نتایج جستجو برای: schiff bases hydrazones

تعداد نتایج: 73325  

2000
K. WoŸniak E. Grech

Structural properties of two model solid Schiff-Mannich bases: 7-[(1-{5-bromo-3[(diethylamino)methyl]-2-hydroxyphenyl}methylidyne)amino]-4-methylcoumarin and N,N -bis{5-bromo-3-[(diethylamino)methyl]salicylidene}-1,2-diaminoethane have been investigated. In both cases a neutral intramolecular O–H...N hydrogen bonding is formed with participation of the Schiff parts of the molecules only. Single...

2009
Grzegorz Romanowski Michał Wera Artur Sikorski

In the crystal structure of the title compound, [V(C(12)H(17)N(2)O)O(2)], the vanadium(V) centre is five-coordinate in a distorted square-pyramidal environment. The three atoms of the deprotonated Schiff base and a double-bonded O atom comprise the basal plane. N-H⋯O hydrogen bonds lead to a zigzag chain structure parallel to [001].

Mohammad Hosein Farjam

The aim of the present study is to synthesize the oxovanadium complex of the V3+ ion with isatin sciff bases. Spectroscopic methods have been used to confirm these models of complexation and to understand the structures of the species formed in methanolic solution. We also have isolated a complex of Vanadium (III) with isatin schiff bases in the solid phase.

2009
Said Nadeem Muhammad Raza Shah Donald VanDerveer

Mol-ecules of the title compound, C(34)H(28)N(2)O(4), a Schiff base precursor for macrocycles, are located on a mirror plane. The C=N double bond is trans configured. Inter-molecular C-H⋯O inter-actions stabilize the crystal packing.

Journal: :iranian journal of science and technology (sciences) 2004
b. etemadi

the crystal structure of the compound c20 h24 n2 o24 was determined by direct methods. thecrystals are monoclinic, space group p21/n, and unit cell parameters are: a= 10.2342 (9), b=4.8763 (5),c=19.3578 (11) a, β =98.9632 (10) o ,v=956.6 (5) a3, z=2, dc=1.239grm-3, dm=1.22grm-3. the final rfactorsare converged to r=0.059 and rw=0.056 for 553 independent observed reflections. themolecules are li...

Journal: :Molecules 2016
Ahmed M Naglah Atallah F Ahmed Zhi-Hong Wen Mohamed A Al-Omar Abd El-Galil E Amr Atef Kalmouch

A series of new Schiff bases were synthesized by condensation of isatins with the nalidixic acid-l-amino acid hydrazides. Prior to hydrazide formation, a peptide linkage has been prepared via coupling of nalidixic acid with appropriate l-amino acid methyl esters to yield 3a-c. The chemical structures of the new Schiff bases (5b and 5d-h) were confirmed by means of IR, NMR, mass spectroscopic, a...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 1999
mohammad m. hashemi behnaz almasi

addition of potassium cyanide to a mixture of schiff base and lithium perchlorate afforded a-aminonitriles in high yields. addition of potassium cyanide to a methanolic solution of schiff base and phosphoric acid afforded a-aminonitriles. when the reaction mixture was refluxed it gave a-amino acids in high yields.

Journal: :International journal of biological macromolecules 2015
Hend E Salama Gamal R Saad Magdy W Sabaa

The Schiff bases of chitosan were synthesized by the reaction of chitosan with 3-(4-substituted-phenyl)-1-phenyl-1H-pyrazole-4-carbaldehyde. The structure of the prepared chitosan derivatives was characterized by FT-IR spectroscopy, elemental analysis, and X-ray diffraction studies and thermogravimetric analysis (TG). The results show that the specific properties of Schiff bases of chitosan can...

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