Syntheses,Structures, and Magnetic Behavior of New Azide Linked Compounds with One‐ and Two‐Dimensional Structures

Three azide based compounds were synthesized employing aliphatic amines as site blocking agents: [Ni(N₃)(C₆H₁₆N₂)₂]ClO₄ ( I ) [C₆H₁₆N₂ = N,N′‐diethylethylenediamine (DEDA)], [Cu₈(N₃)₁₆(C₆H₁₈N₄)₂] ( II ) [C₆H₁₈N₄ = tris(2‐aminoethyl) amine (TREN)], and [Cu₇(N₃)₁₄(C₇H₁₉N₃)₂] · 2H₂O ( III ) [C₇H₁₉N₃ = 3,3′‐diamino‐N‐methyldipropylamine (DMDA)]. The compounds I and II have one‐dimensional structure and III has a two‐dimensional structure. Compound I is a simple linear cationic Ni–azide chain and compound II has Cu₆ azide units forming a column terminated by the copper‐metalloligand generated in‐situ during the course of the reaction. The charge compensation perchlorate anions occupy spaces in between the chains in I . Compound II packs in a herringbone arrangement, which is not commonly observed in low‐dimensional structures. Compound III has one‐dimensional copper‐azide chains connected through copper‐metalloligand forming the two‐dimensional structure. All the three compounds exhibit anti‐ferromagnetic behavior.     

Analytical Solutions to Three-Dimensional Reactive Contaminant Transport Problems Involving Point,Line, and Area Sources

Transport in Porous Media - The proposed study is an attempt to perceive theoretically the heat transfer phenomenon in the flow of temperature-dependent viscous blood through microvessels...     

A one-dimensional barium(II) coordination polymer with a coordinated nitro group of 2-nitrobenzoate

The aqueous reaction of barium carbonate with 2-nitrobenzoic acid (2-nbaH) results in the formation of a one-dimensional coordination polymer, catena-poly[[hexa(aqua)dibarium(II)]bis[(μ ₂-2-nitrobenzoate-O,O,O-NO₂)(μ ₂-2-nitrobenzoate-O,O,O′)]] 1. On heating at 100°C compound 1 is dehydrated to anhydrous barium bis(2-nitrobenzoate) 2. The anhydrous compound can be re-hydrated to 1 on exposure to water vapour. Compounds 1 and 2 were characterized by elemental analysis, IR and UV-Vis spectra, DSC thermograms, weight loss studies and the structure of 1 was determined. 1 and 2 can be thermally decomposed to BaCO₃ by heating at 800°C. The polymer [[Ba(H₂O)₃]₂(μ ₂-2-nba-O,O,O-NO₂)₂ (μ ₂-2-nba-O,O,O′)₂] _n 1 crystallizes in the centrosymmetric triclinic space group Pī and all atoms are located in general positions. The polymeric structure is based on a dimeric unit and consists of three water molecules coordinated to a central Ba(II) and two unique 2-nitrobenzoate (2-nba) anions, one of which (μ ₂-2-nba-O,O,O-NO₂) functions as a tridentate ligand and is linked to a Ba(II) through the oxygen atom of the-NO₂ group and forms a monoatomic μ ₂-carboxylate bridge between two symmetry related Ba(II) ions with a Ba···Ba distance of 4·5726(14) ?. The second unique 2-nba anion (μ ₂-2-nba-O,O,O′) also functions as a tridentate ligand with the carboxylate oxygen atoms linked to a Ba(II) ion in a bidentate fashion and one of the carboxylate oxygen atoms forming a monoatomic bridge between two symmetry related Ba(II) ions resulting in a Ba···Ba separation of 4·5406(15) ?. These differing tridentate 2-nba ligands link {Ba(H₂O)₃} units into a one-dimensional polymeric chain extending along b axis. In the infinite chain each nine coordinated Ba(II) is bonded to three water molecules and further linked to six oxygen atoms of four different 2-nitrobenzoate anions with alternating pairs of Ba(II) ions in the chain bridged by a pair of (μ ₂-2-nba-O,O,O-NO₂) and (μ ₂-2-nba-O,O,O′) ligands resulting in alternating Ba···Ba distances of 4·5406(15) and 4·5726(14) ? across the chain. Dedicated to Prof. S. K. Paknikar on the occasion of his 73rd birthday.     

Synthesis and characterization of a novel non-linear optical (NLO) material

Anthracene is one of the organic molecular crystals, which exhibits peculiar optical and electronic properties. Since the 9, 10 positions are very reactive in anthracene, it undergoes the Diel’s–Alder reaction with maleic anhydride in 99% yield. The synthesis of Diel’s–Alder adduct has been carried out by adopting standard procedure. The product was subjected to various characterization studies such as FTIR, UV and ¹H NMR spectroscopy, and thermal studies to check its purity and determine the applicability of adduct in various applications. The second harmonic generation (SHG) efficiency of the adduct has been observed using Nd:YAG laser.     

A robust palladium-catalyzed cyanation procedure: beneficial effect of zinc acetate

Conditions that ensure a more reproducible Pd(0)-mediated procedure to convert aryl bromides to aryl cyanides have been developed that entail the use of zinc dust to keep the Pd in the zero oxidation state and zinc acetate to ensure high catalytic activity. This procedure is applicable to a wide range of substrates and obviates the need for stringent removal of oxygen from the reaction medium.     

Synthesis and Structure of a Three‐dimensional Organically Templated Zinc Ethylenediphosphonate, [NH3(CH2)2NH3][Zn3{O3P(CH2)2}4]

A hydrothermal reaction of a mixture of ZnO, HCl, ethylenediphosphonic acid, ethylenediamine, acetic acid in a water, THF mixture gave rise to a new three‐dimensional zinc ethylenediphosphonate, [NH₃(CH₂)₂NH₃][Zn₃{O₃P(CH₂)₂}₄], I . The structure, determined by single crystal X‐ray diffraction, (monoclinic, space group = C2/c, a = 16.9948(14), b = 6.7383(6), c = 16.8886(14)Å, β = 1113.568(1)°, V = 1772.7(3)ų, Z = 4, R₁ = 0.0227, wR₂ = 0.0601), consists of a network of strictly alternating ZnO₄ and PO₃C tetrahedral units linked through their vertices forming the three‐dimensional structure. The amine molecules occupy the middle of the 8‐membered channels and interact with the framework through the hydrogen bonds. Unlike other zinc diphosphonates, I appear to have close similarity to zinc phosphate structures reported in the literature. To our knowledge, this is the first three‐dimensional zinc diphosphonate prepared in the presence of an organic amine molecule.