Jin-Tang Wang

3,5‐Bis(2‐thienyl)‐4‐amino‐1,2,4‐triazole as a corrosion inhibitor for copper in acidic media

Purpose – The aim of this paper is to investigate inhibition of copper corrosion by 3,5‐bis(2‐thienyl)‐4‐amino‐1,2,4‐triazole (2‐TAT) in 1 M HCl and 0.5 M H2SO4.Design/methodology/approach – Potentiodynamic polarization curves and electrochemical impedance measurements were carried out on copper in 1 M HCl and 0.5 M H2SO4 containing various concentrations of 2‐TAT, and the effects of temperature were also investigated.Findings – As an efficient inhibitor, 2‐TAT behaves better in 1 M HCl than in 0.5 M H2SO4. 2‐TAT can be classified as cathodic‐type corrosion inhibitor in 1 M HCl and acts as relatively mixed type in 0.5 M H2SO4. Activation energies in the presence and absence of 2‐TAT were obtained by measuring the temperature independence of corrosion current. Adsorption of the inhibitor on the copper surface was found to obey the Langmuir adsorption isotherm.Practical implications – This inhibitor could have application in industries where hydrochloric acid solutions are used to remove scale and salts fro...

N,N-Dimethyl-3-(1-naphth-yloxy)-3-(2-thien-yl)propan-1-amine.

The title compound, C19H21NOS, is an intermediate for the synthesis of duloxetine hydrochloride. In the molecular structure, the thiophene and naphthalene ring systems make a dihedral angle of 87.5°. All bond lengths and angles involving heteroatoms are as expected. In the crystal structure, no classical hydrogen bonds are found.

1,2-Bis(1,3-benzothia-zol-2-yl)benzene.

The title compound, C20H12N2S2, was prepared by the reaction of o-phthalic acid and 2-aminothiophenol under microwave irradation. The phenyl ring, A, and the benzothiazolyl rings, B and C, are planar; the dihedral angles are A/B = 19.9 (11), A/C = 87.8 (3) and B/C = 84.4 (4)°. Weak intermolecular C—H⋯N hydrogen bonds link the molecule, forming zigzag chains parallel to the c axis.

N,N′-Di-p-tolyl­ethyl­enediamine

The asymmetric unit of the title compound, C16H20N2, contains two independent molecules. The rings in each molecule are oriented at dihedral angles of 78.94 (3) and 77.76 (3)°.

2-[1-Chloro-3-(2-methyl-5-nitro-1H-imidazol-1-yl)propan-2-yloxycarbonyl]benzoic acid

The asymmetric unit of the title compound, C15H14ClN3O6, contains two independent molecules. The imidazole rings are oriented with respect to the benzene rings at dihedral angles of 19.66 (3) and 21.64 (3)°. In the crystal structure, intermolecular O—H⋯N hydrogen bonds link the molecules into infinite chains.

Dimethyl 2,2-bis­(2-cyano­ethyl)malonate

The asymmetric unit of the title compound, C11H14N2O4, contains one half-molecule; a twofold rotation axis passes through the central C atom. Intermolecular C—H⋯N hydrogen bonds link the molecules into a one-dimensional supramolecular structure.

2-(2,4-Dichloro­phen­yl)-3-[5-(4-methoxy­phen­yl)-1,3,4-thia­diazol-2-yl]-1,3-thia­zolidin-4-one

In the molecule of the title compound, C18H13Cl2N3O2S2, the thiazolidinone ring has an envelope conformation with the S atom displaced by 0.394 (3) Å from the plane of the other ring atoms. The thiadiazole ring is oriented at a dihedral angle of 7.40 (4)° with respect to the 4-methoxyphenyl ring. Intramolecular C—H⋯S, C—H⋯N and C—H⋯Cl hydrogen bonds result in the formation of two planar and two non-planar five-membered rings. The planar five-membered rings are oriented at a dihedral angle of 6.23 (3)°. The 2,4-dichlorophenyl ring is oriented at dihedral angles of 84.21 (4) and 83.55 (3)° with respect to the thiadiazole and 4-methoxyphenyl rings, respectively. In the crystal structure, intermolecular C—H⋯O hydrogen bonds link the molecules into centrosymmetric dimers.

Microwave-assisted synthesis of 1,3,4-thiadiazole aroylurea derivatives

A rapid and efficient microwave-assisted synthesis method for the preparation of 1-aroyl-3-(5-aryl-1,3,4-thiadiazol-2-yl)urea is described. These 1,3,4-thiadiazole aroylureas (5a–f) were identified by IR, 1H NMR, elemental analyses and N-[5-(4-methoxyphenyl)-1,3,4-thiadiazol-2-ylcarbamoyl]-2,6-difluorobenzamide was confirmed by single-crystal X-ray diffraction. The target compounds were prepared under microwave in a shorter reaction time compared with conventional heating methods.

4,4-Diacetyl-hepta-nedinitrile.

The asymmetric unit of the title compound, C11H14N2O2, contains one half-molecule as the central C atom of the molecule lies on a twofold rotation axis. In the crystal structure, weak intermolecular C—H⋯N hydrogen bonds link the molecules into zigzag chains along c.

Diethyl {(4-methoxy-phen-yl)[5-(4-nitro-phen-yl)-1,3,4-thia-diazol-2-ylamino]meth-yl}phospho-nate.

The title compound, C20H23N4O6PS, was synthesized by the reaction of N-(4-methoxybenzylidene)-5-(4-nitrophenyl)-1,3,4-thiadiazol-2-amine and diethyl phosphite. The thiadiazole and nitro-substituted phenyl rings in the molecule are approximately coplanar, the dihedral angle being 5.3 (2)°. The dihedral angle formed by the mean plane through all non-H atoms of both the thiadiazole and the nitro-substituted phenyl ring with the plane of the methoxy-substituted phenyl ring is 48.9 (2)°. In the crystal structure, molecules form centrosymmetric dimers as a result of N—H⋯O bonds involving amine H and phosphine oxide O atoms.