Response of anammox to organics with different degradation characteristics and exposure time: Performance, sludge characteristics and bacterial community.

The effects of typical organic compounds including easily degradable organic matters sodium acetate, yeast and methanol, and refractory organic matter (ROM) humic acid on anaerobic ammonium oxidation (anammox) systems in short-term and medium-term exposure time were studied. During short-term experiments, nitrogen removal activity (NRA) was inhibited at sodium acetate level of 150 mg L-1 total organic carbon (TOC) and methanol level of 30-150 mg L-1 TOC, but humic acid and yeast (≤150 mg L-1 TOC) enhanced nitrogen removal in anammox systems. The greatest NRA of 30.10 mg TN g-1 VSS h-1 was recorded at yeast level of 90 mg L-1 TOC. In medium-term experiments, organics significantly inhibited the nitrogen removal ability. As a ROM, humic acid enhanced sludge aggregation and biological diversity, but decreased the bioactivity and extracellular polymeric substances levels. Due to the endogenous denitrification, the relative abundance of anammox bacteria (AnAOB) was decreased. Candidatus Kuenenia is still dominant in sludge with methanol and humid acid, but AnAOB are not dominant due to the addition of sodium acetate and yeast. This research would be beneficial for the full-scale application of the anammox process in treating real wastewater with organics and ammonia.

Administering immunotherapy after anti-vascular targeted therapy improves overall survival of patients with metastatic clear cell renal cell carcinoma.

BACKGROUND: The Food and Drug Administration of the United States has approved several drugs for treating advanced metastatic renal cell carcinoma, including anti-vascular tyrosine kinase inhibitors (TKIs) and immune checkpoint inhibitors (ICIs). Options for first-line therapy include monotherapy or combination therapy. However, selecting a suitable first-line and second-line treatments to improve overall survival remains an unresolved issue. OBJECTIVE: To evaluate the overall survival (OS) and progression-free survival (PFS) of patients with metastatic clear cell renal cell carcinoma (mRCC). Patients were divided into several grouped according to the treatment sequence of TKI and anti PD-1 administration. The overall survival benefit was evaluated based on the order of administration of anti PD-1 and TKI. PATIENTS AND METHODS: In this retrospective propensity-matched cohort study, we identified 135 patients with mRCC treated at the Affiliated Cancer Hospital of Shandong First Medical University from January 1, 2017, to December 31, 2022. These patients had received anti PD-1 treatment as part of their first or second line of therapy. Statistical analysis was performed from June 1, 2023, to August 1, 2023. The primary outcome measure was OS, from the date of diagnosis to death or the last follow-up. PFS was monitored during treatment. Survival analyses were conducted using Cox proportional hazards regression and Kaplan-Meier estimates. By comparing the complete treatment course of patients, the survival of patients in different groups was compared according to the number of immunotherapy lines. RESULTS: The final cohort comprised 135 patients, of whom 84 received first-line therapy with anti PD-1 (include 6 patients treated with anti PD-1 (tislelizumab, carrelizumab, toripalimab or sintilizumab) alone and 78 patients treated with anti PD-1 combined with anti-vascular TKI (axitinib, sunitinib, solfanitinib or pazopanib)). The remaining 51 patients were treated with anti PD-1 as second-line therapy following an initial regime of TKIs. Patients were initially categorized based on whether anti PD-1 were used in the first-line treatment. It was observed that the OS of patients receiving first-line targeted therapy was higher than those receiving first-line immunotherapy, with a median OS of 33 months versus 15 months. To investigate this outcome further, we refined the patient groups based on the administration sequence of anti PD-1 and TKIs in the treatment regimen. We found that the median PFS of patients with first-line treatments of TKI combined with anti PD-1 was 3.5 months, compared to 14.5 months when TKI combined with anti PD-1 followed first-line TKI (p=0.0092). The median PFS for second-line treatments was 6.5 months versus 15 months (p=0.0014). Similarly, the median OS was 16.66 months and 31.88 months, respectively (p=0.008). CONCLUSIONS: This study indicates that administering immunotherapy following anti-vascular therapy significantly enhances both OS and PFS compared to other sequences of therapies. This finding provides valuable insights and robust data support for clinical decision-making regarding treatment sequencing.

Effects of Bright Light Therapy on Agitation Among Older Adults Living with Dementia in Macao: A Pilot Study.

A randomized controlled trial was conducted to examine the effects of bright light therapy on agitation in older adults with dementia in Macao. This study involved 31 participants: 10 in the outdoor light treatment group, 11 in the indoor light-box treatment group, and 10 in the control group. Significant reductions in agitation were observed in the two treatment groups over four weeks compared to the control group. However, no statistical difference in cognitive function between experimental and control groups was found. This study supports the use of bright light therapy to reduce agitation in older people with dementia.

Determination of optimal mining width for coal mining under the slope by of using numerical simulation.

The stability of slope is critical important topic in rock mass engineering. In Panzhihua #7 Coal Mine, the coal mining is occurred under the slope, to obtain the optimal mining width, 125 numerical simulations were conducted, and the corresponding FOS was calculated. From the analysis of the numerical simulation results, it can be found that FOS decrease and then increase with increasing of filling length, meanwhile, the FOS is minimum value when the filling length is within the ranges of 10 m and 20 m, which is under the toe of slope. Furthermore, the minimum FOS decrease with increasing of mining width. Considered the stability of the slope and mining economy, the mining width is set to 6m, and the numerical simulation results is applied to the engineering practice. To guarantee the safety of the slope, some monitoring points were distributed on the slope, the displacement from numerical simulation and engineering practice is quite close, indicating the numerical simulation results is reliable, and the mining width is reasonable.

Shape-Persistent Dendrimers.

Dendrimers have a diverse and versatile morphology, frequently consisting of core, linking, and peripheral moieties. Dendrimers with flexible linkers, such as PAMAM, cannot retain the persistent shape of molecules, and this has been widely explored and reviewed previously; nevertheless, dendrimers with stiff linkers can preserve the persistent shape of the dendrimers, which has been reported considerably less. This review thus focuses on addressing shape-persistent dendrimers with rigid linking moieties discovered in recent years, i.e., from 2012 to 2023. Shape-persistent dendrimers with an interstitial gap between the dendritic frames in the solid state may or may not let the intramolecular void space be accessible for guest molecules, which largely depends on whether their peripheral groups are flexible or non-flexible. In this paper, eight articles on shape-persistent dendrimers with a flexible alkyl periphery, which may exhibit mesogenic phases upon thermal treatment, and eight articles on shape-persistent dendrimers with a non-flexible periphery, which may allow external ions, gases, or volatile organic compounds to access the interstitial gaps between dendritic frames, are reviewed.

Dendrimers with Tetraphenylmethane Moiety as a Central Core: Synthesis, a Pore Study and the Adsorption of Volatile Organic Compounds.

Reasonable yields of two dendrimers with central tetraphenylmethane and peripheral 3,5-di-(tert-butanoylamino)benzoylpiperazine moieties are prepared. These dendrimers have a void space in the solid state so they adsorb guest molecules. Their BET values vary, depending on the H-bond interaction between the peripheral moiety and the gas molecules, and the dendritic framework that fabricates the void space is flexible. In the presence of polar gas molecules such as CO2, the BET increases significantly and is about 4-8 times the BET under N2. One dendrimer adsorbs cyanobenzene to a level of 436 mg/g, which, to the authors' best knowledge, is almost equivalent to the highest reported value in the literature.

Strategies to improve electrocatalytic performance of MoS2-based catalysts for hydrogen evolution reactions.

Electrocatalytic hydrogen evolution reactions (HERs) are a key process for hydrogen production for clean energy applications. HERs have unique advantages in terms of energy efficiency and product separation compared to other methods. Molybdenum disulfide (MoS2) has attracted extensive attention as a potential HER catalyst because of its high electrocatalytic activity. However, the HER performance of MoS2 needs to be improved to make it competitive with conventional Pt-based catalysts. Herein, we summarize three typical strategies for promoting the HER performance, i.e., defect engineering, heterostructure formation, and heteroatom doping. We also summarize the computational density functional theory (DFT) methods used to obtain insight that can guide the construction of MoS2-based materials. Additionally, the challenges and prospects of MoS2-based catalysts for the HER have also been discussed.

Converting non-Mesogenic to Mesogenic Stacking of Amino-s-Triazine-Based Dendrons with p-CN Phenyl Unit by Eliminating Peripheral Dipole.

Three new amino-s-triazine-based dendrons, 1a, 1b, and 1c, containing an aryl-CN moiety in the dendritic skeleton were prepared in 72-81% yields (1a: R1 = - N(n-C8H17)2, R2 = n-OC8H17, 1b: R1 = R2 = - N(n-C8H17)2, 1c: R1 = - N(n-C8H17)2, R2 = - N(n-C4H9)2). Dendrons 1a with N(n-C8H17)2 and n-OC8H17 peripheral substituents, surprisingly, did not show any mesogenic phase during the thermal process. However, non-mesogenic 1a can be converted to mesogenic 1b or 1c by eliminating the peripheral dipole arising from the alkoxy substituent; dendron 1b only comprising the same N(n-C8H17)2 peripheral groups showed a ~25 °C mesogenic range on heating and ~108 °C mesogenic range on cooling. In contrast, dendron 1c possessing different N(n-CmH2m+1)2 (m = 8 versus m = 4) peripheral units, having similar stacking as 1b, exhibited a columnar phase on thermal treatment, but its mesogenic range (~9 and ~66 °C on heating and cooling, respectively) was much narrower than that of 1b, attributed to 1c's less flexible alkyl chains in the peripheral part of dendron. Dendron 1a with the alkoxy substituent in the peripheral skeleton, creating additional dipole correspondingly, thus, leads to the dendritic molecules having a non-mesogenic stacking. Without the peripheral dipole for intermolecular side-by-side interaction, dendrons 1b and 1c exhibit a columnar phase on thermal treatment because of the vibration from the peripheral alkyl chain.

Electrochemically synthesized SnO2 with tunable oxygen vacancies for efficient electrocatalytic nitrogen fixation.

Electrochemical nitrogen reduction reaction (NRR) driven by a renewable energy source offers a sustainable and environmentally benign route to produce ammonia (NH3), but it is highly dependent on efficient and specific catalysts to reduce the high reaction barrier and improve the selectivity. Defect engineering is extensively used to regulate the surface properties of materials to improve their catalytic performance. Herein we synthesized SnO2 with different oxygen vacancy concentrations by a controllable electrochemical method for electrocatalytic nitrogen (N2) fixation. The prepared SnO2 was used as an electrocatalyst and exhibited excellent NRR performance with an optimal NH3 yield rate of 25.27 µg h-1 mgcat.-1 and faradaic efficiency of 11.48% at -0.6 V (vs. the reversible hydrogen electrode) in 0.1 M Na2SO4. Oxygen vacancies provide more active sites and greater electron transfer ability on the catalyst surface to facilitate N2 adsorption and activation. The electrocatalytic NRR performance of SnO2 was enhanced with the increase in oxygen vacancy concentration. The density functional theory calculations indicate that the oxygen vacancies in SnO2 promote the electrocatalytic NRR performance by increasing the number of valence electrons of Sn and decreasing the energy barrier of the potential-determining step, thus promoting the activation of the N-N bond to further achieve efficient N2 fixation.

Unconventional Approaches to Prepare Triazine-Based Liquid Crystal Dendrimers.

Most triazine-based liquid crystalline (LC) dendrimers reported thus far are the main-chain LC macromolecules with long flexible chains at their periphery and attached to internal rigid or semi-rigid frameworks. Their formation of mesogenic phases often depends on the intermolecular face-to-face π-π interactions between dendritic molecules, which are unusual. Their mesogenic phases can also be formed by incorporation of mesogenic units to the dendritic skeletons through long flexible chains, as most side-chain LC dendrimers, in which the peripheral mesogenic units generally play the important roles. For main-chain triazine-based dendrimers, their morphology is maintained by restricted freedom of rigid or semi-rigid connecting units, and their formations of LC phases are therefore not straightforward to be controlled. In this review, we thus describe modulating of the intermolecular face-to-face π-π interactions between the triazine-based dendritic molecules, with the aim of forming LC phases through molecular design.

Adsorbing Volatile Organic Chemicals by Soluble Triazine-Based Dendrimers under Ambient Conditions with the Adsorption Capacity of Pyridine up to 946.2 mg/g.

Two triazine-based dendrimers with peripheral 1,3,5-triamidobenzene (1-3-5-TAB) functionality were prepared, and their void spaces in the bulk solid were investigated. We examined dendrimers of three core lengths and determined the one with the longest core exhibits the largest void space because the peripheral amides were not imbedded in the internal space of each dendritic molecule. The new dendrimers as solids were observed to adsorb volatile organic chemicals efficiently. Importantly, because the dendrimers are soluble in organic solvents, the adsorbed VOCs can be quantified by 1H-NMR spectroscopy by choosing a chemical shift (δ) of dendrimers as the internal standard to exclude interfering impurity signals, a much simpler and more efficient protocol than the traditional GC technique for the VOC quantification. One dendrimer was found to adsorb 24 equivalents of pyridine, so its adsorption capacity is equivalent to 946.2 mg/g. This is a more than 2-fold increase than the reported values by other porous materials.

BTLA-Expressing Dendritic Cells in Patients With Tuberculosis Exhibit Reduced Production of IL-12/IFN-α and Increased Production of IL-4 and TGF-ß, Favoring Th2 and Foxp3+ Treg Polarization.

Little is known about how tuberculosis (TB) impairs dendritic cell (DC) function and anti-TB immune responses. We previously showed that the B and T lymphocyte attenuator (BTLA), an immune inhibitory receptor, is involved in TB pathogenesis. Here, we examined whether BTLA expression in TB affects phenotypic and functional aspects of DCs. Active TB patients exhibited higher expression of BTLA in myeloid dendritic cells (mDCs) and plasmacytoid DCs (pDCs) subsets compared with healthy controls (HCs). BTLA expression was similarly high in untreated TB, TB relapse, and sputum-bacillus positive TB, but anti-TB therapy reduced TB-driven increases in frequencies of BTLA+ DCs. BTLA+ DCs in active TB showed decreased expression of the DC maturation marker CD83, with an increased expression of CCR7 in mDCs. BTLA+ DCs in active TB displayed a decreased ability to express HLA-DR and to uptake foreign antigen, with a reduced expression of the co-stimulatory molecule CD80, but not CD86. Functionally, BTLA+ DCs in active TB showed a decreased production of IL-12 and IFN-α as well as a reduced ability to stimulate allogeneic T-cell proliferative responses. BTLA+ mDCs produced larger amounts of IL-4 and TGF-ß than BTLA- mDCs in both HCs and APT patients. BTLA+ DCs from active TB patients showed a reduced ability to stimulate Mtb antigen-driven Th17 and Th22 polarizations as compared to those from HCs. Conversely, these BTLA+ DCs more readily promoted the differentiation of T regulatory cells (Treg) and Th2 than those from HCs. These findings suggest that TB-driven BTLA expression in DCs impairs the expression of functional DC surrogate markers and suppress the ability of DCs to induce anti-TB Th17 and Th22 response while promoting Th2 and Foxp3+ Tregs.

Paddlewheel SBU based Zn MOFs: Syntheses, Structural Diversity, and CO2 Adsorption Properties.

Four Zn metal⁻organic frameworks (MOFs), {[Zn2(2,6-ndc)2(2-Pn)]·DMF}n (1), {[Zn2(cca)2(2-Pn)]·DMF}n (2), {[Zn2(thdc)2(2-Pn)]·3DMF}n (3), and {[Zn2(1,4-ndc)2(2-Pn)]·1.5DMF}n (4), were synthesized from zinc nitrate and N,N'-bis(pyridin-2-yl)benzene-1,4-diamine (2-Pn) with naphthalene-2,6-dicarboxylic acid (2,6-H2ndc), 4-carboxycinnamic acid (H2cca), 2,5-thiophenedicarboxylic acid (H2thdc), and naphthalene-1,4-dicarboxylic acid (1,4-H2ndc), respectively. MOFs 1⁻4 were all constructed from similar dinuclear paddlewheel {Zn2(COO)4} clusters and resulted in the formation of three kinds of uninodal 6-connected non-interpenetrated frameworks. MOFs 1 and 2 suit a topologic 48·67-net with 17.6% and 16.8% extra-framework voids, respectively, 3 adopts a pillared-layer open framework of 48·66·8-topology with sufficient free voids of 39.9%, and 4 features a pcu-type pillared-layer framework of 412·6³-topology with sufficient free voids of 30.9%. CO2 sorption studies exhibited typical reversible type I isotherms with CO2 uptakes of 55.1, 84.6, and 64.3 cm³ g-1 at 195 K and P/P0 =1 for the activated materials 1', 2', and 4', respectively. The coverage-dependent isosteric heat of CO2 adsorption (Qst) gave commonly decreased Qst traces with increasing CO2 uptake for all the three materials and showed an adsorption enthalpy of 32.5 kJ mol-1 for 1', 38.3 kJ mol-1 for 2', and 23.5 kJ mol-1 for 4' at zero coverage.

Design of a Peripheral Building Block for H-Bonded Dendritic Frameworks and Analysis of the Void Space in the Bulk Dendrimers.

Three dendrimers, (t-Bu-G 2 N) 2 , CC(t-Bu-G 1 N) 3 and (t-Bu-G 1 N) 2 , with 3,5-di-tert-butyl amidobenzene as a common peripheral moiety were prepared in 64-83% yields and characterized. The bulk solids had high BET surface areas of 136-138 m2/g, which were similar for the three dendrimers in spite of their different molecular weight (ranging from 1791 to 2890). It was concluded that the peripheral amide groups do not imbed in the interstitial space of neighbouring dendrimer molecules but rather build a supramolecular architecture through strong intermolecular H-bonds. This mode of assembly generates voids in the bulk dendrimers responsible for sorption properties. The X-ray crystal structure analysis of a compound representing the peripheral moiety of the dendrimers and the FT-IR and powder-XRD data for (t-Bu-G 1 N) 2 suggest the proposed supramolecular structure. The isosteric heats of CO2 sorption (Q st) for (t-Bu-G 2 N) 2 were significantly higher than those for the other two dendrimers, which is consistent with the formation of a different type of voids within the interstitial space of the molecule. It is suggested that the interstitial void space can be designed and tuned to adjust its properties to a particular task, such as the separation of gases or a catalytic reaction facilitated by the dendrimer.

The synthesis of three new Cu5, Cu8 and Cu12 clusters via the use of a semi-flexible aminotriazine-based bis-methylpyridine ligand.

The synthesis of three new polynuclear Cu5, Cu8 and Cu12 clusters has been achieved using a semi-flexible aminotriazine-based bis-methylpyridine ligand, N2,N2-dibenzyl-N4,N6-di(pyridylmethyl)-1,3,5-triazine-2,4,6-triamine (H2dpmta). The reaction of Cu(ClO4)2·6H2O with H2dpmta in i-PrOH afforded the complex [Cu5(OH)4(H2dpmta)2(ClO4)4(H2O)4](ClO4)2·Et2O·5i-PrOH (1). A similar reaction of Cu(ClO4)2·6H2O and H2dpmta in the presence of PhCO2Na in i-PrOH/CH2Cl2 gave the complex [Cu8(OH)6(O2CPh)4(H2dpmta)2(ClO4)4(i-PrOH)2](ClO4)2·2CH2Cl2·2i-PrOH (2). The complex [Cu12O3(OH)2(Hdpmta)2(dpmta)2(O2CMe)8](ClO4)2·2MeCN (3) was produced from the reaction of [Cu2(O2CMe)4]·2H2O with H2dpmta and NaClO4 in MeCN/CH2Cl2. Single-crystal X-ray diffraction measurements were carried out on these complexes. The Cu5 cluster of 1 consisted of a planar [Cu5(µ-OH)4]6+ core in a rectangle-like arrangement. The Cu12 cluster of 2 represented a [Cu8(µ3-OH)4(µ-OH)2]10+ core infusion of two [Cu4(OH)2]6+ butterfly subunits. Complex 3 possesses a bent [Cu12(µ4-O)3(µ-OH)2]16+ core structure, in which a central [Cu4(µ4-O2-)] square planar moiety was fused with two butterfly-like [Cu4(µ4-O)(µ3-OH)] subunits. The magnetic properties of these three complexes were characterized by the measurements of variable-temperature and field magnetic susceptibility. The magnetic analysis showed that a strong antiferromagnetic interaction was mediated between Cu(ii) ions by the single OH- bridge in 1 and resulted a S = 3/2 spin ground state. In complex 2, both intramolecular antiferro- and ferromagnetic interactions were dominated between Cu(ii) ions resulting a spin ground state of S = 2. Indeed, complex 3 displayed an overall antiferromagnetic coupling.

BTLA-expressing CD11c antigen presenting cells in patients with active tuberculosis exhibit low capacity to stimulate T cell proliferation.

Despite past extensive studies on B and T lymphocyte attenuator (BTLA)-mediated negative regulation of T cell activation, the role of BTLA in antigen presenting cells (APCs) in patients with active pulmonary tuberculosis (ATB) remains poorly understood. Here, we demonstrate that BTLA expression on CD11c APCs increased in patients with ATB. Particularly, BTLA expression in CD11c APCs was likely associated with the attenuated stimulatory capacity on T cells (especially CD8+ T cell) proliferation. BTLA-expressing CD11c APCs showed lower antigen uptake capacity, lower CD86 expression, higher HLA-DR expression, and enhanced IL-6 secretion, compared to counterpart BTLA negative CD11c APCs in healthy controls (HC). Interestingly, BTLA-expressing CD11c APCs from ATB patients displayed lower expression of HLA-DR and less IL-6 secretion, but higher expression of CD86 than those from HC volunteers. Mixed lymphocyte reaction suggests that BTLA expression is likely associated with positive rather than conventional negative regulation of CD11c APCs stimulatory capacity. This role is impaired in ATB patients manifested by low expression of HLA-DR and low production of IL-6. This previous unappreciated role for BTLA may have implications in the prevention and treatment of patients with ATB.

Tuberculosis-sensitized monocytes sustain immune response of interleukin-37.

Roles of human IL-37 in infections remain poorly characterized. Although plasma IL-37 is elevated in patients with tuberculosis (TB), IL-37 source and immune correlate in TB have not been investigated. It is also unknown whether and how TB can influence the ability of immune cells to mount innate responses of IL-37 and pre-inflammatory cytokines. Here, we demonstrated that IL-37b-producing monocytes coincided with a source of elevated plasma IL-37b in TB patients. While IL-37b production in TB was associated with prolonged/complicated TB, TB burdens and inflammatory reactions, it negatively correlated with immune responses of pro-inflammatory cytokines IL-1ß, IL-6 and TNF-α or IL-10. Interestingly, mycobacterial re-infection of monocytes from TB patients, but not healthy BCG-vaccinated controls, enhanced or sustained IL-37b production by cultured monocytes. TB-sensitized monocytes from TB patients mounted more robust immune responses of IL-37b than those of pre-inflammatory cytokines during mycobacterial re-infection in culture. Our data represent new findings in terms of IL-37b responses, immune correlates and potential mechanisms in TB patients.

Converting Nonliquid Crystals into Liquid Crystals by N-Methylation in the Central Linker of Triazine-Based Dendrimers.

Two triazine-based dendrimers were successfully prepared in 60-75% yields. These newly prepared dendrimers 2a and 2b containing the -NMe(CH2)2NMe- and the -NMe(CH2)4NMe- linkers between two G3 dendrons, respectively, exhibit columnar phases during the thermal process. However, the corresponding dendrimers 1a and 1b containing the -NH(CH2)2NH- and the -NH(CH2)4NH- linkers between two G3 dendrons, respectively, do not show any LC phases on thermal treatment. Computational investigations on molecular conformations reveal that N-methylation of the dendritic central linker leads dendrimers to possess more isomeric conformations and thus successfully converts non-LC dendrimers (1a and 1b) into LC dendrimers (2a and 2b).

Elevated serum IL-35 and increased expression of IL-35-p35 or -EBI3 in CD4(+)CD25(+) T cells in patients with active tuberculosis.

Despite the recent appreciation of interleukin 35 (IL-35) function in inflammatory diseases, little is known for IL-35 response in patients with active tuberculosis (ATB). In the current study, we demonstrated that ATB patients exhibited increases in serum IL-35 and in mRNA expression of both subunits of IL-35 (p35 and EBI3) in white blood cells and peripheral blood mononuclear cells. Consistently, anti-TB drug treatment led to reduction in serum IL-35 level and p35 or EBI3 expression. TB infection was associated with expression of p35 or EBI3 protein in CD4(+) but not CD8(+) T cells. Most p35(+)CD4(+) T cells and EBI3(+)CD4(+) T cells expressed Treg-associated marker CD25. Our findings may be important in understanding immune pathogenesis of TB. IL-35 in the blood may potentially serve as a biomarker for immune status and prognosis in TB.

Anion-Directed Copper(II) Metallocages, Coordination Chain, and Complex Double Salt: Structures, Magnetic Properties, EPR Spectra, and Density Functional Study.

A series of Cu(II) metallo-assemblies showing anion-directed structural variations, including five metallocages [(G(n-) )⊂{Cu2 (Hdpma)4 }]((8-n)+) (A(-) )8-n (G(n-) =NO3 (-) , ClO4 (-) , SiF6 (2-) , BF4 (-) , SO4 (2-) ; A(-) =NO3 (-) , ClO4 (-) , BF4 (-) , CH3 SO4 (-) ; Hdpma=bis(3-pyridylmethyl)ammonium cation), a complex double salt, namely, (H3 dpma)4 (CuCl4 )5 Cl2 , and a coordination chain, namely, [Cu2 (dpma)(OAc)4 ], are reported. The influence of the anion can be explained by its coordinating ability, the affinity of which for the Cu(II) center interferes significantly with metallocage formation, and its shape, which offers host-guest recognition ability to engage in weak metal-anion coordination and hydrogen bonding to the organic ligand, which are responsible for metallocage templation. EPR studies of these metallocages in the powder phase at room temperature and 77 K showed a trend of the g values (g|| >2.10>g⊥ >2.00) indicating a dx2-y2 -based ground state with square-pyramidal geometry for the Cu(II) centers. The magnetism of these metallocages can be interpreted as the result of a combination of relatively small magnetic coupling integrals and a substantial contribution of temperature-independent paramagnetism (TIP). The weak magnetic interaction is corroborated by the results of DFT calculations and the EPR spectra. Availability of the low-lying state for spin population was confirmed by a magnetization study, which revealed a magnetic moment approaching 2Nß, which would explain the presence of the larger TIP term.