Molecular Characteristics of Virulence Genes in Carbapenem-Resistant and Carbapenem-Sensitive Klebsiella Pneumoniae in Relation to Different Capsule Serotypes in Ningbo, China.

Background: Klebsiella pneumoniae (KP) is a common nosocomial pathogen. Capsules are an important component of KP's virulence, among which the K1, K2, K5, K20, K54, and K57 serotypes are predominant and exhibit varying degrees of virulence. Methods: The capsule and virulence genes of 150 carbapenem-resistant Klebsiella pneumoniae (CRKP) and 213 carbapenem-sensitive Klebsiella pneumoniae (CSKP) isolates were examined by polymerase chain reaction (PCR). The isolates were tested for hypermucoviscosity by string tests. Phylogenetic relationships between KP isolates were analyzed using multilocus sequence typing (MLST) and a Galleria mellonella infection model confirmed the differences in virulence. Results: A total of 111 of 363 isolates of KP were detected, the highest detected serotypes were K1, K5, and K2, and CSKP was detected more frequently than CRKP. There was a greater prevalence of K1 and K2 serotypes in CSKP, while in CRKP, K5 serotypes were more prevalent. K1 isolates had the highest detection rates for hypermucoviscosity Klebsiella pneumoniae (hmKP) and hypervirulent Klebsiella pneumoniae (hvKP), and carried the most virulence genes. K54 isolates had the lowest detection rate of hmKP while K5 isolates had the lowest detection rate of hvKP and carried the fewest virulence genes. MLST results for serotypes K1, K20, and K57 showed significant homogeneity, while those for serotypes K2, K5, and K54 showed diversity. The Galleria mellonella infection model showed that the K1 serotype was the most virulent and the K54 serotype was the weakest. Conclusion: CSKP isolates were detected more frequently than CRKP isolates for capsular serotype detection. K1 isolates had the most virulence gene and strongest virulence, K5 isolates carried the fewest virulence genes, and K54 isolates had the weakest virulence. Furthermore, significant homogeneity was observed among K1, K20, and K57 isolates.

Differences in molecular characteristics and expression of virulence genes in carbapenem-resistant and sensitive Klebsiella pneumoniae isolates in Ningbo, China.

Background: In recent years, Klebsiella pneumoniae has attracted attention because of its increasing drug resistance. At the same time, the migration and pathogenicity caused by its virulence genes also bring many difficulties to the diagnosis and treatment of clinical infections. However, it is currently unclear whether there are differences in virulence and pathogenicity with changes in drug resistance. Objective: To understand the differences in molecular characteristics and expression of virulence genes in carbapenem-resistant Klebsiella pneumoniae (CRKP) and carbapenem-sensitive Klebsiella pneumoniae (CSKP). Methods: Using polymerase chain reaction (PCR), we examined capsule polysaccharide-related genes and virulence genes in 150 clinical isolates of CRKP and 213 isolates of CSKP from the local area in Ningbo, China. Multilocus sequence typing (MLST) was used to analyze the phylogenetic relationships of clinical Klebsiella pneumoniae isolates. Furthermore, real-time quantitative PCR (RT-qPCR) was used to analyze the expression differences of common virulence genes in CSKP and CRKP, and the virulence was further verified by the larval model of Galleria mellonella. Results: The study found that the detection rates of genes rmpA, iroB, peg-344, magA, aerobactin, alls, kfu, and entB were significantly higher in CSKP compared to CRKP. The capsule gene types K1 and K2 were more common in CSKP, while K5 was more common in CRKP. Hypervirulent Klebsiella pneumoniae (hvKP) was predominantly from CSKP. CRKP strains exhibited noticeable homogeneity, with ST11 being the predominant sequence type among the strains. CSKP strains showed greater diversity in ST types, but ST23 was still the predominant sequence type. Carbapenem-sensitive hypervirulent Klebsiella pneumoniae (CS-hvKP) had higher expression of rmpA and rmpA2 genes compared to carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKP). In the wax moth virulence model, the survival rate of CS-hvKP was significantly lower than that of CR-hvKP. Conclusion: There is a significant difference in the distribution of virulence genes between CSKP and CRKP, with CSKP carrying a significantly greater number of virulence genes. Furthermore, compared to CSKP, CRKP strains exhibit noticeable homogeneity, with ST11 being the predominant sequence type among the strains. Additionally, in terms of virulence gene expression efficiency and virulence, CSKP is significantly higher than CRKP.

Convergence of plasmid-mediated Colistin and Tigecycline resistance in Klebsiella pneumoniae.

Objective: The co-occurrence of colistin and tigecycline resistance genes in Klebsiella pneumoniae poses a serious public health problem. This study aimed to characterize a K. pneumoniae strain, K82, co-harboring a colistin resistance gene (CoRG) and tigecycline resistance gene (TRG), and, importantly, investigate the genetic characteristics of the plasmid with CoRG or TRG in GenBank. Methods: K. pneumoniae strain K82 was subjected to antimicrobial susceptibility testing, conjugation assay, and whole-genome sequencing (WGS). In addition, comparative genomic analysis of CoRG or TRG-harboring plasmids from K82 and GenBank was conducted. K. pneumoniae strain K82 was resistant to all the tested antimicrobials including colistin and tigecycline, except for carbapenems. Results: WGS and bioinformatic analysis showed that K82 belonged to the ST656 sequence type and carried multiple drug resistance genes, including mcr-1 and tmexCD1-toprJ1, which located on IncFIA/IncHI2/IncHI2A/IncN/IncR-type plasmid pK82-mcr-1 and IncFIB/IncFII-type plasmid pK82-tmexCD-toprJ, respectively. The pK82-mcr-1 plasmid was capable of conjugation. Analysis of the CoRG/TRG-harboring plasmid showed that mcr-8 and tmexCD1-toprJ1 were the most common CoRG and TRG of Klebsiella spp., respectively. These TRG/CoRG-harboring plasmids could be divided into two categories based on mash distance. Moreover, we found an IncFIB/IncHI1B-type plasmid, pSYCC1_tmex_287k, co-harboring mcr-1 and tmexCD1-toprJ1. To the best of our knowledge, this is the first report on the co-occurrence of mcr-1 and tmexCD1-toprJ1 on a single plasmid. Conclusion: Our research expands the known diversity of CoRG and TRG-harboring plasmids in K. pneumoniae. Effective surveillance should be implemented to assess the prevalence of co-harboring CoRG and TRG in a single K. pneumoniae isolate or even a single plasmid.

Neglected vitamin K deficiency causing coagulation dysfunction in an older patient with pneumonia: a case report.

BACKGROUND: The development of coagulation disorders can be dangerous and fatal in the older people, especially those with multiple medical conditions. Vitamin K-dependent coagulation disorders are easily overlooked when anticoagulant drugs are not used and the patient shows no signs of bleeding. CASE PRESENTATION: We report a case of a 71-year-old male suffering from pulmonary infection with severe coagulation disorder without bleeding symptoms. He also had a history of Parkinson's disease, Alzheimer's disease and cardiac insufficiency. Coagulation tests were normal at the time of admission, prothrombin time (PT) is 13.9 (normal, 9.5-13.1) seconds and the activated partial thromboplastin time (APTT) is 30.2 (normal, 25.1-36.5) seconds. But it turned severely abnormal after 20 days (PT: 136.1 s, APTT: 54.8 s). However, no anticoagulants such as warfarin was used and no bleeding symptoms were observed. Subsequent mixing studies with normal plasma showed a decrease in prothrombin times. Vitamin K deficiency was thought to be the cause of coagulation disorders considering long-term antibiotic therapy, especially cephalosporins, inadequate diet and abnormal liver function. After supplementation with 20 mg of vitamin K, coagulation dysfunction was rescued the next day and serious consequences were effectively prevented. CONCLUSIONS: Overall, timely vitamin K supplementation with antimicrobials that affect vitamin K metabolism requires clinician attention, especially in older patients who are multimorbid, frail or nutritionally compromised, and are admitted to hospital because of an infection that needs antimicrobial therapy are at risk of clotting disorders due to abnormal vitamin K metabolism secondary to altered gut flora, which can exacerbate existing nutritional deficiencies.

Distribution and Molecular Characterization of Functional Class 2 Integrons in Clinical Proteus mirabilis Isolates.

BACKGROUND: Integrons are the main mode of horizontal transmission of drug-resistance genes and are closely related to drug resistance in clinical bacteria. In this study, the distributions of class 1, 2, and 3 integron gene cassettes were investigated in 150 Proteus mirabilis (P. mirabilis) isolates from patients, and molecular characterization of functional class 2 integrons was further analyzed. METHODS: Class 1, 2, and 3 integrons were screened by polymerase chain reaction (PCR) in 150 clinical P. mirabilis isolates. The variable regions of the integrons were determined by restriction analysis and sequencing. Internal stop codons mutations in class 2 integrons and their common promoters were also determined by sequencing. Enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) was used to analyze the phylogenetic relations of class 2 integron-positive isolates. RESULTS: Class 1 integrons were detected in 69 (46%) of 150 P. mirabilis isolates, and six different gene cassette arrays were detected, with the most prevalent being dfrA32-aadA2. Class 2 integrons were detected in 61 (40.7%) of 150 P. mirabilis isolates, and three different gene cassette arrays were detected, including sat2-aadA1, which was detected for the first time in a class 2 integron. Nearly similar ERIC-PCR fingerprinting patterns were detected in 45 (73.8%) of 61 class 2 integron-positive isolates. The functional class 2 integron was detected in three P. mirabilis isolates having the same gene cassette, dfrA1-sat2-aadA1, in the variable region and four novel open reading frames with unknown functions. Same PintI2 and Pc promoters were detected in these three functional class 2 integron isolates, as was found in other class 2 integron isolates. However, these three strains did not totally show identical homology and drug sensitivity. CONCLUSION: Although functional class 2 integrons have low distribution and relatively conserved molecular characteristics, they can still form clinical dissemination and drug resistance expression.

Performance measurement for green supplier selection based on data envelopment analysis.

With increasing global awareness of sustainable development and environmental protection, the importance of green supplier selection has become widely recognized. Recently, more and more literature focus on the green supplier selection issue and measurement of supplier performance; the measurement indicators mainly defined two sets of criteria, including management criteria and green criteria. A novel methodology based on data envelopment analysis (DEA) has been developed, which is effective for solving multi-criteria decision problems in supplier selection and evaluating the performance of a set of homogeneous decision-making units (DMUs). To solve the green supplier selection problem, previous studies apply the DEA method by dividing management criteria as inputs and green criteria as outputs. This paper aims to propose a DEA-type green supplier selection methodology by considering the management criteria and green criteria. Unlike the previous method, we define a reasonable and effective division of measurement indicators, where management criteria consist of input variables, desirable and undesirable output variables, while green criteria consist of desirable and undesirable output variables. We also provide an improved model with multi-criteria and multi-objective programming by considering DEA efficiency decomposition, which evaluates management, green, and overall efficiency of candidate suppliers simultaneously. The multi-criteria decision model will help companies to select the best green supplier. To demonstrate the applicability and effectiveness of our proposed model, we present a numerical example at last.

Next generation of anti-PD-L1 Atezolizumab with enhanced anti-tumor efficacy in vivo.

FDA-approved anti-PD-L1 antibody drug Atezolizumab is a human IgG1 without glycosylation by an N297A mutation. Aglycosylation of IgG1 has been used to completely remove the unwanted Fc-mediated functions such as antibody-dependent cytotoxicity (ADCC). However, aglycosylated Atezolizumab is very unstable and easy to form aggregation, which causes quick development of anti-drug antibody (ADA) in 41% of Atezolizumab-treated cancer patients, eventually leading to loss of efficacy. Here, we report the development of the anti-PD-L1 antibody drug Maxatezo, a glycosylated version of Atezolizumab, with no ADCC activity, better thermo-stability, and significantly improved anti-tumor activity in vivo. Using Atezolizumab as the starting template, we back-mutated A297N to re-install the glycosylation, and inserted a short, flexible amino acid sequence (GGGS) between G237 and G238 in the hinge region of the IgG1 heavy chain. Our data shows that insertion of GGGS, does not alter the anti-PD-L1's affinity and inhibitory activity, while completely abolishing ADCC activity. Maxatezo has a similar glycosylation profile and expression level (up to 5.4 g/L) as any normal human IgG1. Most importantly, Maxatezo's thermal stability is much better than Atezolizumab, as evidenced by dramatic increases of Tm1 from 63.55 °C to 71.01 °C and Tagg from 60.7 °C to 71.2 °C. Furthermore, the levels of ADA in mice treated with Maxatezo were significantly lower compared with animals treated with Atezolizumab. Most importantly, at the same dose (10 mg/kg), the tumor growth inhibition rate of Maxatezo was 98%, compared to 68% for Atezolizumab.

Recombinant SARS-CoV-2 spike S1-Fc fusion protein induced high levels of neutralizing responses in nonhuman primates.

The COVID-19 outbreak has become a global pandemic responsible for over 2,000,000 confirmed cases and over 126,000 deaths worldwide. In this study, we examined the immunogenicity of CHO-expressed recombinant SARS-CoV-2 S1-Fc fusion protein in mice, rabbits, and monkeys as a potential candidate for a COVID-19 vaccine. We demonstrate that the S1-Fc fusion protein is extremely immunogenic, as evidenced by strong antibody titers observed by day 7. Strong virus neutralizing activity was observed on day 14 in rabbits immunized with the S1-Fc fusion protein using a pseudovirus neutralization assay. Most importantly, in <20 days and three injections of the S1-Fc fusion protein, two monkeys developed higher virus neutralizing titers than a recovered COVID-19 patient in a live SARS-CoV-2 infection assay. Our data strongly suggests that the CHO-expressed SARS-CoV-2 S1-Fc recombinant protein could be a strong candidate for vaccine development against COVID-19.

In vivo Screen Identifies Zdhhc2 as a Critical Regulator of Germinal Center B Cell Differentiation.

Germinal center (GC) B cell differentiation is critical for the production of affinity-matured pathogen-specific antibodies, the dysregulation of which may lead to humoral immunodeficiency or autoimmunity. The development of an in vivo screening system for factors regulating GC B cell differentiation has been a challenge. Here we describe a small-scale in vivo screening system with NP-specific B1-8hi cells and a retroviral shRNA library targeting 78 candidate genes to search for B cell-intrinsic factors that specifically regulate GC B cell differentiation. Zdhhc2, a gene encoding palmitoyltransferase ZDHHC2 and highly expressed in GC B cells, is identified as a strong positive regulator of GC B cell differentiation. B1-8hi cells transduced with Zdhhc2-shRNA are severely compromised in differentiating into GC B cells. A further analysis of in vitro differentiated B cells transduced with Zdhhc2-shRNA shows that Zdhhc2 is critical for the proliferation and the survival of B cells stimulated by CD40L, BAFF, and IL-21 and consequently impacts on their differentiation into GC B cells and post-GC B cells. These studies not only identify Zdhhc2 as a novel regulator of GC B cell differentiation but also represent a proof of concept of in vivo screen for regulators of GC B cell differentiation.

Rational design of peptides for identification of linear epitopes and generation of neutralizing monoclonal antibodies against DKK2 for cancer therapy.

Dickkopf-related protein 2 (DKK2)is a member of the Dickkopf family in Wnt signaling pathway. Recently, we found that antibodies against DKK2 could activate natural killer (NK) and CD8+ T cells in tumors and inhibit tumor growth. In this paper, we report the rational design of peptides for identification of linear epitopes and generation of neutralizing monoclonal anti-DKK2 antibodies. To break the immune tolerance, we designed and chemically synthesized six peptides corresponding to different regions of DKK2 as immunogens and found five of them could generate mouse polyclonal antibodies that can bind to the active recombinant human DKK2 protein. Neutralizing mouse monoclonal antibodies (5F8 and 1A10) against human DKK2 were successfully developed by immunizing the mice with two different peptides (34KLNSIKSSL42 and 240KVWKDATYS248) conjugated to Keyhole limpet hemocyanin (KLH). The monoclonal antibodies not only abolish DKK2's suppression of Wnt signaling in vitro but also inhibits tumor growth in vivo. Currently, those two mAbs are undergoing humanization as immunotherapy candidates and may offer a new drug for treatment of human cancers.

Novel strategy for expression and characterization of rabies virus glycoprotein.

Rabies is a fatal zoonosis which could affect all mammals. Glycoprotein (G protein) from the rabies virus plays an important role in the binding of virus to target cells. However, expression of the G protein with native conformation has been a great challenge for many years. In this study, we solved this problem by replacing the original signal peptide of rabies virus G protein with the one from the heavy chain of human IgG. The expression levels of recombinant G protein dramatically increased from a few µg/L to 50 mg/L in the culture supernatants. The identity of the recombinant G protein was confirmed by western blotting using both 6XHis mAb 6E2 and rabies G protein mAb 7G3. The correct conformation of the recombinant G protein was shown by using rabies virus neutralizing antibodies. In addition, the recombinant G protein had immune-reactivities with mice sera raised against rabies vaccines and vice versa. Taken together, our data suggested that by replacing the signal peptide, the expression level of the G protein with native conformation could be significantly improved. This would help the development of a rabies subunit vaccine, structural studies of rabies G protein, elucidation of the signal pathway of RABV infection.

Rabies virus glycoprotein serology ELISA for measurement of neutralizing antibodies in sera of vaccinated human subjects.

BACKGROUND: Vaccination provides protection against infection by inducing VNAs mainly against RABV surface GP. The measurement of VNAs to RABV is commonly used to assess the level of immunity in humans and animals after vaccination. A VNA titer of  ≥ 0.5 IU/mL of sera indicates adequate response to vaccination. Here, we report the development and validation of a RABV GP serology ELISA kit for semi-quantitative measurement of VNA titers in sera of vaccinated human subjects. METHODS: Using a recombinant RABV GP expressed in mammalian cells as the capture antigen, the ELISA method was established using HuMAb NM57 reference initially and HRIG reference subsequently. The limit of detection (LOD), linear range, reproducibility, and precision of the method were examined. Specificity and sensitivity were established to assess the diagnostic accuracy. RESULTS: RABV GP for ELISA plate coating and optimal dilution of human serum sample was 1 µg/mL and 1:20, respectively. Multiple assays were carried out by different technicians at different laboratories for assay standardization. Using the HRIG reference, the LOD was found to be 0.02-0.06 IU/mL and the linear range was 0.2-10.0 IU/ mL. The inter-assay CVs were in the range of 6.60-10.79%, indicating the reproducibility. None of the 12 known negative human sera, tested positive by ELISA, highlighting the specificity. A total of 415 unknown positive human sera were double-blind tested by the RFFIT and ELISA. The VNA titer cut-off value of ELISA was set at 1.5 IU/mL to ensure no false-positive. The diagnostic specificity and sensitivity were 100% and 91.1%, respectively. CONCLUSIONS: The validation data characterize this ELISA as a suitable method for semi-quantitative measurement of VNA titers in human serum samples to assess vaccination status. The ELISA kit can offer simplicity, speed, low cost and high throughput, making it a practical tool for monitoring the immune response following vaccination.

Expression, purification and characterization of the plant Snf1-related protein kinase 1 from Escherichia coli.

The SnRK1 (SNF1 related protein kinase 1), a plant homologue of SNF1 (Sucrose non-fermenting 1)/AMPK (AMP-activated protein kinase), is an important metabolic sensor involving in catabolic and anabolic processes. SnRK1 is essential for plant metabolism regulation and response to environmental stresses. The plant SnRK1 consists of one catalytic (α1/α2 subunit) and two regulatory subunits (ß1/ß2/ß3 and γ/ßγ subunits), and functions as a heterotrimeric complex. Here we took advantage of a tricistronic expression vector and successfully purified the holoenzyme containing three subunits of SnRK1 from the E.coli. Using advantages of the E.coli system, we would be able to purify SnRK1 complex with high yield and high purity. Moreover, the complex is stable with high homogeneity. Using the purified complex, we confirmed that the ßγ rather than the γ subunit of the plant SnRK1 acts as the canonical regulatory subunit. Besides, some basic characters of the SnRK1 holoenzyme was studied. Together, our results provide a convenient way for purify the plant SnRK1 complexes, and this would be helpful for follow-up study on SnRK1's structure and mechanism.

Production of monoclonal antibodies for measuring Avastin and its biosimilar by Sandwich ELISA.

The development of Bevacizumab (Avastin) biosimilar products has grown rapidly over the last ten years as the original Avastin's patent will expire soon. The approval of Avastin biosimilars requires the demonstration of similarity between the biosimilar and the reference product. To support pre-clinical and clinical studies, pharmacokinetic (PK) assays are required to measure the biosimilar and Avastin with comparable precision and accuracy. The PK assay of Avastin employed by Genentech was a Sandwich ELISA which could detect the total drug concentration. However, it was developed in-house and not commercially available. Therefore, in most of the Avastin biosimilar pre-clinical studies, the antibody drug concentrations were measured using an indirect ELISA against coated VEGF, which could only measure the free instead of the total antibody drugs. It failed the essential requirement to develop the biosimilars. In this study, we reported the generation of mouse monoclonal antibodies (mAbs) that specifically recognize Avastin in a VEGF non-competitive manner. Using a pair of non-VEGF competing anti-Avastin mAbs, a Sandwich ELISA was developed with a lower limit of quantitation (LLOQ) at 400 ng/mL and upper limit of quantitation (ULOQ) at 12800 ng/mL. The assay validation was carried out with serum samples from monkey treated with Avastin biosimilar at seven different time points. Our data showed that the Sandwich ELISA kit we developed is sensitive, simple, reproducible and ready for use in human clinical trials.

A unique dysprosium selenoarsenate(iii) exhibiting a photocurrent response and slow magnetic relaxation behavior.

A redox, substitution and self-assembly reaction offers a novel dysprosium selenoarsenate(iii) with As3+ [Dy2(tepa)2(µ2-OH)2Cl2]3[As3Se6]2 (1, tepa = tetraethylenepentamine), which provides the first example of chair conformation ring [As3Se6]3- combined with lanthanide complexes as counterions. 1 exhibits a photocurrent response and slow magnetic relaxation behavior.

A 3-D net based on weak metallophilic (CuCu) interactions.

A novel 3-D binary copper(i) polymer [Cu(IN)]n (1, IN = isonicotinate) has been solvothermally synthesized. 1-D [Cu(IN)] chains of 1 are interconnected by weak metallophilic (CuCu) interactions to form a 3-D net. The theoretical band structure and photocatalytic and fluorescence properties have also been studied.

The first examples of 1-D organic hybrid lanthanoid thioarsenates based on two [As(V)S4](3-) linkage modes.

A series of new 1-D organic hybrid lanthanoid thioarsenates [Ln(dap)2]2(µ-η(1):η(1):η(1):η(1)-AsS4)(µ-η(1):η(1)-As(V)S4)]n {Ln = Ce (Ia), Pr (Ib), Nd (Ic), and Sm (Id); dap = diaminopropane} have been prepared under solvothermal conditions and structurally characterized. Compounds Ia-d contain two [As(V)S4](3-) linkage modes, namely µ-η(1):η(1):η(1):η(1)-As(V)S4 and µ-η(1):η(1)-As(V)S4, which are linked alternately with [Ln(dap)2](3+) groups into 1-D neutral chains [Ln(dap)2]2(µ-η(1):η(1):η(1):η(1)-As(V)S4)(µ-η(1):η(1)-As(V)S4)]n, which represent the first examples of 1-D organic hybrid lanthanoid thioarsenates based on two [As(V)S4](3-) linkage modes. To learn more about the influence of lanthanide contraction on the formation of lanthanoid thioarsenates, five organic hybrid lanthanoid thioarsenates [Ln(dap)3As(V)S4] [Ln = Tb (IIa), Dy (IIb), Ho (IIIc), and Er (IIId)] and [Er(dien)2As(V)S4] (III, dien = diethylenetriamine) are also provided. Both II and III contain neutral lanthanide-centred complexes, where the tetrahedral anion [As(V)S4](3-) acts as a chelating ligand to the complex [Ln(dap)3](3+)/[Er(dien)2](3+) cation. Their optical properties have been characterized by UV-vis spectra, and the density functional theory calculation of Ia has been performed.

A series of new manganese thioarsenates(v) based on different unsaturated [Mn(amine)x](2+) complexes.

A series of new manganese thioarsenates(V) [Mn(en)2Cu(AsVS4)]n (1, en = ethylenediamine), [Mn(dien)2][Mn(dien)(AsVS4)]2 (2, dien = diethylenetriamine), [Mn(teta)(AsVS4)]n (3, teta = triethylenetetramine), and {[Mn(dap)2][Mn(dap)(AsVS4)]2}n (4, dap = 1,2-diaminopropane) have been solvothermally synthesized and structurally characterized. 1 displays a neutral heterometallic [Mn(en)2Cu(AsVS4)]n chain built up from the linkages of [Mn(en)2]2+ complexes and infinite heterometallic [Cu(AsVS4)2−]n chains, and represents the only example of incorporation of an unsaturated [Mn(en)2]2+ complex into the 1-D [Cu(AsVS4)2−]n framework. 2 consists of a discrete {[Mn(dien)]2(AsVS4)2}2− cluster and a charge compensating complex cation [Mn(dien)2]2+. 3 shows a 1-D neutral [Mn(teta)(AsVS4)]n chain constructed by the combination of both complex [Mn(teta)]2+ ions and tetrahedral [AsVS4]3− anions. 4 exhibits a rare 2-D {[Mn(dap)2][Mn(dap)(AsVS4)]2}n layer based on the linkages of [AsVS4]3− anions and [Mn(dap)x]2+ (x = 1, 2) groups. These results show that different unsaturated [Mn(amine)x]2+ complexes are directly bonded to [AsVS4]3− anions to give different manganese thioarsenates(V), which have a significant structure directing effect on the structures of manganese thioarsenates(V) under similar solvothermal conditions. The present compounds exhibit wide-band-gap semiconducting properties with absorption band edges between 2.00 and 2.58 eV, and density functional theory calculations for compounds 1, 3 and 4 have also been performed.

A series of new lanthanoid thioarsenates: insights into the influence of lanthanide contraction on the formation of new lanthanoid thioarsenates.

A series of new lanthanoid thioarsenates [Ln(teta)(µ-η(1):η(2):η(1)-As(III)S3)]n {Ln = Ce (Ia), Pr (Ib), Nd (Ic), and Sm (Id); teta = triethylenetetramine} and [Ln(teta)(en)(µ-η(1):η(1):η(1)-As(V)S4)]n {Ln = La (IIa), Ce (IIb), Pr (IIc), and Nd (IId); en = ethylenediamine} were prepared by the solvothermal reaction of K3AsO3, S, LnCl3 and organic amines and structurally characterized. Compounds Ia­d crystallise in the orthorhombic space group Aba2 and display 1-D neutral chains [Ln(teta)(µ-η(1):η(2):η(1)-As(III)S3)]n, which represent the first examples of 1-D organic hybrid lanthanoid sulfides built up from trigonal-pyramidal [As(III)S3](3-) acting as tetradentate bridging ligands to interlink [Ln(teta)](3+) ions, while compounds IIa­d crystallise in the orthorhombic space group P2(1)2(1)2(1) and consist of other 1-D neutral chains [Ln(teta)(en)(µ-η(1):η(1):η(1)-As(V)S4)]n, which are built up from the linkages of the tetrahedral [As(V)S4](3-) ion and the [Ln(teta)(en)](3+) ion. To learn more about the influence of lanthanide contraction on the formation of lanthanoid thioarsenates, three organic hybrid lanthanoid thioarsenates [Ln(teta)(en)As(V)S4] [Ln = Dy (IIIa), Ho (IIIb), and Tm (IIIc)] with the neutral molecular structure type in the monoclinic centrosymmetric space group P2(1)/c are also presented. Their optical and magnetic properties have been investigated, and density functional theory calculations of Ia and IIa have also been performed.