Yan-Qiong Sun

A series of luminescent lanthanide–cadmium–organic frameworks with helical channels and tubes

Lanthanide (Ln) oxides and cadmium (Cd) salts as sources of metals provided the first series of luminescent Ln-Cd-organic frameworks, [LnCd(imdc)(SO4)(H2O)3].0.5H2O (Ln = Tb, Eu, Dy, Gd, Er, Yb, Y, Nd, Pr; H3imdc = 4,5-imidazoledicarboxylic acid), in which the Ln atoms are linked by imdc ligands with skew coordination orientation, resulting in novel hetero-metallic-organic frameworks with left-/right-handed helical tubes (L1/R1) and channels (L2/R2) along the b axis.

Two novel luminescent lanthanide sulfate–carboxylates with an unusual 2-D bamboo-raft-like structure based on the linkages of left- and right-handed helical tubes involving in situ decarboxylation

Two novel 2-D bamboo-raft-like lanthanide luminescent materials [Ln(Himc)(SO4)(H2O)] (Ln = Dy, Eu; H2imc = 4-imidazolecarboxylic acid), constructed from alternate left- and right-handed helical tubes, were synthesized and characterized; interestingly, H2imc came from the in situ decarboxylation of the 4,5-imidazoledicarboxylic acid (H3imdc) in the hydrothermal reactions.

A uudd Cyclic Water Tetramer and an Opened Octameric Water Cluster in the Charge-Transfer Salts of the Bipyridinium Cation

Two novel charge-transfer salts, [(Bpyph)(SCN)2]·2H2O 1 and {(HBpyph)[Fe(CN)6]}·5.5H2O 2, have been synthesized and characterized using elemental analysis, IR spectroscopy, and X-ray single-crystal diffraction studies. Compound 1 is the first bipyridinium charge-transfer salt containing a cyclic water tetramer, in which the uudd cyclic water tetramers built from four symmetry related water molecules join the Bpyph2+ cations to the dimer by hydrogen bonds between the water molecules and the nitrogen atoms of Bpyph2+. The cooperation of the hydrogen-bonding and π–π stacking interactions between the pyridyl groups results in the formation of an infinite ribbon with a herringbone arrangement. An opened water octamer has been observed in 2. It presents a new association mode of water molecules that is not predicted theoretically nor found experimentally. The water octamer is hydrogen-bonded to two HBpyph3+ cations and two [Fe(CN)6]3− anions to form water octamer-bridged HBpyPh-Fe(CN)6 dimers, which are further connected to each other via π–π offset stacking interactions to generate an infinite one-dimensional ribbon.

Hydrothermal syntheses, characterizations and crystal structures of three new cadmium (II) amino-diphosphonates: effects of substitute groups on the structures of metal phosphonates

Abstract Hydrothermal reactions of cadmium(II) chloride with three amino-diphosphonic acids, C6H5CH2N(CH2PO3H2)2 (H4L1), C6H5CH2CH2N(CH2PO3H2)2 (H4L2) and 4-CH3–C6H4CH2N (CH2PO3H2)2) (H4L3) resulted in three new metal amino-diphosphonates, namely, Cd(H3L1)2, 1 Cd(H3L2)2·2H2O 2 and Cd(H3L3)2 3. In all three complexes, the Cd(II) ion is octahedrally coordinated by six phosphonate oxygen atoms from six ligands. Complexes 1 and 3 have a similar structure in which the CdO6 octahedra are cross-linked by bridging ligands into a double chain along the c-axis, such double chains are further interlinked via hydrogen bonds between non-coordinated phosphonate oxygen atoms to form 〈100〉 and 〈200〉 layers with the phenyl groups of the ligands orientated toward the interlayer space. The structure of complex 2 features a 〈100〉 cadmium(II) diphosphonate layer. The effects of the substitute groups attached to the amine groups on the structures of the metal phosphonates are also discussed.

A novel polyoxovanadium borate incorporating an organic amine ligand: synthesis and structure of [V12B16O50(OH)7(en)]7−

A novel 1D chain organic-inorganic hybrid polyoxovanadium borate Na[V(12)B(16)O(50)(OH)(7)(en)](2)(enH(2))(6)(enH)(2)(OH)(H(2)O)(19) (1, en = ethylenediamine), based on a [V(12)B(16)O(50)(OH)(7)(en)](7-) cluster unit, has been hydrothermally synthesized and characterized. Interestingly, organic amine is incorporating into the V(12)B(16) clusters.

Hydrothermal synthesis, characterization and crystal structures of two new layered lead(II) diphosphonates

Hydrothermal reactions of N-benzyliminobis(methylenephosphonic acid), C6H5CH2N(CH2PO3H2)2 (H4L), with lead(II) chloride and lead(II) acetate resulted in two novel lead(II) phosphonates, namely, Pb5(H2L)2(HL)2·2H2O (1) and Pb3(H2L)2Cl(H2O)3·Cl·2H2O (2). Compound 1 is orthorhombic, Pbca, with Z = 4. Compound 1 features a layered structure in which the lead(II) ions are bridged by phosphonate groups.Two lead(II) ions (Pb1 and Pb3) are three-coordinated with a distorted tetrahedral geometry in which one apex is occupied by the lone pair of the lead(II) ion, the third lead(II) ion (Pb2) is six-coordinated by six phosphonate oxygen atoms from six ligands. Two ligands are doubly protonated whereas the other two are singly protonated. Compound 2 crystallizes in I2/a with Z = 4. In compound 2, one lead(II) ion is six-coordinated by four phosphonate oxygen atoms from four ligands, one aqua ligand and one chloride anion in a distorted octahedral geometry; the other lead(II) ion is coordinated by four phosphonate oxygen atoms from four ligands and two aqua ligands with a severely distorted octahedral geometry. One phosphonate group of the ligand bridges with five lead(II) ions, whereas the other one is unidentate. The interconnection of the lead(II) ions through bridging phosphonate groups results in the formation of a 〈040〉 layer. In both compounds, the phenyl groups of the ligand are oriented toward the interlayer space.

Cd(2,2′-bipy)(H2PO4)2: the first cadmium phosphate with an organic amine acting as a ligandElectronic supplementary information (ESI) available: IR spectrum, X-ray powder diffraction patterns (experimental and simulated) and TGA curve for Cd(2,2′-bipy)(H2PO4)2, and table of hydrogen bond lengths and angles. See http://www.rsc.org/suppdata/jm/b2/b211928e/

A novel cadmium phosphate, Cd(2,2′-bipy)(H2PO4)2, has been hydrothermally synthesized in the presence of 2,2′-bipyridine (2,2′-bipy), which acts as a ligand. The structure consists of a network of CdO4N2 octahedra and H2PO4 tetrahedra, forming an infinite one-dimensional chain.

Syntheses and structures of two novel copper complexes constructed from unusual planar tetracopper(II) SBUs

Two novel polymeric copper complexes constructed from unusual planar tetracopper(II) SBUs have been prepared and characterized.

Ln–Cd heterometal organic–inorganic hybrid materials based on diverse Ln–Cd oxo-cluster chains: syntheses, structures and visible luminescence

Three novel Ln–Cd heterometal organic–inorganic hybrid materials, [LnCd(phen)(ox)1.5(SO4)(H2O)2]·H2O (type I: Ln = Sm 1a; Eu 1b; phen = 1,10-phenanthroline; H2ox = oxalic acid) and [EuCd2(Meimdc)2(Ac)(H2O)2]·H2O (type II: 2; H3Meimdc = 2-methyl-imidazole-4,5-dicarboxylic acid; HAc = acetic acid) have been successfully synthesized under hydrothermal conditions. The type I compounds are the first examples of Ln–Cd heterometal organic–inorganic hybrid sulfate–carboxylates with a lattice bilayer structure. The extended structure of type II consists of EuCd(Meimdc) and Cd2(Meimdc) helices cross-linked through Ln–Cd oxo-cluster chains, showing a 3D microporous architecture with left-/right-handed helical tubes (L1/R1) and channels (L2/R2) along the b axis. The luminescence properties of complexes 1b and 2 exhibit the characteristic emission bands of Eu3+ ions. The photoluminescence spectra of 1b and 2 show characteristic line-splitting at room temperature, depending on the site-symmetry of Eu3+ ions in the complexes.

A fluorescent, photochromic and thermochromic trifunctional material based on a layered metal–viologen complex

The azide anion as an energy acceptor and an electron donor has been introduced into a metal-viologen compound to form a 2D layered viologen-based trifunctional material, which exhibits the rare discolored function of reversible photochromism and thermochromism. Interestingly, its fluorescence can be switched by visible light irradiation and heating in air.