TY - JOUR
T1 - Chromeno-carbonitriles as corrosion inhibitors for mild steel in acidic solution
T2 - electrochemical, surface and computational studies
AU - Quadri, Taiwo W.
AU - Olasunkanmi, Lukman O.
AU - Akpan, Ekemini D.
AU - Alfantazi, Akram
AU - Obot, I. B.
AU - Verma, Chandrabhan
AU - Al-Mohaimeed, Amal M.
AU - Ebenso, Eno E.
AU - Quraishi, M. A.
N1 - Funding Information:
EDA thankfully acknowledge the North-West University (Ma-keng Campus), South Africa for postdoctoral research fellowship. The authors also acknowledge the Centre for High Performance Computing (CHPC), CSIR, South Africa for granting access to computing resources. The authors extend their appreciation to the Researchers supporting project number (RSP-2020/247) King Saud University, Riyadh, Saudi Arabia.
Publisher Copyright:
© 2021 The Royal Society of Chemistry.
PY - 2021/1/11
Y1 - 2021/1/11
N2 - Three novel N-hydrospiro-chromeno-carbonitriles namely, 2-amino-7,7-dimethyl-1′,3′,5-trioxo-1′,3′,5,6,7,8-hexahydrospiro[chromene-4,2′-indene]-3-carbonitrile (INH-1), 3-amino-7,7-dimethyl-2′,5-dioxo-5,6,7,8-tetrahydrospiro[chromene-4,3′-indoline]-2-carbonitrile (INH-2) and 3′-amino-7′,7′-dimethyl-2,5′-dioxo-5′,6′,7′,8′-tetrahydro-2H-spiro[acenaphthylene-1,4′-chromene]-2′-carbonitrile (INH-3) were synthesized using the principles of green chemistry and applied as corrosion inhibitors for mild steel in acidic medium using computational simulations and experimental methods. Experimental and computational studies revealed that inhibition effectiveness of the INHs followed the sequence: INH-3 (95.32%) > INH-2 (93.02%) > INH-1 (89.16%). The investigated compounds exhibit mixed-type corrosion inhibition characteristics by blocking the active sites on the surface of mild steel. EIS study revealed that the INHs behave as interface-type corrosion inhibitors. EDX analyses supported the adsorption mechanism of corrosion inhibition. A DFT study carried out for gaseous and aqueous forms of inhibitor molecules indicated that interactions of INHs with the mild steel surface involve charge transfer phenomenon or donor-acceptor interactions. A Monte Carlo (MC) simulation study revealed that only a fractional segment of the molecule lies parallel to the steel surface, since the INH molecules are not completely planar. The results of computational studies and experimental analyses were in good agreement.
AB - Three novel N-hydrospiro-chromeno-carbonitriles namely, 2-amino-7,7-dimethyl-1′,3′,5-trioxo-1′,3′,5,6,7,8-hexahydrospiro[chromene-4,2′-indene]-3-carbonitrile (INH-1), 3-amino-7,7-dimethyl-2′,5-dioxo-5,6,7,8-tetrahydrospiro[chromene-4,3′-indoline]-2-carbonitrile (INH-2) and 3′-amino-7′,7′-dimethyl-2,5′-dioxo-5′,6′,7′,8′-tetrahydro-2H-spiro[acenaphthylene-1,4′-chromene]-2′-carbonitrile (INH-3) were synthesized using the principles of green chemistry and applied as corrosion inhibitors for mild steel in acidic medium using computational simulations and experimental methods. Experimental and computational studies revealed that inhibition effectiveness of the INHs followed the sequence: INH-3 (95.32%) > INH-2 (93.02%) > INH-1 (89.16%). The investigated compounds exhibit mixed-type corrosion inhibition characteristics by blocking the active sites on the surface of mild steel. EIS study revealed that the INHs behave as interface-type corrosion inhibitors. EDX analyses supported the adsorption mechanism of corrosion inhibition. A DFT study carried out for gaseous and aqueous forms of inhibitor molecules indicated that interactions of INHs with the mild steel surface involve charge transfer phenomenon or donor-acceptor interactions. A Monte Carlo (MC) simulation study revealed that only a fractional segment of the molecule lies parallel to the steel surface, since the INH molecules are not completely planar. The results of computational studies and experimental analyses were in good agreement.
UR - http://www.scopus.com/inward/record.url?scp=85099750977&partnerID=8YFLogxK
U2 - 10.1039/d0ra07595g
DO - 10.1039/d0ra07595g
M3 - Article
AN - SCOPUS:85099750977
SN - 2046-2069
VL - 11
SP - 2462
EP - 2475
JO - RSC Advances
JF - RSC Advances
IS - 4
ER -