Mg2+,K+//Cl-,B4O2-7-H2O四元体系288 K固液相平衡

采用等温溶解平衡法研究了288 K时Mg2+,K+//Cl-,B4O2-7-H2O四元体系的相平衡关系,测定该体系在288 K时平衡液相的溶解度和密度.依据实验测定的平衡溶解度数据及对应的平衡固相,绘制了该四元体系的平衡相图以及其密度-组成图.研究结果表明,四元体系Mg2+,K+//Cl-,B4O2-7-H2O 288 K时的固液相平衡实验中,有复盐KCI·MgCl2·6H2O生成,平衡相图中有3个共饱点,7条单变量曲线,5个结晶区,对应的平衡固相分别为MgB4O7·9H2O,K2B4O7·4H2O,KCl,MgCl2·6H2O,KCl·Mgcl2·6H2O.简要讨论了实验结果.     

Mg2+, K+//Cl-, B4O2-7-H2O四元体系288 K固液相平衡

采用等温溶解平衡法研究了288 K时Mg2+, K+//Cl-, B4O2-7-H2O四元体系的相平衡关系, 测定该体系在288 K时平衡液相的溶解度和密度. 依据实验测定的平衡溶解度数据及对应的平衡固相, 绘制了该四元体系的平衡相图以及其密度-组成图. 研究结果表明, 四元体系Mg2+, K+//Cl-, B4O2-7-H2O 288 K时的固液相平衡实验中, 有复盐KCl·MgCl2·6H2O生成, 平衡相图中有3个共饱点, 7条单变量曲线, 5个结晶区, 对应的平衡固相分别为MgB4O7·9H2O, K2B4O7·4H2O, KCl, MgCl2·6H2O, KCl·MgCl2·6H2O. 简要讨论了实验结果.     

Mg^2＋，K^＋//Cl^-，B4O7^2——H2O四元体系288K固液相平衡

采用等温溶解平衡法研究了288K时Mg^2＋,K^＋//Cl^-,B4O7^2--H2O四元体系的相平衡关系,测定该体系在288K时平衡液相的溶解度和密度．依据实验测定的平衡溶解度数据及对应的平衡固相,绘制了该四元体系的平衡相图以及其密度一组成图．研究结果表明,四元体系Mg^2＋,K^＋//Cl^-,B4O7^2--H2O288K时的固液相平衡实验中,有复盐KCl·MgCl2·6H2O生成,平衡相图中有3个共饱点,7条单变量曲线,5个结晶区,对应的平衡固相分别为MgB4O7·9H2O,K2B4O7·4H2O,KCl,MgCl2·6H2O,KCl·MgCl2·6H2O．简要讨论了实验结果．     

四元体系RbCl-CeCl3-HCl-H2O(25 ℃)的相平衡及其新相化合物

测定了四元体系RbCl-CeCl3-HCl-H2O在25℃时的溶度数据, 绘制了相应的溶度图. 该四元体系是由3个固相区RbCl(原始盐), RbCl·CeCl3·4H2O, CeCl3·7H2O(原始盐)组成的复杂体系, 其中RbCl·CeCl3 ·4H2O是固液同成分溶解度的化合物. 在相平衡结果指导下, 制备了化合物RbCl·CeCl3 ·4H2O, 并对其进行了X射线粉末衍射鉴定和热重分析, 结果表明, 该化合物在84～216 ℃通过两步失去其结晶水. 用RD496-Ⅲ-2000微量热计测定了298.15 K下新相化合物在水中的溶解焓(-23.70±0.11) kJ·mol-1, 计算出其标准摩尔生成焓为(-2735.6±1.1) kJ·mol-1.     

298.16K下K+,Mg2+//Cl-,NO-3-H2O体系液固相平衡

采用等温溶解平衡法研究298.16K时四元体系K+,Mg2+//Cl-,NO-3-H2O的液固相平衡关系,测定了溶解度数据,并绘制出平衡相图.研究表明,在298.16K时,该体系相图有5个单盐结晶区、6条单变量溶解度曲线和3个零变量点.5个单盐结晶区分别对应于KNO3、KCl、Mg(NO3)2·6H2O、MgCl2O和复盐KCI·MgCl2·6H2O,其中KNO3的结晶区最大,MgCl2·6H2O的结晶区最小.     

Na+, K+//Cl-, B4O2-7-H2O四元体系273 K介稳相平衡

采用等温蒸发法研究了四元体系Na+, K+//Cl-, B4O2-7-H2O 273 K时的介稳相平衡与相图. 测定了该体系273 K平衡液相中各组分的溶解度及平衡液相的密度; 绘制了该体系的介稳相图. 该四元体系273 K相图由5条溶解度单变量线、4个结晶区及2个共饱和点组成. 体系无复盐或固溶体形成. 四个结晶区分别对应单盐NaCl、KCl、K2B4O7·4H2O 和Na2B4O7·10H2O. 共饱点E1处KCl、NaCl及Na2B4O7·10H2O三盐共饱和,所对应的平衡液相组成为w(Cl-)=29.15%, w(B4O2-7)=0.64%, w(K+)=5.97%, w(Na+)=15.55%; 共饱和点E2处盐KCl、Na2B4O7·10H2O和K2B4O7·4H2O的三盐共饱和, 所对应的平衡液相组成为w(Cl-)=22.84%, w(B4O2-7)=10.98%, w(K+)=28.01%, w(Na+)=1.53%. 同体系298 K时的稳定相图相比, 273 K时硼酸钠的结晶区变大, 而硼酸钾、氯化钠结晶区变小.     

五元交互体系Li+,Na+,K+//CO2-3,Cl--H2O在298.15 K的相平衡研究

针对西藏扎布耶盐湖卤水组成, 采用等温溶解平衡法研究了五元交互体系Li+, Na+, K+// CO2-3, Cl--H2O 于298.15 K时的相平衡, 并绘制了相图(空间立体图和Li2CO3饱和的投影图). 结果表明, 该五元体系相图含有7个结晶区、 13条单变量线和4个无变量点. 7个结晶区由6个单盐结晶区和1个复盐结晶区组成, 分别为LiCl*H2O, NaCl, KCl, Li2CO3, K2CO3*3/2H2O, Na2CO3*10H2O和NaKCO3*6H2O, 没有形成固溶体和天然碱(Na2CO3*NaHCO3*2H2O). 4个无变量点标记成K1, K2, K3和K4, 所对应的平衡固相盐分别是: Li2CO3+NaKCO3*6H2O+Na2CO3*10H2O+KCl, Li2CO3+NaKCO3*6H2O+K2CO3*3/2H2O+KCl, Li2CO3+NaCl+KCl+LiCl*H2O和Li2CO3+NaCl+Na2CO3*10H2O+KCl.     

四元交互体系Li~ ,Na~ //CO_3~(2-),B_4O_7~(2-)-H_2O 298K相关系的理论预测及实验研究

采用三元体系的溶解度数据 ,运用多元线性回归法拟合了 Li2 CO3(a) ,Na2 CO3(b) ,Li2 B4O7(c)的单盐参数、溶解平衡常数及有关的混合离子作用参数 .它们的值分别为 :β(0 )a =-1 .2 3 5 5 ,β(1)a =-2 .65 46,Ca=-0 .0 0 4660 7,β(0 )b =-3 .0 3 0 6,β(1)b =-3 .0 2 3 8,Cb=-0 .2 90 89,β(0 )c =-0 .2 93 0 4,β(1)c =2 .1 5 5 6,Cc=-0 .0 0 42 5 60 ,θL i,Na=1 .0 41 8,θB,C=-2 .63 0 5 ,ΨL i,Na,C=-0 .0 63 91 ,ΨL i,Na,B=0 .493 5 6,ΨL i,B,C=-0 .47842 ,ΨNa,B,C=0 .3 0 61 6,ln K(Li2 CO3) =-8.962 9,ln K(Na2 CO3· 1 0 H2 O) =3 .0 64 6,ln K(Li2 B4O7·3 H2 O) =-7.3 5 66,ln K(Na2 B4O7· 1 0 H2 O) =-7.4778.以盐的溶解平衡常数为判据 ,运用 Pitzer方程计算了四元体系 Li ,Na //CO2 -3,B4O2 -7-H2 O 2 98K时的溶解度 ,并采用等温溶解平衡法 ,对该体系 2 98K时溶解度进行了实验测定 ,同计算值相比 ,二者基本吻合     

MgSo4—C2H5OH—H2O三元系汽—液—固平衡的研究

H测定过MgSO_4-C_2H_5OH-H_2三元系在25℃、50℃、75℃的液固平衡和部分不饱和溶液汽液平衡的总压和分压。本文补充了30℃、0℃和-5℃时的溶解度数据,得到分层温度和浓度范围,绘出了溶解度图。测定了25℃和30℃饱和溶液的密度,粘度和平衡总压力。根据Jaques“假二元系”理论用Wilson、Uniquac和NRTL活度方程计算了溶     

MgO·nB_2O_3-18%MgSO_4-H_2O体系0℃时的热力学非平衡态液固相关系

在MgO·nB2 O3 18%MgSO4 H2 O体系 0℃结晶过程的动力学研究、用物理方法和化学分析确定析出固相的组成和测定固相共饱和点的基础上 ,给出了该体系 0℃时的热力学非平衡态液固相关系图 .该相图存在四个相区 ,分别与H3 BO3 ,MgO·3B2 O3 ·7.5H2 O ,MgO·2B2 O3 ·9H2 O和 2MgO·3B2 O3 ·15H2 O(多水硼镁石 )相对应 .结果表明MgCl2 和MgSO4介质对镁硼酸盐的析出有不同的影响 .     

Thermotropic Liquid Crystals Based on Extended 2,5‐Disubstituted‐1,3,4‐Oxadiazoles: Structure–Property Relationships,Variable‐Temperature Powder X‐ray Diffraction,and Small‐Angle X‐ray Scattering Studies

A class of extended 2,5‐disubstituted‐1,3,4‐oxadiazoles R¹‐C₆H₄‐{OC₂N₂}‐C₆H₄‐R² (R¹=R²=C₁₀H₂₁O 1 a , p‐C₁₀H₂₁O‐C₆H₄‐C?C 3 a , p‐CH₃O‐C₆H₄‐C?C 3 b ; R¹=C₁₀H₂₁O, R²=CH₃O 1 b , (CH₃)₂N 1 c ; F 1 d ; R¹=C₁₀H₂₁O‐C₆H₄‐C?C, R²=C₁₀H₂₁O 2 a , CH₃O 2 b , (CH₃)₂N 2 c , F 2 d ) were prepared, and their liquid‐crystalline properties were examined. In CH₂Cl₂ solution, these compounds displayed a room‐temperature emission with λ_max at 340–471 nm and quantum yields of 0.73–0.97. Compounds 1 d , 2 a – 2 d , and 3 a exhibited various thermotropic mesophases (monotropic, enantiotropic nematic/smectic), which were examined by polarized‐light optical microscopy and differential scanning calorimetry. Structure determination by a direct‐space approach using simulated annealing or parallel tempering of the powder X‐ray diffraction data revealed distinctive crystal‐packing arrangements for mesogenic molecules 2 b and 3 a , leading to different nematic mesophase behavior, with 2 b being monotropic and 3 a enantiotropic in the narrow temperature range of 200–210 °C. The structural transitions associated with these crystalline solids and their mesophases were studied by variable‐temperature X‐ray diffractometry. Nondestructive phase transitions (crystal‐to‐crystal, crystal‐to‐mesophase, mesophase‐to‐liquid) were observed in the diffractograms of 1 b, 1 d , 2 b, 2 d , and 3 a measured at 25–200 °C. Powder X‐ray diffraction and small‐angle X‐ray scattering data revealed that the structure of the annealed solid residue 2 b reverted to its original crystal/molecular packing when the isotropic liquid was cooled to room temperature. Structure–property relationships within these mesomorphic solids are discussed in the context of their molecular structures and intermolecular interactions.     

Halogen,hydrogen and electrostatic interactions in 2‐amino‐5‐chloro‐1,3‐benzoxazol‐3‐ium nitrate and 2‐amino‐5‐chloro‐1,3‐benzoxazol‐3‐ium perchlorate

In the title compounds, C₇H₆ClN₂O⁺·NO₃⁻ and C₇H₆ClN₂O⁺·ClO₄⁻, the ions are connected by N—H...O hydrogen bonds and halogen interactions. Additionally, in the first compound, co‐operative π–π stacking and halogen...π interactions are observed. The energies of the observed interactions range from a value typical for very weak interactions (1.80 kJ mol⁻¹) to one typical for mildly strong interactions (53.01 kJ mol⁻¹). The iminium cations exist in an equilibrium form intermediate between exo‐ and endocyclic. This study provides structural insights relevant to the biochemical activity of 2‐amino‐5‐chloro‐1,3‐benzoxazole compounds.     

Polyoxometalate Ionic Liquids as Self‐Repairing Acid‐Resistant Corrosion Protection

Corrosion is a global problem for any metallic structure or material. Herein we show how metals can easily be protected against acid corrosion using hydrophobic polyoxometalate‐based ionic liquids (POM‐ILs). Copper metal disks were coated with room‐temperature POM‐ILs composed of transition‐metal functionalized Keggin anions [SiW₁₁O₃₉TM(H₂O)]^n? (TM=Cu^II, Fe^III) and quaternary alkylammonium cations (C_nH_{2 n+1})₄N⁺ (n=7–8). The corrosion resistance against acetic acid vapors and simulated “acid rain” was significantly improved compared with commercial ionic liquids or solid polyoxometalate coatings. Mechanical damage to the POM‐IL coating is self‐repaired in less than one minute with full retention of the acid protection properties. The coating can easily be removed and recovered by rinsing with organic solvents.     

Effect of L64 on the Phase Behavior of 1-Dodecyl-3-methylimidazolium Chloride/Water System

Phase behavior of ternary system involving surfactant‐like ionic liquid 1‐dodecyl‐3‐methylimidazolium chloride ([C₁₂mim]Cl), water, and nonionic surfactant PEO‐PPO‐PEO block copolymer (Pluronic L64) is investigated at 25°C. Hexagonal (H₁) and lamellar liquid crystal phase (Lα) are found in [C₁₂mim]Cl/H₂O/L64 system by using polarized optical microscopy (POM), small‐angle X‐ray scattering (SAXS) techniques and ²H NMR spectra. The phase structure (H₁ phase), which is formed in [C₁₂mim]Cl/H₂O binary system, is not changed when L64 with a low concentration is added. However, phase transitions will occur from hexagonal to multiphases of H₁ and cubic phases (C), then to Lα+C phases with constant [C₁₂mim]Cl/H₂O ratio and increasing L64 concentration. Moreover, at given L64 (5%, 20%) concentration, the lattice parameter of H₁ or Lα phase decreases with increasing [C₁₂mim]Cl/H₂O ratio. Fourier transform infrared (FTIR) spectra indicate that the H‐bonded network comprising an imidazolium ring, chloride ion and water formed in [C₁₂mim]Cl/H₂O binary system is disrupted upon addition of L64. This is helpful to the phase transition, due to the decreasing of interfacial curvature induced by dehydration of hydrated layer after the addition of PEO block of L64.     

Two salts of 5‐sulfosalicylic acid and 3‐aminopyridine

5‐Sulfosalicylic acid (5‐SSA) and 3‐aminopyridine (3‐APy) crystallize in the same solvent system, resulting in two kinds of 1:1 proton‐transfer organic adduct, namely 3‐aminopyridinium 3‐carboxy‐4‐hydroxybenzenesulfonate monohydrate, C₅H₇N₂⁺·C₇H₅O₆S⁻·H₂O or 3‐APy·5‐SSA·H₂O, (I), and the anhydrous adduct, C₅H₇N₂⁺·C₇H₅O₆S⁻ or 3‐APy·5‐SSA, (II). Both compounds have extensively hydrogen‐bonded three‐dimensional layered polymer structures, with interlayer homo‐ and heterogeneous π–π interactions in (I) and (II), respectively.     

3‐Cyano‐6‐hydroxy‐4‐methyl‐2‐pyridone: two new pseudopolymorphs and two cocrystals with products of an in situ nucleophilic aromatic substitution

Four crystal structures of 3‐cyano‐6‐hydroxy‐4‐methyl‐2‐pyridone (CMP), viz. the dimethyl sulfoxide monosolvate, C₇H₆N₂O₂·C₂H₆OS, (1), the N,N‐dimethylacetamide monosolvate, C₇H₆N₂O₂·C₄H₉NO, (2), a cocrystal with 2‐amino‐4‐dimethylamino‐6‐methylpyrimidine (as the salt 2‐amino‐4‐dimethylamino‐6‐methylpyrimidin‐1‐ium 5‐cyano‐4‐methyl‐6‐oxo‐1,6‐dihydropyridin‐2‐olate), C₇H₁₃N₄⁺·C₇H₅N₂O₂⁻, (3), and a cocrystal with N,N‐dimethylacetamide and 4,6‐diamino‐2‐dimethylamino‐1,3,5‐triazine [as the solvated salt 2,6‐diamino‐4‐dimethylamino‐1,3,5‐triazin‐1‐ium 5‐cyano‐4‐methyl‐6‐oxo‐1,6‐dihydropyridin‐2‐olate–N,N‐dimethylacetamide (1/1)], C₅H₁₁N₆⁺·C₇H₅N₂O₂⁻·C₄H₉NO, (4), are reported. Solvates (1) and (2) both contain the hydroxy group in a para position with respect to the cyano group of CMP, acting as a hydrogen‐bond donor and leading to rather similar packing motifs. In cocrystals (3) and (4), hydrolysis of the solvent molecules occurs and an in situ nucleophilic aromatic substitution of a Cl atom with a dimethylamino group has taken place. Within all four structures, an R₂²(8) N—H...O hydrogen‐bonding pattern is observed, connecting the CMP molecules, but the pattern differs depending on which O atom participates in the motif, either the ortho or para O atom with respect to the cyano group. Solvents and coformers are attached to these arrangements via single‐point O—H...O interactions in (1) and (2) or by additional R₄⁴(16) hydrogen‐bonding patterns in (3) and (4). Since the in situ nucleophilic aromatic substitution of the coformers occurs, the possible Watson–Crick C–G base‐pair‐like arrangement is inhibited, yet the cyano group of the CMP molecules participates in hydrogen bonds with their coformers, influencing the crystal packing to form chains.     

6‐Propyl‐2‐thiouracil versus 6‐methoxymethyl‐2‐thiouracil: enhancing the hydrogen‐bonded synthon motif by replacement of a methylene group with an O atom

The understanding of intermolecular interactions is a key objective of crystal engineering in order to exploit the derived knowledge for the rational design of new molecular solids with tailored physical and chemical properties. The tools and theories of crystal engineering are indispensable for the rational design of (pharmaceutical) cocrystals. The results of cocrystallization experiments of the antithyroid drug 6‐propyl‐2‐thiouracil (PTU) with 2,4‐diaminopyrimidine (DAPY), and of 6‐methoxymethyl‐2‐thiouracil (MOMTU) with DAPY and 2,4,6‐triaminopyrimidine (TAPY), respectively, are reported. PTU and MOMTU show a high structural similarity and differ only in the replacement of a methylene group (–CH₂–) with an O atom in the side chain, thus introducing an additional hydrogen‐bond acceptor in MOMTU. Both molecules contain an ADA hydrogen‐bonding site (A = acceptor and D = donor), while the coformers DAPY and TAPY both show complementary DAD sites and therefore should be capable of forming a mixed ADA/DAD synthon with each other, i.e. N—H…O, N—H…N and N—H…S hydrogen bonds. The experiments yielded one solvated cocrystal salt of PTU with DAPY, four different solvates of MOMTU, one ionic cocrystal of MOMTU with DAPY and one cocrystal salt of MOMTU with TAPY, namely 2,4‐diaminopyrimidinium 6‐propyl‐2‐thiouracilate–2,4‐diaminopyrimidine–N,N‐dimethylacetamide–water (1/1/1/1) (the systematic name for 6‐propyl‐2‐thiouracilate is 6‐oxo‐4‐propyl‐2‐sulfanylidene‐1,2,3,6‐tetrahydropyrimidin‐1‐ide), C₄H₇N₄⁺·C₇H₉N₂OS⁻·C₄H₆N₄·C₄H₉NO·H₂O, (I), 6‐methoxymethyl‐2‐thiouracil–N,N‐dimethylformamide (1/1), C₆H₈N₂O₂S·C₃H₇NO, (II), 6‐methoxymethyl‐2‐thiouracil–N,N‐dimethylacetamide (1/1), C₆H₈N₂O₂S·C₄H₉NO, (III), 6‐methoxymethyl‐2‐thiouracil–dimethyl sulfoxide (1/1), C₆H₈N₂O₂S·C₂H₆OS, (IV), 6‐methoxymethyl‐2‐thiouracil–1‐methylpyrrolidin‐2‐one (1/1), C₆H₈N₂O₂S·C₅H₉NO, (V), 2,4‐diaminopyrimidinium 6‐methoxymethyl‐2‐thiouracilate (the systematic name for 6‐methoxymethyl‐2‐thiouracilate is 4‐methoxymethyl‐6‐oxo‐2‐sulfanylidene‐1,2,3,6‐tetrahydropyrimidin‐1‐ide), C₄H₇N₄⁺·C₆H₇N₂O₂S⁻, (VI), and 2,4,6‐triaminopyrimidinium 6‐methoxymethyl‐2‐thiouracilate–6‐methoxymethyl‐2‐thiouracil (1/1), C₄H₈N₅⁺·C₆H₇N₂O₂S⁻·C₆H₈N₂O₂S, (VII). Whereas in (I) only an AA/DD hydrogen‐bonding interaction was formed, the structures of (VI) and (VII) both display the desired ADA/DAD synthon. Conformational studies on the side chains of PTU and MOMTU also revealed a significant deviation for cocrystals (VI) and (VII), leading to the desired enhancement of the hydrogen‐bond pattern within the crystal.     

Tetra­methyl­ammonium pentaborate 0.25‐hydrate

The title compound, tetramethylammonium 4,4′,6,6′‐tetrahydroxy‐2,2′‐spirobi(cyclotriboroxane) 0.25‐hydrate, C₄H₁₂N⁺·B₅H₄O₁₀⁻·0.25H₂O, was synthesized under mild solvothermal conditions. The B₅O₆(OH)₄⁻ clusters are connected by strong hydrogen‐bonding interactions into a three‐dimensional structure containing rectangular channels along the a axis, in which the C₄H₁₂N⁺ ions and water mol­ecules are located.     

Gas‐phase fragmentation reactions of protonated benzofuran‐ and dihydrobenzofuran‐type neolignans investigated by accurate‐mass electrospray ionization tandem mass spectrometry

We have investigated gas‐phase fragmentation reactions of protonated benzofuran neolignans (BNs) and dihydrobenzofuran neolignans (DBNs) by accurate‐mass electrospray ionization tandem and multiple‐stage (MSⁿ) mass spectrometry combined with thermochemical data estimated by Computational Chemistry. Most of the protonated compounds fragment into product ions B ([M + H–MeOH]⁺), C ([ B –MeOH]⁺), D ([ C –CO]⁺), and E ([ D –CO]⁺) upon collision‐induced dissociation (CID). However, we identified a series of diagnostic ions and associated them with specific structural features. In the case of compounds displaying an acetoxy group at C‐4, product ion C produces diagnostic ions K ([ C –C₂H₂O]⁺), L ([ K –CO]⁺), and P ([ L –CO]⁺). Formation of product ions H ([ D –H₂O]⁺) and M ([ H –CO]⁺) is associated with the hydroxyl group at C‐3 and C‐3′, whereas product ions N ([ D –MeOH]⁺) and O ([ N –MeOH]⁺) indicate a methoxyl group at the same positions. Finally, product ions F ([ A –C₂H₂O]⁺), Q ([ A –C₃H₆O₂]⁺), I ([ A –C₆H₆O]⁺), and J ([ I –MeOH]⁺) for DBNs and product ion G ([ B –C₂H₂O]⁺) for BNs diagnose a saturated bond between C‐7′ and C‐8′. We used these structure‐fragmentation relationships in combination with deuterium exchange experiments, MSⁿ data, and Computational Chemistry to elucidate the gas‐phase fragmentation pathways of these compounds. These results could help to elucidate DBN and BN metabolites in in vivo and in vitro studies on the basis of electrospray ionization ESI‐CID‐MS/MS data only.     

Syntheses,Structures, Electrochemistry,and Electrocatalysis of Three Copper(II) Coordination Polymers constructed from 5‐[4‐(1H‐Imidazol‐1‐yl)phenyl]‐1H‐tetrazole

Three coordination polymers (CPs) based on the 5‐[4‐(1H‐imidazol‐1‐yl)phenyl]‐1H‐tetrazole ( HL ) ligand, namely, [Cu(μ₂‐ L )(μ₄‐pbda)(H₂O)] ( 1 ), [Cu₂(μ‐Hbtc)(H₂btc)(μ₃‐OH)(μ₄‐ HL )] ( 2 ) and [Cu₅(μ₃‐ L )(μ₄‐ L )(μ₃‐ip)(μ₃‐OH)(H₂O)₂] · 2H₂O ( 3 ) (H₂pbda = 1,4‐benzenedicarboxylic acid, H₃btc = 1,3,5‐benzenetricarboxylic acid, H₂ip = isophthalic acid) were hydrothermally synthesized and structurally characterized. Complex 1 represents “weave”‐type 2D layers consisting of wave‐like 1D chains and 1D straight chains, which are further connected by hydrogen bonds to form a 3D supramolecular structure. Complex 2 exhibits a uninodal (4)‐connected 2D layer with a point symbol of {4⁴ · 6²}, in which the L ligand can be described as μ₅‐bridging and the H₂btc^– ions display multiple kinds of coordination modes to connect Cu^II ions into 1D “H”‐type Cu‐H₂btc chains. In complex 3 , 2D Cu‐ L layers with two kinds of grids and 1D “stair”‐type Cu‐ip chains link each other to construct a 3D {4¹² · 6³} framework, which contains the pentanuclear subunits. Deprotonated degree and coordination modes of carboxylate ligands may consequentially influence the coordination patterns of main ligands and the final structures of complexes 1 – 3 . Furthermore, electrochemical behaviors and electrocatalytic activities of the title complexes were analyzed at room temperature, suggesting practical applications in areas of electrocatalytic reduction toward nitrite and hydrogen dioxide in aqueous solutions, respectively.