Ru-Qi Huang

Novel organic-inorganic composite coordination polymers generated from new multidentate schiff-base ligand and Ag(I) salts

Two novel organic-inorganic hybrid coordination polymers were synthesized based on a new multidentate Schiff-base ligand and Ag(i) salts

Co-crystallization of oxadiazole-bridged pyridyl-N-oxide building modules with R-aromatics (R = –OH, –NH2 and –COOH)

The reaction of oxadiazole bridging pyridyl-N-oxides (2,5-bis(4-pyridyl-N-oxide)-1,3,4-oxadiazole (A1) and 2-(4-pyridyl)-5-(4-pyridyl-N-oxide)-1,3,4-oxadiazole (A2)) with different substituted aromatics (R-aromatics, R = –OH, –NH2, –COOH) have been investigated. Eight new organic co-crystals of 1–8 were synthesized and characterized by elemental analysis, FTIR spectroscopy, 1H NMR and single-crystal X-ray diffraction. The results display the distinct substituent effect on the hydrogen-bonded self-assembly systems. In addition, the luminescent properties of A1–A2 and 1–8 were investigated in the solid state.

New Ag(I) inorganic–organic coordination polymers and M(II)(M = Co(II) and Mn(II)) molecular complexes generated from a new type of fulvene ligand

One new fulvene-type ligand 1 was synthesized successfully by aroylation reaction of substituted cyclopentadienyl anions. The coordination chemistry of fulvene ligands 1 and 2 were investigated. The study demonstrated that these fulvene-type ligands could be used as bidentate or chelating ligands to coordinate transition metal ions into coordination polymers or supramolecular complexes. Two novel one-dimensional Ag(I)–fulvene coordination polymers, namely [Ag(1)2(PF6)]·C6H6 and [Ag(1)2(SbF6)]·2C7H8, consisting of an Ag2(ligand)2 unit and two M(II) (M = Co(II) and Mn(II)) complexes, namely Co(1)2·2C2H5OH and Mn(2)2·2C2H5OH, with unusual seven-membered metallo-ring units were synthesized successfully. In the solid state, complexes 5 and 6 adopt a novel hydrogen-bonded one-dimensional chain motif.

Synthesis and characterization of new coordination polymers generated from oxadiazole-containing ligand and inorganic M(II) [M = Cu(II), Co(II)] salts

The coordination chemistry of the oxadiazole-containing ligand 2,5-bis(4-pyridyl)-1,3,4-oxadiazole (L5) with inorganic Cu(II) and Co(II) salts has been investigated. Three new coordination polymers (1–3) and one H-bonded polymer (4) were prepared by solution reactions. [Cu(L5)(H2O)(SO4)]·2(H2O) (1) adopts a novel chiral three-dimensional motif with rhombus channels (ca. 6.04 × 14.09 A). [Co(L5)(CH3OH)2(SO4)](CH3OH)(H2O)3.5 (2) features a novel two-dimensional network. [Cu(L5)2(H2O)2](L5)2(ClO4)2(CH3OH)(H2O) (3) features a two-dimensional rhombus-grid-type layer with inner grid cavity dimensions of 13.22 × 13.22 A2. Compound 4, however, is a molecular complex that is bound together by strong N⋯H–O and O⋯H–O hydrogen bonds into a three-dimensional H-bonded network.

A Binuclear Cu II Metallacycle Capable of Discerning between Pyrazine and Its Different Methyl-Substituted Derivatives Based on Reversible Intracage Metal-Ligand Binding

Squashy cage: A flexible, spongelike, and reversible metal-binding Cu(2)L(2) cage that can adjust its internal space in response to pyrazine and its derivatives based on a recognition sequence of pyrazine, 2,5-dimethylpyrazine, and 2-methylpyrazine (see figure) is described.

Bird-like spiro-metallacyclic complexes based on a bent oxadiazole bridging ligand

The coordination chemistry of a new symmetric organic ligand 2,5-bis(3-(1H-1,2,4-triazol-1-ylmethyl)phenyl)-1,3,4-oxadiazole (L2) with inorganic M(II) (M = Cd, Co, Cu and Mn) salts has been investigated. Eight new bird-like spiro-metallocyclic complexes (1–8) were synthesized. In addition, the luminescent properties of 1–8 and the electrical conductivity of 6 were investigated primarily.

4-[5-(4-Pyrid-yl)-1,3,4-oxadiazol-2-yl]pyridine N-oxide-isophthalic acid (1/1).

The title compound, C12H8N4O2·C8H6O4, was synthesized from 4-[5-(4-pyridyl)-1,3,4-oxadiazol-2-yl]pyridine N-oxide and isophthalic acid. The two molecules are linked through O—H⋯O and O—H⋯N hydrogen bonds. Weak intramolecular π–π interactions between the two hydrogen-bonded chains result in the formation a one-dimensional supramolecular curved tape (the face-to-face distance between the pyridine N-oxide ring and the benzene ring is 3.7 Å).

Cocrystallization of two tautomers: 4-(1-{[4-(dimethylamino)benzylidene]hydrazono}ethyl)benzene-1,3-diol and 6-[(E)-1-{[4-(dimethylamino)benzylidene]hydrazino}ethylidene]-3-hydroxycyclohexa-2,4-dien-1-one (1/1).

Two different tautomeric forms of a new Schiff base, C(17)H(19)N(3)O(2).C(17)H(19)N(3)O(2), are present in the crystal in a 1:1 ratio, namely the enol-imine form 4-(1-{[4-(dimethylamino)benzylidene]hydrazono}ethyl)benzene-1,3-diol and the keto-amine form 6-[(E)-1-{[4-(dimethylamino)benzylidene]hydrazino}ethylidene]-3-hydroxycyclohexa-2,4-dien-1-one. The tautomers are formed by proton transfer between the hydroxy O atom and the imine N atom and are hydrogen bonded to each other to form a one-dimensional zigzag chain along the crystallographic b axis via intermolecular hydrogen bonds.

A two-dimensional network formed by self-associating silver(I) perchlorate with 3-[4-(2-thienyl)-2H-cyclopenta[d]pyridazin-1-yl]benzonitrile.

In the organometallic silver(I) supramolecular complex poly[[silver(I)-mu(3)-3-[4-(2-thienyl)-2H-cyclopenta[d]pyridazin-1-yl]benzonitrile] perchlorate methanol solvate], {[Ag(C(18)H(11)N(3)S)](ClO(4)).CH(3)OH}(n), there is only one type of Ag(I) center, which lies in an {AgN(2)Spi} coordination environment. Two unsymmetric multidentate 3-[4-(2-thienyl)-2H-cyclopenta[d]pyridazin-1-yl]benzonitrile (L) ligands link two Ag(I) atoms through pi-Ag(I) interactions into an organometallic box-like unit, from which two 3-cyanobenzoyl arms stretch out in opposite directions and bind two Ag(I) atoms from neighboring box-like building blocks. This results in a novel two-dimensional network extending in the crystallographic bc plane. These two-dimensional sheets stack together along the crystallographic a axis to generate parallelogram-like channels. The methanol solvent molecules and the perchlorate counter-ions are located in the channels, where they are fixed by intermolecular hydrogen-bonding interactions. This architecture may provide opportunities for host-guest chemistry, such as guest molecule loss and absorption or ion exchange. The new fulvene-type multidentate ligand L is a good candidate for the preparation of Cp-Ag(I)-containing (Cp is cyclopentadienyl) organometallic coordination polymers or supramolecular complexes.

Coordination-directed one-dimensional coordination polymers generated from a new oxadiazole bridging ligand and HgX2 (X=Cl, Br and I).

A new 1,3,4-oxadiazole bridging bent organic ligand, 2,5-bis{5-methyl-2-[(4-pyridyl)methoxy]phenyl}-1,3,4-oxadiazole, C(28)H(24)N(4)O(3), L, has been used to create three novel one-dimensional isomorphic coordination polymers, viz. catena-poly[[[dichloridomercury(II)]-μ-2,5-bis{5-methyl-2-[(4-pyridyl)methoxy]phenyl}-1,3,4-oxadiazole] methanol monosolvate], {[HgCl(2)(C(28)H(24)N(4)O(3))]·CH(3)OH}(n), catena-poly[[[dibromidomercury(II)]-μ-2,5-bis{5-methyl-2-[(4-pyridyl)methoxy]phenyl}-1,3,4-oxadiazole] methanol monosolvate], {[HgBr(2)(C(28)H(24)N(4)O(3))]·CH(3)OH}(n), and catena-poly[[[diiodidomercury(II)]-μ-2,5-bis{5-methyl-2-[(4-pyridyl)methoxy]phenyl}-1,3,4-oxadiazole] methanol monosolvate], {[HgI(2)(C(28)H(24)N(4)O(3))]·CH(3)OH}(n). The free L ligand itself adopts a cis conformation, with the two terminal pyridine rings and the central oxadiazole ring almost coplanar [dihedral angles = 5.994 (7) and 9.560 (6)°]. In the Hg(II) complexes, however, one of the flexible pyridylmethyl arms of ligand L is markedly bent and helical chains are obtained. The Hg(II) atom lies in a distorted tetrahedral geometry defined by two pyridine N-atom donors from two L ligands and two halide ligands. The helical chains stack together via interchain π-π interactions that expand the dimensionality of the structure from one to two. The methanol solvent molecules link to the complex polymers through O-H···N and O-H···O hydrogen bonds.