Acta Phys. -Chim. Sin. ›› 2015, Vol. 31 ›› Issue (10): 1872-1879.doi: 10.3866/PKU.WHXB201509072


Density Functional Theory and Surface Enhanced Raman Spectroscopy Studies of Dicyandiamide Adsorbed on Au Clusters

Shu-Fen. DENG1,Wei. HUANG1,Ji-Fang. ZHANG1,Ling. LIN1,Jia-Wei. HE1,Xun-Tao. BIAN1,Wen-Kai. CHEN2,Jian-Jun. SUN1,*()   

  1. 1 Key Laboratory of Analysis and Detection for Food Safety, Fuzhou University, Fuzhou 350108, P. R. China
    2 College of Chemistry, Fuzhou University, Fuzhou 350108, P. R. China
  • Received:2015-06-11 Published:2015-10-10
  • Contact: Jian-Jun. SUN
  • Supported by:
    the National Natural Science Foundation of China(J1103303, 21475023, 21275030);Key Projects in the NationalScience & Technology Pillar Program during the Twelfth Five-Year Plan Period, China(2012BAD29B06)


Dicyandiamide is a dimer of cyanamide that generally isomerizes into imino and amino forms. The behaviors of tautomeric dicyandiamide adsorbed on gold surface were studied by the density functional theory method combined with surface enhanced Raman spectroscopy (SERS). By using DFT method the energies, molecular orbital, vibration spectral information of imino and amino forms of dicyandiamide and the SERS spectra of tautomeric dicyandiamide adsorbed on Au clusters were given. The results show that both tautomeric dicyandiamides form stable complexes with Au3 clusters, and the N(2) atom preferentially adsorbs on Au clusters. The experimental results are consistent with the calculated results, which show that the tautomeric dicyandiamides coexist on the Au substrate, are adsorbed vertically on the gold surface through the N(2) atom, and the SERS enhancement factors conform to electromagnetic-field enhancement mechanism.

Key words: Tautomerism, Dicyandiamide, Surface enhanced Raman scatting, Density functional theory, Au cluster