Ionothermal reactions of 1,4-benzenedicarboxylic acid (H2BDC) and 4,4′-biphenyldicarboxylic (H2BPDC) with Mn(OAc)2 resulted in 12 compounds divided into four kinds of structural models: [RMI]2[Mn3(BDC)3X2] (1–5, type A), [EMI]2[Mn3(BPDC)4] (6, type B), [RMI]2[Mn2(BPDC)3(H2O)3] (7–9, type C) and [RMI]6[Mn9(BPDC)9(HBPDC)2(OAc)4] (10–12, type D). A combination effect of ligands and IL components can be observed in the structural construction, which also is reflected in the properties of thermal stability and fluorescence. The decomposition temperatures of Mn–BDC compounds are higher than those of Mn–BPDC compounds. The decomposition temperatures decrease with the alkyl chain in [RMI]+, due to a +I inductive effect. The maximum emissions of compounds 1–5 and 6–12 located at ca. 410 or 407 nm are assigned to ILCT of H2BDC and H2BPDC ligands, respectively.

•This work presents six d10-metal coordination polymers based on mixed 5-sulfoisophthalate and 1,2,4-triazole ligands.•The compounds show a mixed ligand directed structure diversity.•The compounds exhibit high thermal stability, blue fluorescence and fluorescence thermal quenching.This work presents six d10-metal coordination polymers based on mixed ligands of 5-sulfoisophthalate (H2SIP–) and 1,2,4-triazoles (1H-1,2,4-triazole (Htr), 3-amino-1H-1,2,4-triazole (Hatr)), 3D [Zn7(SIP)2(tr)8(H2O)4]·4H2O (1), 3D [Zn4(SIP)(atr)5(H2O)2]·3H2O (2), 2D [Zn2(SIP)(atr)(H2O)3]·2H2O (3), 2D [Ag(H2SIP)(Hatr)] (4 and 5), and 3D [Cd3(SIP)(tr)2(OH)]·H2O (6) under hydrothermal conditions. The structural analysis indicates a ligand directed structural diversity in the metal-(H)SIP-triazole system. The characterizations of 1–6 indicate that the bulk samples are pure phases, the thermal decomposition temperatures are beyond 300 °C, and the fluorescence are blue. The maximum emissions of 1–3 and 6 at around 410 nm are related with the intraligand π→π* transitions of 1,2,4-triazole moieties, and those at ca. 350 nm in 4 and 5 are assigned to intraligand transitions of (H)SIP ligands. The temperature-dependent fluorescence of 1–6 show thermal quenchings with fluorescence quenching rates ranging 22.9–74.2%, and the fluorescence cannot recover fully when it is back to ambient temperature.This work presents six d10-metal coordination polymers based on mixed ligands of 5-sulfoisophthalate and 1,2,4-triazoles, which show a structure diversity, high thermal stabilities, and blue florescence.Download high-res image (281KB)Download full-size image

Hydrothermal syntheses of 2-carboxyethyl(phenyl)phosphinic acid (H2CEPPA) with Bi(NO3)3 and Cd(NO3)2 produce two layered complexes [Bi2(μ3-O)(CEPPA)2]n (1) and [Cd(HCEPPA)2]n (2). Compound 1 is comprised of [Bi4(μ3-O)2(POO)4(COO)4] SBUs which grow into a double wave-like 2D layer with–CH2CH2–spacers. Compound 2 crystallizes in the orthorhombic noncentrosymmetric space group Pca21, exhibiting a double lattice-like layer. Through edge-to-face d∙∙∙π stacking, a 3D supramolecular framework is formed based on 2D lattices. Topological analyses indicate that 1 and 2 have sql (or Shubnikov tetragonal plane net) and kgd (or Shubnikov (3.6.3.6) plane net) topological networks respectively. 1 and 2 are isolated as single crystal pure phases, which is confirmed by powder XRD. TGA shows high thermal stabilities with decomposition temperatures of 1 and 2 being 373 and 303°C respectively. The fluorescent spectra exhibit fluorescence quenching in 1 and sharp emission at 292 nm in 2, which is assigned to intraligand emission.

Two types of 2D [RMI]2[Zn3(BDC)3X2] (Type A) and 3D [Zn(BDC)(H2O)] (Type B) (H2BDC = 1,4-benzenedicarboxylate acid) compounds were synthesized with three kinds of 1-alkyl-3-methyl imidazolium halide ([RMI]X) ionic liquids. Type A is the primary structure model showing a (3,6) network. Type B can be obtained from [BMI]Cl, [AMI]Cl and [AMI]Br media, showing a 4,4-connected {42·84} network. The structure, TG, and fluorescence analyses demonstrate the combination effect of the RMI+ templating effect and X− controlling the structure types. The boundary between Types A and B is from [PMI]Cl, via [BMI]Br, to [AMI]I as the reaction media. The decomposition temperatures of the compounds in Type A decrease with increased RMI+, while X− anions exert the influence that compounds containing Br− supply the highest thermal stability. Similarly, with increased RMI+, or X = I−, the compounds show red shifts compared to the emissions of the ligand.

•Two discrete ring-like and one layered compounds were ionothermally synthesized.•Metal species, metal concentration and soaking time deconstruct the H-bondings in 1.•1 can be transformed to 3 through ionothermal reaction, otherwise forbidden.Ionothermal reactions of 1,3,5-benzenetricarboxylate acid (H3BTC) and Ni(NO3)2, Co(NO3)2 and Cu(NO3)2 gave two discrete 32-membered ring-like allomers, [M2(HBTC)2(NH2CONH2)2(H2O)4]·3H2O (M=Ni(1), Co(2)) and one layered [Cu2(BTC)Cl(H2O)4] (3). The weak interactions in 1 can be deconstructed to some degree in ion exchange by exploring the factors of divalent and trivalent metal species, metal concentration and soaking time, which are demonstrated by PXRD and N2 absorption. Cu2+ has the highest N2 adsorbance when soaking with 1, and 1 can keep structure stable when Cu2+ below 0.16 mol L−1 and the soaking time within 24d. As Cu2+ beyond 0.16 mol L−1 and the soaking time beyond 24d, the structure of compound 1 starts to transform with the crystal morphology from clear pale green to opaque blue. Ionothermal reactions of compound 1 with different Cu2+ amounts obtained Ni2+-Cu2+ hetero complexes, whose PXRD patterns are similar to that of 3 and EDS indicates Cu2+% increases with Cu2+ additions and close to 100% as Cu2+ being 1.6 mmol. It suggests that 3 is a controlled product and Cu2+ can transform discrete compound 1 into 2D compound 3.Three compounds were synthesized through ionothermal reactions. The weak interactions in compound 1 can be deconstructed by ion exchange and discrete compound 1 can be transformed into layered compound 3.

Two types of 2D [RMI]2[Zn3(BDC)3X2] (Type A) and 3D [Zn(BDC)(H2O)] (Type B) (H2BDC = 1,4-benzenedicarboxylate acid) compounds were synthesized with three kinds of 1-alkyl-3-methyl imidazolium halide ([RMI]X) ionic liquids. Type A is the primary structure model showing a (3,6) network. Type B can be obtained from [BMI]Cl, [AMI]Cl and [AMI]Br media, showing a 4,4-connected {42·84} network. The structure, TG, and fluorescence analyses demonstrate the combination effect of the RMI+ templating effect and X− controlling the structure types. The boundary between Types A and B is from [PMI]Cl, via [BMI]Br, to [AMI]I as the reaction media. The decomposition temperatures of the compounds in Type A decrease with increased RMI+, while X− anions exert the influence that compounds containing Br− supply the highest thermal stability. Similarly, with increased RMI+, or X = I−, the compounds show red shifts compared to the emissions of the ligand.