A new linear bismuth coordination polymer based on 1,10-phenanthroline-2,9-dicarboxylic acid: ionothermal synthesis, crystal structure and fluorescence properties.

A new linear bismuth(III) coordination polymer, catena-poly[[chloridobismuth(III)]-µ3-1,10-phenanthroline-2,9-dicarboxylato-κ(6)O(2):O(2),N(1),N(10),O(9):O(9)], [Bi(C14H6N2O4)Cl]n, has been obtained by an ionothermal method and characterized by elemental analysis, energy-dispersive X-ray spectroscopy, IR spectroscopy, thermal stability studies and single-crystal X-ray diffraction. The structure is constructed by Bi(C14H6N2O4)Cl fragments in which each Bi(III) centre is seven-coordinated by one Cl atom, four O atoms and two N atoms. The coordination geometry of the Bi(III) cation is distorted pentagonal-bipyramidal (BiO4N2Cl), with one bridging carboxylate O atom and one Cl atom located in the axial positions. The Bi(C14H6N2O4)Cl fragments are further extended into a one-dimensional linear polymeric structure via subsequent but different centres of symmetry (bridging carboxylate O atoms). Neighbouring linear chains are assembled via weak C-H···O and C-H···Cl hydrogen bonds, forming a three-dimensional supramolecular architecture. Intermolecular π-π stacking interactions are observed, with centroid-to-centroid distances of 3.678 (4) Å, which further stabilize the structure. In addition, the solid-state fluorescence properties of the title coordination polymer were investigated.

A linear heterometallic bismuth-copper coordination polymer containing two types of organic ligands.

In the linear coordination polymer catena-poly[[[aqua(1,10-phenanthroline-κ(2)N,N')copper(II)]-µ-pyridine-2,6-dicarboxylato-κ(4)O(2):O(2'),N,O(6)-[(nitrato-κ(2)O,O')bismuth(III)]-µ-pyridine-2,6-dicarboxylato-κ(4)O(2),N,O(6):O(6')] dihydrate], {[Bi(III)Cu(II)(C7H3NO4)2(NO3)(C12H8N2)(H2O)]·2H2O}n, the Bi(III) cation is O,N,O'-chelated by the two pyridine-2,6-dicarboxylate ligands and O,O'-chelated by the nitrate anion, the nine coordinating atoms conferring a tricapped trigonal prismatic environment on the metal centre. Each pyridine-2,6-dicarboxylate ligand uses one of its carboxylate O atoms to bind to an aqua(1,10-phenanthroline)copper(II) unit, the Cu-O dative bonds giving rise to the formation of a ribbon motif. The Cu(II) cation exhibits a square-pyramidal geometry. The ribbon motif propagates along the shortest axis of the triclinic unit cell and the solvent water molecules are hydrogen bonded to the same ribbon.

Reticular three-dimensional 3d-4f frameworks constructed through substituted imidazole-dicarboxylate: syntheses, luminescence and magnetic properties study.

A family of heteronuclear metal organic frameworks (MOFs) using lanthanide and transition metal ion based on a rigid ligand of substituted imidazoledicarboxylic acid, namely, {[Ln2Zn2 (µ3-Hmimda)2 (µ3-mimda)2·4H2O]n·mn H2O}, Ln = Nd, m = 2 (1), Ln = Ho, m = 3 (2), Ln = Er, m = 2 (3), Ln = Yb, m = 3 (4), [Tb2Co2(µ3-Hmimda)2 (µ3-mimda)2·4H2O]n·2nH2O} (5) and [Dy2Co2 (µ3-Hmimda)2 (µ3-mimda)2·4H2O]n·nH2O} (6), (H3mimda = 1H-2-methyl-4,5-imidazole-dicarboxylic acid), have been developed and characterized. All the complexes (except for a little disparity for 1) are isostructural, and all crystallize in the monoclinic system. They possess an extended reticular-like porous structure constructed from corrugated 2D layers. Direct current (dc) magnetic susceptibility measurements for 1-5 indicated depopulation of the Stark components at low temperature and/or possible weak anti-ferromagnetic interactions within hetero-nuclear MOFs. Alternating current (ac) susceptibility studies reveal that the Dy(III)-Co(II) complex exhibits both possible ferromagnetic couplings and frequency-dependent out-of-phase signals, behaviour of single-ion magnet nature. Fluorescence properties of series complexes both in near-infrared (NIR) and visible regions have been comparatively studied.

A novel dinuclear bismuth(III) coordination compound: bis(µ-pyridine-2,6-dicarboxylato)-κ4O2,N,O6:O6';κ4O2:O2',N,O6-bis[(azido-κN)(1,10-phenanthroline-κ2N,N')bismuth(III)] tetrahydrate.

A novel dinuclear bismuth(III) coordination compound, [Bi2(C7H3NO4)2(N3)2(C12H8N2)2]·4H2O, has been synthesized by an ionothermal method and characterized by elemental analysis, energy-dispersive X-ray spectroscopy, IR, X-ray photoelectron spectroscopy and single-crystal X-ray diffraction. The molecular structure consists of one centrosymmetric dinuclear neutral fragment and four water molecules. Within the dinuclear fragment, each Bi(III) centre is seven-coordinated by three O atoms and four N atoms. The coordination geometry of each Bi(III) atom is distorted pentagonal-bipyramidal (BiO3N4), with one azide N atom and one bridging carboxylate O atom located in axial positions. The carboxylate O atoms and water molecules are assembled via O-H···O hydrogen bonds, resulting in the formation of a three-dimensional supramolecular structure. Two types of π-π stacking interactions are found, with centroid-to-centroid distances of 3.461 (4) and 3.641 (4) Å.

A novel alkaline earth strontium(II) coordination polymer: poly[hexaaquatetrakis(µ5-pyridine-2,6-dicarboxylato)bis(µ4-pyridine-2,6-dicarboxylato)(µ7-sulfato)heptastrontium(II)].

The title compound, [Sr7(C7H3NO4)6(SO4)(H2O)6]n, has been synthesized by an ionothermal method using the ionic liquid 1-ethyl-3-methylimidazolium ([Emim]Br) as solvent, and characterized by elemental analysis, energy-dispersive X-ray spectroscopy, IR and single-crystal X-ray diffraction. The structure of the compound can be viewed as a three-dimensional coordination polymer composed of Sr(2+) cations, pyridine-2,6-dicarboxylate anions, sulfate anions and water molecules. The compound not only exhibits a three-dimensional structure with a unique coordination mode of the sulfate anion, but also features the first example of a heptanuclear strontium(II) coordination polymer. The structure is further stabilized by O-H···O hydrogen bonds and π-π stacking interactions.

catena-Poly[bis(µ-2,2'-bipyridin-6-olato)-κ³N,N':O;O:N,N'-dicopper(I,II) [[tetrafluoridoniobium(V)]-µ-oxido]].

A novel copper-niobium oxyfluoride, {[Cu2(C10H7N2O)2][NbOF4]}n, has been synthesized by a hydrothermal method and characterized by elemental analysis, EDS, IR, XPS and single-crystal X-ray diffraction. The structural unit consists of one C2-symmetric [NbOF4]⁻ anion and one centrosymmetric coordinated [Cu2(obpy)2]⁺ cation (obpy is 2,2'-bipyridin-6-olate). In the [NbOF4]⁻ anion, each NbV metal centre is five-coordinated by four F atoms and one O atom in the first coordination shell, forming a square-pyramidal coordination geometry. These square pyramids are then further connected to each other via trans O atoms [Nb-O = 2.187 (3) Å], forming an infinite linear {[NbOF4]⁻}n polyanion. In the coordinated [Cu2(obpy)2]⁺ cation, the oxidation state of each Cu site is disordered, which is confirmed by the XPS results. The disordered Cu sites are coordinated by two N atoms and one O atom from two different obpy ligands. The [NbOF4]⁻ and [Cu2(obpy)2]⁺ units are assembled via weak C-H∙∙∙F hydrogen bonds, resulting in the formation of a three-dimensional supramolecular structure. π-π stacking interactions between the pyridine rings [centroid-centroid distance = 3.610 (2) Å] may further stabilize the crystal structure.

A series of Zn-4f heterometallic coordination polymers and a zinc complex containing a flexible mixed donor dicarboxylate ligand.

A new zinc compound, together with a corresponding series of Zn-4f heterometallic coordination polymers, namely, [Zn(H2PBDA)(PBDA)]n (1), {[Ln2(PBDA)2·2H2O] [Zn2(PBDA)2Cl2]}n [H2PBDA = 3-(pyridin-3-yl-oxy) benzene-1,2-dicarboxylic acid, and Ln = Pr(2), Nd(3), Eu(4), Gd(5), Dy(6), Ho(7), Er(8)] have been hydrothermally synthesized and characterized systematically. Polymers 2-8 feature two-dimensional (2D) 4,4 networks, containing the original 1D heterometallic double stranded chains composed of [Ln2Zn2(PBDA)2] entities. The extensive hydrogen bonding and π-π stacking interactions were observed to stabilize the extended architectures. The luminescence emission spectra of the polymers vary depending on the lanthanide(III) ion present. Informative magnetic susceptibility measurements show that the same carboxylate bridging fashion of the PBDA ligand results in the different magnetic properties occurring within the heterometallic coordination polymers. In addition, polymer 6 exhibits an interesting slow magnetic relaxation behavior at lower temperatures.

Aqua-chlorido(3,5-dinitro-2-oxidobenzo-ato-κ(2)O(1),O(2))(1,10-phenanthroline-κ(2)N,N')chromium(III).

In the title compound, [Cr(C(7)H(2)N(2)O(7))Cl(C(12)H(8)N(2))(H(2)O)], the Cr(III) atom displays a distorted octa-hedral coordination geometry, with the chelating phenantroline and 3,5-dinitro-salicylate ligands in trans positions. In the crystal, mol-ecules are connected via O-H⋯O hydrogen bonds into a two-dimensional framework parallel to (100). In addition, there are π-π stacking inter-actions between phenanthroline ligands along the c axis, with a mean inter-planar distance of 3.456 (4) Å.

5,6-Dihydro-1,10-phenanthroline-1,10-diium µ-oxido-bis-[penta-fluoridotantalate(V)].

In the title compound, (C(12)H(12)N(2))[Ta(2)F(10)O], the doubly protonated 5,6-dihydro-1,10-phenantroline-1,10-diium cation is located on a twofold rotation axis, whereas the isolated [Ta(2)OF(10)](2-) dianion has -1 symmetry. In the so far unknown dianion, the symmetry-related Ta(V) atoms are octa-hedrally coordinated by five F atoms and a bridging O atom, the latter being located on an inversion centre. The two pyridine rings in the cation make a dihedral angle of 22.8 (4)°. The cations and dianions are arranged in layers parallel to (100) and are connected through N-H⋯F and C-H⋯F hydrogen-bonding inter-actions into a three-dimensional structure.

Bis[bis-(2,2'-bipyridine-κN,N')chloridocopper(II)] bis-(µ-2,6-pyridine-dicarboxyl-ato)-κO,N,O:O;κO:O,N,O-bis-[aqua-dichloridobismuthate(III)] penta-hydrate.

In the title compound, [CuCl(C(10)H(8)N(2))(2)](2)[Bi(2)Cl(4)(C(7)H(3)NO(4))(2)(H(2)O)(2)]·5H(2)O, the dianion [Bi(2)Cl(4)(C(7)H(3)NO(4))(2)(H(2)O)(2)](2-) is located about an inversion center. The Cu(II) atom of the cation is coordinated by four N atoms of the two chelating 2,2'-bypyridine ligands and one Cl(-) ion, completing a distorted trigonal-bipyramidal coordination environment. In the anion, each Bi(III) atom is seven-coordinate and is bonded to a tridentate pyridine-2,6-dicarboxyl-ate ligand, a water mol-ecule, two chloride ions and a bridging carboxyl-ate O atom of another carboxyl-ate ligand. The coordination geometry of Bi(III) is distorted penta-gonal-bipyramidal with the Cl(-) ions located in axial positions. The structure of the dianion is additionally stabilized by an intra-molecular O-H⋯O hydrogen bond between the coordinated water mol-ecule and carboxyl-ate O atom. In the crystal, O-H⋯O hydrogen bonds occur . The H atoms of the solvent water mol-ecules could not be located.

Study on the heterogeneous degradation of chitosan with H(2)O(2) catalyzed by a new supermolecular assembly crystal: [C(6)H(8)N(2)](6)H(3)[PW(12)O(40)].2H(2)O.

A new supermolecular assembly crystal, [C(6)H(8)N(2)](6)H(3)[PW(12)O(40)].2H(2)O (DMB-PWA), was synthesized with phosphotungstic acid (PWA) and 1,2-diaminobenzene (DMB) under hydrothermal conditions and was characterized by Fourier-transform infrared spectra (FTIR) and single-crystal X-ray diffraction analysis. DMB-PWA could effectively catalyze oxidative degradation of chitosan with H(2)O(2) in the heterogeneous phase. The optimum degradation conditions were determined by orthogonal tests as follows: amount of chitosan 1.00 g, 30% (wt %); H(2)O(2), 3.0 mL; dosage of catalyst, 0.06 g; reaction temperature, 85 degrees C; and reaction time, 30 min. The water-soluble chitosan with a viscosity-average molecular weight (M(v)) of 4900 was obtained under the optimum degradation conditions and was characterized by FTIR, ultraviolet-visible diffuse reflection spectra (UV-vis DRS), and X-ray powder diffraction analysis.

Hepatic resection: an analysis of the impact of operative and perioperative factors on morbidity and mortality rates in 2008 consecutive hepatectomy cases.

BACKGROUND: Hepatectomy is a standard hepatic surgical technique. The safety of hepatectomy has been improved in line with improvements in surgical techniques. This study analyzed the operative and perioperative factors associated with hepatectomy. METHODS: A total of 2008 patients who underwent consecutive hepatectomies between January 1986 and December 2005 were investigated retrospectively. Diagnoses were made based on pathological findings. RESULTS: Malignant and benign liver diseases accounted for 58.5% and 41.2%, respectively, of the conditions requiring resections. Primary liver cancers accounted for 76.1% of the malignant tumors, while hilar cholangiocarcinomas accounted for 6.7%. Hemangiomas (41.7%) and hepatolithiasis (29.6%) were the most common of the benign conditions. Microwave in-line coagulation was used in 236 of our liver resection cases. The overall postoperative complication rate was 14.44%, of which 12.54% of resections were performed for primary liver cancer, 16.40% for secondary liver cancer, and 16.32% for hepatolithiasis. The overall hospital mortality was 0.55%, and that for malignant liver disease was 0.51%. A high mortality (2.53%) was associated with extensive liver resections for hilar cholangiocarcinomas (two deaths in 79 cases). Microwave in-line pre-coagulation resection, Child-Pugh grading, operating time, postoperative length of stay, and preoperative serum albumin level were independent predictors of morbidity. Blood loss, Child-Pugh grading, operating time and preoperative serum albumin level were independent predictors of mortality. CONCLUSIONS: Hepatectomy can be performed safely with low morbidity and mortality, provided that it is carried out with optimal perioperative management and innovative surgical techniques.

[Determinants of long-term survival after pancreaticoduodenectomy for ampulla of Vater carcinoma].

OBJECTIVE: To investigate the determinants of long-term survival for ampulla of Vater carcinoma treated by pancreaticoduodenectomy. METHODS: A total of 77 patients with ampulla of Vater carcinoma undergoing pancreaticoduodenectomy were reviewed. Kaplan-Meier method was used to analyze the survival rate. Independent t test was used for statistical comparison and COX regression model for multivariate analysis. RESULTS: No patient died as a result of surgery. The overall 5-year survival was 40.7%. Univariate analysis showed that perioperative serum carcinoembryonic antigen (CEA) level (P = 0.012), tumor invasion depth (P = 0.000), UICC stage (P = 0.000) and tumor size (P = 0.001) were significant prognostic factors of ampulla of Vater carcinoma; in multivariate analysis, only the tumor size (P = 0.000) was an independent prognostic factor of ampulla of Vater carcinoma. CONCLUSION: Pancreaticoduodenectomy is associated with significant survival. Tumor size is the most important influencing factor of outcome after pancreaticoduodenectomy; in addition, perioperative serum CEA level, tumor invasion depth and UICC stage may also influence the survival rate, there exists a need for further follow-up studies.

[Liver resection: single center experiences of 2008 consecutive resections in 20 years].

OBJECTIVE: To analyze operative and perioperative factors associated with hepatectomy. METHODS: 2008 consecutive patients undergoing hepatectomy from January 1986 to December 2005 at Chinese People's Liberation Army General Hospital were investigated retrospectively according to their medical documentation. Diagnoses were made on basis of pathological results. RESULTS: Malignant and benign liver diseases accounted for 58.5% and 41.2%, respectively. In the former, primary liver cancer accounted for 76.1% and hilar cholangiocarcinoma for 6.7%. Hemangioma (41.7%) and hepatolithiasis (29.6%) were listed in the first two in the latter group with relatively more patient ratios. Isolated caudate lobe resection was performed in 25 patients and micro-wave inline coagulation was induced in 236 cases of liver resection. In all cases, those with blood loss less than 200 ml accounted for 50.5% (1015/2008), whereas those with more than 400 ml accounted for 28.4% (570/2008). In patients performed micro-wave inline coagulation liver resection, those with blood loss less than 200 ml and more than 400 ml accounted for 60.6% (143/236) and 19.9% (47/236), respectively, which differed significantly from the average level (P < 0.05). The postoperative complication incidence was 14.44% for all cases, 12.54% for primary liver cancer, 16.40% for secondary liver cancer, and 16.32% for hepatolithiasis. Complication incidence of primary liver cancer with tumor size smaller than 5 cm was 11.65% and that with tumor larger than 10 cm was 14.69%. There was no significant difference between the two groups. All-case hospital mortality was 0.55% and that for liver malignant disease was 0.60%, hilar cholangiocarcinoma 2.53%. CONCLUSION: Hepatectomy can be performed safely with low mortality and low complication incidence, provided that it is carried out with optimized perioperative management and innovative surgical technique.

Severe biliary complications after hepatic artery embolization.

AIM: To study the mechanism and treatment of severe biliary complications arising from hepatic artery embolization(HAE). METHODS: Of seven cases of intra- and extrahepatic biliary damage resulting from hepatic artery embolization reported since 1987, 6 patients suffered from hepatic haemangioma, the other case was due to injection of TH compound into the hepatic artery during operation. The hepatic artery was injected with ethanol so as to evaluate the liver damage in experimental rats. RESULTS: All the cases were found to have destructive damage of intra- and extrahepatic bile duct at the hilum with biliary hepatocirrhosis. Experimental results revealed necrosis of the liver parenchyma, especially around the portal tract and obliteration of intrahepatic bile duct. CONCLUSIONS: To prevent the severe biliary complications of HAE, the use of HAE for hepatic haemangioma which was widely practiced in China, should be re-evaluated. Hepatic arterial embolization of hepatic haemangioma may resulte in severe destructive biliary damages and its indiscriminate use should be prohibited.