Elemental Selenium Research Articles

Nucleophilic Selenocyclization Reaction of Benzodiynes Promoted by Sodium Selenide: Synthesis of Isoselenochromenes.

We describe here the synthesis of isoselenochromenes via a nucleophilic selenocyclization reaction of benzodiynes with sodium selenide. The central parameters that affect this cyclization reaction were studied, and the best reaction conditions were applied to different substrates to determine the scope of the method. The results indicated that isoselenochromenes were obtained in higher yields when the reactions were performed by the addition of NaBH4 (3 equiv), at room temperature, under nitrogen atmosphere, to a solution of elemental selenium (2 equiv) in dimethylformamide (2 mL). After 1 h, a benzodiynes (0.25 mmol) solution in EtOH (3 mL) was added at room temperature. The reaction was stirred at 75 °C until the starting material was consumed. The best conditions were applied to benzodiynes having electron-rich, electron poor aromatic rings, and alkyl groups directly bonded to the alkynes. The same reaction condition was extended to isothiochromene derivatives but failed to prepare isotelurochromenes. The isoselenochromenes were easily transformed into three new classes of organoselenium compounds using classical methods available in the literature. We also conducted several control experiments to propose a reaction mechanism.

Comparative Antioxidant Efficacy of Green-Synthesised Selenium Nanoparticles From Pongamia pinnata, Citrus sinensis, and Acacia auriculiformis: An In Vitro Analysis.

Aim This study aims to synthesise selenium nanoparticles (SeNPs) using extracts from Citrus sinensis peel (CSP), Millettia pinnata Leaf (MPL), and Acacia auriculiformis bark (AAB) as eco-friendly reducing agents. It seeks to compare the effectiveness of these plant extracts in the production of SeNPsand evaluate the antioxidant activities of the synthesised nanoparticles, establishing a link between the phytochemical constituents of the extracts and the antioxidant capacity of SeNPs for their potential applications in drug development and environmental sustainability. Introduction Nanotechnology offers innovative solutions in various fields, including medicine, environmental science, and materials engineering. SeNPs are of particular interest due to their unique properties and potential applications. The methods for synthesizing nanoparticles often involve hazardous chemicals, posing risks to the environment and human health. In response, green synthesis methods utilizing plant extracts have emerged as a sustainable alternative. This study focuses on utilizing CSP, MPL, and AAB extracts, rich in natural reducing agents such as flavonoids and phenolic acids, for the eco-friendly synthesis of SeNPs. These plant sources are chosen based on their known phytochemical profiles and potential antioxidant activities, and we aim to explore the correlation between the extracts' phytochemical composition and the antioxidant capabilities of the synthesised SeNPs. Methods SeNPs were synthesised using aqueous extracts of CSP, MPL, and AAB through a reduction process, in which selenium ions (Se4+) are reduced to elemental selenium. The presence of SeNPs was first visually monitored by colour change and then confirmed through UV-Vis spectroscopy and Fourier transform infrared (FTIR) spectroscopy analyses. The antioxidant activity of the synthesised SeNPs was assessed using the 1,1-diphenyl-2-picryl hydroxyl (DPPH) radical scavenging assay and the efficacy of SeNPs synthesised from different plant extracts was compared. Results The UV-Vis spectral analysis indicated a successful synthesis of SeNPs, as evidenced by the characteristic absorption peaks. The FTIR analysis confirmed the presence of organic molecules derived from the plant components on the outer layer of SeNPs, suggesting successful capping and stabilization of nanoparticles by phytochemicals in the extracts. Among the three types of SeNPs, those synthesised using Citrus sinensis peel extract (CSPE) exhibited the highest DPPH radical scavenging activity, indicating superior antioxidant properties compared to SeNPs synthesised from Millettia pinnata leaf extract (MPLE) and Acacia auriculiformis bark extract (AABE). This suggests that the antioxidant capacity of SeNPs is significantly influenced by the phytochemical composition of the plant extract used for synthesis. Conclusion The study highlights the potential of CSPE as an effective natural source for synthesising antioxidant-rich SeNPs and underscores the importance of green synthesis approaches in producing environmentally friendly and biologically active nanomaterials.

Achromobacter seleniivolatilans sp. nov. and Buttiauxella selenatireducens sp. nov., isolated from the rhizosphere of selenium hyperaccumulator Cardamine hupingshanesis.

Two Gram-stain-negative bacterial strains, R39T and R73T, were isolated from the rhizosphere soil of the selenium hyperaccumulator Cardamine hupingshanesis in China. Strain R39T transformed selenite into elemental and volatile selenium, whereas strain R73T transformed both selenate and selenite into elemental selenium. Phylogenetic and phylogenomic analyses indicated that strain R39T belonged to the genus Achromobacter, while strain R73T belonged to the genus Buttiauxella. Strain R39T (genome size, 6.68 Mb; G+C content, 61.6 mol%) showed the closest relationship to Achromobacter marplatensis LMG 26219T and Achromobacter kerstersii LMG 3441T, with average nucleotide identity (ANI) values of 83.6 and 83.4 %, respectively. Strain R73T (genome size, 5.22 Mb; G+C content, 50.3 mol%) was most closely related to Buttiauxella ferragutiae ATCC 51602T with an ANI value of 86.4 %. Furthermore, strain A111 from the GenBank database was found to cluster with strain R73T within the genus Buttiauxella through phylogenomic analyses. The ANI and digital DNA-DNA hybridization values between strains R73T and A111 were 97.5 and 80.0% respectively, indicating that they belong to the same species. Phenotypic characteristics also differentiated strain R39T and strain R73T from their closely related species. Based on the polyphasic analyses, strain R39T and strain R73T represent novel species of the genera Achromobacter and Buttiauxella, respectively, for which the names Achromobacter seleniivolatilans sp. nov. (type strain R39T=GDMCC 1.3843T=JCM 36009T) and Buttiauxella selenatireducens sp. nov. (type strain R73T=GDMCC 1.3636T=JCM 35850T) are proposed.

Aluminum-catalyzed direct conversion of lactones to selenolactones in the presence of elemental selenium and its application in the indium-catalyzed syntheses of dibenzyl selenides from benzyl acetates

Se-containing compounds exhibit novel chemical properties and unique pharmacological effects. Although various methods of preparing selenoesters have been reported, the synthetic focus on the related cyclic selenoesters remains insufficient. The conventional methods of synthesizing selenolactones generally involve multistep processes. In this study, an AlBr3/PhSiH3 (Ph = Phenyl) reducing system selectively catalyzed the one-pot conversion of γ-aryl-γ-lactones and elemental Se to γ-aryl-γ-selenolactones in good yields. This reducing system strongly activates elemental Se rather than elemental S. Additionally, an In(OAc)3/PhSiH3 (OAc = acetate) reducing system effectively catalyzed the direct conversion of linear benzyl acetates, which constitute substructures of lactones, and elemental Se to dibenzyl selenide derivatives.

Construction, characterization, antioxidant activity and effects on properties in vitro digestion of selenium nanoparticles decorated with Cyperus esculentus polysaccharides

In this study, in order to obtain selenium complex with high antioxidant activity and low release rate, selenium nanoparticles (SeNPs) were decorated by chemical reduction with Cyperus esculentus polysaccharides (CEP) as stabilizers (CEP-SeNPs). The characterization, construction mechanism, stability, and effects on properties in vitro digestion of CEP-SeNPs were investigated. CEP-SeNPs were orange-red in color and uniformly distributed in a spherical shape with an average diameter of 138.33 ± 0.57 nm, exhibiting good stability which could be stored at 4 °C. The selenium element in CEP-SeNPs was selenium in a zero-valent amorphous state. The O-H and C=O bonds in CEP were bound to selenium by an inductive effect to construct CEP-SeNPs for infrared analysis, and no new covalent bonds were formed in this process. CEP as stabilizer on selenium nanoparticles were physical combination. At the same time, the synergistic effects at antioxidant activity of polysaccharides and selenium was found which made CEP-SeNPs had a higher antioxidant activity than CEP. Above all, CEP-SeNPs showed better pH and enzyme stability in simulated digestion. The selenium release rate of CEP-SeNPs were only 18.52 % ± 0.17 % after intestinal digestion. The antioxidant activity of CEP-SeNPs were higher than that of CEP in the simulated digestion. It provides a theoretical basis for the development and utilization of rich selenium products.

En Route to a Molecular Terminal Tin Oxide.

In the pursuit of terminal tin chalcogenides, heteroleptic stannylenes bearing terphenyl- and hexamethyldisilazide ligands were reacted with carbodiimides to yield the respective guanidinato complexes. Further supported by quantum chemical calculations, this revealed that the iso-propyl-substituted derivative provides the maximum steric protection achievable. Oxidation with elemental selenium produced monomeric terminal tin selenides with four-coordinate tin centers. In reactions with N2O as oxygen transfer reagent, silyl migration toward putative terminal tin oxide intermediates gave rise to tin complexes with terminal ─OSiMe3 functionality. To prevent silyl migration, the silyl groups were substituted with cyclohexyl moieties. This analogue exhibited distinctively different reactivities toward selenium and N2O, yielding a 1,2,3,4,5-tetraselenastannolane and chalcogenide-bridged dimeric compounds, respectively.

The effect of gadolinium and lanthanum orthovanadate nanoparticles on the content of vitamins (B2, A, E) and trace elements (Cu, Zn, Se) in the blood serum and liver of broiler chickens

As a result of scientific progress, substances in the nanoscale state are increasingly being introduced into various areas of human activity, including animal husbandry (poultry farming). In particular, nanotechnology is used successfully to enrich food products with minerals, vitamins, antioxidants, that is, they can increase the bioavailability of nutrients by oral administration. In this study, the content of vitamins (A, E, and B2 ) and trace elements (Zn, Cu, and Se) in the blood serum and liver of broiler chickens under the influence of gadolinium orthovanadate, lanthanum orthovanadate, and a mixture of all these was investigated. It was established that their administration to broiler chickens for 10 days at a dose of 0.2 mg/l of drinking water (an average of 0.09 mg/kg body weight) increases the bioavailability of vitamins B2 , A, and E and the trace elements selenium, copper and zinc, which was manifested by an increase in their concentrations in the blood serum compared to the control group (from 8.6% to 3.0 times for vitamins, and from 17.8% to 2.5 times for trace elements, P<0.05) and liver deposition (from 9.4% to 4.6 times for vitamins and from 6.3 to 56.3% for trace elements, P<0.05), with a prolonged effect after administration was stopped. The introduction of nanoparticles (both in mono-solutions and in a mixture), along with a vitamin preparation, indicates the possibility of increasing the content of vitamins and trace elements without their additional introduction, using the dietary resource more fully.

Multi-pathways-mediated mechanisms of selenite reduction and elemental selenium nanoparticles biogenesis in the yeast-like fungus Aureobasidium melanogenum I15

Selenium (Se) plays a critical role in diverse biological processes and is widely used across manufacturing industries. However, the contamination of Se oxyanions also poses a major public health concern. Microbial transformation is a promising approach to detoxify Se oxyanions and produce elemental selenium nanoparticles (SeNPs) with versatile industrial potential. Yeast-like fungi are an important group of environmental microorganisms, but their mechanisms for Se oxyanions reduction remain unknown. In this study, we found that Aureobasidium melanogenum I15 can reduce 1.0 mM selenite by over 90% within 48 h and efficiently form intracellular or extracellular spherical SeNPs. Metabolomic and proteomic analyses disclosed that A. melanogenum I15 evolves a complicated selenite reduction mechanism involving multiple metabolic pathways, including the glutathione/glutathione reductase pathway, the thioredoxin/thioredoxin reductase pathway, the siderophore-mediated pathway, and multiple oxidoreductase-mediated pathways. This study provides the first report on the mechanism of selenite reduction and SeNPs biogenesis in yeast-like fungi and paves an alternative avenue for the bioremediation of selenite contamination and the production of functional organic selenium compounds.

Selenium Inhibitor Coating on NiTi Shape Memory Alloys by Using Thermal Evaporation System

Abstract NiTi-based memory alloys are often used as intracorporeal implant materials because of their superelasticity and shape memory properties. However, over time, the release of nickel from the NiTi alloy into the body becomes unfavorable; therefore, studies should be conducted to reduce the negative impact of nickel leakage. In this study, the biocompatible selenium element was used to coat NiTi alloys with different thicknesses. The coating process was performed using the thermal evaporation technique. Scanning electron microscopy-Energy Dispersive X-ray Analysis measurements revealed that the surfaces of the samples were well covered. Also, the atomic force microscope device determined the surface roughness of the alloys. The roughness of the surface increased after the coating process. The Tafel test was accomplished to determine the biocompatibility of the coated and uncoated alloys in an artificial body fluid. The corrosion test reveals that Se-coated NiTi alloys have high corrosion resistance.

Comparative kinetics of oxidation and GPx-like activity of 7,8-dimethoxy-9-selenabicyclo[4.2.1]nonane and 2,6-Dimethoxy-9-selenabicyclo[3.3.1]nonane

The first representative of a new class of organoselenium bicyclic compounds, 7,8-dimethoxy-9-selenabicyclo[4.2.1]nonane, was prepared by the iodine-mediated reaction of elemental selenium and 1,3-cyclooctadiene. Comparative kinetics of the oxidation of 7,8-dimethoxy-9-selenabicyclo[4.2.1]nonane 1 and its isomer 2,6-dimethoxy-9-selenabicyclo[3.3.1]nonane 2 were studied by 1H NMR spectroscopy and found to be dozens of times faster for the former. The catalytic activity of 7,8-dimethoxy-9-selenabicyclo[4.2.1]nonane 9-oxide formed in situ from 1 and simulating the GPx-like activity in oxidation of thiols by H2O2 in MeOH, is shown to be higher than that of the isomeric 2,6-dimethoxy-9-selenabicyclo[3.3.1]nonane 9-oxide.

The clinical significance of monitoring serum levels of glutathione peroxidase and selenium in patients with polycystic ovary syndrome

[Objective] This study aims to analyze the levels of the trace element selenium (Se), glutathione peroxidase (GSH-Px), and total antioxidant capacity (TAC) in the serum of women with polycystic ovary syndrome (PCOS) compared to women with normal menstrual cycles. By examining the relationship between Se levels, oxidative stress (OS), and PCOS, the study provides a theoretical basis for the supplementation of the potent antioxidant Se in women with PCOS, aiming to improve the prevention and management of PCOS and reduce its complications.[Methods] Sixty-six females diagnosed with PCOS for the first time from June 2022 to June 2023 at the Shenzhen Hospital of Guangzhou University of Chinese Medicine (Futian) were selected as the observation group. Sixty-eight healthy volunteers with regular menstrual cycles were randomly selected as the control group. Serum levels of GSH-Px, TAC, and Se were measured and statistically analyzed for both groups.[Results] Serum levels of Se, TAC, and GSH-Px were significantly lower in the observation group compared to the control group (P<0.05), indicating a statistically significant difference.[Conclusion] The deficiency of the trace element Se leads to a reduction in OS indicators, including levels of GSH-Px and TAC. It is inferred that Se deficiency may be associated with the pathogenesis of PCOS to a certain extent.

Synthesis, structure, and stability of a set of C-stereogenic heteroditopic P, S ligands

This study focuses on synthesis and investigation of coordination modes of phosphorus and sulfur-containing C-stereogenic compounds, prepared from thioanisole. Isolation of the C-stereogenic organolithium compound [RR'CHLi·2THF]2 (R = C6H5S, R’ = (CH3)3Si, THF = tetrahydrofuran) instead of in situ usage turned out to be mandatory for controlled reactivity. Variation of the steric and electronic properties of the substituents at phosphorus furnished three different phosphane substituted P, S ligands RR'CHPPh2, RR'CHP(N(C2H5)2)2, and RR'CHP(t-C4H9)2. Furthermore, the corresponding chalcogenphosphoranes were synthesized by oxidation with elemental sulfur and selenium. Preliminary investigation of the coordination behavior of RR'CHP(t-C4H9)2, RR'CHP(S)(t-C4H9)2 and RR'CHP(Se)(t-C4H9)2 towards coinage metals was explored with Au(tht)Cl, both for the phosphanes and the corresponding phosphoranes. Intermolecular aurophilic interactions have been observed for the selenophosphorane exclusively.

Feasibility study of micronutrient status and body mass index of newly diagnosed pediatric oncology patients: Research commentary.

We conducted a feasibility study to evaluate micronutrients and body mass index (BMI). Fat soluble vitamins A, D, E and trace elements copper (Cu), selenium (Se), and zinc (Zn) levels were evaluated. Weight, height, BMI, and Z-scores were recorded. Side effects or specific adverse events were documented. No patient had a Z-score for height, weight, or BMI of less than 2 SD or greater than 2 SD. Ninety percent of patients had one or more micronutrient levels below normal. These results suggest that micronutrient abnormalities are common despite no obvious evidence of malnutrition. Side effects of chemotherapy may be exacerbated by micronutrient depletion.

Reduction in Placental Metal and Metalloid in Preeclampsia: A Case-Control Study.

Preeclampsia is a primary placental disorder, with impaired placental vascularization leading to uteroplacental hypoperfusion. We aimed to investigate differences in metal and metalloid content between the placentas of women with preeclampsia and healthy controls. This was a case-control study in 63 women with preeclampsia and 113 healthy women. Clinical data were obtained from medical records. Inductively coupled plasma mass spectrometry (ICP-MS) was used to measure the placental metals and metalloids content. Compared with healthy control subjects, preeclampsia was associated with a significantly lower concentration of essential elements (magnesium, calcium, iron, copper, zinc, and selenium) in the placental tissue. After multivariable adjustment, an interquartile range (IQR) increase in selenium concentration was associated with a reduced risk of preeclampsia with an OR of 0.50 (95% CI: 0.33-0.77). The joint effects of multiple selected metals and metalloids were associated with a reduced risk of preeclampsia. The lower placental magnesium, chromium, iron, zinc, and selenium concentrations of preeclampsia cases indicate a potential link to its pathogenesis. It also provides an intriguing avenue for future research in revealing the underlying mechanisms and potential intervention strategies for preeclampsia.

Evaluation of urinary trace element levels in patients with opioid use disorder undergoing methadone treatment in western Iran

The monitoring of essential and toxic elements in patients with Opioid Use Disorder (OUD) undergoing methadone treatment (MT) is important, and there is limited previous research on the urinary levels of these elements in MT patients. Therefore, the present study aimed to analyze certain elements in the context of methadone treatment compared to a healthy group. In this study, patients with opioid use disorder undergoing MT (n = 67) were compared with a healthy group of companions (n = 62) in terms of urinary concentrations of some essential elements (selenium (Se), zinc (Zn), copper (Cu), iron (Fe), manganese (Mn), calcium (Ca)) and toxic elements (lead (Pb), cadmium (Cd), arsenic (As), and chromium (Cr)). Urine samples were prepared using the acid digestion method with a mixture of nitric acid and perchloric acid and assessed using the ICP-MS method. Our results showed that the two groups had no significant differences in terms of gender, education level, occupation, and smoking status. Urinary concentrations of Se, Cu, and Fe levels were significantly lower in the MT group compared to the healthy subjects. However, the concentrations of Pb, Cd, As, Mn, Cr, and Ca in the MT group were higher than in the healthy group (p < 0.05). No significant difference was established between the levels of Zn in the two groups (p = 0.232). The results of regression analysis revealed that the differences between the concentration levels of all metals (except Zn) between two groups were still remained significant after adjusting for all variables (p < 0.05). The data obtained in the current study showed lower urinary concentrations of some essential elements and higher levels of some toxic elements in the MT group compared to the healthy subjects. These findings should be incorporated into harm-reduction interventions.

Effects of Low-Level Inorganic Selenium on Selenium Bioaccumulation in Escherichia coli: A Bioanalytical Study Using Graphite Furnace Atomic Absorption Spectrometry (GFAAS)

This study aimed to assess the bioaccumulation of selenite – Se(IV) – and selenate – Se(VI) – in Escherichia coli ATCC 11775 biomass. Escherichia coli cultures were exposed to low selenium concentrations (0.3–30.0 µM), and subsequent effects on growth and viability were evaluated. Selenium content in biomass was quantified using graphite furnace atomic absorption spectroscopy (GFAAS) and inductively coupled plasma mass spectrometry (ICP-MS), with Se recovery assessed through mass balance analysis. The average percentage of bioaccumulated Se exhibited variability depending on the Se species at different concentrations. At a concentration of 30.0 μM, elemental selenium formation emerged within the Se(IV) assay, leading to a significantly higher mean percentage of bioaccumulated selenium for Se(IV) (41.1%) compared to Se(VI) (15.8%). While the mean percentage of bioaccumulated selenium showed no significant variance across the Se(VI) concentrations, a significant difference was observed across the Se(IV) concentrations (ranging from 6.1% to 41.1%). Considering the percentage of Se recovered in the solid and liquid phases, the mass balance ranged from 82.1% to 94.5%. These findings underscore the ability of Escherichia coli ATCC 11775 to accumulate notable quantities of selenium, with the amount of bioaccumulated Se influenced by Se(IV) concentration but not by Se(VI). Furthermore, bacterial viability remained unaffected by selenium species and concentrations. This study contributes valuable insights into the bioaccumulation dynamics of Se(IV) and Se(VI) in non-genetically modified Escherichia coli, shedding light on factors governing selenium accumulation in bacterial biomass, particularly regarding natural biological representation, standardization, comparability, and applicability to environmental studies.

Electrochemical Multicomponent Cascade Reaction for the Synthesis of Selenazol-2-amines with Elemental Selenium.

The first example of an electrochemical multicomponent synthesis of selenium-containing compounds with inexpensive and abundant elemental selenium as the selenating reagent was developed. A variety of selenazol-2-amines were constructed in high yields with good functional group tolerance under metal-free and chemical oxidant-free conditions.

Controlled Ring Opening of a Tetracyclic Tetraphosphane with Twofold Metallocene Bridging.

A direct route to a doubly ferrocene bridged tetracyclic tetraphosphane 1 was developed via reductive coupling of Fe(CpPCl2)2 (2 a), where a chlorine terminated linear P4-compound 3 could be identified as an intermediate. Selective P-P bond activation was further achieved by reacting 1 with elemental selenium or [Cp*Al]4, where regioselective insertion of Se or Al atoms resulted in ferrocenylene bridged [P4Se] (4) or [P4Al] (7) moieties. Compound 7 can be transformed to a hydrogen terminated linear P4 species, 8, with protic solvents. Methylation of compound 1 with MeOTf, proceeds via intermediate formation of monomethylated species 5, which gradually produced Me2-terminated dicationic 6, again containing a linear P4-unit. Besides spectroscopic characterization, the structural details of compounds 1, 4, 6, and 8 could be determined by SC-XRD. Moreover, DFT calculations were used to rationalize the reactivity of 1, derived compounds and intermediates. As a key feature, 1 undergoes ring opening polymerization to a linear polyphosphane 9.

Recent Progress of Transition Metal Selenides for Electrochemical Oxygen Reduction to Hydrogen Peroxide: From Catalyst Design to Electrolyzers Application.

Hydrogen peroxide (H2O2) is a highly value-added and environmental-friendly chemical with various applications. The production of H2O2 by electrocatalytic 2e- oxygen reduction reaction (ORR) has emerged as a promising alternative to the energy-intensive anthraquinone process. High selectivity Catalysts combining with superior activity are critical for the efficient electrosynthesis of H2O2. Earth-abundant transition metal selenides (TMSs) being discovered as a classic of stable, low-cost, highly active and selective catalysts for electrochemical 2e- ORR. These features come from the relatively large atomic radius of selenium element, the metal-like properties and the abundant reserves. Moreover, compared with the advanced noble metal or single-atom catalysts, the kinetic current density of TMSs for H2O2 generation is higher in acidic solution, which enable them to become suitable catalyst candidates. Herein, the recent progress of TMSs for ORR to H2O2 is systematically reviewed. The effects of TMSs electrocatalysts on the activity, selectivity and stability of ORR to H2O2 are summarized. It is intended to provide an insight from catalyst design and corresponding reaction mechanisms to the device setup, and to discuss the relationship between structure and activity.

Generation and Reactivity of Polychalcogenide Chains in Binuclear Cobalt(II) Complexes.

A series of six binuclear Co(II)-thiolate complexes, [Co2(BPMP)(S-C6H4-o-X)2]1+ (X = OMe, 2; NH2, 3), [Co2(BPMP)(μ-S-C6H4-o-O)]1+ (4), and [Co2(BPMP)(μ-Y)]1+ (Y = bdt, 5; tdt, 6; mnt, 7), has been synthesized from [Co2(BPMP)(MeOH)2(Cl)2]1+ (1a) and [Co2(BPMP)(Cl)2]1+ (1b), where BPMP1- is the anion of 2,6-bis[[bis(2-pyridylmethyl)amino]methyl]-4-methylphenol. While 2 and 3 could allow the two-electron redox reaction of the two coordinated thiolates with elemental sulfur (S8) to generate [Co2(BPMP)(μ-S5)]1+ (8), the complexes, 4-7, could not undergo a similar reaction. An analogous redox reaction of 2 with elemental selenium ([Se]) produced [{Co2(BPMP)(μ-Se4)}{Co2(BPMP)(μ-Se3)}]2+ (9a) and [Co2(BPMP)(μ-Se4)]1+ (9b). Further reaction of these polychalcogenido complexes, 8 and 9a/9b, with PPh3 allowed the isolation of [Co2(BPMP)(μ-S)]1+ (10) and [Co2(BPMP)(μ-Se2)]1+ (11), which, in turn, could be converted back to 8 and 9a upon treatment with S8 and [Se], respectively. Interestingly, while the redox reaction of the polyselenide chains in 9a and 11 with S8 produced 8 and [Se], the treatment of 8 with [Se] gave back only the starting material (8), thus demonstrating the different redox behavior of sulfur and selenium. Furthermore, the reaction of 8 and 9a/9b with activated alkynes and cyanide (CN-) allowed the isolation of the complexes, [Co2(BPMP)(μ-E2C2(CO2R)2)]1+ (E = S: 12a, R = Me; 12b, R = Et; E = Se: 13a, R = Me; 13b, R = Et) and [Co2(BPMP)(μ-SH)(NCS)2] (14), respectively. The present work, thus, provides an interesting synthetic strategy, interconversions, and detailed comparative reactivity of binuclear Co(II)-polychalcogenido complexes.