CH3OH Solution Research Articles

Simultaneous Fabrication of P and M Helices in One‐component Chiral System by Methanol‐Water Mediated Dual Assembly Pathway

The synergetic evolution of multiple chiral structures stemmed from same building units is ubiquitous in nature and vital to living systems, but achieving it in artificial systems remains a challenge. Herein, we report a methanol‐water mediated dual assembly pathway strategy for simultaneous construction of P and M helices in one‐component chiral system. The conformation of l‐phenylaniline derivates (LBpyF) is controlled to folded state in CH3OH due to the hydrogen bonds as well as C‐H···π interaction between LBpyF and CH3OH. Addition of H2O into above CH3OH solution of LBpyF results in the simultaneous occurrence of two self‐assembly pathways and double networks of P and M helices were therefore formed, due to the synchronous process of 1) self‐assembly of folded LBpyF into M‐helices and 2) H2O induced unfolding of folded LBpyF molecules followed by self‐assembly of them into P‐helices. The bipyridine core, phenyl ring, amide unit all adapted into different stacking modes in M‐helices and P‐helices, and energy analysis indicated that the minority M‐helices were more thermodynamically favored products. This study provides an approach to explore synergetic evolution of multiple chiral structures by manipulating the multiple assembly pathway.

Construction of Mo/S/Ag Cluster Complexes from Dinuclear Molybdenum Precursors [R4N]2[(edt)2Mo2S2(μ‐S)2] (R = Et, nPr; edt = −SCH2CH2S−)

AbstractWe have demonstrated that complexes [(edt)2Mo2O2(μ‐S)2Ag2(dppm)2]·4CH3OH·DMF (2, edt = 1,2‐ethanedithiolate dianion, dppm = bis(diphenylphosphino)methane, DMF = N,N‐dimethylformamide) and [(μ‐Cl)2Ag4(μ3‐Cl)2(dppm)2]·4DMF (3), were generated by combining a dinuclear molybdenum precursor [Et4N]2[(edt)2Mo2S2(μ‐S)2] (1a) with two equimolar AgCl and dppm in a CH3OH‐DMF mixed solution. Treatment of complex 1a with one equimolar AgCl and DPEPhos in CH3OH and DMF mixed solutions, producing complex [Et4N][(edt)2Mo2S2(μ‐S)2Ag(DPEPhos)]·CH3OH (4, DPEPhos = bis(2‐diphenylphosphinophenyl)ether). Treatment of complex [nPr4N]2[(edt)2Mo2S2(μ‐S)2] (1b) with AgBr in acetonitrile followed by addition of (NH4)2S produced a dodecanuclear Mo–Ag–S cage cluster [nPr4N]2[{Mo2Ag2S2O2(edt)2}3(μ6‐S)]·1.5CH3CN (5). Complexes 2−5 have been characterized by infrared(IR), 1H NMR, UV‐vis, and fluorescence spectroscopies. Moreover, molecular structures of complexes 2−5 have been established by single‐crystal X‐ray crystallography.

Triply Interlocked [2]catenanes: Rational Synthesis, Reversible Conversion Studies and Unprecedented Application in Photothermal Responsive Elastomer

AbstractTriply interlocked [2]catenane complexes featuring two identical, mechanically interlocked units are extraordinarily rare chemical compounds, whose properties and applications remain open to detailed studies. Herein, we introduce the rational design of a new ligand precursor, L1, suitable for the synthesis of six triply interlocked [2]catenanes by coordination‐driven self‐assembly. The interlocked compounds can be reversibly converted into the corresponding simple triangular prism metallacage by addition of H2O or DMF solvents to their CH3OH solutions, thereby demonstrating the importance of π⋅⋅⋅π stacking and hydrogen bonding interactions in the formation of triply interlocked [2]catenanes. Moreover, extensive studies have been conducted to assess the remarkable photothermal conversion performance. Complex 6 a, exhibiting outstanding photothermal conversion performance (conversion efficiency in solution : 31.82 %), is used to prepare novel photoresponsive elastomer in combination with thermally activated liquid crystal elastomer. The resultant material displays robust response to near‐infrared (NIR) laser and the capability of completely reforming the shape and reversible actuation, paving the way for the application of half‐sandwich organometallic units in photo‐responsive smart materials.

Tailoring Spinel with Perovskite: Sr Substitution in the Perovskite Phase of CoFe2O4–LaCoO3 Nanocomposite for Oxygen Evolution and Methanol Oxidation in Alkaline Medium

CoFe2O4–La1−xSrxCoO3 (x = 0.2, 0.6, 0.8) composites have been synthesized using a two‐step, low‐temperature wet chemical approach that combines coprecipitation and sol–gel techniques. The composite materials have been physicochemically analyzed using Fourier‐transform infrared spectroscopy, X‐ray diffraction, and scanning electron microscope. The electrocatalytic properties of the composite materials have been assessed in terms of their performance in oxygen evolution reaction (OER) and methanol oxidation reaction (MOR) in alkaline medium. Cyclic voltammetry has been used for analyzing the redox behavior of the materials in 1 M KOH solution. The electrocatalytic activity of the materials has been assessed using anodic polarization curves on Ni substrate and the CoFe2O4–La0.2Sr0.8CoO3 film electrode demonstrates excellent activity, with current densities of 11.1 mA cm−2 for OER and 47.4 mA cm−2 for MOR at 650 mV. Also, the CoFe2O4–La0.2Sr0.8CoO3 film electrode has the maximum specific activity of 1.1 × 103 mA cm−2 g−1 at 650 mV toward OER. The electrodes’ stability has been assessed through chronoamperometric experiments and additional insight into the enhancement of electrocatalytic activity gained through the electrochemical surface area estimations using electrochemical impedance spectroscopy. From chronoamperometric experiment, it has been observed that the CoFe2O4–La0.2Sr0.8CoO3 film electrode attains stability within 114 s with a current density of 108.7 mA cm−2. Furthermore, the thermodynamic parameters, including the standard enthalpy of activation (ΔH°#), standard entropy of activation (ΔS°#), and standard electrochemical energy of activation (), have been estimated by anodic polarization curve recorded in KOH as well as KOH with CH3OH solutions at various temperatures.

TS-1 zeolite encapsulated Pt clusters with enhanced electronic metal-support interaction of Pt−O(H)−Ti for nearly-zero-carbon-emitting photocatalytic hydrogen production from methanol

Photocatalytic H2 production from methanol is sustainable, yet challenges remain in avoiding carbon-containing gaseous by-products. Titanium silicalite-1 (TS-1) zeolite possesses attractive photocatalytic performance, but lack of modification strategies due to its microporous framework. Herein, we developed a pre-anchoring strategy to confine ultra-small Pt clusters inside TS-1 with ultra-low loading (0.2 mol%), in which Pt were anchored in Ti−OH nests by electronic metal-support interaction (EMSI). The optimal catalyst achieved a remarkable H2 generation rate of 63.2 mmol g–1 h–1 in CH3OH solutions, along with the production of high-value chemical HCHO as the oxidation product with 96.9% selectivity. Investigations reveal that the EMSI between Pt and Ti facilitated the selective decomposition of CH3OH to H2 and HCHO, leading to a nearly zero-carbon-emission process. Accordingly, we propose a light-driven carbon-negative "CO2→CH3OH→H2" route, coupling CO2 utilization and green H2 production with CH3OH as the intermediate, therefore offering a new perspective for "liquid sunshine".

B doped cobalt-nickel bimetallic phosphide as bifunctional catalyst for ethanol oxidation reaction and hydrogen evolution reaction

The ethanol oxidation reaction (EOR) is an ideal alternative to the oxygen evolution reaction (OER) towards energy efficient hydrogen production. Here, the chrysanthemum-shaped B doped cobalt-nickel bimetallic phosphide with heterogeneous structure grown on nickel foam (B-Ni2P/CoP/NF) are synthesized and can act as a high activity bifunctional electrocatalysts for both the hydrogen evolution reaction (HER) and EOR. In 1.0 M KOH, the obtained catalyst shows good activity and excellent long-term stability (no decay after 108 h) for HER, with an overpotential of only 33 mV (vs. RHE) to reach a current density of 10 mA cm−2. The calculation of turnover frequency (TOF) and transfer coefficient (β) prove that the catalyst has good intrinsic catalytic activity, For EOR, in 1.0 M KOH+1.0 M C2H5OH solution, the B-Ni2P/CoP/NF catalyst requires only 1.45 V (vs. RHE) oxidation potential to reach the current density of 50 mA cm−2, which is 270 mV less than OER. Using B-Ni2P/CoP/NF as a bifunctional catalyst, the current density of 20 mA cm−2 can be achieved with only 1.48 V cell voltage in 1.0 M KOH+ 1.0 M C2H5OH solution, which is remarkably lower than the required cell voltage of water electrolysis (1.63 V) to achieve the same current density. This study demonstrates an efficient bimetallic phosphide as earth-abundant bifunctional electrocatalysts for green hydrogen production coupled with electrolysis of ethanol.

Mixing time of homogeneous/heterogeneous solutions in a micro-mixer with free impinging jets

Abstract We have developed a micro-mixer based on a free impinging liquid-sheet jet technique. We identified a mixing position where two different solutions were mixed uniformly and evaluated corresponding mixing times in the liquid-sheet jets, with a homogeneous combination (H2O and H2O) and heterogeneous combination (C2H5OH and H2O). A quenching reaction was observed and the mixing times were evaluated to be 36 μs for the homogeneous combination (H2O/H2O) and 46 μs for the heterogeneous combination (C2H5OH/H2O). To clarify the mixing mechanism in the liquid-sheet jet, the theoretical mixing times were calculated using two different models, assuming laminar and turbulence flows. The calculated mixing times based on energy dissipation in the turbulence flow were in agreement with the observed mixing times for both H2O/H2O and C2H5OH/H2O combinations. These results indicate that turbulent mixing is a dominant mixing mechanism in the liquid-sheet jet, and that no clear interface is formed between H2O solutions and between C2H5OH and H2O solutions. The liquid-sheet jet technique provides a windowless and ultra-thin target and would be useful to investigate intermediates in mixing-driven chemical reactions, such as oxidation in solution and a folding reaction of proteins proceeding in a microsecond time scale.

Thermodynamic Modeling the Solid–Liquid Phase Equilibrium of a Water–Methanol–Potassium Dihydrogen Phosphate Ternary System with a Mixed-Solvent Electrolyte (MSE) Model

The solubility measurement of potassium dihydrogen phosphate (MKP) in a water–methanol system is of great significance for the salting-out crystallization of MKP. The solubility of MKP in the H2O–CH3OH solution was determined by the static equilibrium method in the range of 283.15–343.15 K, and the molar fraction of CH3OH varied from 0.0588 to 0.6923. The mixed-solvent electrolyte model (MSE) was used to regress the experimental results, and new parameters were obtained. Based on it, the thermodynamic model of the H2O–CH3OH–MKP system was established, which is in good agreement with the experimental results, with a relative average absolute deviation of 6.46%. Then, the change in the ion concentration and the activity coefficients in the system were predicted by the thermodynamic model. Finally, the Pixact Crystallization Monitoring (PCM) system and a scanning electron microscope (SEM) were used to observe the crystallization process and the morphology of MKP in the H2O–CH3OH system, respectively.

Hydrophobic, Ultrastable Cuδ+ for Robust CO2 Electroreduction to C2 Products at Ampere-Current Levels.

Copper (Cu) is the only known material that can efficiently electrocatalyze CO2 to value-added multicarbon products. Owing to the instability of the Cuδ+ state and microscopic structure in reactions, Cu catalysts are still facing big challenges with low selectivity and poor durability, particularly at high current densities. Herein, we report a rational one-step surface coordination approach for the synthesis of Cu dendrites with an ultrastable Cuδ+ state and hydrophobicity (Cu CF), even after exposure to air for over 6 months. As a result, Cu CF exhibited a C2 FE of 90.6% at a partial current density of 453.3 mA cm-2 in a flow cell. A 400 h stable electrolysis at 800 mA and even a ground-breaking stable operation at a large industrial current of 10 A were achieved in the membrane electrode assembly (MEA) form. We further demonstrated a continuous production of C2H5OH solution with 90% relative purity at 600 mA over 50 h in a solid-electrolyte reactor. Spectroscopy and computation results suggested that Cu(II) carboxylate coordination species formed on the surface of Cu CF, which ensured the stability of the Cuδ+ state and hydrophobicity. As a result, rich active sites and a stable three-phase interface on the catalyst surface were achieved, along with the optimized *CO adsorption strength and adsorption configuration. The mixed *CO adsorption configurations on Cu CF made the *CO dimerization process easier, which promoted the conversion of CO2 to C2 products. This work provides a promising paradigm for the design and development of Cu-based catalysts with ultrahigh stability under industrial current densities.

CoNi nanocrystal anchoring on MOF derived carbon skeleton autocatalytic growth N-doped carbon nanotubes for efficient bifunctional electrocatalyst towards methanol oxidation/oxygen reduction

In this paper, a novel bifunctional catalyst consisting of nitrogen doped carbon nanotubes (NCNTs) in situ grafted on CoNi-MOF derivative (named CoNi@NC/NCNTs) is controllable synthesized by simple two-steps. Characterization analysis reveal that the interconnected three-dimensional CoNi@NC-NCNTs heterostructure not only atomically dispersed CoNi nanocrystalline, but also autocatalytic grow NCNTs on its surface. The size of CoNi alloy is less than 10 nm, and the crystallization degree of coated graphene carbon layer is extraordinary high. Especially, NCNTs wrapped on CoNi@NC in dihydrodiamine vapour atmosphere form a spatial conductive network, which make the optimized CoNi@NC/NCNTs-400 deliver faster catalytic kinetics toward methanol oxidation reaction (MOR) and oxygen reduction reaction (ORR) compared with the CoNi@NC and Co@NC. The peak current density is as high as 58.37 mA cm−2 at the scanning rate is 30 mV s−1 in 0.5 M KOH + 1 M CH3OH solution. Furthermore, the CoNi@NC/NCNTs-400 hybrids display excellent ORR catalytic efficiency in terms of half-wave potential (E1/2 = 0.810 V vs RHE) and high stability. The satisfactory electrocatalytic activity is ascribed to the synergetic effect between CoNi nanoparticles embedded in nitrogen-doped carbon framework and NCNTs, which includes the high conductivity, highly dispersed active sites, optimized electronic configuration and reaction pathways.

Unusual In Situ Transformation of Metastable Co-Crystal Forms into a Stable Form, in Solution and Solid State, and the [2 + 2] Photochemical Reactivity in the Crystalline Forms

Isolation of multiple composition co-crystals from a one-pot crystallization flask and in situ transformations of the crystals are not common phenomena. We describe, herein, thoroughly characterized three unusual co-crystals of citric acid (CA) and 1,2-bis(4-pyridyl)ethene (bpyee) with different molecular compositions (1:1, α; 2:2, β; and 2:3, γ) that were obtained from a one-pot crystallization flask of a CH3OH solution with equimolar co-formers. The three co-crystals can be distinguished by their morphology and appearance at various stages of the crystallization process. In the first instance, needle-shaped (β) crystals are formed on the edge of the flask, followed by plates (γ) in the bulk of the solution, and finally, the entire flask with only rod-shaped crystals (α), indicating the in situ conversion of β- and γ-forms into α-form. Interestingly, in the solid state, isolated crystals are observed to undergo conversion, but in a different way than solution growth, as characterized by in situ variable-temperature powder X-ray diffraction, with β- and α-forms converting into γ-form. Furthermore, all of the forms undergo [2 + 2] photochemical reactivity upon UV irradiation due to the favorable Schmidt’s photoreactive distance between the adjacent bpyee molecules in α- and γ-forms, with the former following a single-crystal-to-single-crystal transformation process also, while β-form, despite having bpyee molecules separated by 7.68 Å, through conversion into γ-form.

Air-Stable Dy(III)-Macrocycle Enantiomers: From Chiral to Polar Space Group

Air-Stable Dy(III)-Macrocycle Enantiomers: From Chiral to Polar Space Group

Hydrate phase equilibrium of hydrogen-natural gas blends: Experimental study and thermodynamic modeling

Blending hydrogen (H2) into natural gas pipelines has become an effective way to transport H2 on a large scale. Due to the difference in properties between H2 and natural gas, the natural gas hydrate (NGH) phase equilibrium will be changed after blending H2, which influences the flow assurance in pipelines. In this work, hydrate phase equilibrium for CH4 + H2, CH4 + C2H6 + H2, and CH4 + C2H6 + C3H8 + H2 multicomponent systems had been measured at a temperature range from 274.24 K to 289.59 K by the isochoric pressure-search method. The results show the inhibition effect on CH4 hydrate formation of blending H2 to 20% is a little better than the 5.0 wt.%CH3OH solution. In addition, the Chen–Guo model was adopted to predict hydrogen-natural gas blends (HNGB) hydrates formation conditions, and model results have a good agreement with the experimental data. Average enthalpies of HNGB hydrates dissociation were also calculated utilizing the Clausius-Clapeyron equation, which was in the range of 68.02 kJ/mol and 90.17 kJ/mol. These studies provide basic data for flow assurance when transporting HNGB in pipelines.

Water-assisted crystallization and densification of sol–gel-derived TiO2 films during low-temperature heating

ABSTRACT The crystallization and densification behavior of TiO2 films during heating at below 400°C was studied for sol–gel coatings and the effect of the H2O content in the precursor solutions on the nucleation and crystal growth of anatase at such relatively low temperature was discussed. TiO2 gel films were prepared from Ti(OC3H7 i )4:HNO3:H2O:C2H5OH solutions, followed by heating at 200–400°C for 10 min–6 h in air, where the H2O/Ti(OC3H7 i )4 mole ratio (x) was varied from 1.0 to 8.0. The degree of crystallization and the crystallite size of the heat-treated TiO2 films were not significantly affected by the H2O content, while the surface structure became denser with an increase in x. The dense TiO2 films of x = 8.0 heated at 300–400°C for 6 h exhibited a refractive index of 2.22–2.25, which was higher than that of x = 1.0 heated at 800°C.

Tuning the photophysical properties of lanthanide(iii)/zinc(ii) 'encapsulated sandwich' metallacrowns emitting in the near-infrared range.

A family of Zn16Ln(HA)16 metallacrowns (MCs; Ln = YbIII, ErIII, and NdIII; HA = picoline- (picHA2−), pyrazine- (pyzHA2−), and quinaldine- (quinHA2−) hydroximates) with an ‘encapsulated sandwich’ structure possesses outstanding luminescence properties in the near-infrared (NIR) and suitability for cell imaging. Here, to decipher which parameters affect their functional and photophysical properties and how the nature of the hydroximate ligands can allow their fine tuning, we have completed this Zn16Ln(HA)16 family by synthesizing MCs with two new ligands, naphthyridine- (napHA2−) and quinoxaline- (quinoHA2−) hydroximates. Zn16Ln(napHA)16 and Zn16Ln(quinoHA)16 exhibit absorption bands extended into the visible range and efficiently sensitize the NIR emissions of YbIII, ErIII, and NdIII upon excitation up to 630 nm. The energies of the lowest singlet (S1), triplet (T1) and intra-ligand charge transfer (ILCT) states have been determined. LnIII-centered total (QLLn) and intrinsic (QLnLn) quantum yields, sensitization efficiencies (ηsens), observed (τobs) and radiative (τrad) luminescence lifetimes have been recorded and analyzed in the solid state and in CH3OH and CD3OD solutions for all Zn16Ln(HA)16. We found that, within the Zn16Ln(HA)16 family, τrad values are not constant for a particular LnIII. The close in energy positions of T1 and ILCT states in Zn16Ln(picHA)16 and Zn16Ln(quinHA)16 are preferred for the sensitization of LnIII NIR emission and ηsens values reach 100% for NdIII. Finally, the highest values of QLLn are observed for Zn16Ln(quinHA)16 in the solid state or in CD3OD solutions. With these data at hand, we are now capable of creating MCs with desired properties suitable for NIR optical imaging.

Theoretical computation of interaction parameters for the complexation of GSH with Pr(III) and Mg(II) in solution: Analysis of their reaction dynamics and thermodynamic characters

The current research focuses on the computation of absorption spectral parameters like energy interaction parameters viz. Slater-Condon factor (Fk), Racah (Ek), Lande spin-orbit interaction (ζ4f), nephelauxetic ratio (β), bonding parameter (b1/2), per cent covalency (δ), and the intensity parameters like oscillator strength (P) and Judd-Ofelt Tλ, (λ ​= ​2,4,6) parameters, of Pr3+ ion complexes with reduced Glutathione (GSH) in the presence and absence of Mg2+ in different aqueous solutions of CH3OH, C4H8O2, CH3CN and DMF. The variations in the values of the energy interaction and intensity parameters clearly demonstrates the relative sensitivity of the 4f-4f transitions and its correlation with ligand structure and the nature of metal-ligand interaction. Further, the reaction dynamics and thermodynamic properties for the complexation of Pr3+ with glutathione and Mg2+ ligand have been investigated using different computed parameters like rate constant (k), activation energy (Ea), A (pre-exponential factor) and thermodynamic parameters, ΔH0, ΔG0 and ΔS0.

Polyaniline pyrolysis assisted by ITO to prepare Pt catalyst support for methanol oxidation reaction

A good support is essential for the activity and durability of the supported catalysts. In this work, nitrogen-doped carbon with fluffy structure and high content of pyridinic-N and pyrrolic-N is prepared by the pyrolysis of polyaniline/ITO composite, which is conducive to uniform and firm loading of Pt catalysts. Herein, polyaniline is used as carbon and nitrogen sources, and ITO is used as a pyrolysis auxiliary due to the reaction of polyaniline dopant (proton acid) and ITO during the pyrolysis. Pt catalyst supported on above optimal support shows an excellent electrocatalytic performance for the methanol oxidation reaction, especially its stability, achieving an activity retention rate of 89.3% after 1000 cycles of cyclic voltammetry in 0.5 M H2SO4 and 0.5 M CH3OH solution. This work provides a new strategy for preparing Pt-based catalyst with a high activity and a good durability.

Synthesis and electrochemical study of some derived of hydrazines ferrocene

The aim of this work is the synthesis of three Hydrazines ferrocene derivatives; to achieve this we target, we combine [(Trimethylammonio)methyl] ferrocene iodide with: 1-Acetyl-2-phenylhydrazine. The electrochemical study of the synthesis compounds has been done by cyclic voltammetry method which carried out in aqueous solution of CH3OH / H2SO4 concentration 0.1 M, by using glassy carbon electrode diameter 02 mm. This study confirmed that the oxidation of the three synthesis compounds is electrochemically stable, rapid and reversible systems. The electrochemical study showed also that, substituted group of Hydrazides on the Ferrocene has a pulling effect, due to shift the potential values in the most positive direction depending the Ferrocene molecule.

Hydrogen Generation over RuO2 Nanoparticle-Decorated LaNaTaO3 Perovskite Photocatalysts under UV Exposure.

The efficacy of LaNaTaO3 perovskites decoration RuO2 at diverse contents for the photocatalytic H2 generation has been explored in this study. The photocatalytic performance of RuO2 co-catalyst onto mesoporous LaNaTaO3 was evaluated for H2 under UV illumination. 3%RuO2/LaNaTaO3 perovskite photocatalyst revealed the highest photocatalytic H2 generation performance, indicating that RuO2 nanoparticles could promote the photocatalytic efficiency of LaNaTaO3 perovskite significantly. The H2 evolution rate of 3%RuO2/LaNaTaO3 perovskite is 11.6 and 1.3 times greater than that of bare LaNaTaO3 perovskite employing either 10% CH3OH or pure H2O, respectively. Interestingly, the photonic efficiency of 3%RuO2/LaNaTaO3 perovskite was enhanced 10 times than LaNaTaO3 perovskite in the presence of aqueous CH3OH solutions as a hole sacrificial agent. The high separation of charge carriers is interpreted by the efficient hole capture using CH3OH, hence leading to greater H2 generation over RuO2/LaNaTaO3 perovskites. This is attributed to an adjustment position between recombination electron–hole pairs and also the reduction of potential conduction alignment as a result of RuO2 incorporation. The suggested mechanisms of RuO2/LaNaTaO3 perovskites for H2 generation employing either CH3OH or pure H2O were discussed. The photocatalytic performances of the perovskite photocatalyst were elucidated according to the PL intensity and the photocurrent response investigations.

Structures and Chromogenic Ion-Pair Recognition of a Catechol-Functionalized 1,8-Anthraquinone Macrocycle in Dimethyl Sulfoxide.

A lariat anthraquinone macrocycle functionalized with catechol (H2L) was synthesized via the Mannich reaction. The Mannich base H2L can be partially decomposed into L1·3H2O and HL1·NO3·2H2O in the presence of tetrabutylammonium hydroxide/Al(NO3)3·9H2O in dimethyl sulfoxide (DMSO). Free L1·3H2O is essentially coplanar, while protonated HL1·NO3·2H2O is highly distorted. Dark-green FeCl3·H2L·2H2O powder and Fe2(HL)2Cl4 crystal can be isolated from ethanol (C2H5OH) in high/low H2L concentration. Anthraquinone in H2L is essentially coplanar but distorted in Fe2(HL)2Cl4. The Fe(III) ion in Fe2(HL)2Cl4 adopts a less common five-coordination with three catecholate O and two Cl atoms in the dimer. The distortion of inbound C═O is much higher than that of outbound C═O in anthraquinone in all of these compounds. H2L responds to chlorides of Li+, Na+, K+, Cs+, Mg2+, Ca2+, Sr2+, Ba2+, Fe3+, Cu2+, Zn2+, and Al3+ in a DMSO solution, which can be observed by differential pulse voltammetry, UV-vis, and 1H NMR. All of these metal ions shift Ep of anthraquinone to positive, especially the second reduction peak of anthraquinone. Fe3+, Zn2+, and Al3+ change the reduction of catechol fundamentally. H2L (0.50 mM) shows a chromogenic response to FeCl3 and Fe(NO3)3 to form uncommon 2:1 and 3:2 (H2L/Fe) complexes, both peaking at 748 nm in DMSO. In the presence of 2 equiv of sodium hydroxide (NaOH), the 748 nm absorbance shifts to 777 nm, identical with Fe2(HL)2Cl4 in DMSO. Different from the fast reaction between H2L and FeCl3, Fe(NO3)3 reacts with H2L rather slowly in DMSO. Catechol can coordinate to FeCl3 without any deprotonation in C2H5OH and DMSO. H2L also shows a chromogenic response to fluorides and hydroxides, which peak at 670 and 684 nm, respectively, in DMSO. The binding ratio between H2L and F-/OH- is 1:2. In a higher concentration of hydroxides, a 684 nm greenish-blue 1:2 complex forms immediately, which gradually transforms to a red complex and peaks at ∼530 nm in minutes at room temperature. No color change can be observed in an C2H5OH solution in the presence of OH-.