Abstract
Infrared (IR) spectra were measured for formamide (FA, HCONH2) solutions of Li(ClO4) and Na(ClO4). Both CN stretch and CO stretch bands of FA are observed to undergo upshifts in the presence of the metal ions. Quantum chemical calculations were performed for Li+(FA)n (n = 1–7) and Na+(FA)n (n = 1–8) complexes in order to model the metal ions in FA solutions. In previous Raman studies of the Li+ system, the so-called chelate configuration was assumed, in which the Li+ ion was put into the center of a ring FA dimer. However, the present calculations reveal that such a configuration is in conflict with the observed band shifts. The experimental IR spectra are reproduced by adopting appropriate isomers of Li+(FA)5 and Li+(FA)6 complexes, in which all FA molecules are coordinated to Li+ via the O atom, with a configuration such that the Li+ ion and NH2 group are on the same side of the CO bond. These complexes, especially Li+(FA)6, are also successful in replicating characteristic features observed in the previous Raman spectra. Similarly, an O-bound isomer of Na+(FA)6 is consistent with the experimental IR and Raman spectra of the Na+ system. A strong coupling among the CO oscillators of FA molecules is shown to be responsible for the upshifts of the νCO modes despite the coordination via the O atom.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Wypych, G. (ed.): Handbook of Solvents, vol. 1, 3rd edn. ChemTec Publishing, Tronto (2019)
Ohtaki, H., Funaki, A., Rode, B.M., Reibnegger, G.J.: The structure of liquid formamide studied by means of X-ray diffraction and ab initio LCGO-MO-SCF calculations. Bull. Chem. Soc. Jpn. 56, 2116–2121 (1983)
Lippard, S.J., Berg, J.M.: Principles of Bioinorganic Chemistry. University Science Books, California (1994)
Ohtaki, H., Radnai, T.: Structure and dynamics of hydrated ions. Chem. Rev. 93, 1157–1204 (1993)
Ohtaki, H., Wada, H.: Structure of solvated lithium and chloride ions in formamide. J. Solution Chem. 14, 209–219 (1985)
Balasubramanian, D., Goel, A., Rao, C.N.R.: Interaction of amides with lithium ion. Chem. Phys. Lett. 17, 482–485 (1972)
Lees, A.J., Straugham, B.P., Gardiner, D.J.: Electrolyte–formamide interactions studied by Raman spectroscopy. J. Mol. Struct. 71, 61–70 (1981)
Powell, D.B., Woollins, A.: Vibrational spectra of metal formamide complexes. Spectrochim. Acta A 41, 1023–1033 (1985)
Bukowska, J., Miaskiewicz, K.: Infrared, Raman, and CNDO studies of the effect of ions on the electron density distribution in formamide. J. Mol. Struct. 74, 1–10 (1981)
Bukowska, J.: Raman and infrared studies of interactions between amides and ions. J. Mol. Struct. 98, 1–10 (1983)
Alves, W.A.: Vibrational spectroscopic and conductimetric studies of lithium battery electrolyte solutions. Vib. Spectrosc. 44, 197–200 (2007)
Alves, W.A.: Vibrational spectroscopic characterization of stable solvates in the LiClO4/formamide:acetonitrile system. J. Mol. Struct. 829, 37–43 (2007)
Silva, E.F., Alves, W.A.: Vibrational study on the solvates formed during interactions of amide with alkaline earth metal ions. Vib. Spectrosc. 62, 264–267 (2012)
Campos, T.B.C., Silva, E.F., Alves, W.A.: A Raman study on the coordination sites and stability of the [Al(formamide)5]Cl3 complex. Vib. Spectrosc. 65, 24–27 (2013)
Ohashi, K., Hikiishi, N., Takeshita, H.: Infrared spectroscopic and computational studies on formamide solutions of Ca2+. Vibrational frequencies of formamide and modes of coordination to Ca2+. Spectrochim. Acta A 206, 112–119 (2019)
Frisch, M.J., et al.: Gaussian 16, Revision A.03. Gaussian, Inc., Wallingford (2016)
Lee, E.C., Lee, H.M., Tarakeshwar, P., Kim, K.S.: Structures, energies, and spectra of aqua-silver (I) complexes. J. Chem. Phys. 119, 7725–7736 (2003)
McNaughton, D., Evans, C.J., Lane, S., Nielsen, C.J.: The high-resolution FTIR far-infrared spectrum of formamide. J. Mol. Spectrosc. 193, 104–117 (1999)
Suzuki, I.: Infrared spectra and normal vibrations of formamide; HCONH2, HCOND2, DCONH2 and DCOND2. Bull. Chem. Soc. Jpn. 33, 1359–1365 (1960)
Rode, B.M.: Quantum chemical aspects of the chelate effect in complexes. Chem. Phys. Lett. 26, 350–355 (1974)
Xuan, X., Zhang, H., Wang, J., Wang, H.: Vibrational spectroscopic and density functional studies on ion solvation and association of lithium tetrafluorobrate in acetonitrile. J. Phys. Chem. A 108, 7513–7521 (2004)
Alía, J.M., Edwards, H.G.M.: Ion solvation and ion association in lithium trifluoromethanesulfonate solutions in three aprotic solvents. An FT-Raman spectroscopic study. Vib. Spectrosc. 24, 185–200 (2000)
Bostick, D.L., Brooks, I.I.I.: Selective complexation of K+ and Na+ in simple polarizable ion–ligating systems. J. Am. Chem. Soc. 132, 13185–13187 (2010)
Finter, C.K., Hertz, H.G.: NMR relaxation study of I– and Na+ solvation structure in formamide (FA) and preferential solvation of these ions in the mixture FA/H2O. Z. Phys. Chem. N. F. 148, 75–96 (1986)
Puhovski, Y.P., Rode, B.M.: Molecular dynamics simulations of Na+ and C1– ions solvation in aqueous mixtures of formamide. Chem. Phys. 222, 43–57 (1997)
Acknowledgements
The computations are carried out by using the computer facilities at Research Institute for Information Technology, Kyushu University. We thank Ryotaro Wakimoto for his help in measuring the IR spectra for the Li+ system.
Author information
Authors and Affiliations
Corresponding author
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Electronic supplementary material
Below is the link to the electronic supplementary material.
Rights and permissions
About this article
Cite this article
Ohashi, K., Hikiishi, N. Vibrational Spectroscopic and Computational Studies on Formamide Solutions of Alkali Metal Ions. J Solution Chem 49, 1442–1457 (2020). https://doi.org/10.1007/s10953-019-00943-6
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10953-019-00943-6