scholarly journals XPS Analysis of 2- and 3-Aminothiophenol Grafted on Silicon (111) Hydride Surfaces

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2712 ◽  
Author(s):  
Chieh-Hua Lee ◽  
Wan-Cian Chen ◽  
Yit Khung

Following on from our previous study on the resonance/inductive structures of ethynylaniline, this report examines similar effects arising from resonance structures with aromatic aminothiophenol with dual electron-donating substituents. In brief, 2- and 3-aminothiophenol were thermally grafted on silicon (111) hydride substrate at 130 °C under nonpolar aprotic mesitylene. From the examination of high resolution XPS Si2p, N1s, and S2p spectrum, it was noticed that there was a strong preference of NH2 over SH to form Si–N linkage on the silicon hydride surface for 2-aminothiophenol. However, for 3-aminothiophenol, there was a switch in reactivity of the silicon hydride toward SH group. This was attributed to the antagonistic and cooperative resonance effects for 2- and 3-aminothiophenol, respectively. The data strongly suggested that the net resonance of the benzylic-based compound could have played an important role in the net distribution of negative charge along the benzylic framework and subsequently influenced the outcome of the surface reaction. To the best of the authors’ knowledge, this correlation between dual electron-donating substituents and the outcome of the nucleophilic addition toward silicon hydride surfaces has not been described before in literature.

2019 ◽  
Vol 25 (6) ◽  
pp. 457-462
Author(s):  
Nadia Hayat ◽  
Nathan W Fenwick ◽  
Amie Saidykhan ◽  
Richard Telford ◽  
William HC Martin ◽  
...  

Competition experiments in which 1,2-phenylenediamine, C6H4(NH2)2, condenses with equimolar quantities of benzil, (C6H5CO)2, and a 3,3′- or 4,4′-disubstituted benzil (XC6H4CO)2 (X = F, Cl, Br, CH3 or CH3O) to form a mixture of 2,3-diphenylquinoxaline and the corresponding 2,3-diarylquinoxaline (Ar = XC6H4) in the microdroplets produced in a nebuliser allow a Hammett relationship with a ρ value of 1.85 to be developed for this accelerated condensation in the nebuliser. This structure reactivity relationship reveals that an appreciable amount of negative charge builds up on the carbon of the carbonyl group of the benzil during the rate-limiting step of the reaction, thus confirming that this process involves nucleophilic addition of the 1,2-phenylenediamine to the benzil. In general, the presence of an electron donating substituent, particularly in the 4 and 4′ positions, in the benzil retards the reaction, whereas an electron attracting substituent, especially in the 3 and 3′ position, accelerates it.


2004 ◽  
Vol 235 (3) ◽  
pp. 260-266 ◽  
Author(s):  
Y. Suzuki ◽  
N. Sanada ◽  
M. Shimomura ◽  
Y. Fukuda
Keyword(s):  

2017 ◽  
Vol 19 (28) ◽  
pp. 18162-18166 ◽  
Author(s):  
Xiao Xu ◽  
Anne Spasojević-de Biré ◽  
Nour Eddine Ghermani ◽  
Yongge Wei ◽  
Sladjana Novaković ◽  
...  

A high resolution X-ray diffraction study has been carried out on [(C4H9)4N]2 [V6O13{(OCH2)3CCH2OCCH2CH3}2] (V6–C3) at 100 K. The V6 core possesses a negative charge, leading to a strong polarization of the anion.


2001 ◽  
Vol 41 (supplement) ◽  
pp. S179
Author(s):  
T. Arakawa ◽  
K. Yonebayashi ◽  
S. Yamaguchi ◽  
M. Tanio ◽  
S. Tuzi ◽  
...  

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