A Series of Metal–Organic Frameworks Constructed From a V‑shaped Tripodal Carboxylate Ligand: Syntheses, Structures, Photoluminescent, and Magnetic Properties

Six novel complexes, namely, {[Zn_1.5(L)­(bix)_1.5(H₂O)]·H₂O}_<i>n</i> (<b>1</b>), {[Co_1.5(L)­(bix)_1.5(H₂O)]·H₂O}_<i>n</i> (<b>2</b>), {[Co₃(L)₂(4,4′-bpy)₃]·5H₂O}_<i>n</i> (<b>3)</b>, {[Cd₃(L)₂(4,4′-bpy)₃]·4.5H₂O}_<i>n</i> (<b>4</b>), {[Cu₃(L)₂(4,4′-bpy)₃]·3H₂O}_<i>n</i> (<b>5)</b>, and {[Ni_1.5(L)­(4,4′-bpy)_1.5(H₂O)₃]·2H₂O}_<i>n</i> (<b>6)</b> have been synthesized by the hydrothermal reaction of 5-(4-carboxy-2-nitrophenoxy)­isophthalic acid (H₃L) with different transition metal ions in the presence of ancillary ligands, 1,4-bis­(imidazol-1-ylmethyl)­benzene (bix) and 4,4′-bipyridine (4,4′-bpy). Complexes <b>1</b> and <b>2</b> are isostructural, possessing a (3,8)-connected <b>tfz</b>-d type topology with the Schläfli symbol of {4³}₂{4⁶·6¹⁸·8⁴}. The 3D structures of complexes <b>3</b>–<b>5</b> are very similar to complex <b>1</b> with only a little difference of the H₃L coordination motif in complexes <b>4</b> and <b>5.</b> Meanwhile, we use 4,4′-bpy instead of bix as the ancillary ligand in all three complexes. Complex <b>6</b> is a mixed one-dimensional chain and two-dimensional sheet structure, which are further linked to each other in a three-dimensional framework by H-bond interactions. All the complexes are characterized by single crystal X-ray diffraction, IR spectroscopy, thermogravimetry analysis, and elemental analysis. In addition, the luminescent properties of complexes <b>1</b> and <b>4</b> are discussed, and the magnetic properties of complexes <b>2</b> and <b>3</b> are also investigated

Syntheses, Structures, and Photoluminescent Properties of Coordination Polymers Based on 1,4-Bis(imidazol-l-yl-methyl)benzene and Various Aromatic Dicarboxylic Acids

Nine coordination polymers, formulated as {[Zn­(p-bdc)­(bix)]­(DMF)₂}_<i>n</i> (<b>1</b>), {[Co­(p-bdc)­(bix)]­(DMF)₂}_<i>n</i> (<b>2</b>), {[Cd­(p-bdc)­(bix)]­(DMF)₂}_<i>n</i> (<b>3</b>), {[Zn­(bpdc)­(bix)]­(DMF)₃}_<i>n</i> (<b>4</b>), {[Co­(bpdc)­(bix)]­(DMF)₃}_<i>n</i> (<b>5</b>), {[Cd­(m-bdc)­(bix)­(H₂O)]­(DMF)}_<i>n</i> (<b>6</b>), {[Zn­(m-bdc)­(bix)]­(solv)_<i>x</i>}_<i>n</i> (<b>7</b>), {[Zn₂(m-bdc)₂(bix)₂]­(solv)_<i>x</i>}_<i>n</i> (<b>8</b>), and {[Zn­(m-bdc)­(bix)]­(solv)_<i>x</i>}_<i>n</i> (<b>9</b>) (p-H₂bdc = 1,4-benzenedicarboxylic acid, H₂bpdc = biphenyl-4,4′-dicarboxylic acid, m-H₂bdc = 1,3-benzenedicarboxylic acid), have been prepared by solvothermal reactions of the semirigid neutral ligand 1,4-bis­(imidazol-l-yl-methyl)­benzene (bix) with metal ions in the presence of various aromatic dicarboxylic acids. These complexes were characterized by Fourier transform infrared (FT-IR) spectroscopy, elemental analysis, thermogravimetric analysis (TGA), and single-crystal X-ray diffraction analysis. Isostructural complexes <b>1</b> and <b>2</b> reveal a 3-fold interpenetrating three-dimensional (3D) framework with <b>dia</b> topological type. Compound <b>3</b> exhibits a non-interpenetrating, highly undulating two-dimensional (2D) network with (4,4) topology. Compounds <b>4</b> and <b>5</b> exhibit (6,3) layer structures consisting of hexagonal meshes and loops. Compound <b>6</b>, from the topological point of view, shows the same (4,4) topology as compound <b>3</b>; however interestingly all the layers can be divided into pairs in the overall network. Complex <b>7</b> also possesses a 3-fold interpenetrated 3D <b>dia</b> framework similar to <b>1</b> and <b>2</b>. Compound <b>8</b> comprises two independent 2D (4,8²) nets that interpenetrate in a parallel manner. Non-interpenetrating 2D (4,4) layers are also observed in compound <b>9</b> that are further packed into a 3D framework featuring one-dimensional (1D) channels. The structural diversity of nine coordination polymers indicates that the structures can be tuned by metal ions, various ditopic carboxylate anions, and changeable conformations of neutral ligand. In addition, photoluminescent properties of four coordination polymers were also investigated in this paper

A Series of Metal–Organic Frameworks Constructed From a V‑shaped Tripodal Carboxylate Ligand: Syntheses, Structures, Photoluminescent, and Magnetic Properties

Six novel complexes, namely, {[Zn_1.5(L)­(bix)_1.5(H₂O)]·H₂O}_<i>n</i> (<b>1</b>), {[Co_1.5(L)­(bix)_1.5(H₂O)]·H₂O}_<i>n</i> (<b>2</b>), {[Co₃(L)₂(4,4′-bpy)₃]·5H₂O}_<i>n</i> (<b>3)</b>, {[Cd₃(L)₂(4,4′-bpy)₃]·4.5H₂O}_<i>n</i> (<b>4</b>), {[Cu₃(L)₂(4,4′-bpy)₃]·3H₂O}_<i>n</i> (<b>5)</b>, and {[Ni_1.5(L)­(4,4′-bpy)_1.5(H₂O)₃]·2H₂O}_<i>n</i> (<b>6)</b> have been synthesized by the hydrothermal reaction of 5-(4-carboxy-2-nitrophenoxy)­isophthalic acid (H₃L) with different transition metal ions in the presence of ancillary ligands, 1,4-bis­(imidazol-1-ylmethyl)­benzene (bix) and 4,4′-bipyridine (4,4′-bpy). Complexes <b>1</b> and <b>2</b> are isostructural, possessing a (3,8)-connected <b>tfz</b>-d type topology with the Schläfli symbol of {4³}₂{4⁶·6¹⁸·8⁴}. The 3D structures of complexes <b>3</b>–<b>5</b> are very similar to complex <b>1</b> with only a little difference of the H₃L coordination motif in complexes <b>4</b> and <b>5.</b> Meanwhile, we use 4,4′-bpy instead of bix as the ancillary ligand in all three complexes. Complex <b>6</b> is a mixed one-dimensional chain and two-dimensional sheet structure, which are further linked to each other in a three-dimensional framework by H-bond interactions. All the complexes are characterized by single crystal X-ray diffraction, IR spectroscopy, thermogravimetry analysis, and elemental analysis. In addition, the luminescent properties of complexes <b>1</b> and <b>4</b> are discussed, and the magnetic properties of complexes <b>2</b> and <b>3</b> are also investigated

Efficient Semisynthesis of (−)-Pseudoirroratin A from (−)-Flexicaulin A and Assessment of Their Antitumor Activities

Accumulating evidence indicates that natural <i>ent</i>-kaurane diterpenoids show great potential for medical treatment of different pathological conditions including cytotoxicity, antibacterial, and anti-inflammatory activity. Among a variety of diterpenoids tested, (−)-pseudoirroratin A displayed a promising antitumor property <i>in vitro</i> and <i>in vivo</i>. However, this diterpenoid could merely be isolated in a limited amount from a rare source of <i>Isodon pseudoirrorata</i>. To overcome such scanty source, we developed a novel, facile, and efficient semisynthetic strategy to prepare (−)-pseudoirroratin A from natural (−)-flexicaulin A, which can be expediently obtained from <i>I. flexicaulis</i> in a great quantity. The three-dimensional structure and the absolute configuration of our synthetic diterpenoid have been determined and confirmed with the X-ray crystallographic analysis. More importantly, we demonstrated for the first time that pseudoirroratin A exerted significant cytotoxicity against human colorectal carcinoma cells via an induction of apoptosis, as well as a remarkable suppression on tumor growth in a colon cancer xenograft mouse model

Concise Synthesis of Natural Phenylphenalenone Phytoalexins and a Regioisomer

Concise total syntheses of the natural phytoalexins 2-hydroxy-8-(4-hydroxyphenyl)­phenalen-1-one (<b>1</b>), 2-hydroxy-8-(3,4-dihydroxyphenyl)­phenalen-1-one (<b>2</b>), and hydroxyanigorufone (<b>4</b>), together with regioisomer <b>3</b> are accomplished in 11 or 12 steps. The synthetic strategy features a Friedel–Crafts acylation to construct the 1<i>H</i>-phenalen-1-one tricyclic core followed by a Suzuki cross-coupling to obtain the target compounds