Based on a strategy of incorporating the SCN− group into the organically templated halocadmate, the reactions of CdCl2, SCN−, and bisimidazole molecules in a strong acidic environment at 4 °C were carried out, creating two new organically templated 2-D layered thiocyanato-chlorocadmates [H2(L1)][Cd2Cl5(SCN)] (L1 = bis(1H-imidazole-1-yl)methane) 1 and [H2L2]2[Cd5Cl12(SCN)2] (L2 = 1,3-bis(2-ethylimidazol-1-yl)propane) 2. Both layers are based on a kind of tetranuclear Cd–Cl cluster. Since the employed organic cations are different, the neighboring tetranuclear Cd–Cl clusters are linked together by the different bridges into the 1-D endless chains. In 1, the Cl− ions act as the bridges, while in 2, the CdCl6 units serve as the bridges. Finally, the 1-D Cd–Cl chains are further linked by SCN− into the 2-D layer networks of 1 and 2. Both layers possess a simple (4,4) topology. Based on the structural characterization of the title compounds, the role of the introduced SCN− group on the organically templated halocadmates is discussed.Two rare organically templated 2-D layered thiocyanato-chlorocadmates were synthesized, and their structures were reported.Download high-res image (101KB)Download full-size image

Under hydrothermal conditions, the simple self-assembly of Ni2+, H2C2O4 and N2H4 created a new 3-D Ni2+ coordination polymer, [Ni(C2O4)(N2H4)]·H2O (C2O42− = oxalate, N2H4 = hydrazine) 1, in which C2O42− ligands link Ni2+ ions into a left-hand helical Ni(C2O4) chain, while N2H4 extends the Ni(C2O4) chains into a 3-D network with a 103 topology. A magnetic susceptibility study indicates that between the neighboring Ni2+ centers, there exist antiferromagnetic interactions.The structural characterization of a new 3-D Ni2+ coordination polymer co-constructed from C2O42− and N2H4 ligands is reported, and its magnetic property was investigated.Download high-res image (235KB)Download full-size image

•Structural characterization of five copper(I) iodides with bisimidazole molecules is reported.•Effect of bisimidazole molecules on copper(I)-iodo topologies and polymeric networks is discussed.•Their photoluminescence properties are investigated.The hydro(solvo)thermal reactions of CuI with diverse bisimidazole molecules were investigated, affording five new copper(I) iodides [Cu4I4(L1)2] (L1=1,3-bis(2-methylimidazol-1-ylmethyl)benzene) 1, [CuI(L2)] (L2=4,4′-bis(imidazolyl)biphenyl) 2, [Cu4I4(L3)] (L3=1,3-bis(2-methylimidazol-1-yl)propane) 3, [Cu4I4(L4)2] (L4=1,4-bis(2-ethylimidazol-1-yl)butane) 4, and [Cu4I4(L5)] (L5=1,4-bis(1-imidazoly)benzene) 5. X-ray single-crystal diffraction analysis reveals that (i) in 1, a tetranuclear Cu-I cluster (stepped cubane) is observed, and the L1 molecule only acts as an ancillary ligand; (ii) in 2, the L2 molecules extend the castellated Cu-I chains into a 2-D layer network with a certain thickness; (iii) in 2-D single-layer network of 3, a 1-D Cu-I column is found, which can be viewed as a longitudinal packing of stepped Cu4I4 cubanes; (vi) in 4, the L4 molecules propagate the cubic Cu4I4 cubanes into a 3-D 4-fold interpenetrated network with a cds topology; and (v) in 5, the L5 molecules link the 1-D Cu-I ribbons into a 2-D single-layer network. The photoluminescence analysis indicates that 1, 2 and 4 emit light (red light for 1; yellow light for 2 and 4), while 3 and 5 are not emissive. Their photoluminescence behaviors are confirmed to be related to the Cu···Cu interactions in the molecules.Structural characterization of five new copper(I) iodides with bisimidazole molecules are reported, and their photoluminescence properties are investigated.Download high-res image (303KB)Download full-size image

Through employing the solvothermal in situ N-alkylation of organic bases with alcohol molecules, four new iodometallates [L1]2[Ag8I12]I2 (L13+ = 1,1′,1′′-(benzene-1,3,5)tris(3-methyl-1H-imidazol-3-ium)) 1, [L1]2[Ag6I12] 2, [L1]2[Pb3I12]·2H2O 3, and [L1][Bi2I9] 4 were obtained. L13+ originates from the in situ N-alkylation between 1,3,5-tri(1H-imidazol-1-yl)benzene (L2) and CH3OH. X-ray single-crystal diffraction analysis reveals that all of the title compounds possess zero-dimensional (0D) structures. The octanuclear anionic cluster [Ag8I12]4− of 1 possesses a sphere-like structure. An Ag6I6 unit with a hexagram structure occupies the equatorial position, while two AgI4 tetrahedra (sharing point) occupy the axial positions. The anionic cluster, [Ag6I12]6−, of 2 exhibits a hexanuclear structure, which can be described as an aggregation of two incomplete cubanes (each lacking an Ag+ corner). The anionic cluster [Pb3I12]6− of 3 can be described as an aggregation of three PbI6 octahedra (sharing face), whereas two BiI6 octahedra (also sharing face) aggregate to form a dinuclear cluster [Bi2I9]3− of 4.

Two hybrid compounds, namely [CuI4(3atrz)4][PMoVI11MoVO40] (1) and [CuI6(3atrz)6][PMo12O40]2 (2), were synthesized through hydrothermal reactions of 3-amino-1,2,4-triazole (3atrz), phosphomolybdic acid (PMA) and appropriate copper salts. Crystal structure analysis reveals that compound 1 contains one-dimensional Cu-3atrz chains. The unit of compound 2 contains a double calyx[3]arene-shaped hexamer, which is composed of six two-coordinated CuI atoms and six 3atrz ligands. Both compounds 1 and 2 present a three-dimensional hybrid structure, which is built by the self-assembly of Cu-3atrz clusters and Keggin-type PMA units. The resulting hybrid compounds can act as highly efficient heterogeneous catalysts for the selective oxidation of olefins with molecular oxygen as the oxidant in the presence of a trace amount of tert-butyl hydroperoxide (t-BuOOH). Their excellent catalytic properties can be mainly attributed to the existence of stabilized CuI complexes with an appropriate chemical environment and a spacious structure, which can interact with t-BuOOH to form catalytic sites for the direct activation of O2. This work demonstrates that the hybrid compounds assembled from copper-3atrz complexes and phosphomolybdic acid may have great potential in molecular O2-mediated catalytic oxidation reactions, which can certainly build a platform for deep insight into the biologically relevant catalytic oxidation processes.

•In situ acylation of two ortho-position carboxylic groups with N2H4 can produce acylhydrazide molecule.•Structural characterization of three acylhydrazidate-coordinated complexes is reported.•Structural characterization of two acylhydrazide molecules is reported.•Character of acylhydrazide molecule is revealed.By utilizing the hydrothermal in situ acylation of organic acids with N2H4, three acylhydrazidate-coordinated compounds [Mn(L1)2(H2O)2] (L1 = 2,3-quinolinedicarboxylhydrazidate; HL1 = 2,3-dihydropyridazino[4,5-b] quinoline-1,4-dione) 1, [Mn2(ox)(L2)2(H2O)6]·2H2O (L2 = benzimidazolate-5,6-dicarboxylhydrazide; HL2 = 6,7-dihydro-1H-imidazo[4,5-g]phthalazine-5,8-dione; ox = oxalate) 2, and [Cd(HL3)(bpy)] (L3 = 4,5-di(3′-carboxylphenyl)phthalhydrazidate; H3L3 = 6,7-dihydro-1H-imidazo[4,5-g]phthalazine-5,8-dione; bpy = 2,2′-bipyridine) 3, as well as two acylhydrazide molecules L4 (L4 = oxepino[2,3,4-de:7,6,5-d′e′]diphthalazine-4,10(5H,9H)-dione) 4 and L5 (L5 = 4,5-dibromophthalhydrazide; L5 = 6,7-dibromo-2,3-dihydrophthalazine-1,4-dione) 5 were obtained. X-ray single-crystal diffraction analysis reveals that (i) 1 only possesses a mononuclear structure, but it self-assembles into a 2-D supramolecular network via the NhydrazineH ⋯ Nhydrazine and OwH ⋯ Ohydroxylimino interactions; (ii) 2 exhibits a dinuclear structure. Ox acts as the linker, while L2 just serves as a terminal ligand; (iii) In 3, L3 acts as a 3-connected node to propagate the 7-coordinated Cd2 + centers into a 1-D double-chain structure; (iv) 4 is a special acylhydrazide molecule. Two OH groups for the intermediates 3,3′-biphthalhydrazide further lose one water molecule to form 4; (v) 5 is a common monoacylhydrazide molecule. Via the NhydrazineH ⋯ Ohydrazine, OhydroxyliminoH ⋯ Oacylamino and the π ⋯ π interactions, it self-assembles into a 2-D supramolecular network. The photoluminescence analysis reveals that 4 emits light with the maxima at 510 nm.By employing IR spectrum, TG curve, powder XRD pattern, X-ray single-crystal diffraction analysis, and photoluminescence analysis, structural characterization of three acylhydrazidate-coordinated complexes and two acylhydrazide molecules is revealed.

•A Zn2 + CP was solvothermally synthesized.•Its structure was revealed.•Its sensing ability on NB was investigated.A new 3-D Zn2 + coordination polymer (CP) [(CH3)2NH2]3[Zn6(ox)4.5(trz)6]⋅ 4H2O (ox = oxalate; trz = 1,2,4-triazolate) 1 was obtained by a simple solvothermal self-assembly. The crystal structural analysis demonstrates that the trz molecules link the Zn2 + ions into a two-dimensional (2-D) layer network, which is based on the trinuclear Zn3(trz)6 clusters. The ox molecules serve as the linkers to propagate the 2-D layers into a three-dimensional (3-D) network of 1. The thermogravimetry (TG) behavior, photoluminescence property, and the sensing ability of 1 are investigated. The sensing experiment on nitrobenzene (NB) reveals that 1 can serve as a fluorescence probe to detect NB at the ppm concentration.A 3-D Zn2 + CP was solvothermally synthesized, its structure was revealed, and its sensing ability was investigated.

Under hydro(solvo)thermal conditions, the reactions between transition-metal salts and tetracarboxylic acid molecules, with the assistance of organic base molecules, created three new coordination polymers, namely [H2(bpp)]2[Zn2(sph)2]·H2O (sph = 4,4′-sulfonediphthalate, bpp = 1,3-bis(piperidyl)propane) 1, [H2(bpp)]2[Ni2(oph)2(H2O)2]·2H2O (oph = 4,4′-oxydiphthalate) 2 and [H2(bpe)]2[Ni(Hfph)2(bpe)] (bpe = 1,2-bis(pyridyl)ethylene; fph = 4,4′-(hexafluoroisopropylidene)diphthalate) 3. X-ray single-crystal diffraction analysis reveals that (i) in 1, the diprotonated bpp molecule acts as a templating agent. The quadruple-bridged sph molecules propagate the tetrahedral Zn2+ ions into a 2-D layer network in 1, where two types of circle loops are found; (ii) in 2, the bpp molecule is also diprotonated. The triple-bridged oph molecules extend the octahedrally coordinated Ni2+ ions into a 2-D layer network, in which a carboxylate-bridged Ni2+ chain is observed; (iii) in 3, the non-protonated bpe molecules link the Ni2+ ions into a 1-D linear chain. The diprotonated bpe molecule acts as the countercation, while the fph molecule serves as the chelating ligand, existing in the form of Hfph3−; and (iv) the 2-D layers for 1 and 2 can both be simplified as a (4,4) net. The photoluminescence analysis reveals that 1 emits blue light with a maximum at 415 nm upon excitation at 355 nm. A magnetic property investigation indicates that antiferromagnetic interactions exist between the Ni2+ ions in 2.Structural characterization of three new semi-rigid tetracarboxylate-containing transition-metal coordination polymers is reported. The photoluminescence behavior of the Zn2+ complex and the magnetic properties of the Ni2+ complex are investigated.

Under hydro(solvo)thermal conditions, two 4-(4-carboxyphenoxy)phthalate-based three-dimensional (3-D) coordination polymers: [Cd3(cpph)2(bpa)2(H2O)]·0.5H2O (cpph = 4-(4-carboxyphenoxy)phthalate, bpa = 1,2-bis(4-pyridyl)ethane) 1, and [H2(bpp)][Mn2(cpph)2(H2O)2] (bpp = 1,2-bis(4-piperidyl)propane) 2 were isolated. In both compounds, the cpph molecules extend the metal ions into a 3-D network: a (4,6)-connected net for 1 and a simple 6-connected net with a pcu topology for 2. The introduced bpa or bpp molecule stabilizes the 3-D metal-cpph architecture in the form of linker or guest molecule. The sensing ability of 1 was investigated, revealing that it can be used as a fluorescence probe to sense nitrobenzene at ppm concentrations.

With various organic base molecules as the countercations, five new thiocyanatocadmates [H2(tmen)][Cd(SCN)4] (tmen = N,N,N′,N′-tetramethylethylenediamine) 1, [H2(tmba)][Cd2(SCN)6] (tmba = N,N,N′,N′-tetramethyl-1,4-butanediamine) 2, [H2(teen)][Cd2(SCN)6] (teen = N,N,N′,N′-tetra-ethylethylenediamine) 3, [H(amp)][Cd(SCN)2(CH3COO)] (amp = 2-amino-6-methylpyridine) 4 and [H(abp)]4[Cd(SCN)4]SO4·H2O (abp = 2-amino-6-bromopyridine) 5, and one new chlorocuprate(II) [H2(cha)][CuCl4] (cha = 1,4-cyclohexanediamine) 6 were obtained from a series of simple room-temperature self-assemblies at pH = 2 or 6.5. X-ray single-crystal diffraction analysis reveals that (i) templated by [(CH3)2NH(CH2)2NH(CH3)2]2+ (H2(tmen)2+), the anion [Cd(SCN)4]2− in 1 shows a 1-D linear single-chain structure, whereas templated by [(CH3)2NH(CH2)4NH(CH3)2]2+ (H2(tmba)2+), the anion [Cd2(SCN)6]2− in 2 shows a 1-D linear double-chain structure. The number of C atoms between the two N atoms in the templating agent controls the width of the anionic chain through the Namino–H⋯NSCN interactions; (ii) templated by [(C2H5)2NH(CH2)2NH(C2H5)2]2+ (H2(teen)2+), the anion [Cd2(SCN)6]2− in 3 exhibits a 3-D open-framework structure, which is based on zigzag anionic chains. A direct change of the substituent group from –CH3 to –C2H5 alters indirectly the shape of the anionic chain from a linear shape to a zigzag shape; (iii) 4 shows a 3-D supramolecular network structure, which is built up from the 1-D zigzag anionic structures by the H(amp)+ molecules via N–H⋯O interactions. The formation of the zigzag chain derives from the chelation of the CH3COO− groups to the Cd2+ centers; (iv) 5 is indeed a double salt of [H(abp)]2[Cd(SCN)4] and [H(abp)]2SO4. SO42− and H(abp)+ form a supramolecular aggregation. Surrounded by the aggregations, the anion [Cd(SCN)4]2− only shows a dinuclear structure; and (v) templated by H2(cha)2+, the anion [CuCl4]2− in 6 displays a 2-D perovskite layer structure. The photoluminescence analysis indicates that upon excitation (λex = 335 nm for 4, λex = 395 nm for 5), 4 and 5 emit light (λem = 365 nm for 4, λem = 470 nm for 5), which can be seen clearly under the UV lamp.

Under ambient conditions, reactions of CdCl2/Cd(CH3COO)2, SCN− and various organic amine molecules in strongly acidic solutions afforded the five new thiocyanatocadmates [H2(abpy)][CdCl2(SCN)2] (abpy = azobispyridine) 1, [H(apy)][Cd(SCN)3] (apy = 4-aminopyridine) 2, [H(ba)]2[CdCl2(SCN)2] (ba = tert-butylamine) 3, [H2(tmen)][Cd3Cl6(SCN)2] (tmen = N,N,N′,N′-tetramethylethylenediamine) 4, and [H(dba)]2[Cd2(CH3COO)2(SCN)4] (dba = dibutylamine) 5. In compound 2 only, the CH3COO− ions in Cd(CH3COO)2 were completely displaced by SCN−, producing a chained thiocyanatocadmate [Cd(SCN)3]−. In the other four compounds, the Cl− or CH3COO− ions appeared in the final inorganic anion frameworks. In compound 1, the Cl− ions doubly bridge the Cd2+ centers, forming a one-dimensional (1-D) infinite chain, and the SCN− group exists in a terminal form, whereas in compound 3, the reverse situation is observed. Due to a trans-mode arrangement for two terminal Cl− or SCN− ions around each Cd2+ center, the inorganic anion chains in compounds 1 and 3 both show a linear shape. In compound 4, Cd2+ and Cl− first aggregate to form a 1-D endless chain with a composition of Cd3Cl6, which can be described as a linear arrangement of the open double cubanes. SCN− serves as the second connector, propagating the Cd3Cl6 chain into a three-dimensional (3-D) network with the occluded H2(tmen)2+ cations. In compound 5, the SCN− groups doubly bridge the Cd2+ centers, forming a 1-D zigzag-shape chain. The formation of the zigzag chain likely derives from chelation of the CH3COO− group to the Cd2+ center. The thermal behavior and the photoluminescence properties of the title compounds were also investigated.

•Structure types of 1:1 adducts of MX2 and N,N′-donor ligands were studied.•Structures of dabco-templated halo(pseudohalo)cadmates were investigated.•Factors of controlling protonated degree of N-heterocyclic molecules were discussed.•Photoluminescence behavior of [CdI2(bpp)] was investigated.Under the solvothermal condition, the reaction of CdI2, bpp and KI at pH = 8 afforded compound [CdI2(bpp)] (bpp = 1,2-bis(4-pyridyl)propane) 1, while at the ambient conditions, the reactions of CdX2, dabco and KX at pH = 4–5 produced compounds [H2(dabco)][CdBr4]·H2O (dabco = 1,4-diazabicyclo[2,2,2]octane) 2 and [(Hdabco)CdI3] 3. X-ray single-crystal diffraction analysis reveals that (i) compound 1 possesses a one-dimensional (1-D) zigzag chain structure. The large volume bpp molecule controls the Cd2+ ion to adopt a tetrahedral geometric configuration; (ii) both compounds 2 and 3 are mononuclear. Interestingly, in the same pH environments, dabco was in situ diprotonated in compound 2, while dabco was in situ monoprotonated in compound 3. The templating effect as well as the X− ion maybe plays a key role in the protonated degree for dabco in an acidic environment. The photoluminescence analysis indicates that compound 1 emits the strong green light, which should be attributed to a combination of two types of charge transfers: the charge transfer between Cd2+ and I−; the charge transfer between Cd2+ and bpp.Structural characterization of three new Cd(II) compounds were reported including 1:1 adduct of CdI2 and bpp, and dabco-templated bromocadmate and iodocadmate.

Under hydrothermal conditions, the reactions of Ba2+/Zn2+, aromatic polycarboxylic acids and N2H4 with or without oxalic acid were carried out, affording four new acylhydrazidate-extended metal–organic frameworks (MOFs) [Ba(pmdh)] (pmdh = pyromellitdihydrazidate) 1, [Ba(sdpth)(H2O)2]·0.5H2O (sdpth = 4,4′-sulfoyldiphthalhydrazidate) 2, [Ba2(cpth)2(H2O)2] (cpth = 4-carboxylphthalhydrazidate) 3 and [Zn2(pdh)2(ox)]·H2O (ox = oxalate, pdh = pyridine-2,3-dicarboxylhydrazidate) 4. The acylhydrazidate molecules pmdh, sdpth, cpth and pdh in compounds 1–4 derived from the hydrothermal in situ acylation of N2H4 with aromatic polycarboxylic acids. X-ray single-crystal diffraction analysis revealed that (i) in compound 1, the pmdh I molecules link the Ba2+ ions into a two-dimensional (2D) layer with a (4,4) topology, and then the pmdh II molecules extend these layers into a three-dimensional (3D) network; (ii) in compound 2, the sdpth molecules link the Ba2+ ions to form a one-dimensional (1D) square tube. Interestingly, the tubes are further linked into a 3D supramolecular network via the N–H⋯O interactions, creating synchronously big channels; (iii) in compound 3, the cpth I molecules link the Ba1 ions into a 3D network with a (10,3) topology. Ba2 and cpth II are distributed on the channels; (iv) in compound 4, Zn2+ and pdh aggregate to form two types of Zn4(pdh)4 clusters. The ox molecules act as the secondary linkers, extending the Zn4(pdh)4 secondary building units (SBUs) into a 3D network with a 66 topology. The photoluminescence analysis indicates that compounds 3 and 4 emit green light with maxima at 495 nm for 3 (λex = 397 nm), and 522 nm for 4 (λex = 395 nm), respectively. At 77 K, the activated 2 and 4 can adsorb N2 in amounts of 58.31 cm3 g−1 for 2 and 38.38 cm3 g−1 for 4, respectively.

In an acidic solution, the room-temperature reactions of CdX2 (X− = Cl−, Br− or CH3COO−) and organic N-heterocyclic molecules with or without SCN−/SeCN−/dca− (dca− = dicyanamide) created the five new hybrid Cd(II) compounds [H2(4,4′-dtdpy)]2[CdBr4]SO4·2.5H2O (dtdpy = dithiodipyridine) 1, [H(2,2′-dtdpy)]2[CdBr4] 2, [(Hbim)2CdCl2(SCN)2] (bim = 2,2′-biimidazole) 3, [H2(pip)][Cd(SCN)4] (pip = piperazine) 4 and [CdL2] (L = HNC(OH)N−CN) 5. X-ray single-crystal diffraction analysis revealed that: (i) compound 1 is a double salt of [H2(4,4′-dtdpy)]SO4 and [H2(4,4′-dtdpy)][CdBr4], [H2(4,4′-dtdpy)]SO4 shows a two-dimensional (2D) supramolecular layer structure and [H2(4,4′-dtdpy)][CdBr4] is distributed in the space between the supramolecular layers; (ii) compounds 2 and 3 are mononuclear molecular entities. Of those, 2,2′-dtdpy and bim were only in situ monoprotonated; (iii) compound 4 contains a 2D supramolecular layered structure which is based on [Cd(SCN)4]2− chains with H2(pip)2+via NSCN⋯Npip interactions; (iv) the three-dimensional (3D) compound 5 exhibits a rutile-related (4·62)2(42·610·83)-topology. The ligand L originates from the in situ nucleophilic addition of H2O with one –CN group of dca−. Upon excitation, the solid-state compounds 3 and 4 emit blue light, and the solid-state compound 5 emits violet light.

Under hydrothermal conditions, at different pH levels adjusted by H2ox (ox = oxalate, C2O42−) or N2H4, the reactions of Zn(CH3COO)2·2H2O, phthalic/3-nitrophthalic acid, N2H4·H2O and triazole/tetrazole afforded four new Zn2+ coordination polymers as [Zn5(OH)2(Hpth)2(pth)2(trz)2] (pth = phthalhydrazidate, trz = 1,2,4-triazolate) 1, [Zn3(OH)2(Hpth)2(datrz)2] (datrz = 3,5-diamino-1,2,4-triazolate) 2, [Zn2(pth)(atez)2] (atez = 5-aminotetrazolate) 3 and [Zn5(OH)2(ox)(apth)2(datrz)2] (apth = 3-aminophthalhydrazidate) 4. The acylhydrazide molecules H2pth and H2apth in compounds 1–4 originated from the hydrothermal in situ acylation of N2H4 with phthalic/3-nitrophthalic acid. When preparing compound 4, the reduction of –NO2 into –NH2 also occurred besides the acylation, creating finally a new acylhydrazide molecule H2apth. The X-ray single-crystal diffraction analysis revealed that (i) in compounds 1, 3 and 4, Zn2+ and pth/apth aggregate into the 1D endless chains. The triazolate/tetrazolate molecules extend the Zn2+-pth/apth chains into the different layer networks of compounds 1 and 4, and a 3D network of compound 3; (ii) in compound 2, the datrz molecules link the Zn2+ ions into a 2D layer network. Pth acts as the ancillary ligand; (iii) ox from H2ox was introduced into the final framework of compound 4; (iv) the acylhydrazide molecules exhibit three types of existing forms in compounds 1–4: the diketo form, the keto-hydroxyl form, and the dihydroxyl form. Of those, the dihydroxyl form was observed for the first time. The solid-state photoluminescence analysis indicated that only compound 4 emits green light, and the others do not emit light.

By employing the hydrothermal in situ acylation of N2H4 with aromatic polycarboxylic acids, three new acylhydrazidate-extended coordination polymers (CPs) [Pb2(3-cppth)2(phen)2] (3-cppth = 4-(3-carboxyphenoxy)phthalhydrazidate, phen = 1,10-phenanthroline) 1, [Cd(4-cppth)(bpy)(H2O)]·H2O (4-cppth = 4-(4-carboxyphenoxy)phthalhydrazidate, bpy = 2,2′-bipyridine) 2 and [Zn(dcpth)2] (dcpth = 4,5-dichlorophthalhydrazidate) 3 were obtained. X-ray single-crystal diffraction analysis revealed that (i) compound 1 possesses a one-dimensional (1-D) double-chain structure. Via the N–H⋯O interactions between the neighboring acylamino groups, two such double chains aggregate together into a 1-D supramolecular chain. The phen molecules are distributed on the outer side of the supramolecular chain, hindering the further extension of the 1-D supramolecular chain; (ii) compound 2 exhibits a 1-D zigzag-type single-chain structure. Via the hydrogen-bonded interactions between the acylamino groups, compound 2 self-assembles into a two-dimensional (2-D) grid-like supramolecular layer network. The π⋯π interactions between the bpy molecules are observed between the supramolecular layers; (iii) in compound 3, two hydroxylimino groups for the dcpth I molecules link first the Zn2+ ions into a dimer, which can be viewed as a tetrahedral node. The dcpth II molecules act as the linkers, extending the tetrahedral nodes into another 1-D double-chain structure, different from that of compound 1.Graphical abstractBy employing the hydrothermal in situ acylation of N2H4 with aromatic polycarboxylic acids, three new acylhydrazidate-extended coordination polymers were obtained.

By employing the hydrothermal in situ acylation of N2H4 with aromatic polycarboxylic acids, three new acylhydrazidate-containing complexes [Zn(N2H4)(dphkh)]·H2O (dphkh = 4,4′-diphthalhydrazidatoketone hydrazone) 1, [Zn(npth)2] (npth = naphthalhydrazidate) 2 and [Mn(mpdh)2(H2O)2]·2H2O 4, and two new acylhydrazide molecules [bpth]·0.5H2O (bpth = 3,3′-biphthalhydrazide) 3 and [(chpth)2] (chpth = 4-chloro-5-hydrazinophthalhydrazide) 5 were obtained. It is noteworthy that (i) compound 1 is a layered Zn2+ coordination polymer with a mixed ligand of dphkh and N2H4. The nucleophilic addition of the keto spacer with N2H4 also occurred, forming the ketone hydrazone; (ii) compound 2 is a unique example of a npth-extended coordination polymer, exhibiting a double-chain structure; (iii) apart from the acylation of N2H4 with dcpha (dcpha = 4,5-dichlorophthalic acid), one Cl was substituted by N2H4, generating a new monoacylhydrazide molecule of compound 5. The solid-state photoluminescence analysis revealed that compounds 1 and 5 exhibit strong luminescence with the maximum at 490 nm for 1 and 535 nm for 5, whereas compounds 2 and 3 show weaker emissions with the peaks at 510 nm for 2 and 440 nm for 3.

At ambient temperature, with various mono(di)protonated N-heterocyclic or diamine molecules as the cations, seven new halo(pseudohalo)cadmates [H2(bpee)][Cd(SCN)4] (bpee = 1,2-bis(4-pyridyl)ethene) 1, [H2(bpyp)][CdBr2(SCN)2] (bpyp = 1,2-bis(4-pyridyl)propane) 2, [H2(mbcha)][Cd3Br2(SCN)6] (mbcha = 4,4′-methylenebis(cyclohexylamine)) 3, [(Hdabco)2Cd3(SCN)8] (dabco = 1,4-diazabicyclo[2,2,2]octane) 4, [H2(bp)][Cd(SeCN)4] (bp = 4,4′-bipiperidine) 5 [H2(pdma)][Cd(SeCN)4]·2H2O (pdma = 1,4-phenylenedimethanamine) 6 and [H2(4,4′-dtdpy)][Cd2Br6] (dtdpy = dithioidipyridine) 7 were obtained. X-ray analysis revealed that (i) compound 1 possesses a three-dimensional (3D) supramolecular network structure with the one-dimensional (1D) channels, constructed from the inorganic [Cd(SCN)4]2− chains by weak S⋯S interactions. The H2(bpee)2+ molecules occupy the space of the channels; (ii) with H2(mbcha)2+ as the cation, the anion [Cd3Br2(SCN)6]2− of compound 3 exhibits a 1D ribbon structure, which can be described as a lengthways packing of planar bi-bridged trimers; (iii) compound 4 is the first example of the cation-controlled 3D thiocyanatocadmate with a composition [Cd3(SCN)8]2−; (iv) with H2(4,4′-dtdpy)2+ as the cation, the anion [Cd2Br6]2− of compound 7 also shows a 1D ribbon structure. This ribbon can be described as a transverse stacking of two planar bi-bridged single chains; (v) the ribbons of compounds 3 and 7 can be visualized as a slice of the two dimensional (2D) CdX2 layer; (vi) in compounds 2, 3, 5, 6 and 7, the organic molecules as the linkers extend the inorganic anionic moieties into various 2D supramolecular layer networks.

The hydrothermal in situ self-assembly of Pb2+, benzene-1,2,4-tricarboxylic acid (BTCA) and N2H4·H2O created two Pb(II) coordination polymers containing 4-carboxylphthalhydrazidate (CPTH), [Pb(CPTH)(phen)] (phen = 1,10-phenanthroline) 1 and [Pb4(OH)2(H2O)3(CPTH)3]·2H2O 2. CPTH is derived from the in situ acylation reaction of BTCA with N2H4·H2O.

Based on an aim of introducing the SCN− or SO42− group into the organically templated chlorocadmates, a series of room-temperature reactions at pH 2 were performed, creating four new Cd(II) hybrids as [L1]4[Cd4Cl6(SCN)10(H2O)2] (L1 = 1,1′-dibenzyl-4,4′-bipyridium) 1, [H4L2][CdCl4(SCN)2] (L2 = 1,4-bis(4-pyridylmethyl)piperazine) 2, [HL3]3[CdCl3]SO4 (L3 = 2-amino-6-chloropyridine) 3, and [HL4]3[CdCl3]SO4 (L4 = 2-amino-6-bromopyridine) 4. X-ray single-crystal diffraction analysis reveals that (i) templated by L12+, 1 shows a 1-D single-chain structure, which is based on the dinuclear [Cd2Cl3(SCN)4(H2O)]3− clusters by the μ-1,3-mode SCN− groups; (ii) templated by H4L24+, 2 only exhibits a mononuclear structure. However, via the intermolecular weak NpyridineH⋯Cl, NpiperazineH⋯Cl and SSCN⋯SSCN interactions, 2 self-assembles into a 3-D supramolecular network with a (4,6)-connected topology; (iii) 3 and 4 possess the similar structures. Via the Npyridine/aminoH⋯O and π⋯π interactions, the introduced SO42− groups and the organic base molecules aggregate together into a 3-D supramolecular network with the 1-D channels. Within the channel, the Cl− ions triplely bridge the Cd2+ centers into a 1-D linear [CdCl3]− chain. Based on the structural information and the previous related reports, the role of the introduced SCN− or SO42− group in the hybrid is revealed. SCN− acts as two roles: (i) a linker; (ii) a cutter. Sometimes SO42− serves as a linker, while sometimes SO42− connects with organic base into a supramolecular aggregation, acting as a new templating agent. The photoluminescence analysis reveals that 2, 3 and 4 emit light with the maxima at 535 nm for 2 (λex = 465 nm), 462 nm for 3 (λex = 428 nm), and 465 nm for 4 (λex = 430 nm), respectively. In particular, the emissions for all are strong, and can be seen under the ultraviolet (UV) lamp.Structures of four new organically templated chlorocadmates(II) with introduced SCN− or SO42− were reported, and their photoluminescence properties were investigated.

Under hydrothermal conditions, the reactions of Ba2+/Zn2+, aromatic polycarboxylic acids and N2H4 with or without oxalic acid were carried out, affording four new acylhydrazidate-extended metal–organic frameworks (MOFs) [Ba(pmdh)] (pmdh = pyromellitdihydrazidate) 1, [Ba(sdpth)(H2O)2]·0.5H2O (sdpth = 4,4′-sulfoyldiphthalhydrazidate) 2, [Ba2(cpth)2(H2O)2] (cpth = 4-carboxylphthalhydrazidate) 3 and [Zn2(pdh)2(ox)]·H2O (ox = oxalate, pdh = pyridine-2,3-dicarboxylhydrazidate) 4. The acylhydrazidate molecules pmdh, sdpth, cpth and pdh in compounds 1–4 derived from the hydrothermal in situ acylation of N2H4 with aromatic polycarboxylic acids. X-ray single-crystal diffraction analysis revealed that (i) in compound 1, the pmdh I molecules link the Ba2+ ions into a two-dimensional (2D) layer with a (4,4) topology, and then the pmdh II molecules extend these layers into a three-dimensional (3D) network; (ii) in compound 2, the sdpth molecules link the Ba2+ ions to form a one-dimensional (1D) square tube. Interestingly, the tubes are further linked into a 3D supramolecular network via the N–H⋯O interactions, creating synchronously big channels; (iii) in compound 3, the cpth I molecules link the Ba1 ions into a 3D network with a (10,3) topology. Ba2 and cpth II are distributed on the channels; (iv) in compound 4, Zn2+ and pdh aggregate to form two types of Zn4(pdh)4 clusters. The ox molecules act as the secondary linkers, extending the Zn4(pdh)4 secondary building units (SBUs) into a 3D network with a 66 topology. The photoluminescence analysis indicates that compounds 3 and 4 emit green light with maxima at 495 nm for 3 (λex = 397 nm), and 522 nm for 4 (λex = 395 nm), respectively. At 77 K, the activated 2 and 4 can adsorb N2 in amounts of 58.31 cm3 g−1 for 2 and 38.38 cm3 g−1 for 4, respectively.

By employing the hydrothermal in situ acylation of N2H4 with aromatic polycarboxylic acids, three new acylhydrazidate-containing complexes [Zn(N2H4)(dphkh)]·H2O (dphkh = 4,4′-diphthalhydrazidatoketone hydrazone) 1, [Zn(npth)2] (npth = naphthalhydrazidate) 2 and [Mn(mpdh)2(H2O)2]·2H2O 4, and two new acylhydrazide molecules [bpth]·0.5H2O (bpth = 3,3′-biphthalhydrazide) 3 and [(chpth)2] (chpth = 4-chloro-5-hydrazinophthalhydrazide) 5 were obtained. It is noteworthy that (i) compound 1 is a layered Zn2+ coordination polymer with a mixed ligand of dphkh and N2H4. The nucleophilic addition of the keto spacer with N2H4 also occurred, forming the ketone hydrazone; (ii) compound 2 is a unique example of a npth-extended coordination polymer, exhibiting a double-chain structure; (iii) apart from the acylation of N2H4 with dcpha (dcpha = 4,5-dichlorophthalic acid), one Cl was substituted by N2H4, generating a new monoacylhydrazide molecule of compound 5. The solid-state photoluminescence analysis revealed that compounds 1 and 5 exhibit strong luminescence with the maximum at 490 nm for 1 and 535 nm for 5, whereas compounds 2 and 3 show weaker emissions with the peaks at 510 nm for 2 and 440 nm for 3.

With various organic base molecules as the countercations, five new thiocyanatocadmates [H2(tmen)][Cd(SCN)4] (tmen = N,N,N′,N′-tetramethylethylenediamine) 1, [H2(tmba)][Cd2(SCN)6] (tmba = N,N,N′,N′-tetramethyl-1,4-butanediamine) 2, [H2(teen)][Cd2(SCN)6] (teen = N,N,N′,N′-tetra-ethylethylenediamine) 3, [H(amp)][Cd(SCN)2(CH3COO)] (amp = 2-amino-6-methylpyridine) 4 and [H(abp)]4[Cd(SCN)4]SO4·H2O (abp = 2-amino-6-bromopyridine) 5, and one new chlorocuprate(II) [H2(cha)][CuCl4] (cha = 1,4-cyclohexanediamine) 6 were obtained from a series of simple room-temperature self-assemblies at pH = 2 or 6.5. X-ray single-crystal diffraction analysis reveals that (i) templated by [(CH3)2NH(CH2)2NH(CH3)2]2+ (H2(tmen)2+), the anion [Cd(SCN)4]2− in 1 shows a 1-D linear single-chain structure, whereas templated by [(CH3)2NH(CH2)4NH(CH3)2]2+ (H2(tmba)2+), the anion [Cd2(SCN)6]2− in 2 shows a 1-D linear double-chain structure. The number of C atoms between the two N atoms in the templating agent controls the width of the anionic chain through the Namino–H⋯NSCN interactions; (ii) templated by [(C2H5)2NH(CH2)2NH(C2H5)2]2+ (H2(teen)2+), the anion [Cd2(SCN)6]2− in 3 exhibits a 3-D open-framework structure, which is based on zigzag anionic chains. A direct change of the substituent group from –CH3 to –C2H5 alters indirectly the shape of the anionic chain from a linear shape to a zigzag shape; (iii) 4 shows a 3-D supramolecular network structure, which is built up from the 1-D zigzag anionic structures by the H(amp)+ molecules via N–H⋯O interactions. The formation of the zigzag chain derives from the chelation of the CH3COO− groups to the Cd2+ centers; (iv) 5 is indeed a double salt of [H(abp)]2[Cd(SCN)4] and [H(abp)]2SO4. SO42− and H(abp)+ form a supramolecular aggregation. Surrounded by the aggregations, the anion [Cd(SCN)4]2− only shows a dinuclear structure; and (v) templated by H2(cha)2+, the anion [CuCl4]2− in 6 displays a 2-D perovskite layer structure. The photoluminescence analysis indicates that upon excitation (λex = 335 nm for 4, λex = 395 nm for 5), 4 and 5 emit light (λem = 365 nm for 4, λem = 470 nm for 5), which can be seen clearly under the UV lamp.

In an acidic solution, the room-temperature reactions of CdX2 (X− = Cl−, Br− or CH3COO−) and organic N-heterocyclic molecules with or without SCN−/SeCN−/dca− (dca− = dicyanamide) created the five new hybrid Cd(II) compounds [H2(4,4′-dtdpy)]2[CdBr4]SO4·2.5H2O (dtdpy = dithiodipyridine) 1, [H(2,2′-dtdpy)]2[CdBr4] 2, [(Hbim)2CdCl2(SCN)2] (bim = 2,2′-biimidazole) 3, [H2(pip)][Cd(SCN)4] (pip = piperazine) 4 and [CdL2] (L = HNC(OH)N−CN) 5. X-ray single-crystal diffraction analysis revealed that: (i) compound 1 is a double salt of [H2(4,4′-dtdpy)]SO4 and [H2(4,4′-dtdpy)][CdBr4], [H2(4,4′-dtdpy)]SO4 shows a two-dimensional (2D) supramolecular layer structure and [H2(4,4′-dtdpy)][CdBr4] is distributed in the space between the supramolecular layers; (ii) compounds 2 and 3 are mononuclear molecular entities. Of those, 2,2′-dtdpy and bim were only in situ monoprotonated; (iii) compound 4 contains a 2D supramolecular layered structure which is based on [Cd(SCN)4]2− chains with H2(pip)2+via NSCN⋯Npip interactions; (iv) the three-dimensional (3D) compound 5 exhibits a rutile-related (4·62)2(42·610·83)-topology. The ligand L originates from the in situ nucleophilic addition of H2O with one –CN group of dca−. Upon excitation, the solid-state compounds 3 and 4 emit blue light, and the solid-state compound 5 emits violet light.

Under ambient conditions, reactions of CdCl2/Cd(CH3COO)2, SCN− and various organic amine molecules in strongly acidic solutions afforded the five new thiocyanatocadmates [H2(abpy)][CdCl2(SCN)2] (abpy = azobispyridine) 1, [H(apy)][Cd(SCN)3] (apy = 4-aminopyridine) 2, [H(ba)]2[CdCl2(SCN)2] (ba = tert-butylamine) 3, [H2(tmen)][Cd3Cl6(SCN)2] (tmen = N,N,N′,N′-tetramethylethylenediamine) 4, and [H(dba)]2[Cd2(CH3COO)2(SCN)4] (dba = dibutylamine) 5. In compound 2 only, the CH3COO− ions in Cd(CH3COO)2 were completely displaced by SCN−, producing a chained thiocyanatocadmate [Cd(SCN)3]−. In the other four compounds, the Cl− or CH3COO− ions appeared in the final inorganic anion frameworks. In compound 1, the Cl− ions doubly bridge the Cd2+ centers, forming a one-dimensional (1-D) infinite chain, and the SCN− group exists in a terminal form, whereas in compound 3, the reverse situation is observed. Due to a trans-mode arrangement for two terminal Cl− or SCN− ions around each Cd2+ center, the inorganic anion chains in compounds 1 and 3 both show a linear shape. In compound 4, Cd2+ and Cl− first aggregate to form a 1-D endless chain with a composition of Cd3Cl6, which can be described as a linear arrangement of the open double cubanes. SCN− serves as the second connector, propagating the Cd3Cl6 chain into a three-dimensional (3-D) network with the occluded H2(tmen)2+ cations. In compound 5, the SCN− groups doubly bridge the Cd2+ centers, forming a 1-D zigzag-shape chain. The formation of the zigzag chain likely derives from chelation of the CH3COO− group to the Cd2+ center. The thermal behavior and the photoluminescence properties of the title compounds were also investigated.

Under hydro(solvo)thermal conditions, two 4-(4-carboxyphenoxy)phthalate-based three-dimensional (3-D) coordination polymers: [Cd3(cpph)2(bpa)2(H2O)]·0.5H2O (cpph = 4-(4-carboxyphenoxy)phthalate, bpa = 1,2-bis(4-pyridyl)ethane) 1, and [H2(bpp)][Mn2(cpph)2(H2O)2] (bpp = 1,2-bis(4-piperidyl)propane) 2 were isolated. In both compounds, the cpph molecules extend the metal ions into a 3-D network: a (4,6)-connected net for 1 and a simple 6-connected net with a pcu topology for 2. The introduced bpa or bpp molecule stabilizes the 3-D metal-cpph architecture in the form of linker or guest molecule. The sensing ability of 1 was investigated, revealing that it can be used as a fluorescence probe to sense nitrobenzene at ppm concentrations.

By employing two types of hydrothermal in situ ligand reactions (acylation of N2H4 with aromatic polycarboxylic acids, reduction of 3-nitrophthalhydrazide by N2H4), three new acylhydrazidate-extended Zn2+ coordination polymers [Zn2(3-apth)(atrz)2] (3-apth = 3-aminophthalhydrazidate; atrz = 3-amino-1,2,4-triazolate) 1, [Zn2(4-apth)(atez)2] (4-apth = 4-aminophthalhydrazidate; atez = 5-aminotetrazolate) 2, and [Zn(3-cppth)(H2O)] (3-cppth = 4-(3-carboxyphenoxy)phthalhydrazidate) 3 were obtained. X-ray single-crystal diffraction analysis revealed that (i) compound 1 possesses a 3-D structure. The triazolate molecules link the Zn2+ ions to form a 2-D layer with a (6,3) topology. Then the acylhydrazidate molecule acts as the second linker, extending the (6,3) nets into a 3-D network of compound 1; (ii) compound 2 also exhibits a 3-D structure. The acylhydrazidate molecules first link the Zn2+ ions into a 1-D infinite chain. The tetrazolate molecules propagate further the chains into a 3-D (4,4)-connected net (symbol: (4·64·8)2(42·62·82)); (iii) compound 3 only shows a 1-D chain structure. The photoluminescence analysis indicates that the three title compounds all emit light, especially compound 2 which emits extremely strong blue light. The side group on the phthalhydrazidate molecule plays a crucial role in the emission behaviors of compounds 1–3. At 77 K, the activated compound 2 can adsorb N2 with a capacity of ca. 41.0 cm3 g−1.