Assembly of Framework‐Isomeric 4 d–4 f Heterometallic Metal–Organic Frameworks with Neutral/Anionic Micropores and Guest‐Tuned Luminescence Properties

Framework‐isomeric three‐dimensional (3D) Cd–Ln heterometallic metal–organic frameworks (HMOFs), {[Ln₂(ODA)₆Cd₃(H₂O)₆] ? 6 H₂O}_n (Ln=Gd ( 1 a ) and Tb ( 1 b ), ODA=oxydiacetic acid) and {[Cd(H₂O)₆] ? [Ln₂(ODA)₆Cd₂] ? H₂O}_n (Ln=Gd ( 2 a ), Tb ( 2 b )), with neutral and anionic pores, respectively, were designed based on a lanthanide metalloligand strategy and synthesized by using a stepwise assembly and a hydrothermal method. Luminescence studies revealed that 1 b and 2 b can act as luminescent metal–organic frameworks and their light‐emitting properties can be modulated by small guest molecules and the manganese counterion, respectively.     

Synthesis,Structure and Photoluminescent Properties of Zn(II)/Cd(II)‐Complexes Containing 2,4,6‐Tris‐(benzimidazolyl‐2‐yl)pyridine Ligand

Hydrothermal reactions of tridentate rigid 2,4,6‐tris‐(benzimidazolyl‐2‐yl)pyridine (pytbzim) ligand and Zn(II)/Cd(II) salts generate binuclear complexes {[Cd₂Cl₂(pytbzim)₂(H₂O)₂]·2NO₃}_n ( 1 ) and two isomorphs {[M₂Cl₂(pytbzim)₂(H₂O)₂]Cl₂·2H₂O}_n [M=Cd ( 2 ), Zn ( 3 )]. All complexes include [M₂Cl₂(pytbzim)₂(H₂O)₂] dimers, which are further connected into a three‐dimensional supramolecular networks through ?‐? stacking interaction and hydrogen bonds. The solid state photoluminescent studies reveal good fluorescent properties of the pytbzim ligand and complexes 1 – 2 at room temperature.     

Syntheses,Crystal Structures,and Magnetic Properties of Three 1D Chain Metal–Nitroxide Complexes Bridged by ­Flexible Dicarboxylate Anions

Three new one‐dimensional (1D) chain metal–nitroxide complexes {[Cu(NIT4Py)₂(suc)(H₂O)] · 3H₂O}_n ( 1 ), {[Cd(NIT4Py)₂(suc)(H₂O)] · [Cd(NIT4Py)₂(suc)(H₂O)₂] · 3H₂O}_n ( 2 ), and {[Zn(NIT4Py)(glu)(H₂O)] · H₂O}_n ( 3 ) [NIT4Py = 2‐(4′‐pyridyl)‐4, 4, 5, 5‐tetramethylimidazoline‐1‐oxyl‐3‐oxide, suc = succinate anion and glu = glutarate anion] were synthesized and structurally characterized. Single‐crystal X‐ray analyses indicate that the three complexes crystallize in neutral 1D chains in which the metal‐nitroxide units are linked by flexible dicarboxylate anions. The succinate anions only adopt trans configuration in complexes 1 and 2 , whereas the glutarate anion has gauche/anti conformation in complex 3 . Magnetic measurements show that complex 1 exhibits weak antiferromagnetic interactions between the copper ions and the nitroxides.     

Zinc and Cadmium Diphenate Coordination Polymers with Conformationally Flexible Dipyridylamide Ligands

Zinc and cadmium diphenate (dip, biphenyl‐2,2′‐dicarboxylate) coordination polymers containing conformationally flexible dipyridylamide ligands show diverse chain and layer topologies as determined by single‐crystal X‐ray diffraction. [Cd(dipH)₂(bdin)]_n ( 1 ) [bdin = N,N′‐(butane‐1,3‐diyl)diisonicotinamide] shows a simple 1D zigzag chain structure. {[Cd(dip)(pdin)(H₂O)] · 1.25H₂O}_n ( 2 ) [pdin = N,N′‐(propane‐1,3‐diyl)diisonicotinamide] shows bilayer slabs formed by interleaving of (4,4) rectangular grid layers. {[Zn₂(dip)₂(3‐pna)₂] · 3H₂O}_n ( 3 ) (3‐pna = 3‐pyridylnicotinamide) manifests a rare 4‐connected 1D ribbon topology. {[Cd(dip)(4‐ppbp)] · 2H₂O}_n ( 4 ) [4‐ppbp = propane‐1,3‐diylbis(piperidine‐4,1‐diyl)bis(pyridin‐4‐ylmethanone)] shows a 3,5‐connected layer with (4²6)(4²6⁷8) 3,5L2 topology. {[Zn₄(dip)₄(H₂O)₂(4‐ppbp)₂] · 12H₂O}_n ( 5 ) exhibits 2D 3,6‐connected layers with (4³)₂(4⁶6⁶8³) kgd topology featuring embedded R(8)A(2) classification 10‐membered water clusters. Compounds 1 , 4 , and 5 undergo violet or blue‐violet fluorescence upon ultraviolet irradiation. Thermal decomposition behavior of the new phases is also discussed.     

Substituent Dependent Dimensionality in Luminescent Zinc Isophthalate Coordination Polymers Containing Bis(3‐pyridylmethyl)piperazine

Divalent zinc coordination polymers containing bis(3‐pyridylmethyl)piperazine (3‐bpmp) and isophthalate ligands have been hydrothermally synthesized and structurally characterized by single‐crystal X‐ray diffraction. {[Zn(ip)(H3‐bpmp)]ClO₄·4H₂O}_n ( 1 , ip = isophthalate) has twofold parallel interpenetrated (4,4) grid cationic coordination polymer nets, with unligated perchlorate ions and intriguing infinite water molecule chains. {[Zn₂(NO₂ip)₃(H₂3‐bpmp)(H₂O)₅]·3H₂O}_n ( 2 , NO₂ip = 5‐nitroisophthalate) exhibits a supramolecular lattice built from 1D chain motifs, revealing a significant dependence of topology on the steric bulk of the dicarboxylate ligand. Luminescent properties for 1 and 2 are also reported.     

An Independent 1D Single‐Walled Metal–Organic Nanotube Transformed from a 2D Layer Exhibits Highly Selective and Reversible Sensing of Nitroaromatic Compounds

The syntheses and structures of two new Zn^II complexes, a 2D graphite‐like layer {[Zn(PIA)H₂O] ? H₂O}_n ( 1 ) and an independent 1D single‐walled metal–organic nanotube (SWMONT) {[Zn₂(PIA)₂(bpy)₂] ? 2.5 H₂O ? DMA}_n ( 2 ), have been reported based on a “Y”‐shaped 5‐(pyridine‐4‐yl)isophthalic acid ligand (H₂PIA). Interestingly, the 2D graphite‐like layer in 1 can transform into the independent 1D SWMONT in 2 with addition of 2,2′‐bipyridine (bpy), which represents the first successfully experimental example of an independent 1D metal–organic nanotube generated from a 2D layer by a “rolling‐up” mechanism.     

Six Coordination Polymers based on 4‐(1H‐Imidazol‐1‐yl)phthalic Acid: Structural Diversities,Magnetism and Luminescence Properties

The coordination polymers (CPs), [Ni(L)(H₂O)₄]_n ( 1 ), [Co(HL)₂(H₂O)₂]_n ( 2 ), {[Cu(L)(H₂O)₃] · H₂O}_n ( 3 ), [Mn(L)(H₂O)₂]_n ( 4 ), [Cd(L)(H₂O)₂]_n ( 5 ), and {[Zn₂(L)₂] · H₂O}_n ( 6 ), were solvothermally synthesized by employing the imidazol‐carboxyl bifunctional ligand 4‐(1H‐imidazol‐1‐yl) phthalic acid (H₂L). Single‐crystal X‐ray diffraction indicated that the L^2–/HL^– ligands display various coordination modes with different metal ions in 1 – 6 . Complexes 1 and 2 show one‐dimensional (1D) chain structures, whereas complexes 3 – 6 show 2D layered structures. The magnetic properties of these complexes were investigated. Complexes 1 and 3 indicate weak ferromagnetic interactions, whereas complexes 2 and 4 demonstrate antiferromagnetic interactions. In addition, luminescence properties of 5 and 6 were measured and studied in detail.     

Assembly of Three 2D Metal‐Organic Frameworks (MOFs) Derived from Flexible Ligands, 1,4‐bis(3‐pyridyl)‐2,3‐diaza‐1,3‐butadiene (3‐bpd) and/or 1,2‐bis(4‐pyridyl)ethane (dpe)

Three coordination polymers, {[Cd(3‐bpd)₂(NCS)₂]×C₂H₅OH}_n ( 1 ), {[Cd(3‐bpd)(dpe)(NO₃)₂]×(3‐bpd)}₂ ( 2 ), {[Cd(dpe)₂(NCS)₂]×3‐bpd×2H₂O}_n ( 3 ) (3‐bpd = 1,4‐bis(3‐pyridyl)‐2,3‐diaza‐1,3‐butadiene; dpe = 1,2‐bis(4‐pyridyl)ethane), were prepared and structurally characterized by a single‐crystal X‐ray diffraction method. In compound 1 , each Cd(II) ion is six‐coordinate bonded to six nitrogen atoms from four 3‐bpd and two NCS^? ligands. The 3‐bpd acts as a bridging ligand connecting the Cd(II) ion to generate a 2D layered metal‐organic framework (MOF) by using a rhomboidal‐grid as the basic building units with the 4⁴ topology. In compound 2 , the Cd(II) ion is also six‐coordinate bonded to four nitrogen atoms of two 3‐bpd, two dpe and two oxygen atoms of two NO₃^? ligands. The 3‐bpd and dpe ligands both adopt bis‐monodentate coordination mode connecting the Cd(II) ions to generate a 2D layered MOF by using a rectangle‐grid as the basic building units with the 4⁴ topology. In compound 3 , two crystallographically independent Cd(II) ions are both coordinated by four nitrogen atoms of dpe ligands in the basal plane and two nitrogen atom of NCS^? in the axial sites. The dpe acts as a bridging ligand to connect the Cd(II) ions forming a 2D interpenetrating MOFs by using a square‐grid as the basic unit with the 4⁴ topology. All of their 2D layered MOFs in compounds 1 ‐ 3 are then arranged in a parallel non‐interpenetrating ABAB—packing manner in 1 and 2 , and mutually interpenetrating manner in 3 , respectively, to extend their 3D supramolecular architectures with their 1D pores intercalated with solvent (ethanol in 1 or H₂O in 3 ) or free 3‐bpd molecules in 2 and 3 , respectively. The photoluminescence measurements of 1 ‐ 3 reveal that the emission is tentatively assigned to originate from π‐π* transition for 1 and 2 and probably due to ligand‐center luminescence for compounds 3 , respectively.     

Two Unusual Two‐dimensional (4,4) Network Cadmium Coordination Polymers Based on Flexible Bis(triazole) and Rigid Benzenedicarboxylate Co‐ligands

Two cadmium(II) coordination polymers {[Cd(btp)(NO₂‐1,3‐bdc)(H₂O)]·H₂O}_n ( 1 ) and {[Cd(btp)(1,2‐bdc)(H₂O)]·H₂O}_n ( 2 ) were synthesized by the reaction of 1,3‐bis(1,2,4‐triazol‐1‐yl)propane (btp), 5‐nitroisophthalate (NO₂‐1,3‐bdc), and 1,2‐benzenedicarboxylate (1,2‐bdc). 1 consists of undulated 2D (4,4) networks. Two identical undulated layers are parallel stacking to give a (2D→2D) polythreaded 2D network. A 3D supramolecular architectute is constructed through the hydrogen bond interactions. 2 has an unusual 2D (4,4) network with a thickness of ca. 10 Å. The btp ligands exhibit the anti‐gauche conformation in 1 and the anti‐anti conformation in 2 . The flexible btp ligand exhibits the key role in the assembly of the topologies of 1 and 2 . The luminescence and thermal stability were investigated.     

Syntheses,Crystal Structures,Thermal and Photoluminescent Properties of Four Coordination Complexes with a Hetero­cyclic Thioether Carboxylate Ligand

A series of transition metal coordination complexes, {[Cu(3‐Sptta)₂] · 1/2H₂O}_n ( 1 ), {[Cd(3‐Sptta)₂] · 1/2H₂O}_n ( 2 ), [Zn(3‐Sptta)₂(H₂O)₄] ( 3 ), and [Co(3‐Sptta)₂(H₂O)₄] ( 4 ) were synthesized under solvothermal and solvent evaporation conditions using the newly designed heterocyclic N/NS carboxylate ligand [2‐(3‐pyridyl)‐1,3,4‐thiadiazole‐5‐]‐thio‐acetate (3‐Sptta) as a main building block. Their structures were determined by single‐crystal X‐ray diffraction analyses and further characterized by elemental analyses and IR spectroscopy. The four complexes exhibit structural diversity: complexes 1 and 2 exhibit similar 2D “wave‐like” double‐layer framework with two shares of mutually parallel left‐handed and right‐handed helical chains, whereas 3 and 4 present mononuclear structures. Moreover, the thermal stabilities of complexes 1 – 4 were investigated. The luminescent properties of complexes 2 , 3 and the free ligand were also studied.     

Metal‐ and Substituent‐Dependent Structural Diversity in ­Cobalt and Nickel Isophthalate Coordination Polymers with Bis(4‐pyridylformyl)piperazine Tethers

Hydrothermal reactions of nickel or cobalt nitrate with the dipyridylamide ligand bis(4‐pyridylformyl)piperazine (4‐bpfp) and either 5‐methoxyisophthalate (H₂omeip) or 5‐methylisophthalate (H₂mip) afforded a series of coordination polymers that were structurally characterized by single‐crystal X‐ray diffraction. Different synthetic conditions afforded the 1D chain phase {[Ni(Homeip)₂(H₂omeip)(bpfp)] · 2H₂O}_n ( 1 ) or the mutually inclined interpenetrated (4, 4) grid system in {[Ni(omeip)(bpfp)(H₂O)] · 2H₂O}_n ( 2 ). The analogous cobalt phase {[Co(omeip)(bpfp)] · 3H₂O}_n ( 3 ) lacks bound water molecules, which enforces a non‐interpenetrated (4, 4) grid structure based on {Co₂(OCO)₂} dinuclear clusters. Similar clusters are seen in {[Co(mip)(bpfp)(H₂O)₂] · 3.5H₂O}_n ( 4 ), which manifests a 1D ribbon structural motif. Its nickel congener {[Ni(Hmip)₂(bpfp)(H₂O)₂] · 2H₂mip}_n ( 5 ) also shows a 1D chain motif. A variable temperature magnetic susceptibility study indicates antiferromagnetic coupling within the dimeric units in 3 and 4 concomitant with single ion effects. Additionally, thermal degradation properties of these new materials are described.     

Structurally Diverse Divalent Metal Adamantanedicarboxylate Coordination Polymers with Hydrogen‐bonding Capable Dipyridyl Pillaring Ligands

Five new divalent metal coordination polymers containing either 1,3‐adamantanedicarboxylate (adc) or 1,3‐adamantanediacetate (ada) and pillaring dipyridyl ligands were prepared and structurally characterized by single‐crystal X‐ray diffraction. Using the V‐shaped linker 4,4′‐dipyridylamine (dpa), three new phases were isolated. {[Zn₂(ada)₂(dpa)₂] · 4.5H₂O}_n ( 1 ) shows a (4,4) grid topology with embedded octameric water clusters. {[Co(ada)(dpa)(H₂O)] · H₂O}_n ( 2 ) also manifests a 2D dimensionality, but with an intriguing novel (4)(12)(4.12⁵) looped topology. {[Cd(adc)(H₂O)₂] · H₂O}_n ( 3 ) did not incorporate dpa ligands during self‐assembly, but exhibits an uncommon 3‐connected 8³ etb network topology. [Co(ada)(ebin)]_n ( 4 ) [ebin = ethanediaminebis(nicotinamide)] possesses a (3,6) triangular net based on {Co₂(OCO)₂} dimeric units. {[Cd(adc)(ebin)] · 2H₂O}_n ( 5 ) also shows dimeric units, although linked into a decorated (4,4) grid topology. Magnetic susceptibility studies of compound 4 revealed a decrease in χ_mT product upon cooling, ascribed to antiferromagnetic coupling concomitant with single‐ion effects [g = 2.39(2) with D = 40(3) cm^–1 and J = –3.55(4) cm^–1]. Compounds 1 and 5 undergo blue‐violet fluorescence upon ultraviolet irradiation; the zinc derivative 1 shows potential as a sensor for the solution‐phase detection of nitrobenzene and m‐nitrophenol. Thermal decomposition behavior of the five new phases is also discussed.     

Syntheses and Structural Characterization of 1D Coordination Polymers of Transition‐Metal Atoms Containing 2,4‐Pyridinedicarboxylate Bridges

By employing one bridging ligand, 2,4‐pyridinedicarboxylate (2,4‐pda^2?), three one‐dimensional (1D) coordination polymers of [Cu(2,4‐pda)(H₂O)₂]_∞ ( 1 ), {[Cu₄(2,4‐pda)₄(H₂O)₈]·3H₂O}_∞ ( 2 ), and {[Cd(2,4‐pda)(H₂O)₃]·H₂O}_∞ ( 3 ) were synthesized. A simple zigzag polymeric chain is observed for both 1 and 3 , but a railroad‐like zigzag polymeric chain is observed for 2. Almost all water molecules, whether coordinated or not, are involved in hydrogen bonding interactions and help to tie up the 1D polymeric chains of 1‐3 into a three‐dimensional (3D) network. A comparison about the coordination geometries in all similar coordination polymers available to date is also included.     

A Substituent Change Exerts a Large Dimensionality and Water Tetramer Morphology Difference in Luminescent Cadmium Succinate Coordination Polymers Containing 3‐Pyridylnicotinamide

Hydrothermal reaction of cadmium nitrate and the conformationally flexible dipyridine 3‐pyridylnicotinamide (3‐pna) with a substituted succinic acid derivative afforded a pair of crystalline coordination polymers, whose dimensionality depends critically on the number of 2‐position methyl groups on the acid precursor. The two new crystalline extended metal‐organic solids were structurally characterized by single‐crystal X‐ray diffraction. {[Cd(msuc)(3‐pna)] · 2H₂O}_n ( 1 ) (msuc = 2‐methylsuccinate) manifests [Cd(msuc)]_n layer motifs that contain {Cd₂(OCO)₂} dimeric units, linked into a non‐interpenetrated 3D 6‐connected pcu network by tethering anti‐conformation 3‐pna ligands. {[Cd₂(dmsuc)₂(3‐pna)₂] · 1.5H₂O}_n ( 2 ) (dmsuc = 2,2‐dimethylsuccinate) shows 1D [Cd(dmsuc)]_n ribbons containing {Cd₂O₂} dimeric units. In turn these are connected into 2D [Cd₂(dmsuc)₂(3‐pna)₂]_n layer motifs via anti‐conformation 3‐pna linkers; the layers are decorated by pendant monodentate 3‐pna ligands. The subtle steric variance alters the supramolecular environment for co‐crystallized water molecule tetramers, with a discrete chain seen in 1 and a cyclic ring in 2 . Thermal and luminescent properties of these two new materials are also presented.     

Syntheses, Structures and Thermal Stabilities of Three Novel Lanthanide Coordination Polymers with 6-Hydroxynicotinic Acid

Three novel lanthanide coordination polymers {[Ce₂(HOnic)₄(Onic)₂(H₂O)₂]·6H₂O}_n ( 1 ), {[Ln(HOnic)(Onic)‐ (H₂O)₅·(HOnicH)]·H₂O}_n [HOnicH=6‐hydroxynicotinic acid, Ln=Nd ( 2 ), Pr ( 3 )] have been synthesized and characterized by elemental analyses, IR spectrum and single crystal X‐ray diffraction. Structure analyses reveal that 1 features a 2D plane structure while compounds 2 and 3 possess a 1D chain‐like polymeric structure. TG analyses indicate that 1 exhibits higher thermostability than 2 and 3 , which was attributed to the layer polymeric structure of 1 .     

Three Novel 1‐H‐Benzimidazole‐5‐Carboxylate‐Based Nickel(II)/Cobalt(II) Coordination Polymers: Synthesis,Crystal Structures,Luminescent, and Magnetic Properties

Three 1H‐benzimidazole‐5‐carboxylate (Hbic^–)‐based coordination polymers, {[Ni(H₂O)(Hbic)₂] · 2H₂O}_n ( 1 ), {[Ni(H₂O)₂(Hbic)₂] · 3H₂O}_n ( 2 ), and {[Co₂(H₂O)₄(Hbic)₄] · 4DMF · 3H₂O}_n ( 3 ) were obtained by reactions of the ligand H₂bic and Ni^II or Co^II salts in the presence of different structure directing molecules. They were structurally characterized by single‐crystal X‐ray diffraction, IR spectra, elemental analysis, thermal stability, luminescent, and magnetic measurements. Structural analysis suggests that the three polymers exhibit a 2D (4, 4) layer for 1 and 1D linear double chains for both 2 and 3 due to the variable binding modes and the specific spatial orientation of the Hbic^– ligand towards the different paramagnetic metal ions, which were further aggregated into different 3D supramolecular architectures by popular hydrogen‐bonding interactions. Weak and comparable antiferromagnetic couplings mediating by Hbic^– bridge are observed between the neighboring spin carriers for 2 and 3 , respectively. Additionally, complexes 1 – 3 also display different luminescence emissions at room temperature due to the ligand‐to‐metal charge transfer.     

Diamond‐ and Graphite‐Like Octacyanometalate‐Based Polymers Induced by Metal Ions

By using cyclohexane‐1,2‐diamine (chxn), Ni(ClO₄)₂ ? 6H₂O and Na₃[Mo(CN)₈] ? 4H₂O, a 3D diamond‐like polymer {[Ni^II(chxn)₂]₂[Mo^IV(CN)₈] ? 8H₂O}_n ( 1 ) was synthesised, whereas the reaction of chxn and Cu(ClO₄)₂ ? 6H₂O with Na₃[M^V(CN)₈] ? 4H₂O (M=Mo, W) afforded two isomorphous graphite‐like complexes {[Cu^II(chxn)₂]₃[Mo^V(CN)₈]₂ ? 2H₂O}_n ( 2 ) and {[Cu^II(chxn)₂]₃[W^V(CN)₈]₂ ? 2H₂O}_n ( 3 ). When the same synthetic procedure was employed, but replacing Na₃[Mo(CN)₈] ? 4H₂O by (Bu₃NH)₃[Mo(CN)₈] ? 4H₂O (Bu₃N=tributylamine), {[Cu^II(chxn)₂Mo^IV(CN)₈][Cu^II(chxn)₂] ? 2H₂O}_n ( 4 ) was obtained. Single‐crystal X‐ray diffraction analyses showed that the framework of 4 is similar to 2 and 3 , except that a discrete [Cu(chxn)₂]²⁺ moiety in 4 possesses large channels of parallel adjacent layers. The experimental results showed that in this system, the diamond‐ or graphite‐like framework was strongly influenced by the inducement of metal ions. The magnetic properties illustrate that the diamagnetic [Mo^IV(CN)₈] bridges mediate very weak antiferromagnetic coupling between the Ni^II ions in 1 , but lead to the paramagnetic behaviour in 4 because [Mo^IV(CN)₈] weakly coordinates to the Cu^II ions. The magnetic investigations of 2 and 3 indicate the presence of ferromagnetic coupling between the Cu^II and W^V/Mo^V ions, and the more diffuse 5d orbitals lead to a stronger magnetic coupling interaction between the W^V and Cu^II ions than between the Mo^V and Cu^II ions.     

Syntheses,Structures and Luminescent Properties of 2D and 3D Cadmium(II) Coordination Polymers Derived from Two Isomeric Perchlorinated Benzenedicarboxylates

The coordination polymers {[Cd(o‐BDC‐Cl₄)(H₂O)₂]·EtOH}_n ( 1 ) and {[Cd(p‐BDC‐Cl₄)(DMF)]·H₂O}_n ( 2 ) (o‐BDC‐Cl₄ = tetrachlorophthalate and p‐BDC‐Cl₄ = tetrachloroterephthalate) were synthesized in different solvents using two isomeric tetrachlorinated benzenedicarboxylic acids. Complex 1 based on o‐BDC‐Cl₄ features an extremely rare 2D trinodal (3,4,6)‐connected network constructed by the combination of 1D [Cd‐H₂O]_n chains and 1D [Cd₂(o‐BDC‐Cl₄)₂]_n loop‐like motifs. Complex 2 based on p‐BDC‐Cl₄ has a 3D framework and shows a uninodal 4‐connected sra topology. Complexes 1 and 2 were characterized by elemental analyses, IR spectroscopy, single‐crystal X‐ray diffraction and thermogravimetric (TG) analyses. The photoluminescence of 1 and 2 were investigated in the solid state at room temperature.     

Two‐Dimensional Divalent Metal Coordination Polymers Containing 3,4′‐Dipyridylketone Tethers: Layer Topology Tuning by Anion Binding Preferences

Slow diffusion of aqueous cobalt thiocyanate or cadmium perchlorate and ethanolic solutions of 3,4′‐dipyridylketone (3,4′‐dpk) generated the coordination polymers {[Co(NCS)₂(3,4′‐dpk)₂]·2H₂O}_n ( 1 ) and {[Cd(H₂O)₂(3,4′‐dpk)₂](ClO₄)₂·2H₂O}_n ( 2 ), which were structurally characterized by single‐crystal X‐ray diffraction. The structure of 1 consists of interdigitated neutral [Co(NCS)₂(3,4′‐dpk)₂]_n (4,4) rectangular grid coordination polymer layers. However, compound 2 manifests cationic [Cd(H₂O)₂(3,4′‐dpk)₂]_n²ⁿ⁺ two‐dimensional (6,3) herringbone lattices connected through hydrogen bonding mediated by interlamellar unligated perchlorate anions. Upon excitation with ultraviolet radiation, 2 emits blue‐violet light, ascribed to π–π* transitions within the pyridyl rings of the 3,4′‐dpk ligands. Thermal decomposition behavior of 1 is also discussed.     

基于4-(1-咪唑基)苯甲酸配体构筑的一个单一配体和两个混和配体配位聚合物的结构与性质

以4-(1-咪唑基)-苯甲酸(HIBA)为配体,与Cu(NO_3)2·6H_2O和Cd(Ac)_2·2H_2O在加入或不加入5-硝基间苯二甲酸(H_2NPA)的情况下,通过水热法得到了3个新的配位聚合物,分别为{[Cu(IBA)_2]·DMF}n(1)、{[Cd(IBA)2(H_2O)]·3H_2O}n(2)和[Cd_3(IBA)_2(NPA)_2]n(3)。配合物1和2分别为4重和3重穿插的具有金刚石拓扑网络的三维框架结构,配合物3是由混合配体形成的基于一维Cd-羧基次级构筑基元的三维框架结构,其一维构筑基元由Cd髤离子通过IBA-和NPA2-配体同时桥联形成的。此外,还表征了这些化合物的晶相纯度以及配合物2和3的荧光性质。