TY - JOUR
T1 - Synthesis and surface investigations of N-substituted 2,5-dithio-7- azabicyclo[2.2.1]heptanes on gold surfaces
AU - Ramsaywack, Sharwatie
AU - Martić, Sanela
AU - Milton, Scott
AU - Gates, Lisa
AU - Grant, Andrew S.
AU - Labib, Mahmoud
AU - Decken, Andreas
AU - Kraatz, Heinz Bernhard
PY - 2012/4/12
Y1 - 2012/4/12
N2 - The reaction of various primary amines and 2,5-dihydroxy-1,4-dithiane in the presence of a catalytic amount of Mg(II) in distilled water provided a series of N-substituted 2,5-dithia-7-azabicyclo[2.2.1]heptanes. The adsorption profiles of the sulfur-containing heterocycles on gold surfaces have been explored by time-of-flight secondary ion mass spectrometry (TOF-SIMS), X-ray photoelectron spectroscopy (XPS), and electrochemistry. SIMS data indicated that these novel bicyclic sulfides interact with gold surfaces favorably, independent of the N-substitution, with minimal fragmentation. An XPS study revealed the three component core levels of S 2p with binding energies at 161, 162, and 163 eV, indicating a combination of the bound and unbound sulfur species. Using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), we found the efficient adsorption of heterocycles onto gold and the formation of densely packed films for alkyl and phenyl analogues. However, the adsorption and film packing properties were greatly compromised by an N-pyridyl substitution. The findings indicate that the surface behavior of N-substituted 2,5-dithia-7-azabicyclo[2.2.1]heptanes varies with respect to the N-substitution and the nature of the substituent, suggesting that the adsorption profiles and the film packing of bicyclic sulfides on gold surfaces are highly dependent on the binding interface and the molecular orientation.
AB - The reaction of various primary amines and 2,5-dihydroxy-1,4-dithiane in the presence of a catalytic amount of Mg(II) in distilled water provided a series of N-substituted 2,5-dithia-7-azabicyclo[2.2.1]heptanes. The adsorption profiles of the sulfur-containing heterocycles on gold surfaces have been explored by time-of-flight secondary ion mass spectrometry (TOF-SIMS), X-ray photoelectron spectroscopy (XPS), and electrochemistry. SIMS data indicated that these novel bicyclic sulfides interact with gold surfaces favorably, independent of the N-substitution, with minimal fragmentation. An XPS study revealed the three component core levels of S 2p with binding energies at 161, 162, and 163 eV, indicating a combination of the bound and unbound sulfur species. Using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), we found the efficient adsorption of heterocycles onto gold and the formation of densely packed films for alkyl and phenyl analogues. However, the adsorption and film packing properties were greatly compromised by an N-pyridyl substitution. The findings indicate that the surface behavior of N-substituted 2,5-dithia-7-azabicyclo[2.2.1]heptanes varies with respect to the N-substitution and the nature of the substituent, suggesting that the adsorption profiles and the film packing of bicyclic sulfides on gold surfaces are highly dependent on the binding interface and the molecular orientation.
UR - http://www.scopus.com/inward/record.url?scp=84859779954&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84859779954&partnerID=8YFLogxK
U2 - 10.1021/jp300866r
DO - 10.1021/jp300866r
M3 - Article
AN - SCOPUS:84859779954
SN - 1932-7447
VL - 116
SP - 7886
EP - 7896
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
IS - 14
ER -