Framework

By treating Cu(NO3)2·3H2O with a V-shaped ligand 4,4ʼ-oxydibenzoic acid (H2oba), a dynamic metal-carboxylate framework [Cu2(oba)2(DMF)2]·5.25DMF (MCF-23) was synthesized, which features a wavelike layer with rhombic grids based on the paddle-wheel secondary building units. These layers stack via strong offset π-π stacking of the phenyl groups of oba ligands to give three-dimensional porosity. MCF-23 synthesized by conventional solvothermal methods always contains considerable and intractable impurities. In contrast, a microwave-assisted solvothermal method was proven to be a faster and greener approach to synthesize phase-pure MCF-23 in high yield. More interestingly, larger crystals suitable for single-crystal diffraction could be obtained by the multistep microwave heating mode. A powder X-ray diffraction study of MCF-23 reveals the dynamic structural transformation accompanying the release and reabsorption of the guest molecules. The N2 (77 K) and CO2 (195 K) gas sorption isotherms of the guest-free ph...

Hydrothermal Synthesis, Crystal Structures and Photoluminescence of Two Novel Metal‐organic Supramolecular Frameworks Based on Mixed Ligands of Dipyrazino[2,3‐f:2′,3′‐h]quinoxaline and Pyridine‐2,5‐dicarboxylic Acid

AbstractTwo novel metal‐organic frameworks [Zn2(Dpq)2(2,5‐pda)2(H2O)2]·2H2O (1) (dipyrazino[2,3‐f:2′3′‐h]quinoxaline=Dpq) and [Cd2(Dpq)2(2,5‐pda)2]·2H2O (2) (pyridine‐2,5‐dicarboxylic acid=2,5‐H2pda) have been obtained from hydrothermal reactions of two different metal(II) nitrates with the same mixed ligands Dpq and 2,5‐H2pda, and structurally characterized by elemental analyses, TG, IR spectroscopy, and single‐crystal X‐ray diffraction analyse. Single‐crystal X‐ray analyses show that the metal ions are bridged by different coordination modes of 2,5‐pda to form a dimer in 1, 2D rhombic grid in 2, respectively. In the compound 1, adjacent dimers are packed through hydrogen bonds and ‐ aromatic stacking interactions to form a distorted α‐Po supramolecular structure. In the compound 2, adjacent polymer layers are further linked by hydrogen bonds to form a distorted α‐Po 3D supramolecular framework stabilized by ‐ stacking interactions. The different structures of compounds 1 and 2 illustrate the influence of the metal ions and ligands on the self‐assembly of polymeric coordination architectures. In addition, the title compounds exhibit blue emission in the solid state at room temperature.

Anion effect on the construction of copper(II) coordination polymers with the twisted ligand bis(4-pyridylthio)methane

The reaction of CuSO 4 · H 2O with 4-bpytm [4-bpytm = bis(4-pyridylthio)methane] in EtOH afforded the complex [Cu(SO 4)(4-bpytm)(H 2O) 3] · H 2O ( 1 · H 2O ) while the reaction of 4-bpytm with Cu(NO 3) 2 · 3H 2O in EtOH afforded the complex [Cu(NO 3) 2(4-bpytm) 2] · H 2O ( 2 · H 2O). The reaction of 4-bpytm with Cu(NO 3) 2 · 3H 2O in EtOH/dmf under microwave irradiation afforded the pseudo-polymorph [Cu(NO 3) 2(4-bpytm) 2] · Solv ( 2 · Solv). Compound 1 · H 2O forms helical chains while compounds 2 · H 2O and 2 · Solv are 2D coordination polymers with a (4,4) topology based on rhombic grids in 2 · H 2O and on a parquet motif in 2 · Solv. The 3D supramolecular organization through hydrogen bonding is analyzed for the three compounds and their thermal behaviour was also investigated.

Template Synthesis of Lanthanide (Pr, Nd, Gd) Coordination Polymers with 2-Hydroxynicotinic Acid Exhibiting Ferro-/Antiferromagnetic Interaction

Lanthanide coordination polymers were synthesized from Pr(III), Nd(III), and Gd(III) salts; 2-hydroxynicotinic acid (Hnica); and MnSO 4.H 2O under hydrothermal conditions. In the absence of (CH 3) 3CCOONa, 1D polymers with an infinite Ln(III)-O-Ln(III) chain structure, [Pr(Hnica)(H 2O) 2SO 4] n ( 1), [Nd(Hnica)(H 2O) 2SO 4] n ( 2), and [Gd(Hnica)(H 2O) 2SO 4] n ( 3), were generated. When (CH 3) 3CCOONa was added to the synthetic systems, 2D coordination polymers {[Pr 3(Hnica) 6(H 2O) 9].3H 2O.SO 4.NO 3} n ( 4), {[Nd 3(Hnica) 6(H 2O) 9].3H 2O.SO 4.NO 3} n ( 5), and {[Gd(Hnica) 2(H 2O) 2]ClO 4.H 2O} n ( 6) were obtained. Complexes 4 and 5 both exhibit Kagome lattice structure, while 6 displays a rhombic grid structure. All complexes were characterized by elemental analysis, IR spectra, UV-vis spectra, and X-ray single-crystal diffraction. The variable-temperature magnetic susceptibility studies reveal ferromagnetic interactions between gadolinium(III) ions in 3 and 6 and antiferromagnetic interactions in 1, 2, 4, and 5.

4,4‘-Dipyridyl-N,N‘-dioxide Complexes of Metal-Thiocyanate/Selenocyanate: π-Stacked Molecular Rods as Three-Dimensional Support for Two-Dimensional Polymeric Sheets and Intra/Interchain S···S Interaction Dependent Architecture of the (8) Synthon Driven Assembly of One-Dimensional Polymeric Chains

Three supramolecular complexes of Co(II) using SCN-/SeCN- in combination with 4,4‘-dipyridyl-N,N‘-dioxide (dpyo), i.e., {[Co(SCN)2(dpyo)2]·(dpyo)}n (1), {[Co(SCN)2(dpyo)(H2O)2]·(H2O)}n (2), {[Co(SeCN)2(dpyo)(H2O)2]·(H2O)}n (3), have been synthesized and characterized by single-crystal X-ray analysis. Complex 1 is a rare example of a dpyo bridged two-dimensional (2D) coordination polymer, and π-stacked dpyo supramolecular rods are generated by the lattice dpyo, passing through the rhombic grid of stacked layers, resulting in a three-dimensional (3D) superstructure. Complexes 2 and 3 are isomorphous one-dimensional (1D) coordination polymers [-Co-dpyo-Co-] that undergo self-assembly leading to a bilayer architecture derived through an (8) H-bonding synthon between coordinated water and dpyo oxygen. A reinvestigation of coordination polymers [Mn(SCN)2(dpyo)(H2O)(MeOH)]n (4) and {[Fe(SCN)2(dpyo)(H2O)2]·(H2O)}n (5) reported recently by our group [Manna et al. Indian J. Chem. 2006, 45A, 1813] reveals brick wall...

Catena-Poly[[trans-diaquamanganese(II)]-di-μ-3-pyridylacetato

The title manganese(II) coordination polymer, [Mn(C7H6NO2)2(H2O)2]n, which was obtained from a solvothermal reaction of 3-pyridylacetic acid hydro­chloride with Mn(ClO4)2·6H2O, is centrosymmetric, so pairs of equivalent ligands lie trans to each other in a slightly distorted octa­hedral geometry such that the MnII center is coordinated by two pyridyl N atoms [Mn—N = 2.287 (4) Å], two carboxyl­ate O atoms [Mn—O = 2.129 (3) Å] and two water mol­ecules [Mn—O = 2.179 (3) Å]. Each unit is further extended into two-dimensional sheets with a rhombic grid through sharing MnII ions, 3-pyridylacetate anionic ligands and intra­molecular O—H⋯O hydrogen bonds with angles at hydrogen of 147°. Adjacent two-dimensional layers are connected via inter­molecular O—H⋯O and weak C—H⋯O hydrogen-bonding contacts, resulting in a three-dimensional framework with oxygen as a trifurcated acceptor atom.

Synthesis and characterization of two new metal-organic materials based on In III/btec

Two new metal-organic materials, In(2,2′-bipy)(btec) 0.5Cl ( 1) and In 2(phen) 4(Hbtec) 2 ( 2) (btec = 1,2,4,5-benzenetetracarboxylate, 2,2′-bipy = 2,2′-bipyridyl, phen = 1,10-phenanthroline) have been synthesized under mild hydrothermal condition. Their structures were determined by single-crystal X-ray diffraction and further characterized by X-ray powder diffraction, thermogravimetric analysis, IR, fluorescence spectroscopy, inductively coupled plasma (ICP) and elemental analysis. The structural analysis reveals that compound 1 exhibits a novel wavelike 2D layer with unusual contorted rhombic grids, while compound 2 possesses dinuclear In 2(phen) 4(Hbtec) 2 complex molecules. It is noteworthy that their structures finally extend to the higher dimensional supramolecular framework structures through the π–π stacking interactions of N-donor ligands. Additionally, these two compounds show strong fluorescence in the solid state at room temperature.

Cobalt(II), Copper(II), and Zinc(II) Framework Systems Derived from Ditopic Pyridyl-Acetylacetone and Pyridyl-Pyrazole Ligands

The synthesis of two new bifuctional ligand sytems incorporating two different “classical” coordination units connected by a bent (but flexible) thioether linkage is reported. The new systems are the β-diketone-pyridyl derivative, 3-(pyridin-4-ylthio)pentane-2,4-dione (L1), and its hydrazine condensation product, the pyridyl-pyrazole species 4-(3,5-dimethyl-1H-pyrazol-4-ylthio)pyridine (L2). Both systems were designed for use in metal−organic framework studies. With L1, four metal-containing products were crystallized, [Cu(L1−H)2]n (1), {[Cu(L1−H)2]·0.5H2O·CHCl3}n (2), {[Zn(L1−H)2]·2H2O}n (3), and [Zn(L1−H)2]·2MeOH}n (4); these display three different array types. Compound 1 incorporates 5-coordinate Cu(II) ions with square pyramidal stereochemistry. The β-diketonato groups from two ligands coordinate in the basal plane with the apical position occupied by a pyridyl nitrogen from a third ligand that bridges to an adjacent copper center. Propagation of this coordination motif produces a 1D chain. In 2, which is a pseudo-polymorphic phase of 1, each Cu(II) ion is 6-coordinate with each metal center being bound by two bidentate β-diketonato groups and two pyridyl donors from four different ligands in a cis configuration. The ligand arrangement bridges each metal to four others producing an infinite 2D rhombic grid [(4,4) net]. The grids stack to form channels containing disordered water and chloroform molecules; the solvent-accessible space is 33% of the crystal volume. Crystals of 3 are isostructural with 2, except that they incorporate water as the only solvate in the channels. The solvent-accessible voids constitute 22% of the crystal volume, reflecting closer packing of adjacent grids. A TGA study showed that the water molecules are removed by 375 K and that the resulting desolvated complex is stable up to 573 K. Compound 4 is a pseudo-polymorph of 3 in which the 6-coordinate Zn(II) coordination is similar to that in 3 but with polymeric connectivity producing a chiral [8,4] type 3D network (space group P41212). Helical channels corresponding to 25% of the crystal volume run parallel to the 4-fold axes and are occupied by methanol guests. With 4-(3,5-dimethyl-1H-pyrazol-4-ylthio)pyridine (L2), an extended array consisting of zwitterionic [Co(L2+H)Cl3]n (5) units linked by hydrogen bonds and the metal-linked molecular framework species{[Zn(L2)Cl2]·0.5H2O}n (6) were obtained. The cobalt center in 5 is tetrahedrally coordinated by three chloride ions and a pyrazole nitrogen from (L2+H); the protonation is present at the pyridyl nitrogen atom. This protonated pyridyl nitrogen forms a charge-assisted hydrogen bond of type N−H+···Cl with a coordinated chloride from an adjacent complex to yield a hydrogen-bonded chainlike array. Intermolecular N−H···Cl hydrogen bonds also exist between the non-deprotonated pyrazole nitrogen and adjacent chloro ligands. Each tetrahedral Zn(II) center in 6 is coordinated to two chloride ions, a pyridyl nitrogen from one L2 ligand and a pyrazole nitrogen from another. Each L2 thus bridges adjacent Zn(II) centers, forming 1D polymeric chains that aggregate in the crystal to produce narrow channels occupied by water molecules.

Guest‐Dependent Flexible Coordination Networks with Fluorinated Ligands

Guest-dependent flexible coordination networks are formed from 1,4-bis(4-pyridylmethyl)tetrafluorobenzene (bpf), 4,4'-bis(4-pyridylmethyl)octafluorobiphenyl (bpfb), 2,6-bis(4-pyridylmethyl)hexafluoronaphthalene (2,6-bpfn), and 2,7-bis(4-pyridylmethyl)hexafluoronaphthalene (2,7-bpfn) with Cd(NO3)2 in the presence of various organic compounds. The reaction of bpf affords one-dimensional cyclic chains, two-dimensional rhombus grid sheets, and three-dimensional diamond frameworks with threefold interpenetration. The reaction of bpfb mainly affords two-dimensional rhombus grid sheets with twofold parallel interpenetration. The reaction of 2,6-bpfn affords a one-dimensional ladder and two-dimensional rhombus grid, twisted grid, and herringbone sheets. The reaction of 2,7-bpfn affords two-dimensional rhombus grid sheets and grid sheets with dumbbell-shaped cavities. This diversity of network topologies is induced by interactions between the guest molecules and the flexible ligand frameworks.

New d10metal–organic coordination polymers with 9,10-bis(triazol-1-ylmethyl)anthracene (L): Syntheses, crystal structures, and luminescent properties

In our continuous efforts to explore the effects of metal ions, ligand structures, counter-anions on the structure and properties of metal–organic complexes, six new d10 metal coordination polymers with an anthracene-triazole ligand, 9,10-bis(triazol-1-ylmethyl)anthracene (L), {[Cu(L)I]}∞ (1), {[Ag(L)(BF4)]}∞ (2), {[Zn(L)(NO3)2]}∞ (3), {[Zn(L)(CH3OH)2(ClO4)2(H2O)]}∞ (4), {[Cd(L)(CH3OH)2(ClO4)2(H2O)]}∞ (5) and {[Hg(L)(Br2)]}∞ (6), were synthesized and structurally characterized by elemental analyses, IR spectroscopy and single-crystal X-ray diffraction. 1–3 and 6 have similar one-dimensional (1-D) chain structures in which 1, 3 and 6 were further linked into infinite two-dimensional (2-D) sheets by inter-chain C–H⋯I, π⋯π or C–H⋯Br weak interactions, respectively, while 2 was extended into three-dimensional (3-D) supramolecular network by Ag⋯F and Ag⋯N weak interactions. 4 and 5 possess similar (4,4) 2-D sheet structure containing only one type of rhombic grid, and the Zn/Cd atoms are regarded as the four-connected nodes and the ligand as bridges. Obviously, the structural differences among them are attributable to the different metal ions and counter anions. In 1–6, L adopts a trans-gauche conformation with the shortest N⋯N distance between the two N donors. Furthermore, the fluorescent properties of 1–6 and ligand L have been investigated.

Cover Picture: Two‐Dimensional Rectangular and Three‐Dimensional Rhombic Grids Created by Self‐Organization of Random Nanoextrusions (Adv. Eng. Mater. 10/2006)

AbstractNanoextrusions on single crystalline Al and Al‐Mg plates under constrained cyclic tension evolve to regular 2D surface rectangular grids and 3D porous rhombic grids. The cover shows AFM images of the plates along with their 3D reconstructions and associated digital Fourier transforms. More about this type of self‐organization can be found in the paper by Y. G. Gordienko et al. on page 957.