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A series of acyclic oligourea receptors which closely resemble the scaffolds and coordination behavior of oligopyridines have been synthesized. Assembly of the receptors with chloride ions afforded mononuclear anion complexes or dinuclear foldamers depending on the number of the urea groups.

A series of dinuclear triple-stranded complexes, [Fe(2)L(3)⊃X]X(6) [X = BF(4)(-) (1), ClO(4)(-) (2)], [Fe(2)L(3)⊃SO(4)](2)(SO(4))(5) (3), [Fe(2)L(3)⊃Br](BPh(4))(6) (4), Fe(2)L(3)(NO(3))Br(6) (5), and [Cu(2)L(3)⊃NO(3)](NO(3))(6) (6), which incorporate a central cavity to encapsulate different anions, have been synthesized via the self-assembly of iron(II) or copper(II) salts with the N,N'-bis[5-(2,2'-bipyridyl)methyl]imidazolium bromide (LBr) ligand. X-ray crystallographic studies (for 1-4 and 6) and elemental analyses confirmed the cagelike triple-stranded structure. The anionic guest is bound in the cage and shows remarkable influence on the outcome of the self-assembly process with regard to the configuration at the metal centers. The mesocates (with different configurations at the two metal centers) have formed in the presence of large tetrahedral anions, while helicates (with the same configuration at both metal centers) were obtained when using the relatively smaller spherical or trigonal-planar anions Br(-) or NO(3)(-).

To explore the incidence rate of people with mild cognitive impairment (MCI) which transferred to Alzheimer's disease (AD) and to study the related influencing factors.600 MCI aged people were experienced screening test which was conducted by WHO-BCA, MMSE and DCR. A three-year follow-up study was conducted to get the information on the aged people with MCI. Data related to demography, behavior, chronic diseases and perception of the elderly with MCI were collected through face to face interview. Characteristics of the elderly with MCI aged people were tested by 16PF. The content of Apoe was tested by PCR. People with NC were investigated by telephone to get the progression and the time to AD. Methodologies on statistics were log-rank test and Cox proportional hazards regression model.The incidence rate of MCI to AD was 6.53% person-years. The incidence rate of the normal people to AD was 1.24% person-years. The hazard of MCI to AD was 5.27 times (95%CI: 3.01 - 9.82) of the normal people to AD. The result of Cox proportional hazards regression model displayed that:older age (RR = 3.14, 95%CI: 2.98 - 7.46), hypertension (RR = 3.28, 95%CI: 3.02 - 8.48), hyperlipemia (RR = 2.22, 95%CI: 1.29 - 3.82), diabetes (RR = 4.87, 95%CI: 2.56 - 9.25), lack of sports (RR = 2.02, 95%CI: 1.29-3.14), anxiety (RR = 4.46, 95%CI: 3.07 - 8.14), dread fullness (RR = 4.08, 95%CI: 3.52 - 5.25), loneliness (RR = 1.89, 95%CI: 1.13 - 3.16), characteristics of anxiety (RR = 5.07, 95%CI: 2.56 - 10.04, introvert characteristics (RR = 2.05, 95%CI: 1.33 - 3.15) and ApoE4 (RR = 1.73, 95%CI: 1.15 - 2.63) were the risk factors of MCI to AD. Higher education (RR = 0.29, 95%CI: 0.07 - 0.43), intellectual work (RR = 0.14, 95%CI: 0.05 - 0.32), often reading books (RR = 0.30, 95%CI: 0.15 - 0.58), often taking part in recreational activities (RR = 0.41, 95%CI: 0.23 - 0.75) seemed to be the protective of MCI to AD.The rate of the elderly with MCI that developing to AD was high, suggesting further study on the cognitive situation among the MCI aged people should be carried out.

To explore the association of serum HBV DNA level with HBV-specific and nonspecific cytotoxic T lymphocytes (CTL) in patients with HBV-induced hepatic cirrhosis.120 patients with HBV-induced hepatic cirrhosis who were positive for HBV DNA, HBeAg and human leucocyte antigen (HLA)-A2 were enrolled in this study. The level of HBV DNA was determined by real time fluorescence quantitative polymerase chain reaction (PCR). HBV-specific and nonspecific CTL were detected by flow cytometry. Liver function tests were done in the 120 patients. The 120 patients were divided into group A and B based on their HBV DNA levels. In group A, there were 68 patients with HBV DNA level of 3-4 log10 copy/ml, and in group B, 52 with 5-6 log10 copy/ml. HBV-specific and nonspecific CTL and liver function were compared between the two groups.HBV DNA levels were (3.68 +/- 0.19) and (5.97 +/- 0.32) log10 copy/ml in Group A and B respectively with P0.001. HBV-specific CTL was higher in group A (0.33% +/- 0.04%) than in group B (0.11% +/- 0.01%) with P0.001. HBV-nonspecific CTL were (11.99% +/- 1.51% ) and (11.91% +/- 1.61%) in group A and B respectively with P0. 05.The level of serum HBV DNA is related to the levels of HBV-specific CTL in patients with HBV-induced hepatic cirrhosis. Patients with higher HBV DNA had lower levels of HBV-specific CTL, and the damage to liver function was severe because of higher levels of HBV DNA. Patients with lower HBV DNA had higher levels of HBV-specific CTL which predict good anti-viral effect.

Background/Aims There has been debate on whether a sodium-restricted diet (SRD) should be used in cirrhotic patients with ascites in China in recent years. The purpose of this study was to compare the effect of sodium-restricted and unrestricted diets on plasma renin activity (PRA), renal blood flow (RBF) and ascites in patients with liver cirrhosis. Methods Two hundred cirrhotic patients with ascites were randomly divided into two groups (98 cases in the sodium-unrestricted diet [SUD] group and 102 cases in the SRD group); 95 patients (96.94%) in the SUD group and 97 patients (95.1%) in the SRD group had post-hepatitis B cirrhosis. Results Blood sodium and RBF were higher in SUD group than in SRD group (p

A series of mononuclear and dinuclear zinc compounds, [Na(Et(2)O)](2)[((H)L(iPr))Zn-Zn((H)L(iPr))] x Et(2)O (1), [Zn(2)((H)L(iPr))(3)K(2)(Et(2)O)(2)](n) (2, (H)L(iPr) = [(2,6-(i)Pr(2)C(6)H(3))NCH](2)), [Zn((H)L(Mes))(2)] (4, (H)L(Mes) = [(2,4,6-Me(3)C(6)H(2))NCH](2)), and [ZnL(Mes)(2)Na(2)(THF)(2)] (5, L(Mes) = [(2,4,6-Me(3)C(6)H(2))NC(Me)](2)), and a potassium complex, [((H)L(iPr))(2)K(4)(THF)(2)](n) (3), have been synthesized by alkali metal reduction of the corresponding LZnCl(2) precursors. The Zn-Zn bond in 1 (2.3673(6) A) is slightly shorter than that in the analogous compounds [M(THF)(2)](2)[L(iPr)Zn-ZnL(iPr)] (L(iPr) = [(2,6-(i)Pr(2)C(6)H(3))NC(Me)](2), M = Na, 2.399(1) A; M = K, 2.393(1) A). Complexes 2 and 3 feature a two- and one-dimensional (linear chain) polymeric structure, respectively, linked by K-C bonds between the potassium ion and aryl carbon atoms. Notably, complex 2 contains a ligand whose central C(2)N(2) core is in the trans conformation, acting as a non-chelating bridge between the two zinc atoms. While the ligands in 1, 2, 3 and 5 are doubly reduced to the dianion, complex 4 contains a pair of monoanionic ligands.

To explore relations between ALT level and hepatitis B virus (HBV) specific CTL and non-specific CTL in patients with chronic hepatitis B (CHB).148 cases of CHB were divided into three groups according to ALT level. 35 cases in group A, ALTor =2 x upper limit of normal value (ULN)--5 x ULN (100-250 IU/L); 53 cases in group B, ALT5 x ULN--or =10 x ULN (251-500 IU/L); 60 cases in group C, ALT10 x ULN (500 IU/L). Flow cytometry is used to determine non-specific CTV. HBV specific CTL was tested on 74 cases of CHB (17 in group A, 27 in group B and 30 in group C) with positive (HLA)-A2. Compare HBV specific CTL, non-specific CTL, HBV DNA levels and positive rate of HBeAg.HBV specific CTL: Group A (0.42 +/- 0.10)% is higher than group B (0.25 +/- 0.08)%, t = 6.37, P0.01, group B is higher than group C (0.17 +/- 0.004)%, t = 5.14, P0.01; Non-specific CTL: Group A (15.01 +/- 3.01)% is lower than group B (18.1 +/- 5.02)%, t = 2.81, P0.01, group B is lower than group C (21.5 +/- 6.11)%, t = 3.07, P0.01; HBV DNA level: Group A [(4.97 +/- 0.86) log10 copies/ml] is lower than group B [(5.92 +/- 0.92) log10 copies/ml], t = 4.87, P0.01. Group B is lower than group C [(6.37 +/- 0.71) log10 copies/ml], t = 2.92, P0.01; Positive HBeAg: Group A (15 cases, 42.86%) is lower than group B (32 cases, 60.38%), chi2 = 2.59, P0.05. Group B is lower than group C (41 cases, 68.33%), chi2 = 0.78, P0.05. Group A is lower than group C, chi2 = 5.929, P0.05.The higher the non-specific CTL of patients with CHB is, the higher the ALT level would be, whereas the lower the HBV specific CTL is, the stronger the HBV replication would be.

†Background Phosphorus (P) is often a limiting mineral nutrient for plant growth. Many soils worldwide are deficient in soluble inorganic phosphate (Pi), the form of P most readily absorbed and utilized by plants. A network of elaborate developmental and biochemical adaptations has evolved in plants to enhance Pi acquisition and avoid starvation. †Scope Controlling the deployment of adaptations used by plants to avoid Pi starvation requires a sophisticated sensing and regulatory system that can integrate external and internal information regarding Pi availability. In this review, the current knowledge of the regulatory mechanisms that control Pi starvation responses and the local and long-distance signals that may trigger Pi starvation responses are discussed. Uncharacterized mutants that have Pirelated phenotypes and their potential to give us additional insights into regulatory pathways and Pi starvationinduced signalling are also highlighted and assessed. †Conclusions An impressive list of factors that regulate Pi starvation responses is now available, as is a good deal of knowledge regarding the local and long-distance signals that allow a plant to sense and respond to Pi availability. However, we are only beginning to understand how these factors and signals are integrated with one another in a regulatory web able to control the range of responses demonstrated by plants grown in low Pi environments. Much more knowledge is needed in this agronomically important area before real gains can be made in improving Pi acquisition in crop plants.

A second-sphere complex [Co(DABP)(3)][Fe(CN)(6)] (1) (DABP = 5,5'-diamino-2,2'-bipyridine) is constructed from [Co(DABP)(3)](3+) and [Fe(CN)(6)](3-) through charge-assisted N-H((NH(2)))N((CN)) hydrogen bonds; hexagonal microrods of 1 are obtained via a facile self-assembly method in the presence of surfactant.

To explore influence of Kurarinol on specific and non-specific cell immunity in patients with chronic hepatitis B.74 cases of CHB were randomly divided into two groups, 36 cases in treatment group, treated with 600 mg Kurarinol glucose injection, IV, once a day. After one month, Kurarinol capsule was used orally, three times a day for 2 months, 200 mg Silybin Meglumine Tablets orally, three times a day for 3 months. 38 cases in control group, only Silybin Meglumine Tablets was used, method and dosage were the same as treatment group. Compare HBV specific CTL, non-specific CTL, sub-group of T cells, changes of Th1 and Th2, negative conversion rate of HBV DNA and HBeAg of the two groups.In treatment group, 3 months after treatment with Kurarinol, HBV specific CTL is higher than that before treatment (P0.01), it is also higher than that of control after treatment, P0.05) . Non-specific CTL is higher than that before treatment (P0.05), it is also higher than that of control after treatment (P0.01). CD4 is higher than that before treatment (P0.05), it is also higher than that of control after treatment (P0.01), Thl is higher than that before treatment (P0.05), it is also higher than that of control after treatment (P0.01) . Negative conversion of HBV DNA and HBeAg is higher than that of control (P0.01).Kurarinol can improve specific and non-specific cell immunity in patients with CHB. It is one of the mechanisms that Kurarinol can clear or inhibit HBV of patients with CHB.

Four kinds of ferrites, M Fe 2 O 4 ( M =Cu, Zn, Cd and Mg), having high specific surface area (40–80 m 2 /g) were prepared by a coprecipitation method and tested for sensing properties to reducing gases of CO, H 2 , LPG, C 2 H 5 OH and C 2 H 2 . The gas sensitivity depended considerably on the kinds of ferrites and the gases to be detected. All of the ferrites were more sensitive to C 2 H 2 , C 2 H 5 OH or LPG than to H 2 or CO. Among the ferrites, the gas sensitivity tended to decrease in the order MgFe 2 O 4 ∼CdFe 2 O 4 >CuFe 2 O 4 >ZnFe 2 O 4 , which was in fact coincident with the increasing (or decreasing) order in specific surface area (or grain size). It was revealed that MgFe 2 O 4 and CdFe 2 O 4 were the most sensitive and selective to LPG and C 2 H 2 , respectively, among the ferrites tested.

The response of patients with chronic hepatitis B (CHB) to antiviral therapy against hepatitis B virus (HBV) is related to the base line level of HBV DNA, but the mechanism is not clear. The present study aimed to understand the possible relationship between the level of HBV DNA and HBV-specific, nonspecific cytotoxic T lymphocytes (CTL) and natural killer (NK) cells of CHB patients and the mechanism how the HBV DNA level influences the antiviral therapeutic effect.Totally 100 adult patients with CHB who were positive for HBV DNA, HBeAg and (HLA)-A2 were enrolled into this study. HBV DNA was tested by real time fluorescence quantitative polymerase chain reaction (PCR). HBV specific and nonspecific CTL and NK cells were tested by flowcytometry. Serum alanine aminotransferase (ALT) and total bilirubin (TBil) were determined for each patient using routine biochemical tests. The 100 cases were assigned to two groups based on their HBV DNA level: group A had 48 cases, their HBV DNA level was 10(4) - 10(5) copies/ml, group B had 52 cases, their HBV DNA level was 10(6) - 10(7) copies/ml. HBV specific CTL, nonspecific CTL, NK cells, ALT and TBil of the two groups were compared.HBV DNA level of groups A and B was (4.81 +/- 0.39) log(10) copies/ml and (6.81 +/- 0.40) log(10) copies/ml, respectively (t = 25.32, P0.001). HBV specific CTL and NK cells of group A were significantly higher than those of group B (P0.001 for both). Nonspecific CTL of group A was significantly lower than that of group B (P0.01). ALT and TBil of group A were significantly lower than those of group B (P0.01 and P0.05, respectively).Serum HBV DNA level of patients with CHB is related to HBV specific CTL, nonspecific CTL and NK cells, which might result in inflammatory reaction of liver and cause more damage to liver function. Mechanism of HBV DNA level affecting the efficacy of anti-viral treatment may be related to the levels of HBV specific CTL and NK cells.

The present study was designed to investigate possible relationships between the genotypes of hepatitis B virus (HBV) and the HBV-specific cytotoxic T lymphocyte (CTL) responses. HBV genotypes, HBV specific CTL HBV DNA and other markers of HBV infection were determined in 138 patients with chronic hepatitis B. The results showed that the patients infected with genotype C (n=62) had a significantly lower HBV-specific CTL response than those who were infected with HBV genotype B (P

To observe the effect of Jiannao Yizhi Decoction (JNYZD) on learning and memory in rats with similar Alzheimer's disease (AD), and to investigate its possible mechanism.The composite AD rat model was established by injecting aggregated Abeta25-35 into the lateral cerebral ventricle of senile rats, and all the modeled rats were divided into 5 groups, the model group, the Donepezil group, the high-, middle-, and low-dose JNYZD group. All rats, except those in the model group, were treated respectively with Donepezil and JNYZD at the daily dose of 0.525 mg/kg, 42.4 g/kg, 21.2 g/kg, 10.6 g/kg for 21 days. The ability of learning and memory of rats in different groups was tested using Morris water maze, and the activity of acetylcholine esterase (AchE) and butyrocholin esterase (BehE) in serum were determined, too.The escape latent period was shorter in all medicated group than in the model group (P0.01 or P0.05), and it was insignificantly different among all medicated groups (P0.05). A decreasing trend of AchE and BchE activity presented in the high- and middle-dose JNYZD groups, but insignificant difference was shown as compared these indexes respectively with those in the Donepezil group. Furthermore, the improvement of learning and memory in similar AD rats was insignificantly different between the Donepezil group and the JNYZD groups (P0.05).JNYZD can improve the learning and memory ability of similar AD rats by influencing the activity of cholinesterase.

Reaction of RLi with lead(II) bromide affords the diaryl lead(II) compounds PbR2 (R1 = 2,4,6-triphenylphenyl, 1; R2 = 2,6-bis(1′-naphthyl)phenyl, 2), which have monomeric, carbene-like structures with bent two-coordinate Pb(II) centers.

Potassium reduction of RZn(mu-I)2Li(OEt2)2 (R = [{(2,6-Pri2C6H3)N(Me)C}2CH]) affords the second compound with a Zn-Zn bond, RZn-ZnR. The air- and moisture-sensitive title compound was characterized by 1H NMR, elemental analyses, and single-crystal X-ray diffraction. The Zn-Zn bond was determined to be 2.3586(7) A; this value is only about 0.05 A longer than the Zn-Zn bond reported for Cp*Zn-ZnCp* (Cp* = C5Me5), the first reported compound with a Zn-Zn bond. In addition, density functional theory (DFT) computations on related model RZn-ZnR compounds provide insight into the intriguing Zn-Zn bond.

Reaction of lead(II) chloride with biphenylmagnesium bromide yields Bp(3)Pb-PbBp(3) and [(THF)(3)Mg(mu-Cl)(3)Mg(THF)(3)][Pb(PbBp(3))(3)](Bp = biphenyl), which, upon single crystal X-ray crystallographic analysis, reveals an interesting variation of Pb-Pb bond distances.

The synthesis and coordination chemistry of a new chiral ligand, 2,2'-bipyridine substituted at the 5 and 5' positions by N-methyl-L-valine methyl ester (5), is presented. The ligand readily forms complexes [M(5)3]2+ where M = Co(II) and Fe(II) in CH3CN, and the complexation reaction is slightly diastereoselective (d.e. =ca. 20%) in favour of the Delta diastereomer. The addition of six equivalents of HCl to these complexes [M(II)(5)3]2+ leads to formation of Delta-[M(II)(5H2)3]8+ with a d.e. of 100%. This high diastereoselectivity can be reversed by the addition of base i.e. the diastereoselectivity can be controlled by the pH. Delta-[Fe(5H2)3]8+ was found to bind chloride ions in CD3OD-CD3CN (6:1) with a binding constant of 260 M(-1). [Co(II)(5)3]2+ can be oxidised to Delta-[Co(III)(5H2)3]9+. Formation constants for both [Co(II)(5)3]2+ and [Co(II)(5H2)3]8+ in acetonitrile were obtained by spectrophotometric titrations. In the former case, the stability constant, log beta3 = 19.5(8), is very similar to that measured for [Co(II)(bipy)3]2+ (log beta3 = 19.3(7)) but this drops significantly when the amine groups of are protonated (log beta3 = 16.5(2)). A dynamic combinatorial library was prepared by mixing three equivalents of, three equivalents of bipy, and two equivalents of Co(II) in CD3CN. The presence of all possible Delta- and Lambda-[Co(II)(5)x(bipy)(3-x)]2+ complexes was inferred from 1H NMR and ES-MS spectra. Addition of protons to this library reduced the number of components by inducing diastereoselectivity, and presence of chloride further simplified the 1H NMR spectrum, indicating that [Cl2 ligand Delta-[Co(II)(5H2)3]]6+ and [Co(II)(bipy)3]2+ were the dominant products.

Three 5,5'-substituted 2,2'-bipyridyl ligands around a metal atom form two clefts which can encapsulate sulfate, perchlorate, or nitrate anions.

A new Mg-Mg-bonded compound stabilized by a doubly reduced alpha-diimine ligand, [K(THF)(3)](2)[LMg-MgL] (L = [(2,6-(i)Pr(2)C(6)H(3))NC(Me)](2)(2-)), has been synthesized and characterized by single-crystal X-ray diffraction and density functional theory analysis. The Mg-Mg bond length is 2.9370(18) A.

The zirconocene-complexed dibismuthene, Cp2Zr(BiR)2 (Cp = C5H5; R = C6H3-2,6-Mes2), was prepared by the reaction of sodium metal with Cp2ZrCl2 and RBiCl2. The air- and moisture-sensitive dark reddish/brown compound is the first organometallic compound containing Bi-Zr bonds and the only example of a ZrBi2 ring. Moreover, our computations on associated model systems offer insight into the nature of the interaction of the heaviest dipnictene with a metallocene center.

The reaction of sodium metal with Cp2ZrCl2 and RGaCl2 in hexane affords Cp2Zr(GaR)2 (R = −C6H3-2,6-(2,4,6-i-Pr3C6H2)2) as deep green-black air-sensitive crystals. Essentially, Cp2Zr(GaR)2 is isoelectronic with the well-known 18-electron zirconocene dicarbonyl, Cp2Zr(CO)2, complex. The title compound is the first example of an organometallic compound containing Ga−Zr bonds (Ga−Zr = 2.6350(8) A).

Three 5,5′-substituted 2,2′-bipyridyl ligands around a metal atom form two clefts which can encapsulate sulfate, perchlorate, or nitrate anions.

A bis-trisurea ligand assembles with the tetraalkylammonium halides to form the flat 'stave' structures or 'barrels' that encapsulate multiple R(4)N(+) guests, depending on the size of the halide anion (Cl(-) or Br(-)) and the R(4)N(+) cation.

A tripodal tris(urea) ligand with 2,2'-bipyridyl (bpy) substituents (L) has been designed and synthesized, which coordinates with three equivalents of Ru(bpy)(2)Cl(2)·2H(2)O, followed by treatment with NH(4)PF(6), to afford the anion receptor [(bpy)(6)Ru(3)L](PF(6))(6) (1). The anion-binding behavior of the ligand L and the Ru(II)-bpy functionalized receptor 1 toward different anions was investigated by (1)H NMR (for L and 1), fluorescence, and UV-vis spectroscopy (for 1). Both compounds showed selective recognition of SO(4)(2-) or H(2)PO(4)(-) ions in the 1:1 binding mode in the NMR studies. The Ru(II) complex 1 displayed the metal-to-ligand charge transfer emission at 600 nm, which was quenched on addition of the sulfate and dihydrogen phosphate ions. Quantitative fluorescence titration experiments were carried out and the stability constants (log K) of the complex 1 with SO(4)(2-) and H(2)PO(4)(-) ions were obtained to be 4.73 and 4.69 M(-1) (1:1 binding mode), respectively.

A bis-bisurea receptor (L) based on the R,R-cyclohexane-1,2-diamino scaffold forms an uncommon 2 : 2 complex (1) with the monohydrogen phosphate ion (HPO(4)(2-)) and a 1 : 1 complex (2) with the sulfate ion (SO(4)(2-)). Solution binding properties of the two anions were studied by (1)H NMR, UV-vis, and circular dichroism (CD) methods.

A sulfate-encapsulating complex, [Cu(1)L(6)]·3[Cu(2)L(2)(DMF)(4)](SO(4))(4) (1, L = N-(1-naphthyl)-N'-(3-pyridyl)urea) is synthesized in which two C(3)-clefts of the octahedral complexes interdigitate to form a cavity to encapsulate the sulfate ion by six urea groups.

Six metal–organic coordination polymers or metallomacrocycles, [Zn2Cl4(L2)2]·3H2O (1), [Zn2Br4(L2)2]·0.5H2O (2), {[Cu(L2)2(H2O)2](NO3)2·4H2O·4CH3OH}n (3), [Zn2Br4(L3)2] (4), (ZnBr2L4)n (5) and (ZnBr2L5)n (6), were prepared from zinc(II) or copper(II) salts with flexible bis(pyridylcarbamate) ligands L2 to L5 [L2 = 3-pyridyl-carbamic-acid-oxydi-1,2-ethanediylester, L3 = 3-pyridinyl-carbamic-acid-1,2-ethanediyl-bis(oxy-2,1-ethanediyl)ester, L4 = 3-pyridinyl-carbamic-acid-1,3-propanediylester and L5 = 3-pyridinyl-carbamic-acid-1,4-butanediylester]. Compounds 1, 2 and 4 are hydrogen-bonded 3D porous nanotubular structures composed of metallomacrocycles. Compound 3 has a racemic framework formed by 2D homochiral layers. Compound 5 is a 1D meso-helical chain and 6 is a 1D linear chain, both of which are further connected by N–H⋯O and C–H⋯O hydrogen bonds and π–π interactions into 3D frameworks. The highly flexible bis(pyridylcarbamate) ligands show dramatically different conformations with various metal ions and counteranions, thus leading to the structural diversity of these complexes.

The assembly of a bis(pyridylurea) ligand, N,N′-ethane-1,2-diylbis(3-pyridin-4-ylurea) (L), with Cu(AcO)2, CuCl2 or CoSO4 led to four 1D coordination polymers, {[Cu2(AcO)3(OH)L]·2.6H2O}n (1), {[CuL2(H2O)2]·2AcO·3CH3OH}n (2), {[CuL2(DMF)2]·2Cl·2H2O}n (3), and {[Co2L3(H2O)4(CH3OH)2]·2SO4·6H2O}n (4). The ligand exhibits the expected flexibility in the formation of the coordination polymers. Compounds 1, 2 and 3 are infinite 1D ribbon-like polymers with metal nodes and flexible ligands in bent/gauche (V-shaped) conformations, while complex 4 shows a 1D ladder structure. Interestingly, the ligand molecules show two different conformations (roughly linear GAG and V-shaped GAA; G = gauche, A = anti) in 4. The tetranuclear copper(II) complex 1 is analyzed by temperature-dependent magnetic measurements, and represents a rare example of a six-coordinate copper complex with an endohedral hydroxide anion.

Three 5,5'-dicarbamate-2,2'-bipyridine ligands (L = L(1)-L(3)) bearing ethyl, isopropyl or tert-butyl terminals, respectively, on the carbamate substituents were synthesized. Reaction of the ligands L with the transition metal ions M = Fe(2+), Cu(2+), Zn(2+) or Ru(2+) gave the complexes ML(n)X(2)·xG (1-12, n = 1-3; X = Cl, NO(3), ClO(4), BF(4), PF(6), ½SO(4); G = Et(2)O, DMSO, CH(3)OH, H(2)O), of which [Fe(L(2))(3) ⊃ SO(4)]·8.5H(2)O (2), [Fe(L(1))(3) ⊃ (BF(4))(2)]·2CH(3)OH (7), [Fe(L(2))(3) ⊃ (Et(2)O)(2)](BF(4))(2)·2CH(3)OH (8), [ZnCl(2)(L(1))][ZnCl(2)(L(1))(DMSO)]·2DMSO (9), [Zn(L(1))(3) ⊃ (NO(3))(2)]·2H(2)O (10), [Zn(L(2))(3) ⊃ (ClO(4))(Et(2)O)]ClO(4)·Et(2)O·2CH(3)OH·1.5H(2)O (11), and [Cu(L(1))(2)(DMSO)](ClO(4))(2)·2DMSO (12) were elucidated by single-crystal X-ray crystallography. In the complexes ML(n)X(2)·xG the metal ion is coordinated by n = 1, 2 or 3 chelating bipyridine moieties (with other anionic or solvent ligands for n = 1 and 2) depending on the transition metal and reaction conditions. Interestingly, the carbamate functionalities are involved in hydrogen bonding with various guests (anions or solvents), especially in the tris(chelate) complexes which feature the well-organized C(3)-clefts for effective guest inclusion. Moreover, the anion binding behavior of the pre-organized tris(chelate) complexes was investigated in solution by fluorescence titration using the emissive [RuL(3)](2+) moiety as a probe. The results show that fluorescent recognition of anion in solution can be achieved by the Ru(II) complexes which exhibit good selectivities for SO(4)(2-).

Two anion receptors with the same tripodal scaffold but different signaling groups are employed to control intermolecular anion transfer via an electrochemical stimulus, which is detected by the change of the fluorescence intensity before and after electrochemical oxidation of the ferrocenyl units.

A fully complementary tris(urea) receptor for phosphate and sulfate anions has been developed by mimicking the scaffold of terpyridine which shows very high affinities and selectivities toward the tetrahedral anions.

The reaction of CoCl2·6H2O or Co(NO3)2·6H2O with a semi-rigid ditopic ligand 2,6-bis(1-(2,6-diisopropyl-4-(pyridin-3-yl)phenylimino)ethyl)pyridine (L) in various solvent systems led to four complexes, {[CoCl2L2]·CH2Cl2}n (1a), {[Co(NO3)2L2]·CH2Cl2}n (1b), {[Co4(μ2-Cl)2(μ2-L)2Cl8]·xH2O}n (2), and [Co4(NO3)8L2(CH3CN)2]·xH2O (3). Compounds 1a and 1b are isostructural 1D looped-chain coordination polymers constructed by 44-membered [Co2L2] macrocyclic units. Compound 2 shows an unprecedented double μ2-Cl bridged 1D chain structure containing 36-membered [Co4L2] macrocycles. Interestingly, the Co(II) ions are partially oxidized to form the CoIII2Cl2 bridges, and the [CoII2L2] metallocycles are linked by these CoIII2Cl2 units to generate the 1D chain. Compound 3 is a discrete 0D 36-membered metallomacrocycle comprised of four Co(II) ions and two bridging ligands. The structural variation of the complexes is related to the conformational changes of the semirigid ligand L induced by different solvent systems.

Self-assembly of two flexible bis-pyridylurea ligands, pentane-1,5-diylbis(3-pyridin-3-ylurea) (L5) and hexane-1,6-diylbis(3-pyridin-3-ylurea) (L6) with ZnSO4 or CdSO4 (metal-to-ligand molar ratio 1 : 2) results in three metal–organic frameworks with (4,4) net structures, {[ML2(H2O)2]SO4·2H2O}n (1: Zn, L5; 2: Cd, L5; and 3: Zn, L6). Single-crystal X-ray diffraction analyses reveal that all the compounds are characteristic of a 3-fold parallel interpenetrated framework with cavities suitable for encapsulating the sulfate anion despite the different spacer lengths ((CH2)5 and (CH2)6) of the two ligands and variation of the metal ions. The ligand adopts an anti–anti conformation and functions as a bridging bidentate linker, while the sulfate ion is selectively bound by four urea functionalities via multiple hydrogen bonds.

A series of isomorphous second-sphere coordination compounds [MII(DABP)3]3[Cr(C2O4)3]2·14H2O (DABP = 5,5′-diamino-2,2′-bipyridine; M = Cu (1), Ni (2), Fe (3), Zn (4), and Mn (5)) have been constructed through multiple charge-assisted N–H‐–O hydrogen-bonding interactions between the oxalate ligands in [Cr(C2O4)3]3– (unit B) and the NH2 groups in the [M(DABP)3]2+ complex (unit A). The chiral [M(DABP)3]2+ cations and [Cr(C2O4)3]3– anions with the same Λ (or Δ) configuration interdigitate alternately, affording linear A3B2 secondary building units. Two adjacent A3B2 units adopting opposite configurations are linked by a six-cornered star-shaped 14-water cluster of S 6 symmetry (unit C) to form a racemic 1D linear chain –A3B2(Λ)–C–A3B2(Δ)–C–. The microstructure of compound 1 shows a 3D flower-like morphology.

Anion complexation of a flexible bis(pyridylcarbamate) receptor, 3-pyridinyl-carbamic-acid-1,2-ethanediylester (L), is reported. Upon addition of a series of inorganic acids (H3PO4, H2SO4, HClO4, HCl and HBr), the ligand L can be doubly protonated and bind the anions through hydrogen bonding interactions, affording the adducts 1–5. The binding modes of the protonated ligand ([LH2]2+) with anions in 1–5 in the solid state are established by X-ray single crystal diffraction. Of particular interest is that the three oxoanion complexes (1–3) feature intriguing anionic polymer fashions, such as the novel double-stranded dihydrogen phosphate chain in 1, the infinite [-sulfate-(H2O)2-]n chain in 2, and hydrogen-bridged helical perchlorate chain in 3. For complexes 4 and 5, the packing diagram displays a layered structure with the halide anions located between the adjacent cationic arrays. Receptor L can selectively crystallize with the sulfate anion from the acid mixture H3PO4, H2SO4, HClO4, HCl and HBr.

Self-assembly of a flexible ligand, butylene bis(3-(3-pyridyl)urea) (L), with ZnCl2 in the presence of different guests results in a metallomacrocycle or a helical chain, the former entrapping a guest molecule in its cavity.

A tripodal tris(3-pyridylurea) receptor (L) assembles with metal sulfate salts MSO(4) (M=Mn, Zn) to afford supramolecular cages [SO(4) subset L(2)] that encapsulate the SO(4)(2-) ion via multiple hydrogen bonds in a three-dimensional structure held by second-sphere coordination; (1)H NMR and negative-ion mode ESI-MS spectra reveal significantly strong sulfate binding in solution.

The anion coordination chemistry of two protonated urea-based ligands, N-(2,4-dimethylphenyl)-N′-(3-pyridy1)urea (1) and N-(2,6-dimethylphenyl)-N′-(3-pyridy1)urea (2) is reported. Reaction of 1 or 2 with inorganic oxo-acids such as perchloric, nitric or sulfuric acid affords the adducts (3–6) of the corresponding anions with protonated ligands (1H+ and 2H+). The solid-state structures of the anion complexes display a rich variety of hydrogen bond motifs involving the urea NH groups, carbonyl, protonated pyridyl NH+ fragment, water molecules, and the anions. While complexes with ligand 1 (3 and 4) crystallize as monohydrate, compounds with 2 (5 and 6) are solvent-free, which leads to notable differences in their hydrogen bond patterns. When crystallized from the acid mixture HClO4/HNO3 or HClO4/H2SO4 both 1 and 2 selectively bind the perchlorate anion.