Yizhi LI | STMIK INTI (original) (raw)
Papers by Yizhi LI
Inorganic Chemistry, 2006
A novel 3D metal-organic framework [Cd2(m-bptc)(4,4&a... more A novel 3D metal-organic framework [Cd2(m-bptc)(4,4'-bpy)(0.5)(H2O)4].H2O (1; m-H4bptc = 1,1'-biphenyl-2,3',3,4'-tetracarboxylic acid, 4,4'-bpy = 4,4'-bipyridine) with interweaving of triple- and single-helical chains has been obtained based on hydro(solvo)thermal reactions.
Inorganica Chimica Acta, 2005
 bis(maleonitriledithiolato)nickel](https://attachments.academia-assets.com/33025411/thumbnails/1.jpg)
](Journal of Solid State Chemistry, 2005
A new ion-pair complex, [1-(4 0 -chlorobenzyl)-4-aminopyridinium](+)bis(maleonitrile-dithiolato)n... more A new ion-pair complex, [1-(4 0 -chlorobenzyl)-4-aminopyridinium](+)bis(maleonitrile-dithiolato)nickel(À),[ClbzPyNH 2 ] [Ni(mnt) 2 ] (1), has been prepared and characterized. X-ray single crystal structure conforms that the Ni(mnt) 2 À anions and [ClbzPyNH 2 ] + cations of 1 form completely segregated uniform stacking columns with the Ni?Ni distance 3.944 Å in the Ni(mnt) 2 À stacking column. The temperature dependence of the magnetic susceptibility reveals that 1 undergoes a magnetic transition, and exhibits ferromagnetic interaction in the high-temperature phase and spin gap system in the low-temperature phase. r 2004 Elsevier Inc. All rights reserved.
Crystal Growth & Design, 2006
... 2003, 42, 2085. Pal, S.; Sankaran, NB; Samanta, A. Angew. ... Mariappan Murali, Sanjit Nayak,... more ... 2003, 42, 2085. Pal, S.; Sankaran, NB; Samanta, A. Angew. ... Mariappan Murali, Sanjit Nayak, José Sánchez Costa, Joan Ribas, Ilpo Mutikainen, Urho Turpeinen, Martin Clémancey, Ricardo Garcia-Serres, Jean-Marc Latour, Patrick Gamez, Geneviève Blondin and Jan Reedijk. ...
Inorganic Chemistry, 2006
Three 3D robust homochiral helical coordination polymers, [Cu(2,2&amp... more Three 3D robust homochiral helical coordination polymers, [Cu(2,2',3,3'-H2odpa)(bpy)] (1), {[Ni4(2,2',3,3'-odpa)2(bpy)4(H2O)4].(H2O)16} (2), and {[Co4(2,2',3,3'-odpa)2(bpy)4(H2O)4].(H2O)14} (3), have been hydrothermally synthesized from a flexible ligand of 2,2',3,3'-odpda (2,2',3,3'-oxydiphthalic dianhydride). Compound 1 crystallized in space group P3(1)21 and has a rare chiral dense qzd 7.(5)9 topology that incorporates single helical substructures with the same accessibility, whereas compounds 2 and 3 crystallized in the space group C2 and possessed isostructural 3D chiral open frameworks based on the homochiral 2D sheets and 4,4'-bpy pillars. TGA and PXRD analyses show that the porous framework of 2 is stable after the removal of solvent water molecules. In contrast, 3 changed its structure to an amorphous one because of the simultaneous loss of solvent and coordination water molecules. 1 is nearly paramagnetic, whereas weak ferromagnetic interactions between M(II) (M = Ni, Co) ions have been found in 2 and 3.
Inorganic Chemistry, 2007
Novel lanthanide(III) coordination polymers based on a flexible tripodal ligand with additional a... more Novel lanthanide(III) coordination polymers based on a flexible tripodal ligand with additional amide groups were obtained with interestingly unprecedented four-connected 4(2)6(4) topology from the pyramidal nodes and reversible crystal-to-amorphous transformation properties.
![Research paper thumbnail of Porous Nonlinear-Optical Material Based on a Twin-Nest-Shaped Heterothiometallic Cluster: {[NH 4 ][W 2 O 2 S 6 Cu 6 I 3 (4,4‘-bipy) 4 ]·5H 2 O} n](https://attachments.academia-assets.com/49009156/thumbnails/1.jpg)
](Inorganic Chemistry, 2007
A novel 3D porous coordination complex based on a twin-nestshaped heterothiometallic cluster has ... more A novel 3D porous coordination complex based on a twin-nestshaped heterothiometallic cluster has been synthesized and characterized. The complex shows an unprecedented structure type and interesting nonlinear-optical properties. Its gas sorption property was studied and shown to be comparable to that of previously reported metal−organic frameworks.
European Journal of Inorganic Chemistry, 2006
Four novel cadmium(II) coordination polymers, [Cd3(TCMB)2(4,4′-bipy)(H2O)16]n (1), [Cd3(TCMB)2(bp... more Four novel cadmium(II) coordination polymers, [Cd3(TCMB)2(4,4′-bipy)(H2O)16]n (1), [Cd3(TCMB)2(bpe)(H2O)13]n (2), [Cd3(TCMB)2(bpe)2(H2O)4]n (3), and [Cd3(TCMB)2(dpp)2(H2O)3]n (4), [TCMB = 1,3,5-tris(carboxymethoxy)benzene, 4,4-bipy = (4,4-bipyridine), bpe = 1,2-bis(4-pyridyl)ethane, dpp = 1,3-bis(4-pyridyl)propane] have been hydrothermally synthesized by the self-assembly of the flexible tripodal acid TCMB and Cd(OAc)2·2H2O with pyridyl-containing ligands possessing different flexibilities. Single-crystal X-ray diffraction analysis reveals that the four polymers exhibit novel frameworks due to diverse coordination modes and different conformations of the flexible TCMB as well as pyridyl-containing ligands. Complex 1 shows a unique twofold parallel interpenetrating 2D honeycomb network structure with an unusual 63 topology, in which two different large hexagonal rings are arranged alternately, with extraordinarydimensions of ca. 22.172(6) × 12.947(2) Å (A) and 17.233(2) × 12.947(2) Å (B) based on the distances of the atoms at the opposite positions of the rings. Complex 2 is almost isostructural to complex 1, except that the bidentate bpe ligands bridge the cadmium centers in an anti conformation, rendering the network more flexible. Complex 3 features a 3D network with one of the scarce eight-connected (46, 614, 88)(43)2 topologies based on the rare CdI2-type layer constructed from secondary building units (SBUs) of rare [Cd3(CO2)4]2– isosceles triangle cadmium clusters. Complex 4 possesses distorted CdI2-type layers constructed from unprecedented ten-connected Cd3 clusters which are linked by more flexible dpp ligands in a trans-gauche (TG) conformation in (4,4) networks, leading to another 3D framework of the unusual (418, 624, 83)(43)2 topology. Such an arrangement represents the highest connected topology presently known for the frameworks. Among them, complex 1 displays photoluminescent properties at 460 nm due to the ligand-to-metal charge transfer (LMCT). (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Inorganic Chemistry, 2005
A phosphodiesterase model with two zinc centers has been synthesized and characterized. The compo... more A phosphodiesterase model with two zinc centers has been synthesized and characterized. The compound, [Zn 2 (L -2H )(AcO)(H 2 O)](PF 6 )‚2H 2 O (Zn 2 L′), was formed using an "end-off" type compartmental ligand, 2,6-bis{[(2pyridylmethyl)(2-hydroxyethyl)amino]methyl}-4-methylphenol (L), and zinc acetate dihydrate. The X-ray crystallographic analysis shows that Zn 2 L′ contains a µ-acetato-µ-cresolato-dizinc(II) core comprised of a quasi-trigonal bipyramidal Zn and a distorted octahedral Zn, and the distance between them is 3.421 Å which is close to the dizinc distance in related natural metalloenzymes. Phosphodiesterase activity of Zn 2 L′ was investigated using bis(4-nitrophenyl) phosphate (BNPP) as the substrate. The pH dependence of the BNPP cleavage in aqueous buffer media shows a sigmoid-shaped pH−k obs profile with an inflection point around pH 7.13 which is close to the first pK a value of 7.20 for Zn 2 L′ obtained from the potentiometric titration. The catalytic rate constant (k cat ) is 4.60 × 10 -6 s -1 at pH 7.20 and 50°C which is ca. 10 5 -fold higher than that of the uncatalyzed reaction. The deprotonated alcoholic group appended on Zn 2 L′ is responsible for the cleavage reaction. The possible mechanism for the BNPP cleavage promoted by Zn 2 L′ is proposed on the basis of kinetic and spectral analysis. The dizinc complex formed in situ in anhydrous DMSO exhibits a similar ability to cleave BNPP. This study provides a less common example for the phosphodiesterase model in which the metal-bound alkoxide is the nucleophile.
Crystal Growth & Design, 2006
Three novel coordination polymers, namely, {[Ni(2,2′,3,3′-H 2 tdpa)(H 2 O) 2 ]‚(H 2 O) 2 } n (1),... more Three novel coordination polymers, namely, {[Ni(2,2′,3,3′-H 2 tdpa)(H 2 O) 2 ]‚(H 2 O) 2 } n (1), [Ni 3 (2,2′,3,3′-Htdpa) 2 (H 2 O) 12 ] n (2), and {[Ni 4 (2,2′,3,3′-tdpa) 2 (bpy) 4 (H 2 O) 4 ]‚(H 2 O) 10 } n , were prepared under hydrothermal conditions through rational control of the hydrolysis of a new flexible ligand of 2,2′,3,3′-tdpda (2,2′,3,3′-tdpda ) 2,2′,3,3′-thiodiphthalic dianhydride; 2,2′,3,3′-H 4 tdpa ) 2,2′,3,3′-thiodiphthalic acid) and characterized by elemental analyses, IR spectra, thermogravimetric analysis, and single-crystal X-ray diffraction analysis. In 1, two neighboring nickel ions are first bridged together through 3-COOin bidentate fashion and µ 2 -H 2 O to form a one-dimensional (1D) Ni chain. These 1D chains are further locked with each other by 2′-COOin monodentate fashion to form a two-dimensional (2D) alternate square tubule sheet. For 2, Ni1 atoms are coordinated by 2,2′-COOin monodentate fashion to form alternate left-and right-helices, which are further bridged together by the coordination interactions between Ni2 atoms and 3-COOto give a 2D helical coordination polymer. 3 has a three-dimensional (3D) chiral open framework with homochiral sheets and 4,4′-bpy pillars. Thermogravimetric analysis and powder X-ray diffraction analysis show that the porous framework of 3 is stable after removal of both solvent and coordination water molecules. Both 1 and 2 show paramagnetic behaviors, while 3 displays a metamagnetic behavior.
Inorganic Chemistry, 2006
Hydro(solvo)thermal reactions between a new flexible multicarboxylate ligand of 2,2′,3,3′-oxydiph... more Hydro(solvo)thermal reactions between a new flexible multicarboxylate ligand of 2,2′,3,3′-oxydiphthalic acid (2,2′,3,3′-H 4 ODPA) and M(NO 3 ) 2 ‚xH 2 O (M ) Zn, x ) 6; M ) Cd, x ) 4) in the presence of 4,4′-bipyridine (bpy) afford two novel homochiral helical coordination polymers {[Zn 2 (2,2′,3,3′-ODPA)(bpy)(H 2 O) 3 ]‚(H 2 O) 2 for 1 and [Cd 2 (2,2′,3,3′-ODPA)(bpy)(H 2 O) 3 ]‚(H 2 O) 2 for 2}.
Chemical Physics Letters, 2004
The preparation, crystal structure and magnetic properties of a new ion-pair complex, [BrFBzNH 2 ... more The preparation, crystal structure and magnetic properties of a new ion-pair complex, [BrFBzNH 2 Py][Ni(mnt) 2 ] (1) [BrFBzNH 2 Py + = 1-(4 0 -bromo-2 0 -flurobenzyl)-4-aminopyridinium, mnt 2À = maleonitriledithiolate] are reported. The NiðmntÞ À 2 anions and [BrFBzNH 2 Py] + cations of 1 form completely segregated uniform stacking columns. The intrachain NiÁ Á ÁNi separation is 4.045 Å in the NiðmntÞ À 2 stacking column. Magnetic susceptibility measurements for 1 in the temperature range 2.0-300 K show the occurrence of significant ferromagnetic interaction in the high-temperature phase (HT), spin gap in the low-temperature phase (LT) and weak ferromagnetism due to spin canting below 5 K.
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Crystal Growth & Design, 2006
Four novel interesting cadmium (II) or zinc (II) metal coordination polymers with different archi... more Four novel interesting cadmium (II) or zinc (II) metal coordination polymers with different architectures were constructed from aromatic polycarboxylate acid in the presence of a highly flexible imidazole-based ligand (bix) used as spacers under mild hydrothermal ...
Journal of Solid State Chemistry, 2005
6 (TabZ4-(trimethylammonio)benzenethiolate) under the existence of Et 3 N or Et 4 NI in open air ... more 6 (TabZ4-(trimethylammonio)benzenethiolate) under the existence of Et 3 N or Et 4 NI in open air gave rise to three novel halogencuprate(I) complexes with 4-(trimethylammonio)phenyldisulphide (Tab-Tab): [Tab-Tab][CuX 3 ] (1: XZ I; 2: XZBr) and {[Tab-Tab][Cu 2 I 4 ]} n . Compounds 1-3 are characterized by elemental analysis, IR spectra and X-ray crystallography. It was found that the Tab-Tab dication in 1-3 serves as a counterion to maintain the electrical neutrality of 1-3. The dianions of 1 and 2 have planar triangular geometry with each halide atom being bound to the central trigonally coordinated copper atom. The dianion structure of 3 has a unique one-dimensional wavy chain composed of butterfly shaped [Cu 2 I 3 ] units linked by m-I bridges. The luminescence properties of 1-3 along with [Tab-Tab]I 2 have also been investigated. q
Crystal Growth & Design, 2007
Two novel 2D and one 3D coordination polymers with (4, 4) and 2-fold interpenetrating PtS topolog... more Two novel 2D and one 3D coordination polymers with (4, 4) and 2-fold interpenetrating PtS topologies have been hydrothermally synthesized by self-assembly of an unexplored tripodal ligand. Complexes 1 and 2 exhibit ferro-ferromagnetic interactions with the chains ...
Inorganic Chemistry, 2007
A highly water soluble 3:2 complex of copper(II) and 2,4,6-tris(di-2-pyridylamine)-1,3,5-triazine... more A highly water soluble 3:2 complex of copper(II) and 2,4,6-tris(di-2-pyridylamine)-1,3,5-triazine (TDAT) has been synthesized and structurally characterized. The complex crystallized in a triclinic P1 space group with a molecular formula of [Cu 3 (TDAT) 2 Cl 3 ]Cl 3 ‚2H 2 O (1), where each copper ion is coordinated by four pyridine nitrogen atoms and an apical chloride. The trinuclear complex is stable at physiological relevant conditions. It can bind to DNA through electrostatic attraction and cleave efficiently the supercoiled pBR322 DNA into its nicked and linear forms at micromolar concentrations. Active oxygen intermediates such as hydroxyl radicals and singlet oxygen generated in the presence of 1 may act as active species for the DNA scission.
Chemical Communications, 2006
A novel host-guest metal-organic compound with both chiral hydrophilic and achiral hydrophobic ch... more A novel host-guest metal-organic compound with both chiral hydrophilic and achiral hydrophobic channels has been obtained through the reaction of Cd(II) ion and a versatile asymmetrical ligand of H(4)bptc (H(4)bptc = 1,1'-biphenyl-2,2',3,3'-tetracarboxylic acid) based on hydro(solvo)thermal reactions.
Angewandte Chemie-international Edition, 2004
... Kai Liang 1 ,; Hegen Zheng Prof ... 2+ building blocks, each linked by four pairs of parallel... more ... Kai Liang 1 ,; Hegen Zheng Prof ... 2+ building blocks, each linked by four pairs of parallel 4,4′-bipy ligands (Figure 1). The W and the four Cu atoms are coplanar in each [WS 4 Cu 4 ] 2+ building block, and the {WS 4 } 2− unit has a tetrahedral structure with W2 S2 bond lengths ...
Inorganica Chimica Acta, 2006
Lanthanide-organic coordination polymeric networks of [Ln(III)2(suc)3(H2O)2].0.5H2O [suc = succin... more Lanthanide-organic coordination polymeric networks of [Ln(III)2(suc)3(H2O)2].0.5H2O [suc = succinate dianion, Ln = Pr (1), Nd (2), Sm (3), Eu (4), Gd (5), and Dy (6)] have been synthesized and characterized by single-crystal X-ray diffraction analyses. The structural determination reveals that complexes are isomorphous, all crystallizing in monoclinic system, space group I2/a(.) The complexes possess a 3D architecture with Ln ion in a nine-coordination geometry attained by eight oxygen atoms from succinate and one oxygen atom from an aqua ligand. Low-temperature magnetic study indicates that ferromagnetic interaction is present in case of Gd(III) and Dy(III). Antiferromagnetic interaction is observed for the rest of the complexes. Density functional theory calculations are performed which support the existence of a superexchange ferromagnetic coupling in Gd(III) ions, whereas classical crystal field model has been applied to study the complexes 1, 2, 3, and 6.
European Journal of Inorganic Chemistry, 2003
An ion-pair complex [FBzPyNH2][Ni(mnt)2] {[FBzPyNH2]+ = [1-(4′-fluorobenzyl)-4-amino]pyridinium a... more An ion-pair complex [FBzPyNH2][Ni(mnt)2] {[FBzPyNH2]+ = [1-(4′-fluorobenzyl)-4-amino]pyridinium and mnt2− = maleonitriledithiolate} has been obtained by I2 oxidation of the corresponding dianion complex. It forms a wellsegregated stacking column structure in the solid state, and exhibits antiferromagnetic ordering below 2.5 K. It is the first complex in this series of complexes containing a maleonitriledithiolate dianion that exhibits metamagnetism. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Inorganic Chemistry, 2006
A novel 3D metal-organic framework [Cd2(m-bptc)(4,4&a... more A novel 3D metal-organic framework [Cd2(m-bptc)(4,4'-bpy)(0.5)(H2O)4].H2O (1; m-H4bptc = 1,1'-biphenyl-2,3',3,4'-tetracarboxylic acid, 4,4'-bpy = 4,4'-bipyridine) with interweaving of triple- and single-helical chains has been obtained based on hydro(solvo)thermal reactions.
Inorganica Chimica Acta, 2005
Journal of Solid State Chemistry, 2005
A new ion-pair complex, [1-(4 0 -chlorobenzyl)-4-aminopyridinium](+)bis(maleonitrile-dithiolato)n... more A new ion-pair complex, [1-(4 0 -chlorobenzyl)-4-aminopyridinium](+)bis(maleonitrile-dithiolato)nickel(À),[ClbzPyNH 2 ] [Ni(mnt) 2 ] (1), has been prepared and characterized. X-ray single crystal structure conforms that the Ni(mnt) 2 À anions and [ClbzPyNH 2 ] + cations of 1 form completely segregated uniform stacking columns with the Ni?Ni distance 3.944 Å in the Ni(mnt) 2 À stacking column. The temperature dependence of the magnetic susceptibility reveals that 1 undergoes a magnetic transition, and exhibits ferromagnetic interaction in the high-temperature phase and spin gap system in the low-temperature phase. r 2004 Elsevier Inc. All rights reserved.
Crystal Growth & Design, 2006
... 2003, 42, 2085. Pal, S.; Sankaran, NB; Samanta, A. Angew. ... Mariappan Murali, Sanjit Nayak,... more ... 2003, 42, 2085. Pal, S.; Sankaran, NB; Samanta, A. Angew. ... Mariappan Murali, Sanjit Nayak, José Sánchez Costa, Joan Ribas, Ilpo Mutikainen, Urho Turpeinen, Martin Clémancey, Ricardo Garcia-Serres, Jean-Marc Latour, Patrick Gamez, Geneviève Blondin and Jan Reedijk. ...
Inorganic Chemistry, 2006
Three 3D robust homochiral helical coordination polymers, [Cu(2,2&amp... more Three 3D robust homochiral helical coordination polymers, [Cu(2,2',3,3'-H2odpa)(bpy)] (1), {[Ni4(2,2',3,3'-odpa)2(bpy)4(H2O)4].(H2O)16} (2), and {[Co4(2,2',3,3'-odpa)2(bpy)4(H2O)4].(H2O)14} (3), have been hydrothermally synthesized from a flexible ligand of 2,2',3,3'-odpda (2,2',3,3'-oxydiphthalic dianhydride). Compound 1 crystallized in space group P3(1)21 and has a rare chiral dense qzd 7.(5)9 topology that incorporates single helical substructures with the same accessibility, whereas compounds 2 and 3 crystallized in the space group C2 and possessed isostructural 3D chiral open frameworks based on the homochiral 2D sheets and 4,4'-bpy pillars. TGA and PXRD analyses show that the porous framework of 2 is stable after the removal of solvent water molecules. In contrast, 3 changed its structure to an amorphous one because of the simultaneous loss of solvent and coordination water molecules. 1 is nearly paramagnetic, whereas weak ferromagnetic interactions between M(II) (M = Ni, Co) ions have been found in 2 and 3.
Inorganic Chemistry, 2007
Novel lanthanide(III) coordination polymers based on a flexible tripodal ligand with additional a... more Novel lanthanide(III) coordination polymers based on a flexible tripodal ligand with additional amide groups were obtained with interestingly unprecedented four-connected 4(2)6(4) topology from the pyramidal nodes and reversible crystal-to-amorphous transformation properties.
Inorganic Chemistry, 2007
A novel 3D porous coordination complex based on a twin-nestshaped heterothiometallic cluster has ... more A novel 3D porous coordination complex based on a twin-nestshaped heterothiometallic cluster has been synthesized and characterized. The complex shows an unprecedented structure type and interesting nonlinear-optical properties. Its gas sorption property was studied and shown to be comparable to that of previously reported metal−organic frameworks.
European Journal of Inorganic Chemistry, 2006
Four novel cadmium(II) coordination polymers, [Cd3(TCMB)2(4,4′-bipy)(H2O)16]n (1), [Cd3(TCMB)2(bp... more Four novel cadmium(II) coordination polymers, [Cd3(TCMB)2(4,4′-bipy)(H2O)16]n (1), [Cd3(TCMB)2(bpe)(H2O)13]n (2), [Cd3(TCMB)2(bpe)2(H2O)4]n (3), and [Cd3(TCMB)2(dpp)2(H2O)3]n (4), [TCMB = 1,3,5-tris(carboxymethoxy)benzene, 4,4-bipy = (4,4-bipyridine), bpe = 1,2-bis(4-pyridyl)ethane, dpp = 1,3-bis(4-pyridyl)propane] have been hydrothermally synthesized by the self-assembly of the flexible tripodal acid TCMB and Cd(OAc)2·2H2O with pyridyl-containing ligands possessing different flexibilities. Single-crystal X-ray diffraction analysis reveals that the four polymers exhibit novel frameworks due to diverse coordination modes and different conformations of the flexible TCMB as well as pyridyl-containing ligands. Complex 1 shows a unique twofold parallel interpenetrating 2D honeycomb network structure with an unusual 63 topology, in which two different large hexagonal rings are arranged alternately, with extraordinarydimensions of ca. 22.172(6) × 12.947(2) Å (A) and 17.233(2) × 12.947(2) Å (B) based on the distances of the atoms at the opposite positions of the rings. Complex 2 is almost isostructural to complex 1, except that the bidentate bpe ligands bridge the cadmium centers in an anti conformation, rendering the network more flexible. Complex 3 features a 3D network with one of the scarce eight-connected (46, 614, 88)(43)2 topologies based on the rare CdI2-type layer constructed from secondary building units (SBUs) of rare [Cd3(CO2)4]2– isosceles triangle cadmium clusters. Complex 4 possesses distorted CdI2-type layers constructed from unprecedented ten-connected Cd3 clusters which are linked by more flexible dpp ligands in a trans-gauche (TG) conformation in (4,4) networks, leading to another 3D framework of the unusual (418, 624, 83)(43)2 topology. Such an arrangement represents the highest connected topology presently known for the frameworks. Among them, complex 1 displays photoluminescent properties at 460 nm due to the ligand-to-metal charge transfer (LMCT). (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Inorganic Chemistry, 2005
A phosphodiesterase model with two zinc centers has been synthesized and characterized. The compo... more A phosphodiesterase model with two zinc centers has been synthesized and characterized. The compound, [Zn 2 (L -2H )(AcO)(H 2 O)](PF 6 )‚2H 2 O (Zn 2 L′), was formed using an "end-off" type compartmental ligand, 2,6-bis{[(2pyridylmethyl)(2-hydroxyethyl)amino]methyl}-4-methylphenol (L), and zinc acetate dihydrate. The X-ray crystallographic analysis shows that Zn 2 L′ contains a µ-acetato-µ-cresolato-dizinc(II) core comprised of a quasi-trigonal bipyramidal Zn and a distorted octahedral Zn, and the distance between them is 3.421 Å which is close to the dizinc distance in related natural metalloenzymes. Phosphodiesterase activity of Zn 2 L′ was investigated using bis(4-nitrophenyl) phosphate (BNPP) as the substrate. The pH dependence of the BNPP cleavage in aqueous buffer media shows a sigmoid-shaped pH−k obs profile with an inflection point around pH 7.13 which is close to the first pK a value of 7.20 for Zn 2 L′ obtained from the potentiometric titration. The catalytic rate constant (k cat ) is 4.60 × 10 -6 s -1 at pH 7.20 and 50°C which is ca. 10 5 -fold higher than that of the uncatalyzed reaction. The deprotonated alcoholic group appended on Zn 2 L′ is responsible for the cleavage reaction. The possible mechanism for the BNPP cleavage promoted by Zn 2 L′ is proposed on the basis of kinetic and spectral analysis. The dizinc complex formed in situ in anhydrous DMSO exhibits a similar ability to cleave BNPP. This study provides a less common example for the phosphodiesterase model in which the metal-bound alkoxide is the nucleophile.
Crystal Growth & Design, 2006
Three novel coordination polymers, namely, {[Ni(2,2′,3,3′-H 2 tdpa)(H 2 O) 2 ]‚(H 2 O) 2 } n (1),... more Three novel coordination polymers, namely, {[Ni(2,2′,3,3′-H 2 tdpa)(H 2 O) 2 ]‚(H 2 O) 2 } n (1), [Ni 3 (2,2′,3,3′-Htdpa) 2 (H 2 O) 12 ] n (2), and {[Ni 4 (2,2′,3,3′-tdpa) 2 (bpy) 4 (H 2 O) 4 ]‚(H 2 O) 10 } n , were prepared under hydrothermal conditions through rational control of the hydrolysis of a new flexible ligand of 2,2′,3,3′-tdpda (2,2′,3,3′-tdpda ) 2,2′,3,3′-thiodiphthalic dianhydride; 2,2′,3,3′-H 4 tdpa ) 2,2′,3,3′-thiodiphthalic acid) and characterized by elemental analyses, IR spectra, thermogravimetric analysis, and single-crystal X-ray diffraction analysis. In 1, two neighboring nickel ions are first bridged together through 3-COOin bidentate fashion and µ 2 -H 2 O to form a one-dimensional (1D) Ni chain. These 1D chains are further locked with each other by 2′-COOin monodentate fashion to form a two-dimensional (2D) alternate square tubule sheet. For 2, Ni1 atoms are coordinated by 2,2′-COOin monodentate fashion to form alternate left-and right-helices, which are further bridged together by the coordination interactions between Ni2 atoms and 3-COOto give a 2D helical coordination polymer. 3 has a three-dimensional (3D) chiral open framework with homochiral sheets and 4,4′-bpy pillars. Thermogravimetric analysis and powder X-ray diffraction analysis show that the porous framework of 3 is stable after removal of both solvent and coordination water molecules. Both 1 and 2 show paramagnetic behaviors, while 3 displays a metamagnetic behavior.
Inorganic Chemistry, 2006
Hydro(solvo)thermal reactions between a new flexible multicarboxylate ligand of 2,2′,3,3′-oxydiph... more Hydro(solvo)thermal reactions between a new flexible multicarboxylate ligand of 2,2′,3,3′-oxydiphthalic acid (2,2′,3,3′-H 4 ODPA) and M(NO 3 ) 2 ‚xH 2 O (M ) Zn, x ) 6; M ) Cd, x ) 4) in the presence of 4,4′-bipyridine (bpy) afford two novel homochiral helical coordination polymers {[Zn 2 (2,2′,3,3′-ODPA)(bpy)(H 2 O) 3 ]‚(H 2 O) 2 for 1 and [Cd 2 (2,2′,3,3′-ODPA)(bpy)(H 2 O) 3 ]‚(H 2 O) 2 for 2}.
Chemical Physics Letters, 2004
The preparation, crystal structure and magnetic properties of a new ion-pair complex, [BrFBzNH 2 ... more The preparation, crystal structure and magnetic properties of a new ion-pair complex, [BrFBzNH 2 Py][Ni(mnt) 2 ] (1) [BrFBzNH 2 Py + = 1-(4 0 -bromo-2 0 -flurobenzyl)-4-aminopyridinium, mnt 2À = maleonitriledithiolate] are reported. The NiðmntÞ À 2 anions and [BrFBzNH 2 Py] + cations of 1 form completely segregated uniform stacking columns. The intrachain NiÁ Á ÁNi separation is 4.045 Å in the NiðmntÞ À 2 stacking column. Magnetic susceptibility measurements for 1 in the temperature range 2.0-300 K show the occurrence of significant ferromagnetic interaction in the high-temperature phase (HT), spin gap in the low-temperature phase (LT) and weak ferromagnetism due to spin canting below 5 K.
[
Crystal Growth & Design, 2006
Four novel interesting cadmium (II) or zinc (II) metal coordination polymers with different archi... more Four novel interesting cadmium (II) or zinc (II) metal coordination polymers with different architectures were constructed from aromatic polycarboxylate acid in the presence of a highly flexible imidazole-based ligand (bix) used as spacers under mild hydrothermal ...
Journal of Solid State Chemistry, 2005
6 (TabZ4-(trimethylammonio)benzenethiolate) under the existence of Et 3 N or Et 4 NI in open air ... more 6 (TabZ4-(trimethylammonio)benzenethiolate) under the existence of Et 3 N or Et 4 NI in open air gave rise to three novel halogencuprate(I) complexes with 4-(trimethylammonio)phenyldisulphide (Tab-Tab): [Tab-Tab][CuX 3 ] (1: XZ I; 2: XZBr) and {[Tab-Tab][Cu 2 I 4 ]} n . Compounds 1-3 are characterized by elemental analysis, IR spectra and X-ray crystallography. It was found that the Tab-Tab dication in 1-3 serves as a counterion to maintain the electrical neutrality of 1-3. The dianions of 1 and 2 have planar triangular geometry with each halide atom being bound to the central trigonally coordinated copper atom. The dianion structure of 3 has a unique one-dimensional wavy chain composed of butterfly shaped [Cu 2 I 3 ] units linked by m-I bridges. The luminescence properties of 1-3 along with [Tab-Tab]I 2 have also been investigated. q
Crystal Growth & Design, 2007
Two novel 2D and one 3D coordination polymers with (4, 4) and 2-fold interpenetrating PtS topolog... more Two novel 2D and one 3D coordination polymers with (4, 4) and 2-fold interpenetrating PtS topologies have been hydrothermally synthesized by self-assembly of an unexplored tripodal ligand. Complexes 1 and 2 exhibit ferro-ferromagnetic interactions with the chains ...
Inorganic Chemistry, 2007
A highly water soluble 3:2 complex of copper(II) and 2,4,6-tris(di-2-pyridylamine)-1,3,5-triazine... more A highly water soluble 3:2 complex of copper(II) and 2,4,6-tris(di-2-pyridylamine)-1,3,5-triazine (TDAT) has been synthesized and structurally characterized. The complex crystallized in a triclinic P1 space group with a molecular formula of [Cu 3 (TDAT) 2 Cl 3 ]Cl 3 ‚2H 2 O (1), where each copper ion is coordinated by four pyridine nitrogen atoms and an apical chloride. The trinuclear complex is stable at physiological relevant conditions. It can bind to DNA through electrostatic attraction and cleave efficiently the supercoiled pBR322 DNA into its nicked and linear forms at micromolar concentrations. Active oxygen intermediates such as hydroxyl radicals and singlet oxygen generated in the presence of 1 may act as active species for the DNA scission.
Chemical Communications, 2006
A novel host-guest metal-organic compound with both chiral hydrophilic and achiral hydrophobic ch... more A novel host-guest metal-organic compound with both chiral hydrophilic and achiral hydrophobic channels has been obtained through the reaction of Cd(II) ion and a versatile asymmetrical ligand of H(4)bptc (H(4)bptc = 1,1'-biphenyl-2,2',3,3'-tetracarboxylic acid) based on hydro(solvo)thermal reactions.
Angewandte Chemie-international Edition, 2004
... Kai Liang 1 ,; Hegen Zheng Prof ... 2+ building blocks, each linked by four pairs of parallel... more ... Kai Liang 1 ,; Hegen Zheng Prof ... 2+ building blocks, each linked by four pairs of parallel 4,4′-bipy ligands (Figure 1). The W and the four Cu atoms are coplanar in each [WS 4 Cu 4 ] 2+ building block, and the {WS 4 } 2− unit has a tetrahedral structure with W2 S2 bond lengths ...
Inorganica Chimica Acta, 2006
Lanthanide-organic coordination polymeric networks of [Ln(III)2(suc)3(H2O)2].0.5H2O [suc = succin... more Lanthanide-organic coordination polymeric networks of [Ln(III)2(suc)3(H2O)2].0.5H2O [suc = succinate dianion, Ln = Pr (1), Nd (2), Sm (3), Eu (4), Gd (5), and Dy (6)] have been synthesized and characterized by single-crystal X-ray diffraction analyses. The structural determination reveals that complexes are isomorphous, all crystallizing in monoclinic system, space group I2/a(.) The complexes possess a 3D architecture with Ln ion in a nine-coordination geometry attained by eight oxygen atoms from succinate and one oxygen atom from an aqua ligand. Low-temperature magnetic study indicates that ferromagnetic interaction is present in case of Gd(III) and Dy(III). Antiferromagnetic interaction is observed for the rest of the complexes. Density functional theory calculations are performed which support the existence of a superexchange ferromagnetic coupling in Gd(III) ions, whereas classical crystal field model has been applied to study the complexes 1, 2, 3, and 6.
European Journal of Inorganic Chemistry, 2003
An ion-pair complex [FBzPyNH2][Ni(mnt)2] {[FBzPyNH2]+ = [1-(4′-fluorobenzyl)-4-amino]pyridinium a... more An ion-pair complex [FBzPyNH2][Ni(mnt)2] {[FBzPyNH2]+ = [1-(4′-fluorobenzyl)-4-amino]pyridinium and mnt2− = maleonitriledithiolate} has been obtained by I2 oxidation of the corresponding dianion complex. It forms a wellsegregated stacking column structure in the solid state, and exhibits antiferromagnetic ordering below 2.5 K. It is the first complex in this series of complexes containing a maleonitriledithiolate dianion that exhibits metamagnetism. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)