RSC Advances
Paper
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likely optimized geometries of the PZCDT/PZbCDT (also in 12 K. Saha, S. S. Agasti, C. Kim, X. Li and V. M. Rotello, Chem.
deprotonated form) and its Ag(n¼1–4) complexes are as shown in
Fig. 2.
Rev., 2012, 112, 2739–2779.
13 L. Chen, N. Qi, X. Wang, L. Chen, H. You and J. Li, RSC Adv.,
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To deduce the adsorption sites of PZCDT/PZbCDT on silver
metal precisely, the molecular electrostatic potential surfaces 14 J. R. Lombardi and R. L. Birke, J. Phys. Chem. C, 2008, 112,
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of the molecules.24,46 The MEP surfaces of the optimized PZCDT/ 17 M. Moskovits and J. S. Suh, J. Chem. Phys., 1984, 88, 5526–
PZbCDT ions and their Ag(n¼1–4) complexes are illustrated in 5530.
Fig. ES3.† In Fig. ES3,† the electron density is localized mostly 18 M. Moskovits, D. P. DiLella and K. J. Maynard, Langmuir,
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atoms of the dithiocarbamate moiety. The DFT computation 6858–6864.
was also performed to determine the adsorption sites of PZCDT/ 20 M. Baia, L. Baia, W. Kiefer and J. Popp, J. Phys. Chem. B, 2004,
PZbCDT on ZnONPs at the same level of calculation as followed 108, 17491–17496.
for [PZCDT/PZbCDT + AgNPs]. According to coordination 21 M. Moskovits and D. H. Jeong, Chem. Phys. Lett., 2004, 397,
chemistry of zinc metal coordination of PZCDT and PZbCDT 91–95.
ions with the ZnONPs take place through the dithiocarbamate 22 A. Rasmussen and V. Deckert, J. Raman Spectrosc., 2006, 37,
moiety showing bidentate interaction and construct a four 311–317.
membered chelate ring (Zn–S–C–S).47,48 The most likely opti- 23 T. d. F. Paulo, R. A. Ando, I. C. N. Diogenes and
´
mized structures and MEP surfaces of the [PZCDT + ZnONPs]
and [PZbCDT + ZnONPs] are shown in Fig. ES4.†
M. L. A. Temperini, J. Phys. Chem. C, 2013, 117, 6275–6283.
24 D. Yang, N. E. Mircescu, H. Zhou, N. Leopold, V. Chi¸s,
M. Oltean, Y. Ying and C. Haisch, J. Raman Spectrosc.,
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25 M. J. Frisch and J. A. Pople, Gaussian 03, Revision A.1,
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Acknowledgements
Om Prakash and PG (Senior Research Fellow) are grateful to the
UGC, India, for providing research fellowship. RKS is grateful to 26 J. M. L. Martin and C. V. Alsenoy, GAR2PED, University of
DFG & AvH Foundation, Germany, and DST and CSIR, New
Antwerp, 1995.
Delhi, for nancial support. Authors are also grateful to 27 S. SenGupta, N. Maiti, R. Chadha and S. Kapoor, Chem. Phys.,
biophysics lab; Department of Physics and Department of
Chemistry, BHU, Varanasi-221005, for providing lab facilities.
2014, 436–437, 55–62.
28 D. C. N. B. F. W. G. G. J. G. Lin-Vien, The Handbook of infrared
and Raman characteristic frequencies of organic molecules,
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