Diethylenetriamine Molecules Research Articles

Sulfonic acid-type hydrothermal carbon microspheres as stable, efficient catalysts for transesterification reactions

With the aim of preparing a sulfonic acid-type solid acid catalyst having a high density of acid sites and excellent stability, this work synthesized sulfonic acid bowl-shaped hydrothermal carbon microspheres (SA-OBHCs), using amine groups as the primary sulfonic acid bonding sites. This material was synthesized via a three-step functionalization process comprising the oxidation, amidation and sulfonation of BHCs. The extent to which chlorosulfonic acid reacted with amine groups in diethylenetriamine molecules on microsphere surfaces was also investigated using density functional theory calculations. These calculations showed that the substitution reaction of primary amines proceeded less readily than that of secondary amines but provided a more stable product. The surface acid density of the SA-OBHCs was as high as 11.2 mmol·g−1 and the –SO3H groups on the SA-OBHCs were found to be thermally stable up to 200 °C. These SA-OBHCs were subsequently used to catalyze the synthesis of fatty acid methyl esters (FAMEs) from a waste frying oil model compound and methanol. Reactions performed using a methanol/oil molar ratio of 20:1 at 140 °C for 3 h gave a FAMEs yield of 93.4 %. After four reuses, an SA-OBHCs specimen provided a FAMEs yield of 77.5 %, demonstrating the significant stability of this material.

Covalent grafting of triazine derivatives onto graphene oxide for preparation of epoxy composites with improved interfacial and mechanical properties

Interface interactions are the important problems in improving the mechanical properties of graphene and polymer composites. In this work, a simple method is proposed to prepare epoxy composites with admirable properties through constructing dendrimers with cyanuric chloride (TCT) and diethylenetriamine (DETA) onto graphene oxide (GO) surface. The FTIR, XRD, XPS, Raman spectroscopy, SEM and TEM were used to confirm the successful grafting of TCT and DETA molecules onto the surface of GO. The interfacial adhesion between GO–TCT–DETA and epoxy resin is enhanced due to the formation of a strong chemical bond between the amino group on the GO surface and the epoxy resins. The tensile and flexural strength of GO–TCT–DETA/epoxy composites have considerable improvement (40.79 and 48.56%) compared with that of epoxy resin due to stronger interfacial interaction. In addition, the strengthening mechanism and dispersion of GO–TCT–DETA in epoxy matrix were also demonstrated.

Hydrothermal synthesis and crystal structure of an inorganic-organic hybrid heteropolymolybdate (C4H16N3)2[NiMo12O40]Cl2 · 9H2O

A novel inorganic-organic hybrid polyoxomolybdate (C4H16N3)2[NiMo12O40]Cl2 · 9H2O has been synthesized under hydrothermal conditions and structurally caracterised by elemental analysis, TG, IR and single crystal X-ray diffraction. The crystals are orthorhombic, a = 10.138(3) A, b = 19.508(2) A, c = 26.790(4) A, Z = 4, sp. gr. Pcnb. Keggin polyoxomolybdate anion [NiMo12O40]4−, protonated diethylen-etriamine molecules, chloride anions and water molecules are linked via a large number of hydrogen bonds.

Supramolecular Self-Assembly of V-Shaped Water Trimers and Diethylenetriamine Molecules in a New Solid State Ferrous Molybdenum(V) Phosphate

A new ferrous molybdenum(V) phosphate, [H2deta]4[H3O]{Na[FeIIMo 12 V O24(OH)6(HPO4)6(PO4)2]}·6H2O 1 (deta = diethylenetriamine) has been prepared under hydrothermal condition and thoroughly characterized by IR, UV–Vis spectroscopy, elemental analyses, single–crystal X-ray diffraction, powder XRD and TG–DTA. The structural analysis reveals that isolated V-shaped water trimers and protonated diethylenetriamine molecules coexist in the crystal lattice of 1 and form an unprecedented 1-D strip-like arrangement via hydrogen bonding interactions. The strip-like arrangement further interacts through intermolecular non-covalent interactions with its surroundings, viz., the new 1-D inorganic anionic chain constructed by the versatile Fe[Mo6P4O31] building blocks which is covalently connected with NaO6 octahedra, and finally results in a supramolecular entity that is favourable in terms of packing efficiency and system energy minimization. The electrochemical properties of the compound 1 is also investigated by voltammetric method.

Acid–base properties of ion exchangers: V. Synthesis and properties of ion exchangers on the base of modacrylic polyacrylonitrile–vinylchloride fibers

Weak base polyfunctional fibrous anion exchangers, containing small amount of carboxylic acid groups were obtained on the base of industrial modacrylic fibers Kanecaron (40% acrylonitrile, 60% vinylchloride) (Kaneka Ltd., Japan) by their reacting with aqueous solutions of diethylenetriamine (DETA). The sample obtained at optimal condition (DETA concentration 70–80%, process time 2–7 h, temperature 95 °С) have anion exchange capacity 3–5 meq/g and water uptake 0.3–0.4 gH 2O/g. Their chemical stability in different media has been studied. On the base of studies of their ion exchange capacity, elemental analysis, potentiometric titration and IR spectra the structure of these ion exchangers has been clarified. Predominant reaction of the modification is substitution of the Cl atoms by nitrogen in DETA molecules with formation of tertiary and secondary amino groups. All three atoms of nitrogen react and the ratio of incoming N atoms and outgoing Cl atoms is close to one.

Thin wetting film from aqueous solution of polyoxyalkylated DETA (Diethylenetriamine) polymeric surfactant

Thin wetting films from aqueous solutions of the polymeric surfactant polyoxyalkylated diethylenetriamine (DETA), have been studied on hydrophilic SiO 2-glass surface. The wetting (receding) contact angles θ r of the solution on the glass surface have been measured, using the sessile drop method. Also the contact angle θ aq of a drop of doubly distilled water on the same glass surface pre-treated with DETA polymeric surfactant solution has been measured. The receding contact angles θ r versus polymeric surfactant concentration C s curves showed a maximum at θ r ≈ 22° in the concentration range of 10 −6–2 × 10 −5 mol dm −3 DETA. The equilibrium thickness h of wetting films from DETA aqueous solution on hydrophilic SiO 2-glass surface, pre-treated with surfactant solution, has been measured using the micro-interferometric method at various concentrations, C s. At very low C s (between 10 −11 and 10 −8 mol dm −3) the h-values are almost constant, then they increase with increasing C s reaching a maximum at 1.5 × 10 −6 mol dm −3, after which they decrease with further increase in C s. Both θ r and h exhibit largest values in the concentration range between 2 × 10 −6 and 2 × 10 −5 mol dm −3 DETA. The analysis of the results obtained shows that the stability of the wetting films from aqueous solutions of DETA is determined by the electrostatic, steric, and hydrophobic components of disjoining pressure, respectively by the adsorption and orientation of the polymeric DETA molecules on the SiO 2-glass surface.

Unprecedented formation of a hydrogen-bonded assembly of water–diethylenetriamine molecules within a new solid state supramolecular molybdenum(V) phosphate complex

An unprecedented H-bonded 2-D arrangement consisting of water dimers, V-shaped water trimers and protonated diethylenetriamine (deta) molecules is crystallographically characterized for the first time in the host crystal lattice of a new reduced molybdenum(V) phosphates [ H 2 deta ] 4 { Na [ NaMo 12 V O 24 ( OH ) 6 ( H 2 PO 4 ) 2 ( HPO 4 ) 4 ( PO 4 ) 2 ] } · 8 H 2 O which is prepared under hydrothermal condition and characterized by elemental analyses, IR, UV–Vis, TG–DTA, cyclic voltammetry and single-crystal X-ray diffraction. The harmonious assembly of the small dimer and trimer water clusters and deta molecules is significant in stabilizing and influencing the arrangement of their surroundings which herein refers to the 1-D inorganic anion chains constructed by the versatile building blocks of the formula [Mo 6P 4O 31] covalently connected with NaO 6 octahedra, giving rise to a 3-D arrays via complex hydrogen bonding interactions.

Controlling the In situ Decomposition of Chain-Type Polyamines To Direct the Crystal Growth of Cobalt−zinc Phosphates

The in situ decomposition of tetraethylene-pentamine, triethylenetetramine, or diethylenetriamine has been controlled to direct the synthesis of three open-framework cobalt−zinc phosphates, CoZnPO4-I, CoZnPO4-II, and CoZnPO4-III. These phosphates can be synthesized as the intergrowth from a single gel at 200 °C in the presence of diethylenetriamine with propylamine as the assistant organic additive. Structure analysis reveals that species encapsulated in the structures of CoZnPO4-I, CoZnPO4-II, and CoZnPO4-III are ammonium, ethylenediaminum, and diethylenetriaminum, respectively, which can be attributed to the in situ decomposition of diethylenetriamine molecules during the crystallization procedure. It has been found that the presence of second organic amine redound to controlling the decomposition of these linear polyamines, such as diethylenetriamine, to form these three CoZnPO4 materials from a single gel. Pure phase of CoZnPO4-I, CoZnPO4-II, and CoZnPO4-III have also been obtained by varying assistant amines, crystallizing at a lower temperature, or using other linear polyamines, such as triethylenetetramine or tetraethylene-pentamine instead of diethylenetriamine as the main organic additives. Single-crystal X-ray diffraction analysis has shown that CoZnPO4-I is a novel metal phosphate. It crystallizes in hexagonal space group p6 3 (No.173), with a = 10.7207(5) Å, c = 8.7241(8) Å, V = 868.36(10) Å3, and Z = 4. Its three-dimensional framework can be considered as the stacking of six-ring sheet with the combination of UDUDUD (U, upward; D, downward) and UUUDDD linkages in the proportion 1:3. Its negative framework is charge-compensated by NH4 + cations, which are encapsulated in 6946 cage of the structure. CoZnPO4-II crystallizes in the tetragonal system, space group P42 bc (No. 106), with a = b = 14.694(2) Å, c = 8.936(2) Å, V = 1929.4(6) Å3, and Z = 8, possesses DFT topology, and is built of ZnO4 (or CoO4), and PO4 tetrahedra with ethylenediaminum cation resided in the 8-member ring channels to compensate the negative framework charge. The three-dimensional architecture of CoZnPO4-III crystallizes in the trigonal system, space group R̅ (No. 148), with a = 13.5393(8) Å, c = 15.0443(10) Å, γ = 120°, V = 2388.3(3) Å3, and Z = 3, is built up of ZnO4(or CoO4), PO4 tetrahedra, and CoO6 octahedra with diethylenetriaminums encapsulated in the channels.

Synthesis, vibrational study, crystal structure and density functional calculations of [Ni(dien) 2] 2+ complexes. Configurational and conformational study of [M(dien) 2] n+ complexes

Two new complexes containing the complex cation [Ni(dien) 2] 2+ (dien=diethylenetriamine) have been synthesised [Ni(dien) 2]CA·2H 2O (CA=chloranilate) ( 1) and [Ni(dien) 2][Ni(CN) 4]·2H 2O ( 2). The structures of compounds have been determined by single crystal X-ray diffraction methods. In the cationic unit of compound 1, the ligand geometry around nickel(II) is nearly octahedral. Two chelating tridentate diethylenetriamine molecules with terminal amino groups in cis and secondary amino groups in trans position define the s-fac geometry. The conformations of the two independent chelate rings are enantiomeric with each other. The nickel atom of [Ni(dien) 2] 2+ unit in compound 2 also shows a distorted octahedral environment, but the two tridentate dien molecules are coordinated meridionally. Crystallographic observations of fused five-membered ring of bis(dien) complexes, retrieved from Cambridge Structural Database, have been mapped and classified using principal component analysis. Several density functional calculations of the geometry of the s-fac and mer isomers of the complex cation [Ni(dien) 2] 2+ have been carried out, and the results have been compared to the crystallographic data.