A three‐dimensional supramolecular framework based on the interlinkage of an interpenetrating diamondoid coordination network

In the development of coordination‐driven crystalline materials, O‐ and N‐atom donors from carboxylate and pyridyl‐based ligands are widely used classes of multidentate bridging ligands composed of several terminal coordinating groups linked by either rigid or flexible spacers. The rigidity of the ligands can play a vital role in the determination of the structures formed. A new Cd^II supramolecular compound, namely poly[μ‐adipato‐κ²O ¹:O⁴‐μ‐adipato‐κ⁴O ¹,O ^1′:O ⁴,O^4′‐diaquabis[μ‐1,4‐bis(pyridin‐4‐yl)‐1,3‐butadiene‐κ²N :N ′]dicadmium(II)], [Cd₂(C₆H₈O₄)₂(C₁₄H₁₂N₂)₂(H₂O)₂]_n , (I), has been synthesized by the self‐assembly of Cd(NO₃)₂·4H₂O, adipic acid (hexane‐1,6‐dioic acid; H₂adp) and the dipyridyl ligand 1,4‐bis(pyridin‐4‐yl)buta‐1,3‐diene (1,4‐bpbd) under hydrothermal conditions. Single‐crystal X‐ray diffraction analysis reveals that each Cd^II centre is located in a distorted octahedral coordination environment, coordinated by one water O atom, three carboxylate O atoms from two different adp²⁻ ligands and two N atoms from two different 1,4‐bpbd ligands. The Cd(H₂O) units are interconnected by the μ₂,κ²‐adp²⁻, μ₂,κ⁴‐adp²⁻ and 1,4‐bpbd ligands, which lie across centres of inversion, to give a 6⁶‐ dia network. Large cavities within a single diamondoid network permit the mutual threefold interpenetration of crystallographically equivalent frameworks. Hydrogen‐bonding interactions between the coordinated water molecules and adp²⁻ carboxylate O atoms anchor the interpenetrating networks into a unique three‐dimensional supramolecular structure. Topologically, taking the coordinated water molecules and Cd^II centres as nodes, the whole architecture can be simplified as a binodal (3,7)‐connected supramolecular framework. The identity of (I) was further characterized by IR spectroscopy, elemental analysis, thermogravimetric analysis and powder X‐ray diffraction. The solid‐state photoluminescence properties of (I) were also investigated.     

Synthesis and characterization of electroactive epoxy‐based interpenetrating polymer network gel

Epoxy/poly(N‐isopropylacrylamide) interpenetrating polymer network gels were prepared by varying the excess amine content in the matrix (0.4–0.6 equivalent). All the samples were characterized for mechanical properties and swelling in distilled water. The topography of polymer network was characterized by atomic force microscopy. The 0.5 equiv. excess amine sample exhibited optimum properties. Studies on swelling at different pH and electroactivity in different aqueous solution were performed. The bending angle observed during first 1 min was 1–5° at 3–10 V and a maximum of 25° in 5 min at 20 V for 0.5 equiv. excess amine in NaCl solution. Copyright © 2011 John Wiley & Sons, Ltd.     

Biphase synthesis of a one‐dimensional coordination polymer based on a dinuclear CdII secondary building unit and a novel semi‐rigid dicarboxylate

A one‐dimensional coordination polymer, namely catena‐poly[[aquapyridinecadmium(II)]‐μ₃‐{4,4′‐[(2,4,6‐trimethyl‐1,3‐phenylene)bis(methylene)]dibenzoato}], [Cd(C₂₅H₂₂O₄)(C₅H₅N)(H₂O)]_n, has been synthesized by a biphasic solvothermal reaction. The Cd^II cation is located in a CdO₅N six‐coordinated environment. The trans 4,4′‐[(2,4,6‐trimethyl‐1,3‐phenylene)bis(methylene)]dibenzoate ligand connects the Cd^II cations to form a one‐dimensional ribbon incorporating centrosymmetric [Cd₂(COO)₂] secondary building units. Inter‐ribbon O—H...O hydrogen bonds extend the one‐dimensional ribbons into a two‐dimensional sheet. No π–π interactions are observed. Comparing products synthesized using a different method, it was found that biphasic solvothermal conditions play a crucial role in obtaining large well‐shaped single crystals; only intractable precipitates were obtained by the traditional single‐phase solvothermal method.     

A novel organic-inorganic hybrid based on a dinuclear copper complex supported on a keggin polyoxometalate

The autoassembly process of copper-oxalate dimers and Keggin type polyoxometalates leads to the first example of a new family of organic-inorganic hybrids, K(14)[(Cu(2)(bpy)(2)(mu-ox))(SiW(11)O(39)Cu(H(2)O))](2)[SiW(11)O(39)Cu(H(2)O)]. approximately 55H(2)O. This compound crystallizes in the monoclinic space group C2/m, a = 37.932(6) A, b = 21.303(3) A, c = 12.546(2) A, beta = 106.16(1) degrees, Z = 2. The crystal structure reveals the presence of a polymeric hybrid built up of alternating dimer and polyoxometalate entities.     

Dielectric properties of self‐catalytic interpenetrating polymer network based on modified bismaleimide and cyanate ester resins

Bismaleimide (BMI) resins with good thermal stability, fire resistance, low water absorption, and good retention of mechanical properties at elevated temperatures, especially in hot/wet environments, have attracted more attention in the electronic and aerospace industries. However, their relatively high dielectric constant limits their application in the aforementioned fields. In this work, a new promising approach is presented that consists of the formation of a self‐catalytic thermoset/thermoset interpenetrating polymer network. Interpenetrating polymer networks (IPNs) based on modified BMI resin (BMI/DBA) and cyanate ester (b10) were synthesized via prepolymerization followed by thermal curing. The self‐catalytic curing mechanism of BMI/DBA‐CE IPN resin systems was examined by differential scanning calorimetry. The dielectric properties of the cured BMI/DBA‐CE IPN resin systems were evaluated by a dielectric analyzer and shown in dielectric properties‐temperature‐log frequency three‐dimensional plots. The effect of temperature and frequency on the dielectric constant of the cured BMI/DBA‐CE IPN resin systems is discussed. The composition effect on the dielectric constant of the cured IPN resin systems was analyzed on the basis of Maxwell's equation and rule of mixture. The obtained BMI/DBA‐CE IPN resin systems have the combined advantages of low dielectric constant and loss, high‐temperature resistance, and good processability, which have many applications in the microelectronic and aerospace industries. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 1123–1134, 2003     

Novel silver‐loaded semi‐interpenetrating polymer network gel films with antibacterial activity

Novel semi‐interpenetrating polymer networks (SIPNs) based on segmented polyurethane‐urea and poly(N‐isopropylacrylamide‐co‐acrylic acid‐co‐butylmethacrylate) (poly(NIPAM‐co‐AA‐BMA)) were synthesized for the fabrication of silver nanoparticles (AgNPs) in the SIPN system that could be useful for wound dressing applications. The obtained SIPN films, after neutralization, showed high swelling in aqueous environments and good mechanical properties in both dry and hydrated states. Analysis of the dried SIPN films by differential scanning calorimetry and dynamic viscoelastic measurements revealed the presence of crosslinked copolymers as well as homopolymers in the SIPN system. The neutralized swollen SIPN film coordinated with the silver ions (Ag⁺) that were incorporated into it. AgNPs were subsequently formed by the reduction of Ag⁺. The formation of AgNPs was characterized by UV‐visible spectroscopy, atomic force microscopy, wide‐angle X‐ray diffraction, and thermogravimetric analysis (TGA). Bactericidal activity tests revealed a distinct zone of microbial inhibition within and around the silver‐doped SIPN films. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4950–4962, 2009     

Synthesis,luminescent sensing based on a three-fold interpenetrating network with flexible carboxylates

A Zn-based complexes with chemical formulae {[Zn(L)_0.5(4,4'-Bipy)] · 2H₂O} (I) (H₄L = 5,5'-(1,4-phenylene-bis(methylene))bis(oxy) diisophthalic acid), has been synthesized and structurally characterized. Single-crystal X-ray crystallography (CIF file CCDC no. 1465538) reveals that compound I shows a three-dimensional three-fold interpenetrating network simplified by a bbf topology (vertex symbol (6⁶)₂(6⁴.8²)). Complex I can work as highly sensitive sensors to Cu²⁺, CrO ₄ ^2- and explosive by luminescent quenching.     

Doubled‐cubic Ca2NF

Crystals of dicalcium nitride fluoride, Ca₂NF, grown from the melt have been characterized by X‐ray diffraction and were found to have a cubic () structure. Owing to ordering of N and F atoms along all three cell axes, the cell edge is doubled relative to the rocksalt‐type structure reported previously. Residual electron density at an interstitial tetrahedral site was refined as a Frenkel defect of F atoms, giving a final composition of Ca₂N(F_0.913)^oct(F_0.087)^tet.     

A twofold interpenetrating three‐dimensional heterometallic metal–organic framework with pcu topology based on 2‐methylbiphenyl‐4,4′‐dicarboxylic acid

The 2‐methylbiphenyl‐4,4′‐dicarboxylate (mbpdc²⁻) ligand has versatile coordination modes and can be used to construct multinuclear structures. Despite this, reports of the synthesis of coordination complexes involving this ligand are scarce. The title compound, poly[[triaquadi‐μ₃‐hydroxido‐hexakis(μ₄‐2‐methylbiphenyl‐4,4′‐dicarboxylato)calcium(II)hexazinc(II)] monohydrate], {[CaZn₆(C₁₅H₁₀O₄)₆(OH)₂(H₂O)₃]·H₂O}_n , has been prepared by the hydrothermal assembly of Zn(NO₃)₂·6H₂O, CaCl₂ and 2‐methylbiphenyl‐4,4′‐dicarboxylic acid. Two Zn^II atoms adopt a four‐coordinated distorted tetrahedral geometry by bonding to three O atoms from three different 2‐methylbiphenyl‐4,4′‐dicarboxylate (mbpdc²⁻) dianionic ligands and one bridging hydroxide O atom. For the remaining Zn^II atom, a five‐coordinate environment is completed half the time by one carboxylate O atom, and then the same carboxylate O atom and an aqua O atom are present the other half of the time, giving a six‐coordinate environment. The Ca^II atom is coordinated by six O atoms to give an octahedral coordination geometry. The supramolecular secondary building unit (SBU) is a hamburger‐like heptanuclear unit (Zn₆CaO₃₀) and these units are interconnected through mbpdc²⁻ carboxylate groups to generate a three‐dimensional framework with the pcu topology. The single net leaves voids that are filled by mutual interpenetration of an independent equivalent framework in a twofold interpenetrating architecture. The title compound shows thermal stability up to 673 K. The excitation and luminescence data showed the emission of a bright‐blue fluorescence.     

A novel small molecule fluorescent sensor for Zn2+ based on pyridine-pyridone scaffold

The development of a water-soluble and small molecular weight fluorescent probe, 3-(4-methoxyphenyl)-4-(methylsulfanyl)-6-(pyridin-2-yl)pyridin-2(1H)-one (3), for detecting Zn²⁺ based on pyridine-pyridone skeleton is reported. We observed a clear chelation enhanced fluorescence effect of 3 in the presence of Zn²⁺. Other fluorescent properties of 3 are discussed.     

A novel cadmium(II) coordination polymer with a four‐connected (4,4)‐net based on a trinuclear cadmium(II) node

In the title cadmium(II) coordination polymer, poly[tri‐μ₄‐adipato‐bis(2‐phenyl‐1H‐1,3,7,8‐tetraazacyclopenta[l]phenanthrene‐κ²N⁷,N⁸)tricadmium(II)], [Cd₃(C₆H₈O₄)₃(C₁₉H₁₂N₄)₂]_n, one of the Cd atoms is in a distorted pentagonal bipyramidal coordination environment, surrounded by five O atoms from three adipate (adip) ligands and two N atoms from one 2‐phenyl‐1H‐1,3,7,8‐tetraazacyclopenta[l]phenanthrene (L) ligand. A second Cd atom occupies an inversion center and is coordinated by six O atoms from six adip ligands in a distorted octahedral geometry. The carboxylate ends of the adip ligands link Cd^II atoms to form unique trinuclear Cd^II clusters, which are further bridged by the adip linkers to produce a two‐dimensional layer structure. Topologically, each trinuclear Cd^II cluster is connected to four others through six adip ligands, thus resulting in a unique two‐dimensional four‐connected framework of (4,4)‐topology. This work may help the development of the coordination chemistry of 1,10‐phenanthroline derivatives.     

Hydrogel‐like elastic membrane consisting of semi‐interpenetrating polymer networks based on a phosphorylcholine polymer and a segmented polyurethane

To obtain a hydrogel‐like elastic membrane, we prepared semi‐interpenetrating polymer networks (IPNs) by the radical polymerization of methacrylates such as 2‐methacryloyloxyethyl phosphorylcholine (MPC), 2‐hydroxyethylmethacrylate, and triethyleneglycol dimethacrylate diffused into segmented polyurethane (SPU) membranes swollen with a monomer mixture. The values of Young's modulus for the hydrated semi‐IPN membranes were less than that for an SPU membrane because of higher hydration, but they were much higher than that for a hydrated MPC polymer gel (non‐SPU). According to a thermal analysis, the MPC polymer influenced the segment association of SPU. The diffusion coefficient of 8‐anilino‐1‐naphthalenesulfonic acid sodium salt from the semi‐IPN membrane could be controlled with different MPC unit concentrations in the membrane, and it was about 7 × 10² times higher than that of the SPU membrane. Fibroblast cell adhesion on the semi‐IPN membrane was effectively reduced by the MPC units. We concluded that semi‐IPNs composed of the MPC polymer and SPU may be novel polymer materials possessing attractive mechanical, diffusive‐release, and nonbiofouling properties. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 68–75, 2003     

A novel dinuclear MoVI complex with tris(3,5‐dimethyl‐1H‐pyrazol‐1‐yl)methane

Recrystallization of [MoO₂Cl{HC(3,5‐Me₂pz)₃}]Cl [where HC(3,5‐Me₂pz)₃ is tris(3,5‐dimethyl‐1H‐pyrazol‐1‐yl)methane] led to the isolation of large quantities of the dinuclear complex dichlorido‐2κ²Cl‐μ‐oxido‐κ²O:O‐tetraoxido‐1κ²O,2κ²O‐[tris(3,5‐dimethyl‐1H‐pyrazol‐1‐yl‐1κN²)methane]dimolybdenum(IV) acetonitrile monosolvate, [Mo₂Cl₂O₄(C₁₆H₂₂N₆)]·CH₃CN or [{MoO₂Cl₂}(μ₂‐O){MoO₂[HC(3,5‐Me₂pz)₃]}]·CH₃CN. At 150 K, this complex cocrystallizes in the orthorhombic space group Pbcm with an acetonitrile molecule. The complex has mirror symmetry: only half of the complex constitutes the asymmetric unit and all the heavy elements (namely Mo and Cl) are located on the mirror plane. The acetonitrile molecule also lies on a mirror plane. The two crystallographically independent Mo⁶⁺ centres have drastically different coordination environments: while one Mo atom is hexacoordinated and chelated to HC(3,5‐Me₂pz)₃ (which occupies one face of the octahedron), the other Mo atom is instead pentacoordinated, having two chloride anions in the apical positions of the distorted trigonal bipyramid. This latter coordination mode of Mo^VI was found to be unprecedented. Individual complexes and solvent molecules are close‐packed in the solid state, mediated by various supramolecular contacts.     

Synthesis and characterization of a novel chitosan‐based network prepared using naturally occurring crosslinker

Novel chitosan‐based polymeric networks were synthesized and characterized by FTIR, UV and C¹³ NMR. A naturally occurring crosslinking reagent—genipin, which has been used in herbal medicine and in the fabrication of food dyes, was used to prepare crosslinked chitosan hydrogel. The heterocyclic compound of genipin crosslinked chitosan was formed by a nucleophilic attack by amino group on the olefinic carbon atom at C‐3 of deoxyloganin aglycone, followed by opening of the dihydropyran ring and attack by the secondary amine group on the intermediate aldehyde group. Additional, secondary amide linkages could be established in the genipin crosslinked chitosan network by the reaction of ester group of genipin with amino group of chitosan. This bifunctional linkages of genipin with amino group of chitosan leads to form crosslinked networks. Genipin reacted with nucleophilic reagent such as chitosan could further go through a polymerization to form oligomer‐bridge in the crosslinked network. The finally formed chitosan networks are blue color, elastic and exhibits pH‐dependent swelling characteristics. The swelling ratio of the chitosan hydrogel increased at pH lower than 3 and higher than 11 due to the hydrolysis of amide linkage in the genipin crosslinked chitosan network by acid or alkaline, followed by the protonation of amine group or ionization of carboxyl acid group in the network. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2804–2814, 2000     

A novel parallel interpenetrating two‐dimensional (4,4) network: poly[[μ2‐1,4‐bis(imidazol‐1‐ylmethyl)benzene](μ2‐naphthalene‐1,4‐dicarboxylato)zinc(II)]

In the title coordination compound, [Zn(C₁₂H₆O₄)(C₁₄H₁₄N₄)]_n, the two Zn^II centers exhibit different coordination environments. One Zn^II center is four‐coordinated in a distorted tetrahedral environment surrounded by two carboxylate O atoms from two different naphthalene‐1,4‐dicarboxylate (1,4‐ndc) anions and two N atoms from two distinct 1,4‐bis(imidazol‐1‐ylmethyl)benzene (1,4‐bix) ligands. The coordination of the second Zn^II center comprises two N atoms from two different 1,4‐bix ligands and three carboxylate O atoms from two different 1,4‐ndc ligands in a highly distorted square‐pyramidal environment. The 1,4‐bix ligand and the 1,4‐ndc anion link adjacent Zn^II centers into a two‐dimensional four‐connected (4,4) network. The two (4,4) networks are interpenetrated in a parallel mode.     

Synthesis,characterization, and biodegradability of novel regular‐network polyester‐amines based on 1,1,1‐triethanolamine

Regular‐network polyester‐amines were prepared from 1,1,1‐triethanolamine (Y_N) and various dicarboxylic acids [HOOC? (CH₂)_n?2? COOH, n = 6–14]. A prepolymer prepared by melt polycondensation was cast from dimethylformamide solution and postpolymerized at 220 °C in a nitrogen flow for various periods of time to form a network. The resultant films were transparent, flexible, and insoluble in organic solvents. The network polyester‐amines obtained were characterized by infrared absorption spectra, wide‐angle X‐ray diffraction analysis, density, DSC, and thermomechanical analysis. The biodegradation experiments for the network polyester‐amine films were carried out in enzymatic solution with Rhizopus delemar or Pseudomonas cepacia lipase and in an activated sludge. The degree and rate of biodegradation were estimated by the weight loss of the films. After incubation in Rhizopus delemar lipase solution for 24 h, weight loss was hardly observed for Y_N6–7, whereas it increased greatly for Y_N8–13 (13–51 g/m²), and then it decreased rapidly for Y_N14. The methylene‐chain dependence of degradation was essentially the same as in the case of network polyesters from glycerol and various aliphatic dicarboxylic acids reported previously. Psedomonas cepacia lipases also degraded Y_Nn films, but the rate of degradation was much slower than Rhizopus delemar lipase. In the exposure to activated sludge for 30 days, the network polyester films with medium methylene‐chain lengths (Y_N7–11) showed the lager weight loss, as in the case of the enzymatic degradation, whereas the rate of biodegradation was much slower than that of the enzymatic degradation with Rhizopus delemar lipase. The effect of the protonation of the film with hydrochloric acid on the enzymatic degradation was also examined. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2896–2903, 2001     

A novel two‐dimensional (4,4) network based on dinuclear cadmium secondary building units: poly[(μ5‐benzene‐1,4‐diacetato)[μ2‐1,4‐bis(1,2,4‐triazol‐1‐yl)butane]cadmium(II)]

In the title mixed‐ligand metal–organic polymeric compound, [Cd(C₁₀H₈O₄)(C₈H₁₂N₆)]_n or [Cd(PBEA)(BTB)]_n [H₂PBEA is benzene‐1,4‐diacetic acid and BTB is 1,4‐bis(1,2,4‐triazol‐1‐yl)butane], the asymmetric unit contains one Cd^II ion, one BTB molecule and one PBEA²⁻ anion. The Cd^II ion is in a slightly distorted pentagonal–bipyramidal geometry, coordinated by five carboxylate O atoms from three distinct PBEA²⁻ anions and by two BTB N atoms. There are two coordination patterns for the carboxylate groups of the PBEA²⁻ ligand, one being a μ₁‐η¹:η¹ chelating mode and the other a μ₂‐η²:η¹ bridging mode, while the BTB molecule shows a trans–trans–trans conformation. The crystal structure is constructed from the secondary building unit (SBU) [Cd₂(CO₂)₄N₂O₂], in which the two metal centres are held together by two PBEA²⁻ linkers. The SBU is connected by BTB and PBEA²⁻ bridges to form a two‐dimensional grid‐like (4,4) layer with meshes of dimensions 14.69 × 11.28 Å.     

A novel ionic‐conduction mechanism based on polyurethane electrolyte

A series of poly(ethylene glycol)–polyurethane (PEG–PU)/sodium perchlorate (NaClO₄) solid electrolytes were prepared, and their properties were characterized with Fourier transform infrared spectroscopy, differential scanning calorimetry, complex impedance analysis, and atomic force microscopy. Results showed that the oxygen atoms of carbonyl and ether oxygen groups had different activities on cations. Both carbonyl and ether oxygen groups participated in the ionic‐transport process in PU‐based electrolytes. There existed a coordination competition between sodium cations and different oxygen atoms in soft and hard segments of PU. For the PEG–PU/NaClO₄ system investigated, amorphous regions and interfacial regions between the amorphous and microcrystalline phases were responsible for ionic conduction. A new ionic‐transport mechanism, based on the existence of conduction pathways not only in amorphous regions but also in interfacial regions of microphase‐separated PU‐based electrolytes, is sketched. Moreover, at a particular concentration of doped salt (EO/NaClO₄ 12), the PEG–PU/NaClO₄ complex revealed a phase‐transition point in the morphology and exhibited minimum apparent activation energy and maximum ionic conductivity. © 2001 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 39: 1246–1254, 2001     

Two novel lead(II) complexes of 2‐(hydroxymethyl)pyridine: a threefold diamondoid supramolecular network based on Pb4O4 cores and a two‐dimensional (4,4) network based on Pb2O2 units

Reactions of 2‐(hydroxymethyl)pyridine (Hhmp) with PbCl₂ and Pb(NO₃)₂ at room temperature led to the formation of two novel compounds, namely tetrakis[μ₃‐(pyridin‐2‐yl)methanolato]‐tetrahedro‐tetrakis[chloridolead(II)], [Pb₄(C₆H₆NO)₄Cl₄], (I), and poly[(μ₂‐nitrato)[μ₂‐(pyridin‐2‐yl)methanolato]lead(II)], [Pb(C₆H₆NO)(NO₃)]_n, (II). Compound (I) exhibits a tetranuclear Pb₄O₄ cubane structure, which is connected through π–π stacking interactions between the pyridine groups of the (pyridin‐2‐yl)methanolate (hmp⁻) ligands and through C—H...Cl interactions to form an interesting threefold diamondoid network. Compound (II) possesses two‐dimensional (4,4)‐sql topology based on a Pb₂O₂ unit, which is further extended into a three‐dimensional supramolecular network through π–π stacking interactions between adjacent pyridine rings and through C—H...O interactions between the pyridine C atoms of the hmp⁻ ligands and the nitrate anions.     

Structural characterization and photochromic behaviour of a novel compound based on a π‐acidic naphthalene diimide derivative and a double hydroxide‐bridged dinuclear AlIII aqua ion cluster

Noncovalent interactions, such as π–π stacking interactions, C—H…π interactions and hydrogen bonding, are important driving forces for self‐assembly in the construction of functional supermolecules and materials, especially in multicomponent supramolecular systems. Herein, a novel compound based on a π‐acidic naphthalene diimide derivative and a double hydroxide‐bridged dinuclear Al³⁺ aqua ion cluster, namely bis[N,N′‐bis(2‐sulfonatoethyl)‐1,4,5,8‐naphthalene diimide] di‐μ‐hydroxido‐bis[tetraaquaaluminium(III)] tetrahydrate, (C₁₈H₁₂N₂O₁₀S₂)₂[Al₂(OH)₂(H₂O)₈]·4H₂O, was obtained using the above‐mentioned common noncovalent interactions, as well as uncommon lone‐pair–π interactions. Functional molecular modules were connected by these noncovalent interactions to generate obvious photochromic properties. The compound was prepared by the self‐assembly of N,N′‐bis(2‐sulfoethyl)‐1,4,5,8‐naphthalene diimide and Al(NO₃)₃·9H₂O under mixed solvothermal conditions, and was characterized in detail by single‐crystal X‐ray diffraction, powder X‐ray diffraction and FT–IR spectroscopy. The thermal stability and photochromic properties were also investigated; furthermore, in‐situ solid‐state UV–Vis absorption spectroscopy and electron spin resonance (ESR) were used to clarify the photochromic mechanism.