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This document is a contents list for the journal "Dalton Transactions: An International Journal of Inorganic Chemistry." It features a compilation of research papers covering various topics such as metal dioxo complexes, piezo-photocatalytic CO2 reduction, and carbonaceous materials for lithium-ion batteries. The journal aims to foster connections within the chemistry community and stimulate innovative ideas. Additionally, the document includes corrections to two previously published papers. [Extracted from the article]

The document is a contents list of the New Journal of Chemistry, published on March 14, 2024. It includes a variety of articles and papers on topics such as SARS-CoV-2 detection, synthesis of branched bottlebrushes, glycosyl sulfonation, catalytic behavior, and more. The journal, published by The Royal Society of Chemistry and the Centre National de la Recherche Scientifique, aims to explore new directions in chemistry. The document provides a comprehensive overview of the articles included in the journal issue, which cover a wide range of topics and provide valuable research and insights in their respective fields. [Extracted from the article]

The document is a contents list for the journal "Dalton Transactions: An International Journal of Inorganic Chemistry." It includes various articles and papers on topics such as copper complexes, lanthanide-based POMs, and coordination polymers. The journal is published by The Royal Society of Chemistry, a leading chemistry community. The document also mentions approved training courses offered by the society. The given document is a list of papers published in the journal Dalton Transactions. The papers cover a range of topics in chemistry, including catalysis, phosphors, materials synthesis, and more. Each paper is identified by its title, authors, and page number. The document also includes a correction and a retraction for two previously published papers. [Extracted from the article]

The document is a contents list for the journal CrystEngComm, which focuses on the design and understanding of solid-state and crystalline materials. It includes a variety of papers on topics such as cocrystals, crystal structures, stimuli-responsive properties, and piezoelectric properties. The journal is published by The Royal Society of Chemistry, a leading chemistry community. The document also mentions approved training courses offered by the society. [Extracted from the article]

The document is a contents list for the journal CrystEngComm. It highlights various papers and communications published in the journal, including topics such as hydrogen storage, coordination polymers, luminescent sensors, and chemical solution deposition. The cover image features the Tembleque Aqueduct World Heritage Site in Mexico. The journal is published by the Royal Society of Chemistry, a leading chemistry community that connects the world with the chemical sciences. [Extracted from the article]

The document is a contents list for the journal CrystEngComm, which focuses on the design and understanding of solid-state and crystalline materials. The list includes various papers on topics such as hybrid materials, growth of single-crystalline particles, high-pressure phase transitions, coordination polymers, and optical properties of crystals. The journal is published by The Royal Society of Chemistry, a leading chemistry community. The document also mentions professional recognition and development opportunities for scientists. [Extracted from the article]

The document is a contents list for the journal CrystEngComm, which focuses on the design and understanding of solid-state and crystalline materials. The contents list includes various papers on topics such as acoustic shockwave-induced morphological transformation, copper-organic frameworks, and the assembly of poly(3-hydroxybutyrate). The journal is published by The Royal Society of Chemistry, a leading chemistry community. The document also mentions other journals in the field of environmental science. [Extracted from the article]

This paper investigates the synthesis, crystal structure, thermal properties, and energetic performance of two 1D coordination polymers (CPs). The CPs, namely, [Zn(atrz)(DNBA)2(H2O)2]n (1) and [Cd(atrz)(DNBA)2(H2O)2]n (2), were designed and synthesized based on the nitrogen-rich ligand 4,4′-azobis-1,2,4-triazole (atrz) and 3,5-dinitrobenzoic acid (HDNBA) via a mixed ligand strategy using a simple and environment-friendly method. The CPs were characterized by various spectroscopic and analytical techniques along with single-crystal X-ray diffraction (SCXRD). SCXRD analysis reveals a distorted octahedral geometry around the metal ions (Zn/Cd), leading to the formation of a 1D coordination polymer while constructing a 2D structural framework through intermolecular hydrogen bonding. Both the CPs exhibit similar thermal stability but considerably differ in their heat of formation values (1 = −894.43, 2 = 1635.93 kJ mol−1). CP 2 has higher detonation velocity (7.24 km s−1) and pressure (23.67 GPa) compared to 1 (detonation velocity: 6.28 km s−1, detonation pressure: 17.57 GPa) owing to its higher heat of formation and density. Both the CPs exhibit ideal insensitivity to friction and impact stimuli, ensuring their safety during transportation and processing. The value of average activation energy obtained from isoconversion ASTM E698 for 1 and 2 was reported to be 143.8 and 168.0 kJ mol−1, respectively. This study explores the development of energetic CPs through the mixed ligand strategy based on the atrz ligand and incorporating HDNBA as the co-ligand to reduce the sensitivity while maintaining the comparable energetic performance of previously reported atrz-based complexes. This paper also highlights the potential use of CPs as explosives by demonstrating higher energetic performance. [ABSTRACT FROM AUTHOR]

In this paper, we report a two-dimensional (2D) Hofmann-type spin-crossover coordination polymer [FeII(o-NTrz)2PtII(CN)4]·H2O (o-NTrz = 4-(o-nitrobenzyl)imino-1,2,4-triazole). Due to the remarkable configurational flexibility of triazole-based ligand, the porous structure of this compound can be reversibly regulated by the loss of guest water molecules as a consequence of rotation of o-NTrz. The 180° reorientation of the o-nitrobenzyl moiety not only induces a response of gate-closing/opening of the porous framework but also significantly modulates the spin transition temperature. The present investigation highlights the potential of Hofmann-type SCO compounds with flexible ligands in exploring unusual physical and chemical phenomena. [ABSTRACT FROM AUTHOR]

Urease may rapidly hydrolyze urea, causing a significant amount of ammonia to be released and decreasing the efficacy of urea fertilizers. However, urease inhibitors (UIs) can prevent the interaction between urease and urea, allowing crops to absorb ammonium nitrogen for an extended period of time. In this paper, by using different O-donor second auxiliary ligands, we have designed and synthesized two Cu-based coordination polymers (Cu-CPs) to operate as UIs by combining two aromatic carboxylic acids and a bis-pyridine-bis-amide ligand, which show excellent urease inhibitory activity. Cu-CP-1 has an obvious inhibitory effect on the inhibitory activity against jack bean urease, with the IC50 of 1 being 0.83 ± 0.01 μM while the IC50 value for Cu-CP-2 was 2.53 ± 0.01 μM, respectively. Furthermore, inhibitory activity against urease, kinetics, molecular docking, and comparisons of the title Cu-CPs and other complex-based materials have been comprehensively investigated. More importantly, the bridging atoms of μ2-OH and μ2-Cl play important roles in urease inhibition activity. The structure–function relationships were further discussed and indicate that Cu-CPs can be used as a kind of UI. [ABSTRACT FROM AUTHOR]

Polar cyano fragments and their isomeric isocyano counterparts have attracted great attention as stimuli-responsive luminescent materials in a wide range of fields including organic light-emitting diode devices, chemical fluorescent sensors, photoelectric semiconductors, anti-counterfeit products, etc., mainly because of their typical electron-deficient activity, noncovalent recognition ability, and variable coordination capacity. The electron-deficient and polar nature of these blocks have significant effects on the properties of the cyano/isocyano-based luminophore materials, especially concerning their condensed state-dependent electronic structures. Among them, donor–acceptor (D–A) derived unimolecular and co-assembled luminophores have attracted more attention because their large delocalized structures and noncovalent interaction recognition sites can rebuild the electronic transfer character in the aggregative state, thus endowing them with outstanding stimuli-responsive luminescent behavior via intermolecular and intramolecular charge transfer in polytropic morphologies. In this perspective paper, we give a brief introduction on stimuli-responsive organic and coordinated luminophores and the documented typical design concepts and applications in recent years. It is expected that this perspective article will not only summarize the recent developments of polar cyano/isocyano-derived luminophores and their coordination compounds via structural tailoring and self-assembly but also throw light on the future of the design of more sophisticated stimuli-responsive architectures and their versatile properties. [ABSTRACT FROM AUTHOR]

CrystEngCommrsc. li/ crystengcomm ISSN 1466- 8033 Volume 26 Number 18 14 May 2024 Pages 2335– 2442 PAPER Juan Olguín et al. Nitro group and K+- based secondary building units for the self- assembly of 3D coordination polymers built on dinuclear dianionic helicate connectors Environmental Science: Atmospheres Connecting communities and inspiring new ideas rsc. li/ submittoEA Fundamental questions Elemental answers GOLD OPEN ACCESS Registered charity number: 207890 [Extracted from the article]

Coordination polymers (CPs) with a d10-configuration containing metal cations offer interesting photoluminescent properties and hence can be employed as sensors to detect various classes of analytes. Moreover, due to their tuneable pore size they can be employed as adsorbents for various species. Herein, a new d10-configuration Cd(II)-based CP with composition {[Cd(bip)4(H2O)2]n·2NO3} (1) (bip = 3,5-bis(1-imidazol)pyridine) has been synthesized and characterized. Single-crystal X-ray analysis reveals that the Cd(II) center adopts octahedral geometry that is satisfied by four N atoms from the four bip linkers and two aqua ligands, and the resultant CP displays sql topology with the point symbol of (44·62). The CP offers prospective application as a photoluminescent sensor for dichromate anions with a limit of detection of 1.28 ppm and a Stern–Volmer constant (KSV) of 1.51 × 105. Furthermore, CP 1 was employed as an efficient adsorbent for dichromate ions, reaching an equilibrium adsorption capacity of 389.82 mg g−1 within 80 min. The effects of temperature, pH and concentration of dichromate were further investigated, which revealed that CP 1 displays the best adsorption at 30 °C and pH 4 with a dichromate concentration of 200 mg L−1. The possible adsorption mechanism has been proposed with the aid of Hirshfeld surface analysis. [ABSTRACT FROM AUTHOR]

Two 3D coordination polymers based on dinuclear dianionic helicates, K2[MII2(L)3] M = MnII (1) and NiII (2), were obtained by slow liquid–liquid diffusion of solutions of 2-hydroxy-5-nitrobenzaldehyde, 4,4′-methylenedianiline, KOtBu and the metal salt at room temperature. The resulting dianionic triply stranded helicates self-assemble into novel 3D coordination polymers, in which the helicate units act as connectors. The assembly is promoted by the phenolate bridging ability and the coordination of the pre-organized NO2 groups to K–(O–N–O)4–K nodes, resulting in robust paramagnetic materials. SC-XRD shows that the metal centers are located 11.257(2) and 11.264(1) Å apart. The Mn–L bond lengths correspond to the high-spin (HS, S = 5/2) state for 1. The magnetic behavior for both complexes shows weak magnetic exchange, as expected due to the spin carrier separation, and the confirmation of the HS-sate for the MnII centers. For complex 1, an antiferromagnetic exchange is detected, whereas for complex 2, a mixture of intramolecular antiferromagnetic and intermolecular ferromagnetic exchanges are detected. Thus, we demonstrated that nitro groups can be used for the stabilization of anionic complexes because coordination to K+ results in stable intricate architectures. [ABSTRACT FROM AUTHOR]

Two 5-nitroisophthalate (NIPA) based cobalt(II) coordination polymers [Co(4-ABPT)(NIPA)(H2O)3], SSICG-6 (4-ABPT = 3,5-di(pyridine-4-yl)-4H-1,2,4-triazol-4-amine, SSICG stands for solid-state and inorganic chemistry group) and [Co(4-ABPT)(NIPA)(H2O)], SSICG-7, have been synthesized using a mixed ligand approach. Strategic utilization of H2NIPA enables tunability in framework formation and generates coordinated water containing coordination polymers. The –NO2 group in H2NIPA is unlikely to bind directly with metal ions but draws solvent molecules near the metal center via H-bonding. The coordinated water molecules in SSICG-6 and 7 are reversible in nature, resulting in unsaturated metal centers that serve as excellent heterogeneous catalysts in CO2 cycloaddition and tone-pot Hantzsch condensation reactions. The near quantitative conversion of epichlorohydrin into its corresponding carbonate compound was successfully accomplished, employing SSICG-6 as a catalyst under solvent-free conditions. The unique coordination characteristics of SSICG-6 enhance its catalytic efficiency for larger substrates in CO2 cycloaddition reactions compared to other one-dimensional polymers. [ABSTRACT FROM AUTHOR]

Herein, we report two autologous phosphates for electrocatalytic water oxidation. Although they have many similarities, the four-coordinated Co sites in Co3(PO4)2 showed higher activity than the six-coordinated Co sites in Co3(OH)2(HPO4)2. This was because the four-coordination CoII possessed a high turnover frequency and could be easily transformed into high-valent active cobalt (hydr)oxide species. [ABSTRACT FROM AUTHOR]

Developing high performance noble-metal-free electrocatalysts as an alternative to Pt-based catalysts for the oxygen reduction reaction (ORR) in energy conversion devices is highly desirable. We report herein the preparation of a coordination-polymer (CP)-derived Fe/CP/C composite as an electrocatalyst for the ORR with excellent activity and stability both in solution and in Zn-air batteries. The Fe/CP/C catalyst was obtained from the pyrolysis of an iron porphyrin Fe(TPP)Cl (5,10,15,20-tetraphenyl-21H, 23H-porphyrin iron(III) chloride) grafted Zn-coordination polymer with dangling functional groups 4,4'-oxybisbenzoic acid and 4,4'-bipyridine ligands. The Fe/CP/C catalyst showed much higher ORR activity with a half-wave potential (E1/2) of 0.90 V (vs. RHE) than the Fe/C catalyst (E1/2 = 0.85 V) derived from the carbon-blacksupported Fe porphyrins in 0.1 M KOH solution. When Fe/CP/C was used as the cathode electrocatalyst in Zn-air batteries (ZABs), the ZABs achieved a significantly higher open circuit voltage (OCV = 1.43 V) and maximum power density (Pmax = 142.8 mW cm-2) compared with Fe/C (OCV = 1.38 V, Pmax = 104.5 mW cm-2) and commercial 20 wt% Pt/C (OCV = 1.41 V, Pmax = 117.6 mW cm-2). Using dangling functional groups in CP to increase the loading efficiency of iron porphyrins offered a facile method to prepare high-performance noble-metal-free electrocatalysts for the ORR, which may provide promising applications to energy conversion devices. [ABSTRACT FROM AUTHOR]

A series of two-dimensional (2D) spin-crossover coordination polymers (SCO-CPs) [FeII(TPE)(NCX)2]·solv (1: X = BH3, solv = H2O·2CH3OH·DMF; 2: X = Se, solv = H2O·2CH3OH·0.5DMF; 3: X = S, solv = H2O·2CH3OH·0.5DMF) were synthesized by employing 1,1,2,2-tetra(pyridin-4-yl)ethene (TPE) and pseudohalide (NCX-) coligands. Magnetic measurements indicated that complexes 1-3 exhibited SCO behaviors with diminishing thermal hysteresis (7/4/0 K) upon decreasing the ligand-field strength. The critical temperatures (Tc) during spin transition were found to be inversely proportional to the coordination ability parameters (a™) with a linear correlation. The guest effect was also investigated in the solvent-exchanged phases 1-SE/2-SE/3-SE wherein the DMF molecules were replaced by methanol molecules. Compared with 1-3, 1-SE/2-SE/3-SE displayed more abrupt and complete single-step SCO behaviors but narrower thermal hysteretic loops. The results reported here demonstrate that the Tc values of these two families were dominated by the ligand-field strength of the NCX- anions (NCBH3 > NCSe > NCS), whereas the guest effect only modulated the kinetic factor of the SCO nature in this system. [ABSTRACT FROM AUTHOR]

A novel series of one-dimensional coordination polymers (CPs) is achieved via a facile one-pot synthesis strategy employing the nitrate salts of trivalent lanthanides, a pentadentate chelating ligand, and triphenylphosphine oxide at a controlled stoichiometry under ambient conditions. All the CPs are characterized comprehensively using spectroscopic, X-ray crystallographic and magnetometric studies. The CPs are found to be thermally stable up to a significantly high temperature and resistant to water for an indefinite time. They are photoactive and exhibit selective fluoride ion (F-) sensing with excellent efficiency both colorimetrically and fluorimetrically in the solid-state as well as in solution. The presence of F- concomitantly sensitizes the photoluminescence enhancement and visual decolourization of the CPs in solution owing to the ground-state intra-molecular proton transfer. The photophysical response of the CPs to F- in solution was found to be instantaneous (<30 s). The sensitivity of detection is observed to be significantly high over a wide range of F- concentrations, covering the beneficial and detrimental domains of F- concentrations in drinking water. The limit of detection (LoD) under ambient conditions was found to be in the micromolar (µM) range--the best being 0.22 µM found using UV-vis spectrometry and 7.5 µM using fluorimetry. In comparison, the USEPA standard cut-off for the upper limit of F- concentration in drinking water is 211 µM, and the LoD of measuring F- concentration using the USEPA standard method using a fluoride-selective electrode is 26.3 µM. The CPs display markedly high selectivity toward F- with negligible-to-no interference from the commonly abundant ions (Cl-, Br-, I-, CH3CO2-, CO32-, SO42-,HPO42-, NH4+, Na+, K+, Mg2+, and Ca2+) in terms of UV-vis spectral change. Moreover, they also exhibit solid-state IR-spectrometric sensitivity towards F- under ambient conditions. [ABSTRACT FROM AUTHOR]

The construction of sulfur-incorporated cluster-based coordination polymers was limited and underexplored due to the lack of efficient synthetic routes. Herein, we report facile mechanochemical ways toward a new series of SFe3(CO)9-based dipyridyl-Cu polymers by three-component reactions of [Et4N]2[SFe3(CO)9] ([Et4N]2[1]) and [Cu(MeCN)4][BF4] with conjugated or conjugation-interrupted dipyridyl ligands, 1,2-bis(4-pyridyl)ethylene (bpee), 1,2-bis(4-pyridyl)ethane (bpea), 4,4'-dipyridyl (dpy), or 1,3-bis (4-pyridyl)propane (bpp), respectively. X-ray analysis showed that bpee-containing 2D polymers demonstrated unique SFe3(CO)9 cluster-armed and cluster-one-armed coordination modes via the hypervalent µ5-S atom. These S-Fe-Cu polymers could undergo flexible structural transformations with the change of cluster bonding modes by grinding with stoichiometric amounts of dipyridyls or 1/[Cu(MeCN)4]+. They exhibited semiconducting behaviors with low energy gaps of 1.55-1.79 eV and good electrical conductivities of 3.26 × 10-8-1.48 × 10-6 S cm-1, tuned by the SFe3(CO)9 cluster bonding modes accompanied by secondary interactions in the solid state. The electron transport efficiency of these polymers was further elucidated by solidstate packing, X-ray photoelectron spectroscopy (XPS), X-ray absorption near-edge spectroscopy (XANES), density of states (DOS), and crystal orbital Hamilton population (COHP) analysis. Finally, the solid-state electrochemistry of these polymers demonstrated redox-active behaviors with cathodically-shifted patterns compared to that of [Et4N]2[1], showing that their efficient electron communication was effectively enhanced by introducing 1 and dipyridyls as hybrid ligands into Cu+-containing networks. [ABSTRACT FROM AUTHOR]

Reactions between 1,2-di(tetrazol-2-yl)ethane (ebtz), 1,6-di(tetrazol-2-yl)hexane (hbtz) or 1,1′-di(tetrazol-1-yl)methane (1ditz) and Fe(BF4)2 in the presence of adiponitrile (ADN), glutaronitrile (GLN) or suberonitrile (SUN) resulted in the formation of coordination polymers [Fe(μ-ebtz)2(μ-ADN)](BF4)2 (1), [Fe(μ-hbtz)2(μ-ADN)](BF4)2 (2), [Fe(μ-1ditz)2(GLN)2](BF4)2·GLN (3) and [Fe(μ-1ditz)2(μ-SUN)](BF4)2·SUN (4). It was established that the application of dinitriles allows an increase in the dimensionality of the ebtz and hbtz based systems while maintaining the structure of the polymeric units characteristic of previously studied mononitrile based analogues. In 3 and 4, regardless of the type of dinitrile coligand, the motif of 2D polymeric layers constituted by 1ditz molecules remains preserved. However, the dimensionality of 1ditz based networks is governed by the coordination modes of dinitriles. 3, based on a shorter molecule of glutaronitrile, crystallizes as a two-dimensional (2D) coordination polymer. In this compound, dinitriles coordinate monodentately or play the role of guest molecules. The substitution of glutaronitrile with suberonitrile enables the bridging of neighboring polymeric layers, resulting in a 3D network. The intentional selection of bis(tetrazoles) and dinitriles as building blocks has led, as expected, to obtaining systems with the structure of the first coordination sphere consisting of four tetrazole rings and two axially coordinated nitrile molecules. It created the conditions required for the occurrence of thermally induced spin crossover. Magnetic measurements and single crystal X-ray diffraction studies were used for the characterization of the spin crossover properties of 1–4. [ABSTRACT FROM AUTHOR]

Four salts of an anionic iron(III) bis-complex, [Fe(L L -thr)2]1−, were synthesized from water or methanol. H2L L -thr is a tridentate ligand derived from the L -threonine amino acid, and the cations used are Li+ (1), Na+ (2), K+ (3), and Ba2+ (4). Single-crystal X-ray diffraction showed that all the complexes are coordination polymers of different dimensionalities. The iron(III) complex binds to cations through its coordinated phenolate and non-coordinated carboxylate oxygen atoms. While Li+ forms a linear chain, all others have a pair of bridged cations intervening the iron(III) complexes. The 3D network of Ba2+ salt has a sizeable solvent-accessible space occupied by aquated chloride ions. The differences in circular dichroism (CD) spectra and significantly lower conductance values in water and methanol support partial retention of the polymeric nature in methanol. The visible spectra of 4 in methanol or water showed an ∼10 nm shift of the charge transfer bands from 3. However, the addition of Al3+ salt to 2 showed a significant colour shift. Further investigation confirmed that the colour shift is due to partial protonation of the complex with protons generated from salt hydrolysis. Most reports on visual aluminium detection consider aluminium's binding as the shift's source. The present results show that protonation due to hydrolysis of aluminium salt can skew the observation. [ABSTRACT FROM AUTHOR]

The construction of multifunctional metal-organic frameworks (MOFs) has attracted considerable attention. Two novel Dy-MOFs namely [Dy2(TPTC-2OMe)1.5(H2O)4·H2O]n (1) and {[Dy2(TPTC-2OMe)(H2TPTC-2OMe) (H2O)2]·2H2O}n (2) were obtained by a solvothermal method using 2′,5′-dimethoxy-[1,1′:4′,1″-terphenyl]- 4,4″-dicarboxylic acid (H4TPTC-2OMe) as the ligand. Structure analysis demonstrates that both MOFs 1 and 2 displayed three-dimensional framework structures, in which MOF 1 was with Dy(III) metal chains as nodes, while MOF 2 was with Dy2 binuclear metal clusters as nodes. Interestingly, MOFs 1 and 2 exhibited high thermal and chemistry stabilities and presented relatively high proton conductivity (σ) values of 1.69 × 10-4 S cm-1 and 3.52 × 10-6 S cm-1 at 50 °C and 98% RH. Although there exist a large number of coordinated or free H2O molecules in both structures, it is easier to form an ordered hydrogen-bonding network between the coordinated H2O molecules in the structure of MOFs, resulting in a more excellent proton conductivity of MOF 1. Moreover, MOF 1 exhibited field-induced single-molecule magnet (SMM) behavior with energy barriers (Ueff) of 37.22 K (τ0 = 9.27 × 10-8 s). Furthermore, MOF 1 exhibits obvious second-order nonlinear optical properties. This research provides guidance for the design of novelty multifunctional MOF materials. [ABSTRACT FROM AUTHOR]

A semi-flexible imidazole-based urea ligand, 1-(3-(1H-imidazol-1-yl)propyl)-3-phenylurea, and three zincdicarboxylate coordination polymers possessing the ligand were synthesized and characterized. The stoichiometry and coordination number of the zinc(II) ions in the coordination polymers were found to be dependent on the positional isomers of the benzene dicarboxylate. The 1,3-benzenedicarboxylate-based coordination polymer has a one-dimensional structure, whereas, the one possessing 1,4-benzenedicarboxylate has a two-dimensional architecture. The solvent used in the synthesis of the zinc-1,3-benzenedicarboxylate coordination polymer with the ligand played a decisive role on the solvation and conformation of the ligand. The anhydrous form was obtained from a reaction in methanol in which one of the urea moieties has a puckered geometry and the assembly has layers from one-dimensional bunches of coordination chains. However, the same reaction in ethanol provided a solvate having water and ethanol as the solvents of crystallization and it has the two ligands with a stretched geometry forming a cleft-like geometry to include the ethanol molecules. The two forms were not inter-convertible. The coordination polymer with 1,4-benzenedicarboxylate has a 2-dimensional structure with 2 × 2 grids having self-included urea that held DMF molecules by hydrogen bonds. [ABSTRACT FROM AUTHOR]

Through a room temperature reactant diffusion strategy, two coordination polymers [Zn(bpycz)Cl2]n (1) and [Zn(bpycz)Br2]n (2) were obtained from 3,6-bis(pyridin-3-yl)-9H-carbazole (bpycz) and the corresponding zinc halides. Single-crystal structural analysis revealed that the Zn(II) center suited a tetrahedral geometry in both 1 and 2, whereas the bpycz ligand adopted an anti,anti conformation in 1 but a syn,syn conformation in 2. As a result, coordination polymer 1 exhibited a wavelike chain structure with an arch bridge manner, whereas 2 also revealed a wavelike chain structure but with a sine wave manner. The differences in the ligand coordination mode and chain structure were most likely due to the influence of halide anions (Cl− in 1 and Br− in 2) with different sizes. X-ray powder diffraction (XRPD) proved that 1 and 2 were highly stable in H2O and various organic solvents, as well as over large pH ranges of 2–13 and 3–11, respectively, for 24 h. Thermogravimetric (TG) analysis confirmed that 1 and 2 have high thermal stability approaching 420 °C and 425 °C, respectively. Upon excitation, 1 and 2 emitted fluorescence at 420 and 412 nm, respectively, in the solid state and at 431 and 433 nm, respectively, in the suspension phase in water. The fluorescence of 2 dispersed in water could be obviously quenched by 4-aminobenzylamine (4-ABA) with a high quenching efficiency, excellent selectivity, and good sensitivity as well as a low limit of detection (LOD, 2.52 μM−1), indicating its potential as a fluorescence turn-off sensor material. Possible sensing mechanisms were explored, suggesting that the photoinduced electron-transfer process might be responsible for the quenching response. [ABSTRACT FROM AUTHOR]

It is attractive but challenging to develop a cocatalyst for CO2/cyclohexene oxide (CHO) copolymerization with a double metal cyanide (DMC) catalyst. In this study, we synthesized three coordination polymers (CPs) [Cd(3N3PY)(NDC)]·0.58H2O (1), [Zn(3N3PY)(IPA)]·3H2O (2) and [Cd(3N3PY)(NPA)]·2DMF·2H2O (3) (3N3PY = 4′-(4-(1H-1,2,4-triazol-1-yl)phenyl)-2,2′:6′,2′′-terpyridine, H2NDC = 2,6-naphthalene dicarboxylic acid, H2IPA = isophthalic acid, H2NPA = 2,2′-dinitro-4,4′-biphenyldicarboxylic acid). Crystal structural analyses show that 1–3 are different one-dimensional (1D) chains that further assemble into three-dimensional (3D) supramolecular structures by π–π and hydrogen bonding interactions. CPs 1–3 were applied as cocatalysts to assist DMC for CO2/CHO copolymerization and the efficient proportion of carbonate P–OC(O)O– in the product is 59% achieved for 2 at 80 °C in 1 MPa CO2. The proportion of carbonate F(CO2) and conversion rate of CHO (CCHO) are 63% and 93%, respectively. The mechanistic study on structure–activity relationship and chemoselectivity was performed. [ABSTRACT FROM AUTHOR]

Herein, we report an efficient and straightforward approach for the synthesis of N-alkylated aminoquinoline derivatives by recyclable Cd-containing coordination polymer-catalyzed reactions of aminoquinolines with primary alcohols via the borrowing hydrogen strategy. In this work, a new type of coordination polymer [Cd(CIA)(phen)2(H2O)]n was successfully designed and fabricated. The molecular structure was corroborated by single-crystal X-ray diffraction and fully characterized by PXRD, FT-IR, TGA, and XPS. Importantly, this polymer revealed high catalytic activity for the N-alkylation reaction of 2-aminoquinoline and 8-aminoquinoline with inexpensive and low-toxicity alcohols as alkylating agents in excellent yields up to 95%. Interestingly, the present synthetic protocol was successfully applied for the gram-level synthesis of several biologically active compounds. In addition, several control reactions were carried out to investigate the possible mechanisms of this transformation. Finally, recycling experiments indicated that the cadmium coordination polymer showed good recovery performance for borrowing hydrogen reactions. [ABSTRACT FROM AUTHOR]

The accurate and rapid detection of antibiotics and heavy-metal-based toxic oxo-anions in water media employing coordination polymers (CPs) as luminescent probes has attracted a lot of attention. Three new Cd(II)-based ternary CPs derived from first-presented L ligands, including [Cd(DCTP)(L)(OH)]n (1), [Cd(TBTA)(L)(OH)]n (2), and [Cd(NPHT)(L)(H2O)]n (3) (L = 2-((1H-imidazol-1-yl)methyl)-5,6-dimethyl-1H-benzo[d]imidazole, H2DCTP = 2,5-dichloroterephthalic acid, H2TBTA = tetrabromoterephthalic acid and H2NPHT = 3-nitrophthalic acid), were successfully assembled and characterized. 1 and 2 show 2D hcb layers, which can be further extended into a 3D supramolecular framework via classic hydrogen bonding interactions. 3 features a 1D double chain that ultimately spreads into a 2D network through weak hydrogen bonding interactions. With the advantages of high stability and excellent luminescent properties, the three CPs display high sensitivity, selectivity, and good anti-interference for the sensing of pefloxacin (PEF) and Cr2O72− ions (LOD values toward PEF: 3.82 × 10−7 mol L−1 for 1, 4.06 × 10−7 mol L−1 for 2, and 1.36 × 10−8 mol L−1 for 3, and toward Cr2O72− ions: 5.97 × 10−7 mol L−1 for 1, 5.87 × 10−7 mol L−1 for 2, and 8.21 × 10−8 mol L−1 for 3). These CPs are the first examples of bifunctional luminescent sensors to detect PEF and Cr2O72− in aqueous solutions. The luminescence quenching mechanisms are explored in detail. [ABSTRACT FROM AUTHOR]

The adjustment of crystal symmetry and intramolecular magnetic coupling is of great importance for the construction of high-performance single-molecule magnets. By using an aggregation-induced-emission-active pyridine-carbohydrazone-based Schiff base ligand and phosphine oxides, four dinuclear and one one-dimensional DyIII-based complexes, [Dy2(TPE-pc)2(Bu3PO)2Cl2]·2CH3CN·2H2O (1), [Dy2(TPE-pc)2(Cy3PO)2Cl2] (2), [Dy2(TPE-pc)2(MePA)2Cl2]·2CH3OH (3), [Dy2(TPE-pc)2(Ph3PO)2Cl2]2 (4) and [Dy2(TPE-pc)2(DPPO)Cl2]n (5) (H2TPE-pc = (E)-N′-(2-hydroxy-5-(1,2,2-triphenylvinyl)benzylidene)picolinohydrazide, MePA = N-phenyl-N′,N′′-bis(morpholinyl) phosphoric triamide, DPPO = piperazine-1,4-diylbis(diphenyl phosphine oxide)), were isolated. All complexes are made up of an enol oxygen-bridged Dy2 unit, where DyIII ions possess a pentagonal bipyramidal geometry with pseudo D5h symmetry. Magnetic measurements reveal that intramolecular DyIII–DyIII couplings are ferromagnetic and all complexes display a significant slow magnetic relaxation phenomenon below 30 K under a zero dc field. Ab initio calculations indicate that the anisotropic magnetic axes of all DyIII ions are approximately perpendicular to the higher-order symmetric axes in all complexes, and that DyIII–DyIII magnetic couplings along the magnetic axes effectively suppress the ground state quantum tunneling effect of magnetization and promote the occurrence of slow magnetic relaxation. Raman relaxation prevails in all complexes. In addition, the H2TPE-pc ligand shows an aggregation-induced emission (AIE) effect; however, all complexes exhibit an aggregation-caused quenching (ACQ) phenomenon. [ABSTRACT FROM AUTHOR]

The construction and investigation of dual-functional coordination polymers (CPs) with proton conduction and luminescence sensing is of great significance in clean energy and agricultural monitoring fields. In this work, an Mn-based coordination polymer (Mn-CP), namely, [Mn0.5(HL)] (H2L = HOOCC6H4C6H4CH2PO(OH)OCH3), was hydrothermally synthesized. Mn-CP has a one-dimensional (1D) chain structure, in which uncoordinated –COOH groups can serve as potential sites for fluorescence sensing. Moreover, Mn-CP shows good water and pH stabilities, offering the feasibility for proton conduction and sensing applications. Mn-CP displays comparatively high proton conductivity of 1.07 × 10−4 S cm−1 at 368 K and 95% relative humidity (RH), which is promising for proton conduction materials. Moreover, it can serve as a repeatable, highly selective, and visualized fluorescence sensor for detecting oxytetracycline (OTC). More importantly, Mn-CP reveals an amazing quantitative sensing of OTC in actual samples such as seawater, aquaculture freshwater, soil infiltration solutions, and tap water. This work proves the excellent application potential of dual-functional CPs in the field of clean energy and environmental protection, especially for the fluorescence detection of antibiotics in aquaculture systems. [ABSTRACT FROM AUTHOR]

Smart chromic materials reacting to physicochemical stimuli are widely applied in optical switches, smart windows, and chemical sensors. Currently, most materials only respond to a single stimulus, but those that respond to multiple external stimuli are still in the minority. Herein, we report a novel porous zinc tungstate@metaloxoviologen framework [Zn3(Bcbpy)6(H2O)2]-[ZnW12O40]·6H2O (ZnW12@MV, H2BcbpyCl2 = 1,1′-bis(3-carboxybenzyl)-4,4′-bipyridinium dichloride), which shows multiple stimulus-responsive properties due to a combination of different functional motifs, namely, viologen electron acceptors, luminescent zinc–oxygen-clusters, porous cationic frameworks, and ZnW12O406− electron donors. Generally, the large-sized polyoxometalate (POM) anions serving as structure-directing agents can easily direct the formation of the oligomeric metaloxoviologen cations, mainly because POMs may break down some linkages leaving larger spaces for themselves. The large ZnW12O406− anions in ZnW12@MV are encapsulated into three-dimensional (3D) metaloxoviologen frameworks built up from the linkages of trinuclear zinc–oxygen clusters and Bcbpy viologens, which offer the first example of a 3D metaloxoviologen framework induced by large-sized POM anions. ZnW12@MV shows a reversible chromic response to X-ray/UV and electricity via different stimulus-induced electron transfers between electron-rich POM anions and electron-deficient metaloxoviologen frameworks, whereas the coloration changes are ascribed to the formation of radical and mixed-valence colored state ZnW12O406− species. The photochromic behavior is accompanied by photoluminescence quenching. The discriminative response to different-sized amines is attributed to the formation of viologen radicals through host–guest electron transfer. These results indicate that the multi-stimulus response ZnW12@MV can be applied in electrochromic devices, inkless erasable printing, and the detection of amines. [ABSTRACT FROM AUTHOR]

A new iodine-rich imidazole derivative 1,4-bis(4,5-diiodo-1H-imidazol-1-yl)butane (bimbI4, 1) features multiple I⋯I interactions in the solid state. Using 1 as a precursor, we prepared 1D and 2D coordination polymers of Co(II) and Cu(I) – {[Co(bimbI4)Cl2]·1.5DMF}n (2) and {[Cu2I2(bimbI4)]}n (3), respectively, also featuring extended systems of halogen bonds within their structures. [ABSTRACT FROM AUTHOR]

Three new PbII complexes [Pb(LI)(SCN)]n, {[Pb(LII)](SCN)}n and {[Pb(HLIII)(SCN)](SCN)}n (HLI = N′-phenyl(pyridin-2-yl)methylene-N-phenylthiosemicarbazide, HLII = N′-amino(pyrazin-2-yl)methylenethiosemicarbazide, HLIII = N′-amino(pyridin-2-yl)methylenethiosemicarbazide) have been synthesized and characterized by spectroscopic techniques and single crystal X-ray diffraction. In all complexes, the corresponding organic ligand behaves as a tridentate N,N′,S-chelating species. A 1D supramolecular polymeric aggregation in complex [Pb(LI)(SCN)]n is dictated by the Pb⋯NCS and Pb⋯S＝C tetrel bonds formed between the [Pb(LI)(SCN)] species. 1D cationic coordination polymers ([Pb(LII)])nn+ in the structure of complex {[Pb(LII)](SCN)}n are linked into a 2D supramolecular polymeric layer through the Pb⋯NCS tetrel bonds and Pb⋯π(NCS) interactions formed with the nitrogen atom and the conjugated system of the free SCN− anions, respectively. The cationic species [Pb(HLIII)(SCN)]+ in the structure of complex {[Pb(HLIII)(SCN)](SCN)}n produce a 1D supramolecular polymer due to the Pb⋯SCN and Pb⋯S＝C tetrel bonds, further stabilized by the Pb⋯π(NCS) interactions formed with the conjugated system of the coordinated NCS− anion. The latter anions also link these 1D chains through the Pb⋯SCN tetrel bonds, yielding 1D supramolecular polymeric ribbons. The energetic relevance of the Pb⋯S and Pb⋯N tetrel bonds has been studied by DFT calculations. The tetrel bonds have been characterized using QTAIM and NCIplot analysis and rationalized using molecular electrostatic potential surface calculations. [ABSTRACT FROM AUTHOR]

An enlarged version of the ubiquitous tetrathiafulvalene-tetrabenzoic acid is described, with 4,4′-biphenyl moieties as spacers between the coordination moieties and the electroactive core. The obtained rectangular ligand has a 14 × 22 Å2 size and is combined with Zn(II) under solvothermal conditions to yield a coordination polymer endowed with large cavities of ca. 15 × 11 Å2/10 × 10 Å2. The topology of the material is discussed in detail using the Points of Extension and Metals (PE&M) or the Straight-rod (STR) representation, and the sqc1121 or tfo topological type of the structure is observed, respectively. Its stability towards solvent removal and electrical properties are discussed. The material does not present any permanent porosity upon desolvation according to nitrogen sorption measurements at 77 K. Nevertheless, a significant increase in conductivity is observed on compressed pellets of the material upon post-synthetic oxidation with iodine. Raman spectroscopy combined with density functional theory (DFT) calculations has been used to characterize the oxidation state of tetrakis(4-carboxylic acid biphenyl)tetrathiafulvalene for coordination polymers. [ABSTRACT FROM AUTHOR]

Coordination polymers are a sub-class of coordination complexes that possess unique opto-electronic properties and hence can be utilized for a wide range of applications such as sensing and photocatalysis. Herein, four new coordination polymers (CPs) with formula [Mn2(HL)(NMP)(H2O)2]n (1), [Mn2(HL)(DMA)2(H2O)·2DMA]n (2), [Mn(H3L)(H2O)2]n (3) and [Mn(H3L)(H2O)(4,4′-bipy)]n (4) (H5L = 3,5-bis(3,4-dicarboxyphenoxy) benzoic acid and NMP = N-methyl pyrrolidone) were synthesized under hydrothermal conditions and characterized. The single-crystal X-ray analysis revealed a distorted octahedral geometry around Mn(II) in these CPs and that they form an extended hydrogen bonding and π⋯π stacking interaction-assisted network. Thermogravimetric studies revealed that the CPs, 1, 2, 3 and 4, have variable thermal stability in the range of 82–194 °C. All four complexes exhibited optical semiconducting behavior and hence were used as photocatalysts for the photodecomposition of antibiotics, including chloramphenicol (CAP), nitrofurazone (NFZ), ornidazole (ODZ), oxytetracycline (OXY) and sulfamethoxazole (SMT). Among the CPs, CP 2 exhibited an impressive 91.93% degradation of NFZ within 60 min. The plausible photocatalytic mechanism was explained with the assistance of Hirshfeld surface analysis. [ABSTRACT FROM AUTHOR]

Chemically and thermally stable permanently porous coordination cages are appealing candidates for separations, catalysis, and as the porous component of new porous liquids. However, many of these applications have not turned to microporous cages as a result of their poor solubility and thermal or hydrolytic stability. Here we describe the design and modular synthesis of iron and cobalt cages where the carboxylate groups of the bridging ligands of well-known calixarene capped coordination cages have been replaced with more basic triazole units. The resultingly higher M–L bond strengths afford highly stable cages that are amenable to modular synthetic approaches and potential functionalization or modification. Owing to the robust nature of these cages, they are highly processable and are isolable in various physical states with tunable porosity depending on the solvation methods used. As the structural integrity of the cages is maintained upon high activation temperatures, apparent losses in porosity can be mediated by resolvation and crystallization or precipitation. [ABSTRACT FROM AUTHOR]

A three-dimensional terbium(III) coordination polymer of formula [Tb(bttb)0.5(2,5-pzdc)0.5]n (1) [H4bttb = 1,2,4,5-tetrakis(4′-carboxyphenyl)benzene and H2-2,5-pzdc = 2,5-pyrazinedicarboxylic acid] was obtained under hydrothermal conditions. The bttb4− tetraanion in 1 adopts the bridging and chelating–bridging pseudo-oxo coordination modes while the 2,5-pzdc2− dianion exhibits a rather unusual bis-bidentate bridging pseudo-oxo coordination mode, both ligands being responsible for the stiffness of the resulting 3D structure. Solid-state photoluminescent measurements illustrate that 1 exhibits remarkable green luminescence emission, the most intense band occurring in the region of 550 nm (5D4 → 7F5) with lifetimes at the millisecond scale. Thermometric performances of 1 reveal a maximum relative sensitivity (Sm) of 0.76% K−1 at 295 K (δT = 0.05 K), constituting a TbIII ratiometric solid luminescent thermometer over the physiological temperature range. Variable-temperature static (dc) magnetic susceptibility measurements for 1 in the temperature range 2.0–300 K show the expected behavior for the depopulation of the splitted mJ levels of the 7F7 ground state of the magnetically anisotropic terbium(III) ion plus a weak antiferromagnetic interaction through the carboxylate bridges. No significant out-of-phase magnetic susceptibility signals were observed for 1 in the temperature range 2.0–10.0 K, either in the absence or presence of a static dc magnetic field. [ABSTRACT FROM AUTHOR]

trans-9,10-Dihydro-9,10-ethanoanthracene-11,12-dicarboxylic acid (deadcH2), in its racemic or R,R enantiomeric forms, has been used to synthesize eight uranyl ion complexes under solvo-hydrothermal conditions. [UO2(deadc)]·1.5CH3CN (1) and [H2NMe2]2[(UO2)2(deadc)3]·2H2O (2) crystallize as monoperiodic coordination polymers in which deadc2− forms both 4- and 7-membered chelate rings. Although synthesized in the same conditions as 2, the enantiomerically pure complex [H2NMe2]4[(UO2)2(O)(R,R-deadc)2]2 (3) is a discrete tetranuclear complex containing two μ3-oxo anions. Association with the zwitterion Ni(tpyc)2, where tpyc− is 2,2′:6′,2′′-terpyridine-4′-carboxylate, gives [(UO2)2(deadc)(deadcH)(NO3)Ni(tpyc)2]·CH3CN·2H2O (4), a rake-shaped monoperiodic assembly. [UO2(deadc)(DMA)] (5), [UO2(deadc)] (6) and [PPh4]2[(UO2)2(R,R-deadc)3] (7) crystallize as diperiodic networks with the fes, sql and hcb topologies, respectively, the thick layers formed being coated on both sides by protruding, hydrophobic dibenzobarrelene groups. Finally, [(UO2)2Ag2(deadc)3(CH3CN)2]·0.5H2O (8) contains monoperiodic uranyl–deadc2− subunits which are assembled into a triperiodic framework by bridging silver(I) cations, the latter interacting with both carboxylate groups and aromatic rings. Except for 6, all these complexes are emissive with photoluminescence quantum yields of 2–26%, and most spectra display the usual vibronic fine structure of uranyl emission. [ABSTRACT FROM AUTHOR]

Herein, we report the synthesis and photoluminescence properties of a new 1,3-dioxo-2-(1H-tetrazol-5-yl)-2,3-dihydro-1H-benzo[de]isoquinoline-6,7-dicarboxylic (H3L) ligand and three coordination polymers (CPs). Compound [Zn(ntca)DMF]n·DMF (1) (ntca2− = 1,4,5,8-naphthalenetetracarboxylate 1,8-monoanhydride, DMF = N,N-dimethylformamide) formed 1D coordination polymer chains packed by hydrogen bonding interactions. On its part, compounds namely [(CH3)2NH2](Zn2(μ-OH)(L)(5-NH2-tetrazolate)n·2H2O (2) and [(CH3)2NH2](ZnL)n (3) (where H3L stands for 1,3-dioxo-2-(1H-tetrazol-5-yl)-2,3-dihydro-1H-benzo[de]isoquinoline-6,7-dicarboxylic acid) crystallize as 2D-layered and 3D anionic frameworks containing dimethylammonium cations occupying the voids. Photoluminescence (PL) measurements have been performed in the solid state on all CPs and ligands to characterize their emission properties, including variable-temperature spectra, lifetime and efficiency. Moreover, the photophysical properties have been studied from the theoretical viewpoint by means of time dependent density functional theory (TD-DFT) in order to elucidate the mechanisms and electronic transitions governing the process. Compounds 1 and 3 present an intense blue luminescence which was originated in the electronic transitions of the ntca2− and the L3− ligands. Compound 2 displays a lower quantum yield which could be tentatively attributed to the weak π–π interactions of the aromatic clouds of L3− or the molecular vibrations and/or possible rotational motions of the 5-amino-tetrazolate co-ligand. [ABSTRACT FROM AUTHOR]

A new π-conjugated bridging-type dicarboxylic acid with a functional alkynyl group, 4,4′-(ethynylimino)bis[benzoic acid] (H2L), was designed and synthesized to construct a Zn(II)-based coordination compound [ZnL(dpa)]n (dpa = 4,4′-dipyridylamine). Compound 1 has two-dimensional layers with alkynyl groups protruding on each side of the layer. The introduction of the ligand dpa ensured the existence of uncoordinated nitrogen atoms. Through Hg⋯C (alkynyl group) and Hg⋯N (amino group) coordination interactions, 1 can effectively detect Hg2+ ions (Ksv = 1.34 × 104 M−1 and LOD = 3.75 × 10−4 mM) by fluorescence quenching. Meanwhile, for Fe3+, in addition to the coordination interactions between Fe3+ ions and the uncoordinated amino groups, competitive absorption was the major contributor to the fluorescence quenching of compound 1. Competitive absorption prompted the sensitive sensing of Fe3+ (Ksv = 3.09 × 104 M−1 and LOD = 1.94 × 10−4 mM) and 4-nitrophenol (Ksv = 7.46 × 104 M−1 and LOD = 4.32 × 10−4 mM). [ABSTRACT FROM AUTHOR]

It is important and challenging to design and construct coordination polymers (CPs) with special architectures and functions. In this study, a novel CP {[(H3O)2(Cd6L6SO4)]·3DMF}n (1) was synthesized using cadmium sulfate and the AIE ligand di(4-carboxyphenyl)-dibenzofulvene (H2L) through a solvothermal reaction with a one-dimensional bamboo-like architecture for the first time, which was constructed using a novel wheel-shaped [Cd6(COO)12SO4]2− cluster and angular L bridges. 1 has good water and thermal stabilities and can sensitively, selectively and cyclically detect TNP and MnO4− in an aqueous medium. In particular, the quenching constants of 1 reached 8.95 × 104 M−1 (TNP) and 1.10 × 105 M−1 (MnO4−), which were higher than those of most CP-based sensor materials. Moreover, the luminescent quenching sensing mechanisms of 1 towards TNP and MnO4− were explored. [ABSTRACT FROM AUTHOR]

In recent years, due to their tunable hierarchical architecture and wide versatility in applications, the synthesis of coordination polymers (CPs) has received wide attention from the scientific community. The present work focuses on the solvothermal synthesis of two novel lanthanoid CPs composed of gadolinium and dysprosium connected with 1H-pyrazole-3,5-dicarboxylic acid (1H-3,5-PDA) and benzene-1,4-dicarboxylic acid (1,4-BDC) linkers. The prepared materials were assessed using elemental analysis, SCXRD, FTIR, PXRD, thermogravimetric analysis and photoluminescence. The synthesized sensor (CP 2) is an efficient chemosensor for the detection of Fe3+ and meta-nitro aniline, thereby acting as a dual sensor. The material exhibits high quenching efficiencies of 98.25% and 98.11% towards the sensing at ppm-level concentrations of Fe3+ and m-NA, respectively. The Ksv values for the detection of Fe3+ and m-NA were found to be 3.76 × 104 L mol−1 and 2.5 × 104 L mol−1, respectively, which the confirm high and efficient sensing ability of the synthesized sensor. [ABSTRACT FROM AUTHOR]

Valence tautomerism (VT) involves the stimulated reversible intramolecular electron transfer between a redox-active metal and ligand. Dinuclear cobalt complexes bridged by bis(dioxolene) ligands can undergo thermally-induced VT with access to {CoIII-cat-cat-CoIII}, {CoIII-cat-SQ-CoII} and {CoII-SQ-SQ-CoII} states (cat2− = catecholate, SQ˙− = semiquinonate, CoIII refers to low spin CoIII, CoII refers to high spin CoII). The resulting potential for two-step VT interconversions offers increased functionality over mononuclear examples. In this study, the bis(dioxolene) ligand 3,3′,4,4′-tetrahydroxy-5,5′-dimethoxy-benzaldazine (thMH4) was paired with Mentpa (tpa = tris(2-pyridylmethyl)amine, n = 0–3 corresponds to methylation at 6-position of the pyridine rings) to afford [{Co(Mentpa)}2(thM)](PF6)2 (1a, n = 0; 2a, n = 2; 3a, n = 3). Structural, magnetic susceptibility and spectroscopic data show that 1a and 3a remain in the temperature invariant {CoIII-cat-cat-CoIII} and {CoII-SQ-SQ-CoII} forms in the solid state, respectively. In contrast, 2a exhibits incomplete thermally-induced VT between these two tautomeric forms via the mixed {CoIII-cat-SQ-CoII} tautomer. In solution, room temperature electronic absorption spectra are consistent with the assignments from the solid-state, with VT observed only for 2a. From electrochemistry, the proximity of the two 1e−-processes for the thMn− ligand indicates weak electronic communication between the two dioxolene units, supporting the potential for a two-step VT interconversion in thMn− containing complexes. Comparison of the redox potentials of the Co and thMn− processes suggests that only 2a has these processes in sufficient proximity to afford the thermally-induced VT observed experimentally. Density functional theory calculations are consistent with the prerequisite energy ordering for a two-step transition for 2a, and temperature invariant {CoIII-cat-cat-CoIII} and {CoII-SQ-SQ-CoII} states for 1a and 3a, respectively. This work presents the third example, and the first formally conjugated example, of a bridging bis(dioxolene) ligand that can afford two-step VT in a Co complex, suggesting new possibilities towards applications based on multistep switching. [ABSTRACT FROM AUTHOR]