Syntheses,crystal structures and fluorescent properties of two 4,4′-dipyridylsulfide based zinc(II) and cadmium(II) helical complexes

Two allomeric helical coordination polymers, {[Zn(4,4′-dps)₂(HSSA)(H₂O)₂] · 3(H₂O)} _n (1) and {[Cd(4,4′-dps)₂(HSSA)(H₂O)₂] · 3(H₂O)} _n (2) (4,4′-dps = 4,4′-dipyridylsulfide, H₃SSA = 5-sulfosalicylic acid), have been synthesized by similar experimental methods and characterized by elemental analysis, single-crystal X-ray diffraction, and fluorescence spectra. Both crystallize in monoclinic system, space group P₂1/n, with a = 11.7947(13) Å, b = 13.7475(15) Å, c = 20.183(2) Å, and Z = 4 for 1 and a = 11.940(7) Å, b = 14.068(8) Å, c = 20.323(12) Å, and Z = 4 for 2. In both complexes, the metal (Zn^II for 1 and Cd^II for 2) are six-coordinate with a N₃O₃ donor set in a distorted octahedron. Half of the 4,4′-dps are μ ₂-bridging, linking adjacent metal centers and forming P₂1/n dimensional helical structures along the b-axis. Fluorescence measurements show that 1 and 2 have medium fluorescent emission at 402 and 405 nm, respectively.     

Synthesis and crystal structures of two new Zn(II) coordination polymers with 4,4′-dipyridyl disulfide and dicarboxylate acid

The title compounds, Zn(C₅H₆O₄)(Dpds) · 5H₂O (I) and Zn(C₆H₈O₄)(Dpds) (II) (C₅H₈O₄ = glutaric acid, Dpds = 4,4??-dipyridyl disulfide, and C₆H₁₀O₄ = adipic acid), are two-dimensional metal-organic coordination polymers. In I, the tetrahedra coordinated Zn atoms are bridged by glutarate anions and Dpds ligand to form a 2D layer parallel to (001) plane, which are connected by the 1D water tape notated as T4(2)₅(2) to build up 3D supramolecular architecture. In II, both Dpds ligands and adipate anions act as bidentate bridges, connecting the Zn(II) centers in a tetrahedral coordination geometry into a two-dimensional (4,4) layer. Each layer polycatenates adjacent layers, exhibiting the rare combination of 2D ?? 2D parallels interpenetration.     

Synthesis and crystal structure of polymeric 4,4′-bipyridine cadmium(II) sulfate trihydrate

Polymeric 4,4′-bipyridinecadmium(II) sulfate trihydrate, [C₁₀H₈CdN₂O₇S] _n , has been synthesized and characterized by X-ray diffraction and spectroscopic methods. The compound crystallizes in space group P6₅22, with a?=?11.4465(15)?Å, c?=?20.7380(18)?Å. The coordination geometry around cadmium is distorted octahedral with Cd–N2?=?2.311(9), Cd–O1W?=?2.278(8) and Cd–O(SO₄)?=?2.247(7)?Å.     

Syntheses,crystal structures and magnetic properties of two cyano-bridged copper(I)–copper(II) mixed-valence complexes

Two cyano-bridged copper(II)–copper(I) mixed-valence assemblies, Cu(EAM)₂[Cu(CN)₂]₂ 1 (EAM?=?ethanolamine) and Cu(DETA)[Cu(CN)₂]₂·0.5H₂O 2 (DETA?=?diethylenetriamine), have been prepared and structurally and magnetically characterized. IR spectra indicate the presence of bridging cyano groups in both 1 and 2, confirmed by structure analyses; Cu(I)–CN–Cu(II), Cu(I)–CN–Cu(I) and Cu(I)–Cu(I) metal bond linkages are evident. In the lattice, a 3D network is formed by two [Cu(CN)₂]?^? units and one [Cu(EAM)₂]²⁺unit for 1. Variable temperature magnetic susceptibilities, measured in the 5–300?K range, indicate weak antiferromagnetic exchange interactions in complex 1.     

Synthesis, crystal structures, and magnetic properties of two three-dimensional octacyanotungstate(IV)- based bimetallic frameworks with 4,4′-bipyridine dioxide (4,4′-dpdo)

The reaction of [HN(n-C4H9)3]3[WV(CN)8]·4H2O, 4,4′-bipyridine dioxide(4,4′-dpdo), and MnCl2·4H2O or CuCl2·2H2O gives two new three-dimensional octacyanometalate-based bimetallic assemblies, {[Mn2 (4,4′-dpdo)(H2O)4] [WIV(CN)8]}·6H2O (1) and {[Cu2(4,4′-dpdo)(H2O)][W(CN)8]}·CH3OH·H2O (2). Compound 1 crystallizes in the orthorhombic system, space group P21212 with cell constants a=10.397(2) -, b= 11.321(2) -, c=12.295(3) - and Z=2, whereas 2 crystallizes in the monoclinic system, space group P21/c with cell con...     

Syntheses and crystal structures of cobalt(II) and zinc(II) complexes with 4′-methoxy-5,6,7-trihydroxyisoflavone-3′-sulfonate

Abstract Sodium 4′-methoxy-5,6,7-trihydroxyisoflavone-3′-sulfonate (1) is synthesized by the sulfonation of 6-hydroxybiochanin A and its structure is characterized by elemental analysis, ¹H-NMR, and IR spectroscopy. It is assembled with cobalt(II) or zinc(II), hexaquacobalt(II) bis(4′-methoxy-5,6,7-trihydroxyisoflavone-3′-sulfonate) tetrahydrate (2) and hexaquazinc(II) bis(4′-methoxy-5,6,7-trihydroxyisoflavone-3′-sulfonate) tetrahydrate (3) are obtained and characterized by IR spectroscopy. Simultaneously, their three-dimensional structures are determined by single-crystal X-ray analysis. It turns out that 2 and 3 are isomorphous and crystallize in the triclinic crystal system, space group P-1. Hydrophilic regions are defined by O–H···O hydrogen bonds involving the coordinated water molecules, the included water molecules, and sulfonate groups. Aromatic π...π stacking interactions assemble the isoflavone skeletons into columns and these columns formed hydrophobic regions. The sulfonate group is an important bridge as a structural link between the hydrophilic regions and the hydrophobic regions. Hydrogen bonds, π...π stacking interactions and the electrostatic interactions assemble 2 and 3 into three-dimensional network structures. Graphical abstract Sodium 4′-methoxy-5,6,7-trihydroxyisoflavone-3′-sulfonate (1) is synthesized and assembled with cobalt(II) or zinc(II). Hexaquacobalt(II) bis(4′-methoxy-5,6,7-trihydroxyisoflavone-3′-sulfonate) tetrahydrate (2) and hexaquazinc(II) bis(4′-methoxy-5,6,7-trihydroxyisoflavone-3′-sulfonate) tetrahydrate (3) are obtained and determined by single-crystal X-ray analysis. It turns out that 2 and 3 are isomorphous and assembled into three-dimensional network structures, characterized by hydrophilic regions defined by hydrogen bonds involving the coordinated water molecules, the included water molecules, and the sulfonate groups and by hydrophobic columns, formed by the isoflavone skeletons, interacting through π...π stacking interactions.      

4,4′-Bipyridine complexes of molybdenum(II) and tungsten(II)

Treatment of [MI₂(CO)₃(NCMe)₂] with two equivalents of 4,4-bipyridine (4,4-bipy) in CH₂Cl₂ at room temperature gave the MeCN displaced products, [MI₂(CO)₃(4,4-bipy-N)₂] (1) and (2). Equimolar amounts of [MI₂(CO)₃(NCMe)₂] and L (L = PPh₃, AsPh₃ or SbPh₃) react to give [MI₂(CO)₃(NCMe)L], which when reacted in situ with 4,4-bipy yield the new complexes, [MI₂(CO)₃(4,4-bipy-N)L] (3)–(8). Reaction of equimolar quantities of [WI₂(CO)(NCMe)( ²-RC₂R)₂] (R = Me or Ph) and 4,4-bipy gave the new bis(alkyne) complexes, [WI₂(CO)(4,4-bipy-N)( ²-RC₂R)₂] (9) and (10). Treatment of [MI₂(CO)₃(NCMe)₂] with two equivalents of (9) or (10) in CH₂Cl₂ at room temperature affords the bimetallic complexes, [MI₂(CO)₃{WI₂(CO)(4,4-bipy-N,N)( ²-RC₂R)₂}₂] (11)–(14). Equimolar quantities of [MI₂(CO)₃(NCMe)(PPh₃)] (prepared in situ) and (9) or (10), react to give the 4,4-bipy-bridged complexes, [MI₂(CO)₃{WI₂(CO)(4,4-bipy-N,N)( ²-RC₂R)₂}(PPh₃)] (15)–(18). All the new complexes, (1)–(18) were characterised by elemental analysis (C, H and N), i.r. and ¹H-n.m.r. spectroscopy.     

Synthesis,crystal structures and catalytic activities of new palladium(II)–bis(oxazoline) complexes

Palladium–bis(oxazoline) complexes (Pd-BOX-A and Pd-BOX-B) were synthesized and characterized by ¹H, ¹³C NMR, IR and elemental analysis. The molecular structures of the complexes were confirmed by single-crystal X-ray analysis. In both cases, the palladium center is coordinated by the nitrogen atoms of the two oxazoline rings and two chloride ligands in a distorted square planar geometry. Despite the fact that the bis(oxazoline) ligand is achiral, the asymmetrical substitution on the phenyl spacer and the rigid backbone of the complex Pd-BOX-A induce inherent chirality and the compound crystallizes as a racemic mixture. Both complexes were found to be highly effective catalysts for Suzuki–Miyaura, Mizoroki–Heck and Sonogashira cross-coupling reactions. They also show excellent catalytic activities toward carbonylative coupling reactions.     

Crystal structures and properties of two Cu(I) complexes based on Keggin-type clusters and diethyl 4,4′-dicarboxy-2,2′-biquinoline acid

Two proton-conductive Cu(I) complexes based on Keggin-type clusters, [Cu(debqdc)₂]₂[HPW₁₂O₄₀]·4H₂O (1), and [Cu(debqdc)₂]₂[HPW₁₂O₄₀]·debqdc·4H₂O (2), where debqdc is diethyl 4,4′-dicarboxy-2,2′-biquinoline, were simply synthesized at room temperature. The products were structurally characterized by elemental analyses, infrared spectroscopy, and single-crystal X-ray diffraction analyses. Single-crystal X-ray diffraction analyses revealed that both complexes crystallized in the triclinic space group P?1 and presented two three-dimensional supramolecular networks with one-dimensional hydrophilic channels via hydrogen-bonding interactions and π–π stacking interactions between the aromatic rings. In the [Cu(debqdc)₂]⁺ ion, debqdc acts as a bidentate nitrogen donor ligand in the chelating fashion. The bulky debqdc ligand constrains the Cu(I) metal center within such a rigid environment in a tetrahedral geometry. The two complexes exhibit good proton conductivities (10^?5 ~ 10^?4 S cm^?1) at 100 °C in the relative humidity range 35 ~ 98%. The luminescence behaviors of these complexes in the solid state at room temperature have also been investigated. Upon excitation at 285 nm, both 1 and 2 display three main emission peaks centered at 470, 520, and 568 nm, respectively.     

Two novel metal organic frameworks of Sn(II) and Pb(II) with Pyridine-2,6-dicarboxylic Acid and 4,4′-Bipyridine: syntheses, crystal structures and solution studies

Two novel compounds with formulae [Sn₂(pydcH)₂(H₂O)₂O]_n, 1, and (4,4′-bpyH₂)_0.5[Pb(pydc)₂(4,4′-bpyH)].4,4′-bpy.4H₂O, 2, were obtained from a one-pot reaction between pyridine-2,6-dicarboxylic acid (pydcH₂) and 4,4′-bipyridine (4,4′-bpy) with corresponding Sn(II) and Pb(II) salts. In compound 1 with a polymeric structure, each Sn(II) atom is six-coordinated by one water molecule, two (pydcH)^? groups and one oxide group resulted in a coordination polymer. Compound 2 has a seven-coordinated environment around Pb(II) atom by two (pydc)^2? groups and one (4,4′-bpyH). The anionic complex is balanced by half a (4,4′- bpyH₂)²⁺ as counter ion. There are four uncoordinated water molecules and one 4,4′-bpy in the crystal lattice. Therefore, in compound 2, we have neutral, mono- and biprotonated forms of 4,4′-bipyridine, simultaneously. Several interactions including O-H??? O, O-H???EN and C-H???O hydrogen bonds, ion pairing, C-O???π (O???Cg 3.324(3) Å and 3.381(3) Å in 1 and O???Cg 3.346(4) Å in 2), C-H???π (C???Cg 3.618(4) Å in 2), and π???π stackings (with Cg ??? Cg distances of 3.613(2) and 3.641 (2) Å in 2) are present to expand and stabilize the structure. The complexation reactions of bpy and pydc-bpy with Sn²⁺ and Pb²⁺ ions in aqueous solution were investigated by potentiometric pH titrations, and the resulting equilibrium constants and species distributions at various pHs for major formed complexes are described.     

Syntheses,crystal structures,and photoluminescent properties of two new Cd(II) coordination polymers based on biphenyl-2,2′,4,4′-tetracarboxylate and dipyridyl-containing ligands

Two new Cd(II) coordination polymers, [Cd₂(btc)(dpe)_1.5(H₂O)]_n (1) and [Cd₂(btc)(bpp)(H₂O)]_n (2), were prepared by the hydrothermal reaction of cadmium nitrate with H₄btc (H₄btc = biphenyl-2,2′,4,4′-tetracarboxylic acid) in the presence of 1,2-di(4-pyridyl)ethylene (dpe) and = 1,2-bis(4-pyridyl)propane (bpp), respectively, structurally characterized by single-crystal X-ray diffraction, and further characterized by elemental analysis, IR spectroscopy, and thermogravimetric analysis. In 1, btc^4? connect six Cd²⁺ ions, forming a 3-D (3,3,6)-connected [Cd₂(btc)] net, and further connected by 1-D [Cd(dpe)]_n chains to construct the final (4,5,6)-connected (4².5².6⁵.7)(4³.6².7)(4⁵.5³.6⁴.7².8) net. In 2, a 3-D [Cd₂(btc)] net is also constructed from btc^4? connecting six Cd²⁺ ions, giving a 3-D (3,4,7)-connected network. The overall structure of 2 can be regarded as a (4,4,6)-connected (4⁵.6⁴) (4².5.6².8) (4³.5⁴.6⁷.7) framework with bpp linking adjacent Cd ions. Structural comparisons show that the secondary auxiliary N-donors have important effects on the final structure and properties. Photoluminescent properties of 1 and 2 are also discussed.     

Synthesis and crystal structures of bis(cyclopentyl)gallium phenoxide dimer and bis (cyclopentyl) gallium naphthoxide dimer

Tricyclopentylgallium reacted with phenol, naphthol respectively to yield phenox-ide (or naphthoxide) of biscyclopentylgallium which have been characterized by elemental analysis, IR, 1H NMR and mass spectrometry. X-ray diffraction analysis of compound 1 indicated that it belongs to the monoclinic system, space groups P21/c, with cell constants 0=9.602(3), 6=14.365(7), c=11.256(4)A, and β=97.54(3)°, Z=2(dimers), R=0.0706. Compound 2 assigned to the triclinic system, space groups P1 with cell constants a=9.392(4), 6=9.928(7), c=11.263(7) A, a=112.48(5), β=104.74(4), γ=99.95(5)°, and Z=l(dimers), R=0.0526. The molecule of 1 or 2 contains an oxygen-bridged coplanar Ga2O2 four-membered ring respectively.     

Synthesis,crystal structures,and magnetic properties of cobalt(II) and nickel(II) complexes of 2,2′-bipyridine-6,6′-dicarboxylate: three three-dimensional networks formed via hydrogen bonding interactions

Three Co(II) and Ni(II) complexes, namely [Co(bpdc)(H₂O)₂] (1), [Ni(bpdc)(H₂O)₂] (2), and [Co₂(bpdc)₂(prz)_0.5(H₂O)₃]·0.5H₂O (3) (H₂bpdc = 2,2′-bipyridine-6,6′-dicarboxylic acid and prz = piperazine), have been synthesized from H₂bpdc and the corresponding metal salts under hydrothermal conditions. The complexes were characterized by physico-chemical and spectroscopic methods, as well as by X-ray crystallography. Compounds 1 and 2 both consist of neutral mononuclear molecules, of [Co(bpdc)(H₂O)₂] and [Ni(bpdc)(H₂O)₂], respectively. Compound 3 consists of a mononuclear molecule of [Co(bpdc)(H₂O)₂] and a binuclear molecule of [Co₂(bpdc)₂prz (H₂O)₂]. The discrete neutral complexes 1–3 further extend their structures into three-dimensional supramolecular architectures by intermolecular O–H⋯O and C–H⋯O hydrogen bonds as well as π–π stacking interactions. Magnetic susceptibility measurements show that complex 3 exhibits weak ferromagnetic interactions between the two Co(II) ions bridged by the prz ligand, with C = 5.41 cm³ mol⁻¹ K and θ = +27.6 K, respectively.     

Syntheses and crystal structures of two Co(II) coordination polymers based on 4,6-bis(4-methylbenzoyl)isophthalic acid and 4,4′-bipyridine

Two coordination complexes, [Co₂L₂(4,4′-bpy)₂(H₂O)₄]?·?6H₂O (1) and [CoL(4,4′-bpy)] (2) (H₂L?=?4,6-bis(4-methylbenzoyl)isophthalic acid and 4,4′-bpy?=?4,4′-bipyridine), have been synthesized with the same starting materials under conventional and hydrothermal condition, respectively. Their structures have been characterized by X-ray diffraction, elemental analysis, IR spectra, and thermogravimetric analysis. Complex 1 features a 2-D sheet structure (space group C2/c) with (4,4) grid units. The non-covalent interactions (O–H?·?·?·?O, C–H?·?·?·?π, and weak π??·?·?·?π interactions) extend 1 into a 3-D supramolecular network. Complex 2 displays a (3,5)-connected network (space group P 1) with a (4²?·?6)(4²?·?6⁸) topology.     

Synthesis and crystal structure of cyclotris-(4,4′-thiodiphenylene ketone)

The side reaction of macrocyclization that occurs during the synthesis of poly-(1,4-phenylenesulfide ketone) by polycondensation of a 4,4-dihalobenzophenone with sodium sulfide was studied. It was found that the major product of this reaction is a cyclic trimer, cyclotris-(4,4"-thiodiphenylene ketone) (1). Despite the fact that ketone bridges are more rigid than sulfide bridges, the yield of the macrocycle is rather high, as it is in the synthesis of poly-(1,4-phenylenesulfide), and reaches 20% under high dilution conditions. The structure of 1 was investigated by X-ray diffraction analysis (R = 0.069 on 3138 reflections). Macrocycle 1 is strongly flattened in the crystal; the conformation observed is determined by the packing, since stereochemical analysis indicates high flexibility of the macrocycle. The solvate acetone molecules incorporated in the crystal are disordered, nevertheless, they are strongly fixed in the cavities and channels of the crystal structure.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1460–1466, August, 1994.     

Self-assembly and crystal structures of coordination polymers constructed by 4′-hydroxyisoflavone-3′-sulfonates with Cs(I) and Rb(I)

Four coordination polymers, [CsL1(H₂O)₂]·H₂O (1), [CsL2(H₂O)₂]·H₂O (2), [Rb₂(L2)₂(H₂O)₂]·2H₂O (3) and [RbL3(H₂O)] (4), were synthesized by Cs(I), Rb(I) and 4′-hydroxyisoflavone-3′-sulfonates L1–L3 [L1 = 7-methoxy-4′-hydroxyisoflavone-3′-sulfonate, L2 = 7-ethoxy-4′-hydroxyisoflavone-3′-sulfonate, L3 = 7-ethoxy-4′,5-dihydroxyisoflavone-3′-sulfonate]. The crystal structures of 1–4 were determined by single-crystal X-ray diffraction. The influences of 4′-hydroxyisoflavone-3′-sulfonate ligands and Cs⁺, Rb⁺ on their structural features and self-assembly were investigated. The sulfonates of L1–L3 not only coordinate with Cs⁺ or Rb⁺ directly, but also bridge the organic region and the inorganic region in 1–4. Non-covalent interactions such as coordination interaction, π–π stacking interaction and hydrogen bonding assembled 1–4 into 3-D networks together with the electrostatic interactions between Cs⁺, Rb⁺ and the sulfonate anions.     

Synthesis,crystal structures,and magnetic properties of two manganese(II) coordination polymers bearing 1,1′-biphenyl-3,3′-dicarboxylate ligands

Two Mn(II) coordination polymers, namely [Mn(bpda)] _n (1) and [Mn(bpda)(bpy)_0.5] _n (2) (H₂bpda = 1,1′-biphenyl-3,3′-dicarboxylic acid and bpy = 4,4′-bipyridine), have been synthesized from H₂bpdc, bpy, and MnSO₄·2H₂O under hydrothermal conditions. The complexes were characterized by physicochemical and spectroscopic methods, as well as by X-ray crystallography. Compound 1 possesses a 3D structure consisting of carboxylate-bridged edge-sharing Mn–O–Mn double chains. Compound 2 features a 3D open structure with a dinuclear Mn(II) secondary building unit. Magnetic susceptibility measurements of compounds 1 and 2 exhibit antiferromagnetic interactions between the nearest Mn(II), with J = –11.3 cm⁻¹ and g = 2.12 for 1, and J = –13.5 cm⁻¹ and g = 2.12 for 2.     

Photochemical Behavior of Platinum(II) and Palladium(II) Complexes of 4,4′-Dimethyl-2,2′-Bipyridine

Several mixed-ligand complexes of formula [MX 2 (MBPY)] {where M is Pd(II) or Pt(II); X is Cl m , I m , N 3 m or NO 2 m and MBPY is 4,4'-dimethyl-2,2'-bipyridine} have been prepared. The UV-Vis spectra of these complexes were found to show a low-lying MLCT band and on irradiation at the MLCT band these complexes sensitize the oxidation of 2,2,6,6-tetramethyl-4-piperidinol (XH) in N , N -dimethylformamide (DMF) to 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinoloxy free radical (XO). This photo-oxidation reaction involves singlet molecular oxygen ( 1 O 2 ) as an intermediate and its presence was confirmed by quenching studies using bis(diethyldithiocarbamato)nickel(II) [Ni(DDTC) 2 ], a well-known 1 O 2 quencher. The ability of the complexes to photosensitize the above photo-oxidation reaction follows the order: [Pt ( N 3 ) 2 ( MBPY ) ] ( 2 ) ～ [Pt ( NO 2 ) 2 ( MBPY ) ] ( 3 ) > [PtCl 2 ( MBPY ) ] ( 4 ) > [PtI 2 ( MBPY ) ] ( 1 ) > [Pd ( NO 2 ) 2 ( MBPY ) ] ( 7 ) ～ [Pd ( N 3 ) 2 ( MBPY ) ] ( 6 ) > [PdCl 2 ( MBPY ) ] ( 8 ) > [PdI 2 ( MBPY ) ] ( 5 ), which reflects the nature of the metal ion and the nature of the ligands present in the complexes.     

Synthesis,crystal structures,magnetic and luminescent properties of nickel(II) and cadmium(II) coordination polymers bearing 5-(2′-carboxylphenyl) nicotate ligands

Two coordination polymers, namely [M(cpna)(phen)(H₂O)] _n (M = Ni, 1; Cd, 2, H₂cpna = 5-(2′-carboxylphenyl) nicotic acid, phen = 1,10-phenanthroline), have been hydrothermally synthesized and characterized by single-crystal X-ray diffraction, magnetic and luminescence measurements. Single-crystal X-ray diffraction studies show that the two complexes are isostructural polymers. They have 1D step-like chain structures, which are further extended into 3D metal–organic supramolecular frameworks by π–π stacking interactions. Magnetic studies for complex 1 show antiferromagnetic coupling between the adjacent Ni(II) centers, with g = 2.10 and J = −4.30 cm⁻¹. Complex 2 displays strong green fluorescent emission at room temperature.