Solid State Synthesis and Hierarchical Supramolecular Self-assembly of Organic Salt Cocrystals

Abstract This paper describes the solid-state synthesis and systematic studies of versatile supramolecular self-assembly of 14 new series of organic salt cocrystals. Hierarchical self-assembly in the solid state utilizes the cooperative interaction of hydrogen bonding, electrostatic and π–π interactions. These salts are crystallized as a highly ordered self-assembly directed by intermolecular non-covalent interaction. Index Abstract Fourteen cocrystals of organic salt have been characterized by single crystal X-ray diffraction and their solid-state packing pattern has been compared. Electronic supplementary material The online version of this article (doi: ) contains supplementary material, which is available to authorized users.     

ADSORPTION OF TANNIN FROM AQUEOUS SOLUTION ONTO MACROPOROUS CROSSLINKED POLY(N-VINYL-ACETAMIDE) VIA HYDROGEN BONDING

I INTRODUCTIONTannin is existed widely in the roots, stems and fruits of many plants 111. Tannin is stronglyastringent and puckery due to the hydrogen bonding between the phenolic hydroxyl groups intarmin and abide groups in Protein al. A series of PYOb\m won\d be abed if t~ is nOIremoved from the products made from plants. For example, the injection site of the patientwould be red and swollen if tannin had not been removed from the injection made from plantssuch as red-rooted sajvia; …     

Nanocomposites Facilitate the Removal of Aβ Fibrils for Neuroprotection

Accumulation of β-amyloid(Aβ) fibrils in the brain is one of the main culprits in Alzheimer’s disease(AD) progression, which initiates the neuronal damage and subsequent neurodegeneration. Various anti-Aβ agents have shown the potentials to dissociate Aβ fibrils. However, these approaches can’t facilitate the removal of Aβ fibrils, resulting in a disappointing therapeutic effect. Herein, we demonstrate an integrated polymer nanocomposite(NP-GLVFF-IgG) that can dissociate Aβ fibrils into fragments and activate microglia to remove the fragments via Fc receptors-mediated phagocytosis. NP-GLVFF-IgG is constructed by an albumin/polymer hybrid nanoparticle with Gly-Leu-Val-Phe-Phe (GLVFF) peptides and Immunoglobulin G(IgG) molecules on the surface. In this design, NP-GLVFF-IgG achieves to dissociate the Aβ fibrils by the strong hydrogen-bonding interactions between Aβ fibrils and GLVFF peptides. Then, NP-GLVFF-IgG activates the microglial phagocytosis, thereby achieving an enhanced phagocytic removal of Aβ fibrils for neuroprotection. Moreover, NP-GLVFF-IgG achieves to trigger the effective removal of Aβ fibrils even under inflammatory condition that usually suppressed phagocytosis. Therefore, NP-GLVFF-IgG has great potential as a novel therapeutic platform for effective AD therapy.     

Syntheses,structures, and fluorescent properties of two uranium coordination polymers with carboxylic acids

Two U(VI)-containing coordination polymers, (UO₂)₂O₂(Suc)(2,2′-bipy)₂ (1) and UO₂(BC)₂(DMF) (2) (2,2′-bipy?=?2,2′-bipyridine, H₂Suc?=?succinic acid, HBC?=?benzoic acid, DMF?=?N,N-dimethylformamide), have been synthesized and characterized via elemental analysis, infrared spectroscopy, UV-Vis spectroscopy, and single-crystal X-ray diffraction. Structural analyses show that 1 is a 1-D chain coordination polymer in which U(VI) ions are connected by succinic acid ligand and the 1-D chain is connected into a 3-D supramolecular network by C?H···O hydrogen bonds between carbon of 2,2′-bipyridine and uranyl oxygen. For 2, monomeric entities are further assembled into a 1-D supramolecular network by C–H···O hydrogen bonds between carbon of DMF molecule and coordinated carboxylate oxygen. Thermogravimetric analyses and photoluminescent properties of 1 and 2 are discussed.     

Synthesis, crystal structure and spectroscopic properties of two new complexes containing azido or dicyanamido bridges

Two new complexes, [Cu(L₁){N(CN)₂}]·ClO₄ (1) (L₁ is 1,8-dimethyl-1,3,6,8,10,13-hexa-azacyclotetradecane) and [Co(L₂)(N₃)₂]·ClO₄ (2) (L₂ is 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetra-azacyclotetradecane) have been synthesized and characterized. The compounds crystallize in the monoclinic system P2₁ space group for 1 and P2₁/n for 2. Single crystal X-ray analysis reveals that the compound 1 assumes a one-dimensional structure via hydrogen-bonding interactions, in which each Cu(II) ion is coordinated by four nitrogen atoms from ligand L₁ and one nitrogen atom from [N(CN)₂]⁻ anion. For compound 2, each Co(III) ion is coordinated by four nitrogen atoms of ligand L₂ and two nitrogen atoms from N₃ ⁻ anion.     

Structural variations in self-assembled cadmium benzoate complexes

A series of mixed ligand cadmium(II) complexes having 3,5-dimethylpyrazole and aromatic carboxylate are structurally characterized. The effect of substituent on aromatic ring and also the effect of composition on co-ordination behavior of these complexes are ascertained. Hydrogen bonded self-assembled mononuclear complexes are obtained from composition [Cd(L)₂(L_a)₂] where L_a = 3,5-dimethylpyrazole L = R–C₆H₄COO– [R = H (1), 2-Cl (2), 4-OH (3), 2-OH (4)]. The cadmium complex (5) having composition [Cd(L)₂(L_a)(H₂O)] (L = 2-NO₂–C₆H₄COO–) is tetra-nuclear. The complex has eight and six co-ordination around cadmium and self-assembles through hydrogen bonding leading to form extended chain structure. The four complexes (1–4) have six co-ordinated trigonal prismatic geometry around cadmium ions. Cadmium complexes having composition [Cd(L)₂(L_a)] such as R = 4-NO₂ (6), 4-Cl (7), and 1-naphthoate complex (8) are co-ordination polymers with seven co-ordination geometry around cadmium. In these co-ordination polymers different Cd–Cd distances are observed for alternate pair of cadmium ions. For example in the case of the co-ordination polymer of 4-nitro-benzoate complex the Cd–Cd distance between alternate pairs are 4.138 Å, and 3.748 Å. The 1-naphthoate complex having pyridine has composition [Cd(L)₂(L_b)₂](H₂O)] (9) where L_b = pyridine and L = 1-naphthoate has seven co-ordination with a distorted pentagonal bipyramid geometry.     

Enantioselective vinylogous aldol reaction of Chan’s diene catalyzed by hydrogen-bonding

Hydrogen-bonding activation of aromatic aldehydes by a TADDOL-derivative promotes the vinylogous aldol reaction of Chan’s diene in moderate efficiency and enantioselectivity. Electron-poor aromatic aldehydes show an enhanced reactivity and a competing asymmetric hetero-Diels-Alder reaction takes place in comparable (or higher) yields and enantiomeric excesses.     

芳香氮化物-CHCl3系列复合物密度泛函法研究

报道对芳香氮化物吡咯（Ｃ４Ｈ５Ｎ）、苯（Ｃ６Ｈ５ＮＨ２）、对位氯代吡啶（Ｃ５Ｈ４ＮＣｌ）、吡啶（Ｃ５Ｈ５Ｎ）及吡咯负离子（Ｃ４Ｈ４Ｎ＾－）与三氯甲烷（ＣＨＣｌ３）形成的系列弱作用复合物的理论计算结果。把复合物看作是一个超分子在密度泛函Ｂ３ＬＹＰ／６－３１１Ｇ（ｄ,ｐ）的水平上进行计算,探讨该系列复合物的稳定性规律、电荷转移及主要几何参数变化等规律,计算结果表明：此类芳香氮化物与三氯甲（ＣＨ３ｌ３）     

Hydrogen-Bonding Interactions in the Crystal Structure of Bis( N -propyl- N -(2-hydroxyethyl)dithiocarbamato- S , S ′)nickel(II): Ni[S2CN(nPr)(CH2CH2OH)]2

Two independent molecules of Ni(S₂CN(Pr)CH₂CH₂OH)₂, each located about a center of inversion, comprise the asymmetric unit. The molecules differ from each other in terms of the relative orientation of the terminal hydroxyl groups. A square planar geometry is found for each nickel atom defined by four sulfur atoms derived from two symmetrically chelating dithiocarbamate ligands. The crystal packing is dominated by O–H···O interactions that lead to extensive cross linking in all directions. The compound crystallizes in the triclinic space group P-1 with a = 6.4008(11) ?, b = 11.480(2) ?, c = 12.517(2) ?, α = 88.021(2)°, β = 82.491(2)°, γ = 89.986(2)°, and Z = 2.     

Crystal and Molecular Structures of Benzyl-(2-chloro-6-methylpyrimidin-4-yl)amine and Benzyl-(4-chloro-6-methylpyrimidin-2-yl)amine: Confirmation of Computationally Predicted Restricted Rotation

Abstract Crystal structures for the isomeric compounds benzyl-(2-chloro-6-methylpyrimidin-4-yl)amine (1), as its hemi-hydrate, and benzyl-(4-chloro-6-methylpyrimidin-2-yl)amine (2) have been determined. Conformational differences lead to multiple molecules, i.e. two and three, in their respective structures. Layers feature in each of the crystal structures and are stabilized by substantial hydrogen-bonding interactions. Compound (1) crystallizes as a hemi-hydrate in the triclinic space group P-1 with a = 8.667(5) ?, b = 11.421(7) ?, c = 12.954(8) ?, α = 78.330(10)°, β = 84.553(10)°, γ = 75.510(9)°, and Z = 4. Compound (2) crystallizes in the monoclinic space group P2₁/c with a = 10.740(3) ?, b = 21.487(6) ?, c = 14.914(4) ?, β = 95.014(5)°, and Z = 12. Index Abstract Substantial hydrogen-bonding interactions leading to layer structures feature in each of the crystal structures of the isomeric title compounds. Electronic supplementary material The online version of this article (doi: ) contains supplementary material, which is available to authorized users.