Pulse radiolysis of 4,4'-bipyridyl aqueous solutions at elevated temperatures: spectral changes and reaction kinetics up to 400 degrees C

The spectral changes as well as the reaction kinetics of the transient species of 4,4'-bipyridyl (4,4'-bpy) have been experimentally investigated by pulse radiolysis techniques up to 400 degrees C. The results show that the transient species such as OH adduct 4,4'-bpyOH*, monoprotonated electron adduct 4,4'-bpyH*, and doubly protonated electron adduct 4,4'-bpyH2+* have 15-20 nm blue shifts from room temperature to 400 degrees C. For a deaerated neutral solution of 4,4'-bpy in the presence of tert-butyl alcohol, ethanol, or NaCOOH, the doubly protonated electron adduct is the main transient species at room temperature. But at temperatures > 350 degrees C, a monoprotonated form, the N-hydro radical 4,4'-bpyH*, becomes predominant. Interestingly, at room temperature, CO2-* could not efficiently react with 4,4'-bpy, but the reaction was accelerated with increasing temperature; at 350 degrees C, this reaction completed within 2 mus. Using an alkaline solution (pH = 11.5) of 4,4'-bpy in the presence of tert-butyl alcohol, we studied the N-hydro radical 4,4'-bpyH* from room temperature to 400 degrees C at 25 MPa. An estimation of the temperature-dependent G(e(aq)-) at 25 MPa agrees with our previous result with methyl viologen as a scavenger.     

Incorporation of anthracene into zeolites: confinement effect on the recombination rate of photoinduced radical cation-electron pair.

FT-Raman spectrometry in combination with diffuse reflectance UV/Vis absorption (DRUVv) and fluorescence emission indicate that complete anthracene (ANT) sorption as intact molecules takes place over 6 months in the medium pores of non-Br?nsted acidic M(n)ZSM-5 zeolites (n=0.0, 3.4, 6.6; M=Na+, K+, Rb+, Cs+) with 1 ANT per unit cell loading. The combined effect of confinement and electrostatic field induced by bulky cations (Rb+, Cs+) leads to specific changes in the occluded ANT Raman spectra after very long organization periods (one year). The laser photolysis (266 nm, 355 nm) of ANT@M(n)ZSM-5 equilibrated samples generates long-lived charge separated species in aluminum rich zeolites (n=3.4, 6.6). The very long-lived radical pairs are characterized by conventional DRUVv and CW-EPR spectroscopy. The direct charge recombination rates of ANT.+-electron pairs are dispersive, extending over a broad range of timescales. The kinetic constant values are found to increase dramatically with the aluminum content and increase markedly with M+ according to the following order Na+ < K+ < Rb+ < Cs+. The small reorganization energy (lambda) of ZSM-5 zeolite pores coupled with large negative free energy changes (-DeltaG degrees ) between the ground state ANT oxidation potential and Fermi level of aluminum rich M(n)ZSM-5 explain the observed trends of the ANT.+@M(n)ZSM-5.- charge recombination rates.     

hree Inorganic-organic Composite Polyoxotungstates:Syntheses, Characterization and Structures of [Cu(2,2'-bpy)2]5[α-PW11.5Cu0.5O40]·2H2O,[Co(2,2'-bpy)2(N3)2]4H3[α-PW12O40]·3H2O and [Cu(2,2'-bpy)2(4,4'-bpy)]2[α-GeW12O40]·4H2O

Three new inorganic-organic composite polyoxotungstates [Cu(2,2'- bpy)2]5[α- PW11.5Cu0.5O40]·2H2O 1, [Co(2,2'-bp3)2(N3)2]4H3[α-PW12O40]·3H2O 2 and [Cu(2,2'-bpy)2(4,4'- bpy)]2[α-GeW12O40].4H2O 3 (2,2'-bpy = 2,2'-bipyridine, 4,4'-bpy = 4,4'-bipyridine) have been hydrothermally synthesized and structurally characterized. 1 crystallizes in the orthorhombie space group Pna21 with α = 27.847(3), b = 21.597(2), c = 20.1179(19) A, V = 12099(2) A3, Z = 4, GOF= 1.038, R = 0.0427 and wR = 0.1035; 2 belongs to the triclinic space group P1 with a= 12.31150(10), b = 16.1954(4), c = 19.36290(10) A, α = 99.366(11), β=105.168(8),γ = 111.836(8)°, V = 3309.98(9) A3, Z = 1, GOF = 1.024, R = 0.0739 and wR = 0.2216; and 3 crystallizes in the monoclinic space group P21/n with a = 12.858(4), b = 20.943(6), c = 15.598(5) A, β = 102.338(5)°, V = 4103(2) A3, Z = 2, GOF = 1.026, R = 0.0557 and wR = 0.1316. The common structural features of 1～3 are that their molecular structures all consist of a saturated a-Keggin polyoxoanion and several discrete metal-organic moieties. Intriguingly, 2 and 3 are composed of metal-organic coordination moieties with two mixed ligands.     

Molecular and multidimensional polyoxotungstates functionalized by {Cu(bpy)}2+ groups

Five new materials built from polyoxotungstates and Cu(ii) ions as linkers have been synthesized by hydrothermal reactions from a mixture of sodium tungstate, copper chloride and bipyridine. The value of the initial pH, the nature of the heteroelement (P or Si) and of the ligand (2,2'- and/or 4,4'-bipyridine) permit the control of the nature of the polyoxotungstate clusters and their connectivity via the copper ions, and hence the dimensionality of the framework. A single phase has been obtained with silicon as heteroelement at an initial pH of 5, namely the 2D material [SiW(12)O(40)][Cu(2,2'-bpy)(2)](2).10H(2)O (1) with saturated Keggin polyoxotungstates linked by {Cu(2,2'-bpy)(2)}(2+) groups. With phosphorous as heteroelement and at the same initial pH, three different structures have been isolated according to the nature of the ligand. Indeed, the two 1D materials [{Cu(5)(2,2'-bpy)(5)(H(2)O)(HPO(4))(PO(4))}PW(11)CuO(39)].6H(2)O (2) with 2,2'-bpy and [4,4'-Hbpy][{Cu(2)(2,2'-bpy)(2)(4,4'-bpy)(2.5)}PW(11)CuO(39)].16H(2)O (3) with a mixture of 2,2'- and 4,4'-bpy have been characterized, and a coordination polymer with polyoxometalate guests Na(3)[4,4'-Hbpy]{Cu(4)(4,4'-bpy)(8)(H(2)O)(8)}[PW(11)CuO(39)(H(2)O)][PW(10)Cu(2)O(38)(H(2)O)(2)].38H(2)O (4) with 4,4'-bpy has been obtained. Finally, in basic medium (pH = 10) the unprecedented molecular cluster Na(2)[{Cu(8)(2,2'-bpy)(8)}(PW(8)O(31))(2)].15H(2)O (5) has been evidenced. Magnetic studies of compound 2 revealed that the predominant interactions involve only 4 paramagnetic centers, which are interacting within pairs, among the 6 Cu(ii) centers. The chi(M)T=f(T) curve can be fitted using the dinuclear expression appropriate to the HDVV isotropic exchange Hamiltonian H=-JS(1)xS(2), with S(1)=S(2)=(1/2) and J=-105.4 cm(-1), showing strong antiferromagnetic interactions within the two Cu(ii) pairs.     

A series of manganese-carboxylate coordination polymers exhibiting diverse magnetic properties

The hydrothermal reactions of an asymmetrical 4-(4-carboxyphenylamino)-3,5-dinitrobenzoic acid (H2cpdba), MnCl2.4H2O, or together with 2,2'-bipyridine (2,2'-bpy) or 4,4'-bipyridine (4,4'-bpy) afford three novel molecule-based magnetic coordination polymers [Mn(cpdba)]n (1), ([Mn2(cpdba)2(2,2'-bpy)2(H2O)2].H2O)n (2) and ([Mn2(cpdba)2(4,4'-bpy)].2H2O)n (3). Compound 1 has a 3D acentric coordination network containing carboxylate-bridged 1D ladder-like manganese chains with spin-canted antiferromagnetism (J = -3.51 cm(-1) for the coupling along the ladder legs, and zJ' = 0.22 cm(-1) for coupling along the ladder rungs), whereas compounds 2 and 3 crystallize in the centrosymmetric space groups P1 and C2/c, respectively. 2 exhibits a 1D chain structure, which is extended into a 3D supramolecular network by pi-pi stacking interactions, while 3 features a quite complex 3D network built up from the cpdba(2-) and 4,4'-bpy spacers as well as the carboxylate-bridged Mn(II) chains. Both 2 and 3 show weak antiferromagnetic coupling interactions (J = -0.55 cm(-1) for 2), and a field-induced spin-flop magnetic transition can also be observed in 2 at ca. 3.2 T at 2 K.     

Cuprophilicity-induced cocrystallization of [Cu2(4,4'-bpy)(CN)2]n sheets and [Cu(SCN)]n chains into a 3-D pseudopolyrotaxane

The cocrystallization of [Cu(SCN)]n chains and [Cu2(4,4'-bpy)(CN)2]n (4,4'-bpy = 4,4'-bipyridine) layers generated a 3-D pseudopolyrotaxane compound, [Cu2(4,4'-bpy)(CN)2].[Cu(SCN)] (1), which can also be viewed as a 3-D network constructed by linkages of 2-D sheets and 1-D chains via unsupported CuI-CuI interactions. The CuI-CuI contact of 2.651(4) A in 1 is the shortest unsupported CuI-CuI distance documented to date, indicating cuprophilic attractions.     

Self-assembly of a mixed-ligand metal-coordination polymeric network of cadmium(II) croconate with 4,4'-bipyridine

A new cadmium croconate (C5O5(2-)) complex, [Cd2(C5O5)2(4,4'-bpy)(H2O)]infinity (4,4-bpy=4,4'-bipyridine) with an extended network has been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction studies. The title compound crystallizes in the monoclinic system, space group P2(1)/n, with empirical formula C20H12Cd2N2O12, a=15.9623(3) A, b=7.5837(1) A, c=18.1181(3) A, beta=99.95(2) degrees, and Z=4. Structural determination reveals that the title compound has a bilayered network, containing two crystallographically independent Cd(II) ions in different coordination environments. Cd(1) lies in a distorted pentagonal bipyramidal environment, consisting of three croconate ions and one 4,4'-bpy nitrogen donor, while Cd(2) lies in a distorted octahedral environment, consisting of two croconate anions, one 4,4'-bpy nitrogen donor, and one water molecule. Of the two crystallographic independent croconate ligands, one presents a bis-bidentate adjacent mu3-coordination mode and the other a new bidentate/three-adjacent mu5-coordination mode. A two-dimensional hybrid layer is formed by two rectangular boxes as the building units through the connectivity between Cd(II) and croconate and 4,4'-bpy ligands.     

六氟磷酸二(2,2'-联吡啶)·(4,4'-二甲基-2,2'-联吡啶) 合钌(Ⅱ)的二维核磁共振谱分析

用一维NMR方法研究了电化学发光物质六氟磷酸二(2,2'-联吡啶)·(4,4'-二甲基-2,2'-联吡啶)合钌(Ⅱ)的立体结构,借助二维1H-1H COSY和1H-13C COSY实验技术对其氢谱和碳谱进行了完全的归属,并给出了其氢谱和碳谱的化学位移值.     

Double-stranded helices and molecular zippers assembled from single-stranded coordination polymers directed by supramolecular interactions

Using three nonlinear dicarboxylates, isophthalate (ipa), 4,4'-oxybis(benzoate) (oba), and ethylenedi(4-oxybenzoate) (eoba), we have prepared five neutral infinite copper(II) dicarboxylate coordination polymers containing lateral aromatic chelate ligands, namely [Cu(ipa)(2,2'-bpy)]n.2nH2O (1), [Cu2(ipa)2(phen)2H2O]n (2), [Cu(oba)(phen)]n (3), [Cu(oba)(2,2'-bpy)]n (4), and [Cu(eoba)(phen)]n (5; 2,2'-bpy = 2,2'-bipyridine, phen = 1,10-phenanthroline) by hydrothermal synthesis. X-ray single-crystal structural analyses of these complexes reveal that the nonlinear flexible or V-shaped dicarboxylates can induce the helicity or flexuousity of the polymeric chains and aromatic chelate ligands are important in providing potential supramolecular recognition sites for pi-pi aromatic stacking interactions. An appropriate combination of the bridging dicarboxylate and aromatic chelate can induce a pair of single-stranded helical or flexuous chains to generate a double-stranded helix or molecular zipper through supramolecular interactions, respectively.     

Combination of lacunary polyoxometalates and high-nuclear transition metal clusters under hydrothermal conditions: IX. a series of novel polyoxotungstates sandwiched by octa-copper clusters

The reaction of CuCl(2).2 H2O with trivacant Keggin polyoxoanions K8Na2[A-alpha-GeW9O34].25 H2O or K10[A-alpha-SiW9O34].25 H2O in the presence of 1,2-diaminopropane (dap), ethylenediamine (en) or 2,2'-bipyridine (2,2'-bpy) under hydrothermal conditions afforded five novel hybrid inorganic-organic octa-Cu sandwiched polyoxotungstates (POTs): H4[CuII8(dap)4(H2O)2(B-alpha-GeW9O34)2].13 H2O (1), (H2en)2[CuII8-(en)4(H2O)2(B-alpha-GeW9O34)2].5 H2O(2), (H2en)2[CuII8(en)4(H2O)2(B-alpha-SiW9-O34)2].8 H2O (3), [CuII(H2O)2]H2[CuII8-(en)4(H2O)2(B-alpha-SiW9O34)2] (4), and [CuII2(H2O)2(2,2'-bpy)2]{[CuII(bdyl)]2-[CuII8(2,2'-bpy)4(H2O)2(B-alpha-GeW9-O34)2]}.4 H2O (bdyl=2,2'-bipyridinyl)(5). Additionally, CuCl(2).2 H2O reacts with the mixture of GeO2, Na2WO(4).2 H2O, H2SiW12O(40).2 H2O in the presence of 2,2'-bpy and 4,4'-bpy under hydrothermal conditions leading to another novel mixed-valent octa-Cu sandwiched POT hybrid: [CuI(2,2'-bpy)(4,4'-bpy)]2[{CuI2(2,2'-bpy)2(4,4'-bpy)]2[CuI2CuII6(2,2'-bpy)2(4,4'-bpy)2(B-alpha-GeW9O34)2}].2 H2O (6). 1, 2, and 3 are discrete dimers constructed from two trivacant Keggin [B-alpha-XW9O34]10- (X=GeIV/SiIV) fragments and an octa-Cu cluster whereas 4 displays the 3D (3,6)-connected nets with (4.6(2))(4(2).6(4).8(7).10(2)) topology, which are built by octa-Cu sandwiched polyoxometalate building blocks through copper cation bridges. 5 is a novel 2D layer based on octa-Cu sandwiched POT clusters and [CuII2(bdyl)] units. Interestingly, the rollover metalation of 2,2'-bpy is firstly observed in the system containing the copper complex under hydrothermal conditions. 6 is a discrete mixed-valent octa-Cu sandwiched POT supported by two CuI-complexes [CuI2-(2,2'-bpy)2(4,4'-bpy)]2+ through 4,4'-bpy bridges, which constructs a novel dodeca-copper cluster. Notably, the octa-Cu cluster in 6 is mixed-valent and is different from those in 1-5. To our knowledge, 1-6 represent a rare family of POTs incorporating novel octa-nuclear transition-metal clusters in polyoxometalate chemistry. They were structurally characterized by FT-IR spectra, elemental analysis, thermogravimetric analysis, and single-crystal X-ray diffraction. The magnetic properties of 1, 4, and 5 were quantitatively analyzed by the MAGPACK software package.     

Two Metal-organic Frameworks（MOFs） Assembled from One Asymmetric Semirigid Multicarboxylate Ligand：Syntheses and Crystal Structural Characterizations

Hydrothermal reactions between a new flexible multicarboxylate ligand of 3-(2-carboxy-phenoxy)-benzoic acid(H2L) and transitional metal cations of M2+(M = Cu2+,Ni2+) in the presence of the secondary ligands of 1,10-phenanthroline(phen),2,2'-bipyridine(2,2?-bpy),and 4,4'-bipyridine(4,4'-bpy) afford two novel coordination polymers Ni2(H2O)2L2(phen)(μ-4,4'-bpy)(1) and CuIIL(2,2'-bpy)(2).Both compounds were characterized by X-ray crystallography.Crystal data of 1:C31H24N3NiO7,Mr = 609.24,monoclinic,space group P21/c,a = 17.560(8),b = 10.528(5),c = 30.613(15) ,V = 5659(5) 3,Z = 4,Dc = 1.430 g/cm3,F(000) = 502,μ = 0.739 mm-1,R = 0.0902,wR = 0.1346(I > 2σ(I)),S = 1.002.Crystal data of 2:C24H16CuN2O5,Mr = 475.93,monoclinic,space group P21/n,a = 9.8904(13),b = 11.0782(16),c = 18.321(3) ,β = 11.0782(16)°,V = 1993.8(5) 3,Z = 4,Dc = 1.585 g/cm3,F(000) = 972,μ = 1.137 mm-1,R = 0.0433,wR = 0.0723(I > 2σ(I)) and S = 1.004.Compound 1 displays a one-dimensional(1D) zigzag chain structure constructed from phen ligands and the deprotonated ligands of L2-,which further forms a ladder-shaped supramolecular architecture via the bridge of 4,4'-bpy ligand.Complex 2 also possesses a ladder-shaped architecture based on the dinuclear CuII units.     

Preparations and characterizations of bichromophoric systems composed of a ruthenium polypyridine complex connected to a difluoroborazaindacene or a zinc phthalocyanine chromophore

This paper describes the synthesis of a new series of molecules composed of a ruthenium cation liganded by a chloro or a thiocyanato, a 4,4'-(diethoxycarbonyl)-2,2'-bipyridine, and a 2,2':6',2' '-terpyridine substituted in its 4' position by a difluoroborazaindacene or a zinc phthalocyanine. A set of conditions are reported to conveniently synthesize these dyads by a Stille cross-coupling reaction between the trimethyltin derivative of the organic chromophore and the corresponding ruthenium complex with 4'-bromo-2,2':6',2' '-terpyridine and 4,4'-(diethoxycarbonyl)-2,2'-bipyridine. The dyads were studied by UV-visible absorption spectroscopy, steady-state fluorescence, and electrochemistry. The results of these studies indicate strong electronic coupling between the zinc phthalocyanine unit and the ruthenium complex but weakly electronically coupled systems in the case of dyads containing a difluoroborazaindacene unit. The new bichromophoric systems display strong absorbance in the visible spectrum. An efficient quenching of the fluorescence of the organic chromophore by the nearby ruthenium complex was also observed in all of the dyads. In dyads connected to the borazaindacene, excitation spectra indicate efficient photoinduced energy transfer from the borazaindacene to the ruthenium complex.     

Assembly of heterometallic clusters and coordination polymers by combining Mo-S-based clusters with Mn2+

Addition of [Mo(V)2O2S2(edt)2]2- (edt =1,2-ethanedithiolate) to acetonitrile and/or methanol solutions of MnII containing bipyridines [4,4'-trimethylenedipyridine (TDP), 4,4'-bipyridine (4,4'-bpy), 2,2'-bipyridine (2,2'-bpy)] or 15-crown-5 produces three new heterometallic cluster coordination polymers, [Mn2[Mo2O2S2(edt)2]2(TDP)3(CH3OH)2(NCMe)2].3CH3OH.0.25MeCN (1), [Mn(TDP)2(H2O)2]2+[Mn[Mo2O2S2(edt)2)2(TDP)2]]2-.6CH3OH (2), [Mn[Mo2O2S2(edt)2](TDP)2(CH3OH)(H2O)].CH3OH (3), and three new multinuclear clusters, [Mn[Mo2O2S2(edt)2](4,4'-bpy)(CH3OH)4].0.5(4,4'-bpy) (4), [Mn[Mo2O2S2(edt)2](2,2'-bpy)2].2CH3OH (5), and (NEt4)2[Mn(15-crown-5)[Mo2O2S2(edt)2]2] (6). All compounds were characterized by X-ray crystallography. The coordination mode of Mn in these compounds depends on the ligands and the crystallization conditions. Compound 2 readily converts to 1 or 3 depending on the reaction and solvent conditions. Compounds 1 and 2 were analyzed using thermogravimetric analysis combined with mass spectroscopy (TG-MS) in the temperature range 25-500 degrees C. The room-temperature magnetic moments for compounds 1-6 were determined.     

Photoionization and Electron Transfer of Biphenyl within the Channels of Al-ZSM-5 Zeolites

Evidence of the photogenerated long-lived biphenyl radical and a trapped electron in the void space of aluminated nonacidic ZSM-5 zeolites has been obtained from the time-resolved UV/Vis absorption, Raman scattering, and EPR spectra. The restoration of the ground states implicates the existence of long-lived positive holes in the framework.     

Electroactive chain-like compounds constructed from trimetallic clusters and 4,4'-bipyridine spacers: one-pot synthesis, characterization and surface binding

This paper reports the synthesis and characterization of a novel series of chain-like compounds where oxo-centered triruthenium cluster moieties are bridged by 4,4'-bipyridine (4,4'-bpy) spacers. A reaction of solvent-coordinated triruthenium "monomer" precursor [Ru(3)O(CH(3)CO(2))(6)(CO)(CH(3)OH)(2)] with a 0.1 equimolar amount of 4,4'-bpy in CH(3)OH gave mixture of chain-like compounds containing "dimers" to "tetramers" which were cleanly separated by column chromatography and characterized by spectroscopic and electrochemical methods. Cyclic voltammetry revealed that all chain-like compounds exhibit reversible and stepwise redox processes in solution with very weak intramolecular coupling between the triruthenium components across the 4,4'-bpy bridge. Photo-induced dissociation of CO from the compounds and electrode surface binding were also investigated.     

Efficient green-blue-light-emitting cationic iridium complex for light-emitting electrochemical cells

A highly luminescent novel cationic iridium complex [iridium bis(2-phenylpyridine)(4,4'-(dimethylamino)-2,2'-bipyridine)]PF6 was synthesized and characterized using NMR, UV-visible absorption, and emission spectroscopy and electrochemical methods. This complex displays intense photoluminescence maxima in the green-blue region of the visible spectrum and exhibits unprecedented phosphorescence quantum yields, 80 +/- 10% with an excited-state lifetime of 2.2 mus in a dichloromethane solution at 298 K. Single-layer light-emitting electrochemical cells with the charged complex as conducting and electroluminescent material sandwiched between indium-tin oxide and Ag electrodes were fabricated, which emit green-blue light with an onset voltage as low as 2.5 V. Density functional theory calculations were performed to provide insight into the electronic structure of the [iridium bis(2-phenylpyridine)(4,4'-(dimethylamino)-2,2'-bipyridine)]PF6 complex, comparing these results with those obtained for [iridium bis(2-phenylpyridine)(4,4'-tert-butyl-2,2'-bipyridine)]PF6.     

Polymeric zinc ferrocenyl sulfonate as a molecular aspirator for the removal of toxic metal ions

A porous bilayered open coordination polymer [Zn(4,4'-bpy)(2)(FcphSO(3))(2)](n) (1; FcphSO(3)Na=m-ferrocenyl benzenesulfonate), has been assembled from Zn(NO(3))(2), m-ferrocenyl benzenesulfonate, and the bridging ligand 4,4'-bipyridine (4,4'-bpy). Ion-exchange induced products [Cd(0.6)Zn(0.4)(4,4'-bpy)(2)(FcphSO(3))(2)](n) (2), [Zn(0.75)Pb(0.25)(4,4'-bpy)(2)(FcphSO(3))(2)](n) (3), and [Cu(0.5)Zn(0.5)(4,4'-bpy)(2)(FcphSO(3))(2)](n) (4) could be obtained directly by suspending a big single crystal of 1 into concentrated solutions of Cd(NO(3))(2), Pb(NO(3))(2), and Cu(NO(3))(2), respectively. Most importantly, the big single crystal of 1 could be partly regenerated after immersion into concentrated aqueous solutions of Zn(NO(3))(2). On the other hand, powdered 1 could also be used as a metal ion adsorbent because of the well-defined pore size and pore shape. Ion exchange takes place along with the process of ion sorption. The big single crystal of 1 removes harmful metal ions by means of ion exchange, whereas powdered 1 removes toxic metal ions mainly through ion sorption. Also, compound 1 could be employed as a multi-ion analysis fluorescent probe to detect dangerous metal ions, such as Pb(2+), Cd(2+), Ag(+), and Cu(2+). The compounds described in this study may have potential applications in the design of new molecular devices.     

Structure,Thermal Behavior and Characterization of a New Hybrid Iron Fluoride FeF4(2,2'-bipyridine)(H2O)2

New crystal of FeF₄(2,2'-bipyridine)(H₂O)₂ was prepared by hydrothermal synthesis. Crystalline structure determination is performed from single crystal X-ray diffraction data. The unit cell is monoclinic space group P2₁/n, with cell parameters a=0.9046(5) nm, b=0.7502(5) nm, c=1.9539(5) nm, β=93.307(5)°, V=1.3238(12) nm³ and Z=4. The structure of FeF₄(2,2'-bipyridine)(H₂O)₂ is built up from FeF₄N₂ octahedra coordinated by two nitrogen atoms of the 2,2'-bipyridine molecules, and four fluorine atoms as well as uncoordinated H₂O molecules. Thermal analysis of the title compound showed that the decomposition introduced four steps. IR spectra confirmed the presence of 2,2'-bipyridine molecules. The optical absorption was measured at the corresponding l_max using UV-Vis diffuse reflectance spectrum.     

Synthesis, crystal structure and luminescent properties of one 3D Cd(II) coordination polymer [Cd(H3BPTC)2(bpy)]n (H4BPTC = 1,1'-biphenyl-2,2',6,6'-tetracarboxylic acid, bpy = 4,4'-bipyridine)

A new 3D metal-organic coordination polymer [Cd(H(3)BPTC)(2)(bpy)](n) (1) (H(4)BPTC = 1,1'-biphenyl-2,2',6,6'-tetracarboxylic acid, bpy =4,4'-bipyridine) has been synthesized and characterized by single X-ray diffraction and IR spectroscopy. The one-dimensional metal-organic chains of the title complex, namely [Cd(H(3)BPTC)(2)](n), are held together through hydrogen bonding and bridging "second" ligand 4,4'-bpy to give a three-dimensional metal-organic network. The thermal stability of complex 1 was studied by thermal gravimetric (TG) and differential thermal analysis (DTA). Compound 1 exhibits photoluminescence with an emission maximum at ca. 380 nm upon excitation at ca. 251 nm.