Synthesis and Crystal Structure of N,N′-Bis(p-nitrophenyl)-2,2′-(p-phenylene-dioxy)diacetamide DMF Monohydrate

A new complex of N,N?-bis(p-nitrophenyl)-2,2?-(p-phenylene-dioxy) diacetamide DMF monohydrate, C25H25N5O9·H2O (Mr = 557.52), has been synthesized and its structure was determined by X-ray crystallography method. The crystal belongs to monoclinic system, space group P21/c with a = 7.2812, b = 25.5894, c = 14.3434 ?, β = 91.110(1)o, V = 2672.0(2) ?3, Dc = 1.386 g/cm3, F(000) = 1168, μ = 0.109 mm-1 and Z = 4. The final R = 0.0493 and wR = 0.1173 for 3389 observed reflections with I > 2σ(I). The asymmetric unit of the title complex consists of monomeric N,N?-bis(p-nitrophenyl)-2,2?-(p-phenyleneioxy)diacetamide 1, one DMF and one water molecule, which are incorporated during recrystallization. The molecules are linked into a three-dimensional network by π…π interactions as well as intermolecular interactions among DMF, water molecule and 1.

A New Diiminopyridyl Cobalt Complex [CoCl_2L](L=2,6-Bis(N,N'-bis(2,6-diisopropyl-4-(2,3-dimethyoxylbenzoylamide)phenylimino))pyridine)

The reaction of CoCl2·6H2O with 2,6-bis（N,N＇-bis（2,6-diisopropyl-4-（2,3-dimethy-oxyl-benzoylamide）phenylimino））pyridine（L） afforded the complex [CoCl2L],which was fully characterized by elemental analysis,UV-vis,IR spectroscopy,fluorescence,and X-ray diffraction analysis.The compound is of triclinic system,space group P1 with a = 13.058（3）,b = 13.798（3）,c = 16.695（3） ,α = 98.191（3）,β = 102.792（3）,γ = 101.820（3）°,V = 2815.0（9） 3,Z = 2,F（000） = 1122,μ = 0.45 mm-1,R = 0.061 and wR = 0.1349 for 9842 observed reflections（Ⅰ 〉 2σ（Ⅰ））.The Co（Ⅱ） center adopts a distorted square-pyramidal coordination geometry.The extended structure shows a one-dimensional zigzag double chain linked by hydrogen bonds and π-π stacking interactions.

Electronic spectroscopy and photochromic mechanism of bis-Schiff bases, N, N'-bis(2-hydroxy-1-naphthylidene)-1,4-phenyldiamine

The steady state and transient state absorption spectra and fluorescence spectra of N,N’-bis(2-hy-droxy-1-napbthylidcne)-1,4-phenyldiamme ( BNP ) in cyclohexane and acetonitrile were determined.The pho-tochromic mechanism was discussed In nonpolar solvents,BNP exists mainly in the enol form and has the absorption maximum in the UV region In polar solvents,however,both the enol and proton transfer tautomer are formed,but the farmer is the main one Fluorescence emissions result from the excited state of proton transfer product.

Curing Behaviors and Thermal Properties of Dimer Fatty Acid （DFA） Modified Multifunctional Epoxy Resin

In order to improve the toughness of the cured aromatic tetrafunctional epoxy resins, a dlmer rarboxylic acid named dlmer fatty acid （DFA） was used to modify an aromatic tetrafunctional epoxy, N, N, N＇, N＇-tetraglycidyl-2,2-bis [ 4-（ 4-aminophcuoxy ） phenyl ] propane （TGBAPP）. The curing behaviors of DFA- TGBAPP/MNA （ methyl nadic anhydride） systems were studied by differential scanning calorimetry （DSC） method. And the thermal properties of the cured epoxy resin were investigated with the thermo-gravimetric analysis （TGA） and dynamic mechanical analysis （DMA）. Besides, the toughness was characterized with the impact strength tested by charpy impact testing. The results indicated that the modification would improve the curing reactions, and the curing temperatures were decreased with the increasing content of DFA. The thermal properties were not influenced obviously, and the toughness could be improved when the epoxy resin was modified with DFA.