Schiff’s base Fufural Phenylhydrazone as a Potential Corrosion Inhibitor for Mild Steel in Hydrochloric Acid Solution

Heterocyclic Schiff base furfural phenylhydrazone [FPH] was prepared and formulated as a corrosion inhibitor for mild steel in 2M hydrochloric acid solution. Mass change measurement and electrochemical methods adapted to study the effectiveness of the FPH during the corrosion process. FPH inhibitor protected 94.53 % corrosion of mild steel at optimum inhibitor strength of 0.0007 M at 303 ±1 K. Route of corrosion protection was interpreted through adsorption of FPH molecules on specimen surfaces in acid solution. Nature of the adsorption was established via Langmuir adsorption isotherm. Stability of the inhibitor was investigated with higher temperatures. Tafel polarization curves revealed, FPH molecules exhibit mixed nature of inhibitor. SEM and AFM images suggested that corroded specimen surface was severely affected in free acid comparatively in presence of FPH inhibitor. FT-IR analysis proved that, chemical interaction takes place between specimen surface atoms with FPH molecules and established chemical bond between them

1-(2-Azido­acet­yl)-3-methyl-2,6-diphenyl­piperidin-4-one

In the title compound, C20H20N4O2, the piperidine ring adopts a distorted boat conformation. The two phenyl rings form dihedral angles of 82.87 (1) and 84.40 (1)° with respect to the piperidine ring. The crystal packing is stabilized by inter­molecular C—H⋯O and C—H⋯N inter­actions

(E)-Ethyl 2-cyano-3-(1H-pyrrol-2-yl)acrylate

All the non-H atoms of the title compound, C10H10N2O2, are nearly in the same plane with a maximum deviation of 0.093 (1) Å. In the crystal, adjacent mol­ecules are linked by pairs of inter­molecular N—H⋯O hydrogen bonds, generating inversion dimers with R 2 2(14) ring motifs

8-[(Hydrazinyl­idene)meth­yl]-4-methyl-2-oxo-2H-chromen-7-yl 4-methyl­benzene­sulfonate

In the title compound, C18H16N2O5S, the coumarin ring system is nearly planar, with a maximum out-of-plane deviation of 0.078 (1) Å (r.m.s. deviation = 0.046 Å). The dihedral angle between the coumarin ring system and the toluene ring (r.m.s. deviation = 0.004 Å) is 2.77 (1)°. The crystal packing is stabilized by C—H⋯O and N—H⋯O inter­molecular hydrogen bonds generating C(8), C(9) and C(11) chains and R 2 2(14), R 2 2(23) and R 4 3(13) ring graph sets

Ethyl 4-(3-bromo­phen­yl)-6-methyl-2-oxo-1,2,3,4-tetra­hydro­pyrimidine-5-carboxyl­ate

In the title compound, C14H15BrN2O3, the dihydro­pyrimidin­one ring adopts a boat conformation. In the crystal, adjacent mol­ecules are linked through N—H⋯O hydrogen bonds forming an R22(8) ring motif and generating a zigzag chain extending in [010]

(Z)-2-[2-(4-Methyl­benzyl­idene)hydrazin­yl]pyridine

Mol­ecules of the title compound, C13H13N3, are essentially planar (r.m.s. deviation for all non-H atoms = 0.054 Å). The dihedral angle between the two aromatic rings is 6.33 (5)°. In the crystal, pairs of centrosymmetrically related mol­ecules are linked through N—H⋯N hydrogen bonds, forming N—H⋯N dimers with graph-set motif R22(8)

(E)-Ethyl 2-cyano-3-(furan-2-yl)acrylate

There are two independent mol­ecules in the asymmetric unit of the title compound, C10H9NO3, in both of which, all non-H atoms except for the methyl C atom lie nearly in the same plane [maximum deviations = 0.094 (3) and 0.043 (2) Å]. In the crystal, each independent mol­ecules is linked by pairs of C—H⋯O inter­actions, generating inversion dimers with R 2 2(10) ring motifs

6-Bromo-3-{2-[2-(diphenyl­methyl­ene)hydrazin­yl]-1,3-thia­zol-5-yl}-2H-chromen-2-one chloro­form monosolvate

In the title compound, C25H16BrN3O2S·CHCl3, the thia­zole ring is approximately planar [maximum deviation = 0.002 (3) Å] and makes dihedral angles of 10.75 (14) and 87.75 (15)/2.80 (14)° with the pyran ring system and the two terminal phenyl rings, respectively. The solvent mol­ecule is disordered over two sets of sites, with refined occupancies of 0.639 (7) and 0.361 (7). In the crystal, mol­ecules are connected via pairs of weak C—H⋯O inter­actions, forming centrosymmetric dimers. An intra­molecular C—H⋯O hydrogen bond generates an S(6) ring motif

1-(3,5-Dichloro­phen­yl)-1H-1,2,3,4-tetra­zole

In the title compound, C7H4Cl2N4, the dihedral angle between the tetra­zole and benzene rings is 17.2 (2)°. In the crystal, C—H⋯N inter­actions link the mol­ecules into a flattened helical chain along the b axis