کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5426409 1395889 2006 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Molecular conformation and electronic properties of protoporphyrin-IX self-assembled monolayers adsorbed on a Pt(1 1 1) surface
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
Molecular conformation and electronic properties of protoporphyrin-IX self-assembled monolayers adsorbed on a Pt(1 1 1) surface
چکیده انگلیسی

Monolayers of protoporphyrin-IX molecules are prepared on a Pt(1 1 1) surface by a self-assembly process in order to manufacture organic devices with controlled electronic properties. Scanning tunnelling microscopy (STM) and two-colour sum-frequency generation (2C-SFG) are performed ex situ in ambient air, in order to characterize their molecular conformation and electronic properties at the monolayer level, respectively. STM measurements performed with functionalized gold tips reveal a high covering rate of the metal surface. 2C-SFG measurements highlight CH stretching modes of vinyl substituted groups (RCHCH2) in the 2800-3200 cm−1 infrared spectral range and particular electronic features in the visible spectral range, i.e. a Soret band red shift and band separation compared to the liquid phase. Moreover, similar measurements are performed on Zn(II)Protoporphyrin-IX and 5-[p-(6-mercaptohexoxy)-phenyl]-10,15,20-triphenylporphin films for comparison. These results suggest a film conformation with the molecules having different tilt angles with respect to the substrate normal, depending on the ion metal presence or the chain length bonded to the porphyrin moiety.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Surface Science - Volume 600, Issue 18, 15 September 2006, Pages 3702-3709
نویسندگان
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