Diblock Polymer Brush (PHEAA- b-PFMA): Microphase Separation Behavior and Anti-Protein Adsorption Performance.

In this paper, a series of amphiphilic diblock polymers of poly(hydroxyethylacrylamide)- b-poly(1H,1H-pentafluoropropyl methacrylate) (PHEAA- b-PFMA) were grafted from silicon wafer via surface-initiated atom transfer radical polymerization (SI-ATRP). Surface wettability and chemical compositions of the modified surfaces were characterized by contact angle goniometer and X-ray photoelectron spectroscopy (XPS) respectively. Molecular weight and polydispersity of each block were measured using gel permeation chromatography (GPC). The topography and the microphase separation behavior of PHEAA- b-PFMA surfaces were investigated by atomic force microscope (AFM). The results show that only when the grafting density (σ) and thickness of PHEAA brush were in the range of 0.9-1.3 (chain/nm2) and 6.6-15.1 nm, respectively, and the ratio of PFMA/PHEAA varied from 89/42 to 89/94, could the diblock copolymer phase separate into nanostructures. Further, the antiprotein adsorption performance of the modified surfaces against BSA, fibrinogen, and lysozyme was studied. The results indicated the modified surfaces could reduce the protein adsorption compared to the pristine silicon wafer. For Fibrinogen, the antiadsorption effect of PHEAA- b-PFMA-modified surfaces with microphase segregation was better than that of corresponding PHEAA modified surfaces. The results provide further evidence that surface composition and microphase segregation of fluorinated moieties of block copolymer brushes significantly impact protein adsorption behaviors.

[The swelling behavior of choline fenofibrate hydrogel matrix tablets using dynamic image analysis].

The purpose of this study is to investigate the effects of formulation on the swelling behavior of choline fenofibrate hydrogel matrix tablets and reveal the relation between swelling property and release profile using dynamic image analysis. The volume swelling ratio (SR) and height/width (k) could evaluate the swelling behavior of matrix tablets well. The mount of hydroxypropyl methylcellulose (HPMC) and the ratio between K15M and K4M affected the volume swelling ratio, while PVP didn't. The three factors all impacted k, which was an indicator of the strength of the gel formed by HPMC. The accumulative release ratio and SR, the rate of swelling and the rate of release were compared. The proper model equations were established for the results with an excellent correlation. The results prove that there is a strong relevance between the swelling behavior and release property. This study provides a guideline in the study design for hydrogel matrix tablets.

[Preparation and properties of thermosensitive in situ gel for ophthalmic formulation containing pearl hydrolyzate].

The study was designed to generate an ophthalmic thermosensitive in situ gel with improved mechanical and mucoadhesive properties that may prolong the retention time to enhance the bioavalability of pearl hydrolyzate. The gene was comprised of poloxamer 407, poloxamer188 and Carbopol 934, which were optimized by central composite design and response surface methodology. The rheological properties, transcorneal permeability, retention time and in vitro release behaviors of the optimal gel formulation were investigated. The gel was Newtonian liquid at 25 ℃ and performed as a semisolid gel with non-Newtonian liquid property with a gelation time of 13 s at 35 ℃. Compared with a conventional eye drops, the ophthalmic in situ gel exhibited a sevenfold increase in retention with a sustained release behavior, which was observed with suitable permeability coefficient at 5.58 cm·s-1. In conclusion, the new gel of pearl hydrolyzate prolonged the release duration of drug, which may decrease the frequency of administration of pearl hydrolyzate.

Pharmacokinetics, safety, and efficacy of Fuqi Guben Gao in the treatment of kidney-yang deficiency syndrome: a randomized, double-blind phase I trial.

Introduction: Fuqi Guben Gao (FQGBG) is a botanical drug formulation composed of FuZi (FZ; Aconitum carmichaelii Debeaux [Ranunculaceae; Aconiti radix cocta]), Wolfberry (Lycium barbarum L. [Solanaceae; Lycii fructus]), and Cinnamon (Neolitsea cassia (L.) Kosterm. [Lauraceae; Cinnamomi cortex]). It has been used to clinically treat nocturia caused by kidney-yang deficiency syndrome (KYDS) for over 30 years and warms kidney yang. However, the pharmacological mechanism and the safety of FQGBG in humans require further exploration and evaluation. Methods: We investigated the efficacy of FQGBG in reducing urination and improving immune organ damage in two kinds of KYDS model rats (hydrocortisone-induced model and natural aging model), and evaluated the safety of different oral FQGBG doses through pharmacokinetic (PK) parameters, metabonomics, and occurrence of adverse reactions in healthy Chinese participants in a randomized, double-blind, placebo-controlled, single ascending dose clinical trial. Forty-two participants were allocated to six cohorts with FQGBG doses of 12.5, 25, 50, 75, 100, and 125 g. The PKs of FQGBG in plasma were determined using a fully validated LC-MS/MS method. Results: FQGBG significantly and rapidly improved the symptoms of increased urination in both two KYDS model rats and significantly resisted the adrenal atrophy in hydrocortisone-induced KYDS model rats. No apparent increase in adverse events was observed with dose escalation. Major adverse drug reactions included toothache, thirst, heat sensation, gum pain, diarrhea, abdominal distension, T-wave changes, and elevated creatinine levels. The PK results showed a higher exposure level of benzoylhypaconine (BHA) than benzoylmesaconine (BMA) and a shorter half-life of BMA than BHA. Toxic diester alkaloids, aconitine, mesaconitine, and hypaconitine were below the lower quantitative limit. Drug-induced metabolite markers primarily included lysophosphatidylcholines, fatty acids, phenylalanine, and arginine metabolites; no safety-related metabolite changes were observed. Conclusion: Under the investigated dosing regimen, FQGBG was safe. The efficacy mechanism of FQGBG in treating nocturia caused by KYDS may be related to the improvement of the hypothalamus-pituitary-adrenal axis function and increased energy metabolism. Clinical Trial Registration: https://www.chictr.org.cn/showproj.html?proj=26934, identifier ChiCTR1800015840.

A highly sensitive fluorescent nanoprobe for the amplified detection of formaldehyde.

Non-conjugated polymer nanoparticles (PNPs) have been widely reported for analytical applications; however, the development of an effective fluorescence signal-amplification scheme based on PNPs remains challenging. In this study, polyethyleneimine-based polymer nanoparticles (PEI-PNPs) were synthesized for interrogating the fluorescence signal-amplification analytical application of the PNPs. The PEI-PNPs with an aggregated PEI polymer structure were able to confine a large density of sub-fluorophores on an individual nanoparticle, enabling the realization of a signal-amplification effect. Herein, formaldehyde (FA) was utilized for enhancing the fluorescence intensity of the PEI-PNPs as a model to confirm our proof-of-concept strategy. Our results showed that a more than 9-fold signaling-enhancing ability for the sensing of FA was observed using the PEI-PNPs prepared with a higher PEI concentration. The possible mechanism for the FA amplified sensing was studied. In particular, the FA-recognition units were sub-fluorophores of PEI-PNPs, which were simultaneously formed with the preparation of the PEI-PNPs avoiding the leakage effect of dyes. We believe that the water-soluble and biocompatible PEI-PNPs are promising candidates for the detection of endogenous FA in living systems.

[Study on chemical compositions and crystallinity changes of bamboo treated with gamma rays].

The structures and qualities of main chemical compositions in cell wall of bamboo treated with gamma rays were tested by nuclear magnetic resonance spectrometer (NMR) and X-ray Diffraction (XRD). The result indicated that the bamboo crystallinity increased at the beginning of irradiation process, while the crystallinity reduced when the irradiation dose was raised to about 100 kGy. During the whole irradiation process, hemicellulose degraded, and with the irradiation doses increased the non-phenolic lignin changed to the phenolic.

Injectable conductive hydrogel can reduce pacing threshold and enhance efficacy of cardiac pacemaker.

Background: Pacemaker implantation is currently used in patients with symptomatic bradycardia. Since a pacemaker is a lifetime therapeutic device, its energy consumption contributes to battery exhaustion, along with its voltage stimulation resulting in local fibrosis and greater resistance, which are all detrimental to patients. The possible resolution for those clinical issues is an injection of a conductive hydrogel, poly-3-amino-4-methoxybenzoic acid-gelatin (PAMB-G), to reduce the myocardial threshold voltage for pacemaker stimulation. Methods: PAMB-G is synthesized by covalently linking PAMB to gelatin, and its conductivity is measured using two-point resistivity. Rat hearts are injected with gelatin or PAMB-G, and pacing threshold is evaluated using electrocardiogram and cardiac optical mapping. Results: PAMB-G conductivity is 13 times greater than in gelatin. The ex vivo model shows that PAMB-G significantly enhances cardiac tissue stimulation. Injection of PAMB-G into the stimulating electrode location at the myocardium has a 4 times greater reduction of pacing threshold voltage, compared with electrode-only or gelatin-injected tissues. Multi-electrode array mapping reveals that the cardiac conduction velocity of PAMB-G group is significantly faster than the non- or gelatin-injection groups. PAMB-G also reduces pacing threshold voltage in an adenosine-induced atrial-ventricular block rat model. Conclusion: PAMB-G hydrogel reduces cardiac pacing threshold voltage, which is able to enhance pacemaker efficacy.

Effectiveness of green tea mouthwash for improving oral health status in oral cancer patients: A single-blind randomized controlled trial.

BACKGROUND: Painful oral mucositis or trismus, caused by cancer therapy, reduces patients' willingness to maintain basic oral hygiene and eventually results in a poor oral health status. Using mouth rinses and cleaning the tongue are popular ways to improve the oral health status. OBJECTIVES: To evaluate the effectiveness of green tea mouthwash for improving the oral health status in oral cancer patients undergoing cancer treatment. DESIGN: This was a prospective, single-blind, randomized, controlled trial. SETTINGS: Patients were recruited from a major regional teaching hospital that provides specialist cancer care services in Chia-Yi, Taiwan, from July 2018 to June 2020. PARTICIPANTS: A total of 63 patients met the following criteria: > 20 years old; newly diagnosed with oral cancer by a physician; treated with oral surgery within one month prior; and completion of follow-up, with or without chemotherapy or radiation therapy. The exclusion criteria were mental illness; an acute and severe illness; complete edentulism; and inability to open the mouth more than 1 cm. METHODS: Patients were randomly assigned to 2 groups: the mouthwash with green tea (intervention) group or the tap water (control) group. After each teeth-brushing procedure, those in the intervention group rinsed the mouth with 100 ml of a green tea solution for 60 seconds, and those in the control group rinsed the mouth with 100 ml of tap water for 60 seconds. The primary outcome was the oral health status, which was evaluated according to the Oral Assessment Guide and measured at baseline and at every monthly outpatient follow-up until six months by the same nurse. RESULTS: There were 31 subjects in the intervention group and 30 subjects in the control group in the final analysis. The results of t-test showed that compared with baseline, the improvement in the oral health status in the intervention group was significantly better than that in the control group at 4 months after the intervention began. At 4 to 6 months after the intervention began, the oral health status score in the intervention group significantly decreased, by 1.71, 2.97 and 2.93 points, respectively, compared with that in the control group. CONCLUSIONS: The oral health status can be improved and maintained for a long time with the continuous use of green tea mouthwash. Green tea mouthwash is a simple, natural, effective and safe intervention that should be recognized as a nonpharmacological treatment option for protecting the oral mucosa. TRIAL REGISTRATION: clinicaltrials.gov identifier NCT04615780.

Association between well-being and compliance with COVID-19 preventive measures by healthcare professionals: A cross-sectional study.

IMPORTANCE: Knowledge and attitude influence compliance and individuals' practices. The risk and protective factors associated with high compliance to these preventive measures are critical to enhancing pandemic preparedness. OBJECTIVE: This survey aims to assess differences in mental health, knowledge, attitudes, and practices (KAP) of preventive measures for COVID-19 amongst healthcare professionals (HCP) and non-healthcare professionals. DESIGN: Multi-national cross-sectional study was carried out using electronic surveys between May-June 2020. SETTING: Multi-national survey was distributed across 36 countries through social media, word-of-mouth, and electronic mail. PARTICIPANTS: Participants ≥21 years working in healthcare and non-healthcare related professions. MAIN OUTCOME: Risk factors determining the difference in KAP towards personal hygiene and social distancing measures during COVID-19 amongst HCP and non-HCP. RESULTS: HCP were significantly more knowledgeable on personal hygiene (AdjOR 1.45, 95% CI -1.14 to 1.83) and social distancing (AdjOR 1.31, 95% CI -1.06 to 1.61) compared to non-HCP. They were more likely to have a positive attitude towards personal hygiene and 1.5 times more willing to participate in the contact tracing app. There was high compliance towards personal hygiene and social distancing measures amongst HCP. HCP with high compliance were 1.8 times more likely to flourish and more likely to have a high sense of emotional (AdjOR 1.94, 95% CI (1.44 to 2.61), social (AdjOR 2.07, 95% CI -1.55 to 2.78), and psychological (AdjOR 2.13, 95% CI (1.59-2.85) well-being. CONCLUSION AND RELEVANCE: While healthcare professionals were more knowledgeable, had more positive attitudes, their higher sense of total well-being was seen to be more critical to enhance compliance. Therefore, focusing on the well-being of the general population would help to enhance their compliance towards the preventive measures for COVID-19.

Factors associated with high compliance behaviour against COVID-19 in the early phase of pandemic: a cross-sectional study in 12 Asian countries.

INTRODUCTION: Regardless of having effective vaccines against COVID-19, containment measures such as enhanced physical distancing and good practice of personal hygiene remain the mainstay of controlling the COVID-19 pandemic. Countries across Asia have imposed these containment measures to varying extents. However, residents in different countries would have a differing degree of compliance to these containment measures potentially due to differences in the level of awareness and motivation in the early phase of pandemic. OBJECTIVES: In our study, we aimed to describe and correlate the level of knowledge and attitude with the level of compliance with personal hygiene and physical distancing practices among Asian countries in the early phase of pandemic. METHODS: A multinational cross-sectional study was carried out using electronic surveys between May and June 2020 across 14 geographical areas. Subjects aged 21 years and above were invited to participate through social media, word of mouth and electronic mail. RESULTS: Among the 2574 responses obtained, 762 (29.6%) participants were from East Asia and 1812 (70.4%) were from Southeast Asia (SEA). A greater proportion of participants from SEA will practise physical distancing as long as it takes (72.8% vs 60.6%). Having safe distancing practices such as standing more than 1 or 2 m apart (AdjOR 5.09 95% CI (1.08 to 24.01)) or more than 3 or 4 m apart (AdjOR 7.05 95% CI (1.32 to 37.67)), wearing a mask when they had influenza-like symptoms before the COVID-19 pandemic, preferring online news channels such as online news websites/applications (AdjOR 1.73 95% CI (1.21 to 2.49)) and social media (AdjOR 1.68 95% CI (1.13 to 2.50) as sources of obtaining information about COVID-19 and high psychological well-being (AdjOR 1.39 95% CI (1.04 to 1.87)) were independent factors associated with high compliance. CONCLUSIONS: We found factors associated with high compliance behaviour against COVID-19 in the early phase of pandemic and it will be useful to consider them in risk assessment, communication and pandemic preparedness.

Mutation in connexin 32 causes Charcot-Marie-Tooth disease in a large Chinese family.

The purpose was to study the clinical features and genetics of a large Chinese family with Charcot-Marie-Tooth (CMT) disease. A genome-wide linkage scan using Applied Biosystems v. 2.5 411 short tandem repeat (STR) markers was performed in this family. Mutation screening was conducted on connexin 32 (Cx32). Prediction of impact of the mutation and sequence alignments of Cx32 in 10 vertebrates were performed using Polyphen and Clustal W, respectively. Twelve family members were diagnosed as CMT type 1. An X-chromosome locus (DXS991) was linked to the phenotype of this family by the genome-wide linkage analysis. An H100Y mutation found in Cx32 was predicted to be possibly damaging to the function of Cx32, with a PSIC score difference of 1.758. The H100 of Cx32 is highly conserved among the 10 vertebrates. A large Chinese family had CMTX1 linked to Xq13.1 caused by an H100Y mutation in the Cx32 gene.

Biosynthesis of nano bimetallic Ag/Pt alloy from Crocus sativus L. extract: Biological efficacy and catalytic activity.

In this project, silver­platinum (AgPt) nanoparticles were prepared by using the Crocus sativus L. plant ethanolic extract. The AgPt nanoparticles were characterized by applying the various method as ultraviolet-visible and infrared spectroscopy, electron microscopy, and X-ray diffraction analysis. The morphology structural indicated that the AgPt nanoparticles were spherical particles with diameter about 36.0 nm. The FTIR spectroscopy shows the efficient stabilization of the AgPt nanoparticles by phytoconstituents. The Ag and AgPt nanoparticles have polyphenolic content, lower than the flavonoids and proanthocyanins contents. The AgPt nanoparticles depicted the highest antioxidant properties compared to the Ag nanoparticles and ascorbic acid. The results showed that the AgPt nanoparticles had a high antioxidant properties. In addition, the AgPt nanoparticles demonstrated the substantial antimicrobial and cytotoxic activities against pathogenic microbes and MCF-7 breast cancer cell line. The environmental chemistry analysis depicts that methyl orange can be degraded from water by catalytic degradation process with sodium borohydride. The AgPt nanoparticles were prosperous in catalytic degrading methyl orange following a first order kinetic model.

[The remove of intraocular foreign body by the assistance of the injection of silicone oil].

OBJECTIVE: To evaluate the effect of the injection of silicone oil in helping the remove of intraocular foreign body throughout pars plana vitrectomy (PPV). METHODS: It was a series case study. This study included 17 eyes with intraocular foreign body from June 2007 to April 2008. Intraocular foreign bodies in these eyes were hardly removed, and all of the eyes had complicated and severe retinal injuries. The intraocular foreign bodies were taken out followed intravitreal injection of silicon oil. The retinal protective effects of silicon oil were studied. RESULTS: All the intraocular foreign bodies were removed successfully without any damage to the retina due to the viscosity of silicon oil and its gasket function. CONCLUSIONS: Intravitreal injection of silicon oil was able to help the removement of hardly-hold intraocular foreign body with PPV and avoid secondary retinal injury in this process.

[Spatio-temporal expression of dentin sialophosphoprotein and collagen â during molar tooth germ development in vps4b knockout mouse].

OBJECTIVE: To verify the effect of the mutant gene vps4b on the expression of tooth development-related proteins, dentin sialophosphoprotein (DSPP) and collagenⅠ (COL-Ⅰ). METHODS: Paraffin tissue sections of the first molar tooth germ were obtained from the heads of fetal mice at the embryonic stages of 13.5, 14.5, and 16.5 days and from the mandibles of larvae aged 2.5 and 7 days after birth. The immunohistochemical method was used to detect the expression and location of DSPP and COL-Ⅰ in wild-type mouse and vps4b knockout mouse. RESULTS: DSPP and COL-Ⅰ were not found in the bud and cap stages of wild-type mouse molar germ. In the bell stage, DSPP was positively expressed in the inner enamel epithelium and dental papilla, whereas COL-Ⅰ was strongly expressed in the dental papilla and dental follicle. During the secretory and mineralized periods, DSPP and COL-Ⅰ were intensely observed in ameloblasts, odontoblasts, and dental follicles, but COL-Ⅰ was also expressed in the dental papilla. After vps4b gene knockout, DSPP was not expressed in the dental papilla of the bell stage and in the dental papilla and dental follicle of the secretory phase. The expression position of COL-Ⅰ in the bell and mineralization phase was consistent with that in the wild-type mice. Moreover, the expression of COL-Ⅰ in the dental papilla changed in the secretory stage. CONCLUSIONS: Gene vps4b plays a significant role in the development of tooth germ. The expression of DSPP and COL-Ⅰ may be controlled by gene vps4b and regulates the development of tooth dentin and cementum together with vps4b.

Internalization of mesoporous silica nanoparticles induces transient but not sufficient osteogenic signals in human mesenchymal stem cells.

The biocompatibility of nanoparticles is the prerequisite for their applications in biomedicine but can be misleading due to the absence of criteria for evaluating the safety and toxicity of those nanomaterials. Recent studies indicate that mesoporous silica nanoparticles (MSNs) can easily internalize into human mesenchymal stem cells (hMSCs) without apparent deleterious effects on cellular growth or differentiation, and hence are emerging as an ideal stem cell labeling agent. The objective of this study was to thoroughly investigate the effect of MSNs on osteogenesis induction and to examine their biocompatibility in hMSCs. Uptake of MSNs into hMSCs did not affect the cell viability, proliferation and regular osteogenic differentiation of the cells. However, the internalization of MSNs indeed induced actin polymerization and activated the small GTP-bound protein RhoA. The MSN-induced cellular protein responses as believed to cause osteogenesis of hMSCs did not result in promotion of regular osteogenic differentiation as analyzed by cytochemical stain and protein activity assay of alkaline phosphatase (ALP). When the effect of MSNs on ALP gene expression was further examined by reverse transcriptase polymerase chain reaction, MSN-treated hMSCs were shown to have significantly higher mRNA expression than control cells after 1-hour osteogenic induction. The induction of ALP gene expression by MSNs, however, was absent in cells after 1-day incubation with osteogenic differentiation. Together our results show that the internalization of MSNs had a significant effect on the transient protein response and osteogenic signal in hMSCs, thereby suggesting that the effects of nanoparticles on diverse aspects of cellular activities should be carefully evaluated even though the nanoparticles are generally considered as biocompatible at present.

[Advances in polymer materials as chiral stationary phase].

The applications of chiral drugs had a profound impact on human health. With the development of disciplines of chemistry, materials and life science, the research on the separation and analysis of chiral drugs became intensified. Chromatography and the selection of chiral stationary phase played important roles in resolving chiral drugs. The optimization of polymer materials and their derivatives as chiral stationary phase become the main issue in recent years. Recent studies as well as prospects in polymer materials used as chiral stationary phase are presented in this paper.

Fabrication of multifunctional cellulose nanocrystals/poly(lactic acid) nanocomposites with silver nanoparticles by spraying method.

The poly (lactic acid) (PLA)/functionalized cellulose nanocrystals formates (CNFs) were prepared by solution casting and then the binary films were sprayed with silver ammonia aqueous solution to fabricate PLA/CNF/Ag ternary nanocomposites. It was found that both deposited silver (Ag) nanoparticles and CNFs showed efficient reinforcing effect on the thermal, mechanical, barrier properties and antibacterial activity of PLA matrix. Especially, the maximum decomposition temperature (Tmax) and Young's modulus of PLA/CNF/Ag(6) nanocomposite film increased by 15.5°C and 48.7%, respectively. Meanwhile an obvious reduction in the water vapor permeability was detected. Furthermore, the migration levels of the ternary nanocomposite films were well below the permitted limits in both non-polar and polar food simulants (60mgkg(-1)), and they showed a significant antibacterial activity influenced by the Ag contents. This study reveals that the novel nanocomposite films will offer a good perspective for food packaging applications.

Safety of polyethylene glycol recombinant human granulocyte colony-stimulating factor in treating non-small cell lung cancer patients at I b stage.

OBJECTIVE: To investigate resistance and safety of HHPG-19K in treating non-small cell lung cancer patients. METHODS: A total of 30 cases were selected and randomly divided into 5 groups: three HHPG-19K groups of different dosage (60 µg/kg/day, 100 µg/kg/day, 200 µg/kg/day), positive control group (Filgrastim, namely G-CSF5 µg/kg/day) and negative control group. Safety indexes of 5 groups were observed and compared. RESULTS: All patients had adverse event (100%) in three HHPG-19K groups, and increased ALP, ALT and AST were main events. The degree was mild to moderate. There was no significant difference in the incidence of adverse event between dosage groups and positive control group no difference. But the incidence of negative control group was 13%, which was significantly lower than dosage groups and positive control group. CONCLUSIONS: non-small cell lung cancer patients have satisfactory tolerance to HHPG-19K, and have no resistance. Besides, dosage at 100 µ g/kg is the most safe.

Two novel 3-D coordination polymers with 5-methoxyisophthalate and flexible N-donor co-ligands showing pentanuclear or alternate mono/binuclear Cu(II) units.

Two novel 3-D coordination polymers with different Cu(II) subunits as nodes and mixed bridging ligands as linkers, namely [Cu(5)(µ(3)-OH)(2)(1,3-bip)(2)(CH(3)O-ip)(4)](n) (1) and {[Cu(4)(1,3-btp)(2)(CH(3)O-p)(4)(H(2)O)(2)]·2H(2)O}(n) (2) (CH(3)O-H(2)ip = 5-methoxyisophthalate, 1,3-bip = 1,3-bis(imidazol)propane, 1,3-btp = 1,3-bis(1,2,4-triazol-1-yl)propane), were prepared under hydrothermal conditions. Complex 1 exhibits a CsCl-type network with [Cu(5)(µ(3)-OH)(2)](8+) clusters acting as nodes, which represents the first 3-D network based on pentanuclear Cu(II) clusters. Complex 2 features a 3-D pillared-layer network with (4,6)-connected (4(4).6(2))(4(4).6(8).8(3))-fsc topology, which is a rare example of homometallic coordination polymers constructed by alternate binuclear metal clusters and single metal centres. Variable-temperature magnetic susceptibility measurements show dominant ferromagnetic interactions in the pentanuclear clusters of 1 and strong antiferromagnetic interactions in the dinuclear paddle-wheel units of 2.

Copper(II) 5-methoxyisophthalate coordination polymers incorporating dipyridyl co-ligands: syntheses, crystal structures, and magnetic properties.

Hydrothermal reactions of mixed ligands 5-methoxyisophthalate (CH(3)O-H(2)ip) and dipyridyl with Cu(OAc)(2).2H(2)O afford five new coordination polymers, including {[Cu(CH(3)O-ip)(bpa)].H(2)O}(n) (1), [Cu(2)(CH(3)O-ip)(2)(bpa)(0.5)(H(2)O)](n) (2), [Cu(2)(CH(3)O-ip)(2)(bpp)(H(2)O)](n) (3), {[Cu(3)(CH(3)O-ip)(3)(bpp)(2)(H(2)O)].3H(2)O}(n) (4) and [Cu(4)(CH(3)O-ip)(3)(bpe)(OH)(2)](n) (5) (bpp = 1,3-di(4-pyridyl)propane, bpa = 1,2-bi(4-pyridyl)ethane, and bpe = 1,2-di(4-pyridyl)ethylene). Compound 1 consists of CH(3)O-ip anion-bridged 1D Cu(II) chains that are linked by trans-bpa into a 2D layer. Compound 2 is a 2D (4,4) layer that is connected by CH(3)O-ip anions. The gauche bpa in 2 lies in the cavity and meets the coordination requirement of the paddle-wheel dimeric copper unit. Compound 3 is an extended 3D polythreading network consisting of 2D (4,4) motifs with dangling bpp lateral arms. Compound 4 exhibits a 3D (4,6)-connected self-penetrating (6(5).8)(6(14).8) network that is composed of binuclear and mononuclear metal nodes. Compound 5 exhibits a 3D network with the tetranuclear [Cu(4)(mu(3)-OH)(2)](6+) cluster acting as nodes, which is constructed by the interconnection of 2D helical layers via bpe pillars. The results of magnetic determination show that the syn-anti carboxylato bridges in our cases induce a weak antiferromagnetic interaction in 1, and the syn-syn carboxylato bridge in 3 and 4 mediates a strong antiferromagnetic interaction.