Two new supramolecular metal diphosphonates: Synthesis, characterization, crystal structure and inhibiting effects on metallic corrosion
- Department of Chemistry, Faculty of Science, Tarbiat Modares University, Tehran (Iran, Islamic Republic of)
- Department of Chemistry, Faculty of Science, University of Birjand, Birjand (Iran, Islamic Republic of)
- Department of Material Engineering, Tarbiat Modares University, Tehran (Iran, Islamic Republic of)
Two new divalent metal(II) aminodiphosphonates with layered structure, namely, Cu(H{sub 3}L{sup 1}){sub 2}·2H{sub 2}O (1), [H4L{sup 1}=methyl-N(CH{sub 2}PO{sub 3}H{sub 2}){sub 2}] and Cd{sub 2}(H{sub 2}L{sup 2}){sub 4}(2), [H{sub 4}L{sup 2}=n-propyl-N(CH{sub 2}PO{sub 3}H{sub 2}){sub 2}] were synthesized and characterized. The Cu(II) ions in complex 1 are octahedrally coordinated by four oxygen atoms from two chelating ligands and two phosphonate oxygen atoms from two neighboring Cu(H{sub 3}L{sup 1}){sub 2} units. The Cu(H{sub 3}L{sup 1}){sub 2} units are interconnected by bridging phosphonate groups, forming a 2-D metal phosphonate layer. The structure of complex 2 contains two unique Cd(II) ions octahedrally-coordinated by six phosphonate oxygen atoms from four H{sub 2}L{sup 2} diphosphonate anions. Corrosion inhibition performances of 1 and 2 were also compared with each other in order to study the effect of combinations of externally added Cd/H{sub 4}L{sup 2} and Cu/H{sub 4}L{sup 1} (1:1 ratio) on corrosion rates of carbon steel. It was found that at pH 3.0, Cd/H{sub 4}L{sup 2} or Cu/H{sub 4}L{sup 1} combinations do not have noticeable corrosion inhibition efficiency for carbon steel. In contrast, at pH 7.0, higher corrosion inhibition efficiency was achieved for Cd/H{sub 4}L{sup 2}. Physical characterizations such as scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS) and Fourier transform infrared spectroscopy (FTIR) were applied to study the corrosion specimens and film material. - Graphical abstract: Two new metal phosphonates have been synthesized and characterized by single-crystal X-ray diffraction and thermogravimetric analysis. corrosion inhibition performances 1 and 2 are also compared.
- OSTI ID:
- 22658077
- Journal Information:
- Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Vol. 243; ISSN 0022-4596; ISSN JSSCBI
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
CARBON STEELS
CHELATING AGENTS
COPPER IONS
CORROSION PROTECTION
CRYSTAL STRUCTURE
FOURIER TRANSFORM SPECTROMETERS
FOURIER TRANSFORMATION
INFRARED SPECTRA
INHIBITION
MONOCRYSTALS
OXYGEN
PHOSPHONATES
SCANNING ELECTRON MICROSCOPY
SYNTHESIS
THERMAL GRAVIMETRIC ANALYSIS
X-RAY DIFFRACTION
X-RAY SPECTROSCOPY