Mei-Feng Wu

A novel metal-organic network with high thermal stability: Nonlinear optical and photoluminescent properties

A novel zinc(II) 4-(5H-tetrazol)benzoic coordination polymer with an in situ generated tetrazole ligand exhibits the gsi (gamma-silicon) topology and high thermal stability; this compound possesses second-order nonlinear optical and interesting heat-induced photoluminescent properties.

Hydrothermal syntheses, crystal structures and luminescent properties of zinc(II) coordination polymers constructed by bifunctional tetrazolate-5-carboxylate ligands

Two bifunctional 1H-tetrazolate-5-carboxylate ligands with different flexibilities, H2tza (1H-tetrazolate-5-acetic acid) and H2tzf (1H-tetrazolate-5-formic acid), were employed in the construction of zinc(II) complexes in the presence/absence of secondary ligands such as 2,2′-bipy and 4,4′-bipy. Three tza coordination polymers and two tzf dinuclear complexes, namely [Zn(tza)(H2O)]n (1), [Zn3(tza)2Cl2(2,2′-bipy)2(H2O)2]n (2), [Zn2(tza)2(4,4′-bipy)]n (3), [Zn(tzf)(H2O)3]2·2H2O (4) and [Zn(tzf)(2,2′-bipy)(H2O)]2·H2O (5), were hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. Polymer 1 is a 3-D two-fold interpenetrating diamond-like network with tetranuclear [Zn(COO)]4 clusters as tertiary building units (TBUs) and µ3-κN3:κO2:κO1,N1 bridging tza as linkers. Polymer 2 presents a 2-D structure formed by the linkage of 1-D Zn-carboxylate [Zn(COO)]n helical chains and µ3-κN4:κO2:κO1,N1 bridging tza. In 3, 2-D (4,4) nets are built up with dinuclear [Zn(COO)]2 clusters and µ3-κN4:κO2:κO1,N1 bridging tza, which are pillared through 4,4′-bipy to gain a 3-D self-penetrating LB-1 (446108) topology. In dinuclear complexes 4 and 5, two Zn(II) atoms are bridged by a tzf ligand in a µ2-κN2:κO1,N1 fashion. The results denote that tetrazolate-5-carboxylate ligands can adopt variable coordination modes in the formation of the complexes, and different Zn-carboxylate aggregates can serve as tertiary building units (TBUs). The effects of the nature of tetrazolate-5-carboxylate ligands and secondary ligands, and hydrothermal reaction conditions on the structural topologies of the obtained complexes have been investigated. The photoluminescent properties and thermal stabilities of 1–5 have also been discussed.

Structures and photoluminescence of zinc(II) coordination polymers based on in situ generated 1H-tetrazolate-5-propionic acid ligands

Hydrothermal reaction of ZnCl2, NCCH2CH2COONa and NaN3, in the absence/presence of auxiliary ligand 2,2′-bipy/4,4′-bipy, gave birth to three novel coordination polymers, namely, [Zn(tzp)]n (1), [Zn2(tzp)(N3)(OH)(2,2′-bipy)]n (2) and [Zn2(tzp)2(4,4′-bipy)]n (3) (H2tzp = 1H-tetrazolate-5-propionic acid). The tzp2− ligand was in situ generated through the [2 + 3] cycloaddition reaction of nitrile and azide, which was first untilized to synthesize coordination compounds. Polymer 1 behaves as a three-dimensional (3-D) network built up by the fusion of one-dimensional (1-D) pseudo-channels formed by the linkage of tzp2− ligands and tetrahedral Zn nodes. When the chelating 2,2′-bipy was introduced into the reaction system, a two-dimensional (2-D) puckered network 2 was constructed, where 1-D pseudo-channels, similar to those in 1, are bridged by azide ions in an end-on (EO) mode. Employment of the linear bridging 4,4′-bipy ligand as the auxiliary ligand resulted in the formation of an unusual 3-D polymer 3, where the connection of Zn and tzp2− produces a 2-D network, which are further joined by 4,4′-bipy. The tzp2− ligands in 1–3 show the flexible conformations and different coordination modes, with the tetrazolate group being the 1,4-N mode and the carboxylate group being the syn–anti, syn–syn and monodentate mode, respectively. The results suggest that the flexible nature of the tzp2− ligand as well as the introduction of auxiliary ligands is responsible for the formations of 1–3. Their photoluminescent properties and thermal stabilities have also been discussed.

Hydrothermal syntheses, crystal structures and magnetic properties of four Mn(II) and Co(II) coordination polymers generated from new carboxylate-introduced 1,2,3-triazole ligands

A new carboxylate-introduced 1,2,3-triazole, 1-(3,5-dicarboxyphenyl)-4-carboxy-1H-1,2,3-triazole (H3dcpct), was synthesized by 1,3-dipolar cycloaddition of a terminal alkyne to azide in the presence of a Cu(II) salt. Hydrothermal reaction of H3dcpct and Mn(NO3)2·6H2O or Co(NO3)2·6H2O in different NaOH/H3dcpct molar ratios afforded four new coordination polymers [Mn(dcpt)(H2O)2]·0.25H2O 1, [Mn(dcpt)(H2O)] 2, [Co(dcpt)(H2O)2]·H2O 3 and [Co(H2O)6][Co2(dcpct)2(H2O)6]·2H2O 4 (H2dcpt = 1-(3,5-dicarboxyphenyl)-1H-1,2,3-triazole). The in situ hydrothermal decarboxylation of H3dcpct into H2dcpt in 1–3 was found and its possible mechanism is proposed. In 1 and 3, dcpt2− ligands bridge Mn(II) and Co(II) ions, respectively, to give two similar 2D layered structures with a (6,3)-connected network topology. Polymer 2 displays a whole achiral 3D open framework with both chiral and achiral channels in the same direction and possesses an unprecedented (3,6)-connected (4·82)(42·812·10) network topology. The structure of 4 features a 1D chained net, in which no decarboxylation occurred. Variable-temperature magnetic susceptibility data show that 1 exhibits a weak ferromagnetic interaction and 2 manifests an overall antiferromagnetic interaction between their respective Mn(II) ions, while 3 and 4 display an antiferromagnetic interaction between Co(II) ions and/or spin-orbital coupling. The thermal stabilities of all obtained polymers have also been examined.

Stabilization of (SnS4)4− anion by coordinating to [TM(π-conjugated-ligand)m]n+ complex: a chain-like thiostannate(IV) {[Mn(phen)]2(SnS4)}n·nH2O exhibiting an unprecedented link mode of the (SnS4)4− anion

The stabilization of the (SnS4)4− anion in the coordination of [Mn(phen)]2+ complexes brings about a novel compound {[Mn(phen)]2(SnS4)}n·nH2O (1), in which an unprecedented link mode of the (SnS4)4− anion is observed. Theoretical calculations indicate that TM complexes with big π-conjugated ligands, such as [Mn(phen)]2+, can serve as an excellent electron reservoir to stabilize the (SnS4)4− anion in 1, despite its strong condensation tendency. Magnetic measurements show the presence of strong antiferromagnetic interactions between the Mn2+ ions in 1.

New Copper(II) and Nickel(II) Complexes with Bifunctional Tetrazolate-5-carboxylate Ligands: Syntheses, Crystal Structures, and Magnetic Properties

Four new complexes with bifunctional tetrazolate-5-carboxylate ligands of 1H-tetrazole-5-formic acid (H2tzf) and 1H-tetrazole-5-acetic acid (H2tza), namely two dinuclear [M(tzf)(H2O)3]2·2H2O (M = Cu 1, Ni 2) and two mononuclear [Cu(tzf)(2,2′-bipy)2]·5H2O 3 and Cu(tza)(2,2′-bipy)H2O 4, were prepared and structurally characterized by single-crystal X-ray diffraction. Two different coordination modes of tetrazolate-5-carboxylate ligands exist: a tridentate N,O-chelated-N-bridged mode in 1 and 2, and a bidentate N,O-chelated mode in 3 and 4, which was first observed for the tetrazolate-5-carboxylate complexes. Extensive hydrogen bonds play an important role in the construction of the supramolecular network. Variable-temperature magnetic susceptibility data show the presence of antiferromagnetic interactions in 1 and 2. The thermogravimetric analyses of complexes 1–4 are also discussed.

An unprecedented organic–inorganic hybrid material with an I3O3 framework based on cadmium hydroxide and in situ generated 1H-tetrazolate-5-acetic acid

Herein, we report a novel high-dimensional I3O3 organic–inorganic hybrid framework, namely [Cd3(OH)2(tza)2]n (1) (H2tza = 1H-tetrazolate-5-acetic acid), where a rare pure ths inorganic connectivity of Cd–Ohydroxyl is observed. Meanwhile, 1 displays blue emission and high thermal stability up to 370 °C.

CCDC 847568: Experimental Crystal Structure Determination

Related Article: Guang-Ning Liu, Xiao-Ming Jiang, Mei-Feng Wu, Guan-E Wang, Guo-Cong Guo, Jin-Shun Huang|2011|Inorg.Chem.|50|5740|doi:10.1021/ic2005562

catena-Poly[di-μ1,1-azido-(1,10-phenanthroline)cadmium(II)]

The asymmetric unit of the title CdII compound, [Cd(N3)2(C12H8N2)]n, contains a CdII atom, located on a twofold axis passing through the middle of the phenanthroline molecule, one azide ion and half of a 1,10-phenanthroline molecule. The CdII atom exhibits a distorted octahedral coordination including one chelating 1,10-phenanthroline ligand and four azide ligands. The crystal structure features chains along the c direction in which azide groups doubly bridge two adjacent CdII atoms in an end-on (EO) mode. Interchain π–π stacking interactions, with centroid–centroid separations of 3.408 (2) Å between the central aromatic rings of 1,10-phenanthroline molecules, lead to a supramolecular sheet parallel to the bc plane.