Conductance of One-Dimensional Metal String Complexes: An STM Study

• Main Author: 林淑宜
• Other Authors: Chun-hsien Chen
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/15832736597878371728

博士 === 國立清華大學 === 化學系 === 91 === The conductance on metal string complexes of [NinL4(NCS)2], [ConL4(NCS)2], [CrnL4(NCS)2] (n = 3, 5, or 7; L = dpa, tpda, teptra ; dpa = dipyridylamido anion, tpda = tripyridylamido anion, teptra = tetrapyridylamido anion) are studied by scanning tunneling microscopy (STM). Self-assembled monolayers (SAMs) of n-decanethiol, n-dodecanethiol and n-hexadecanethiol are employed as the two-dimensional matrix to isolate the metal string complexes, which exhibit as protrusions under the measurements of STM imaging. As revealed by their relative heights against the same alkanethiol matrix, the conductance of the metal string complexes is dependent on the type of metal ions, although the physical dimensions of the complexes are very silimlar. For pentanuclear complexes subjected to one-electron oxdiation, pentanickel complexe becomes more conductive than its netral form, while pentacobalt remain unchanged and pentachromium complexes are less conductive. Because the metal strings are wrapped with identical ligands and thus should exhibit similar molecular orientation within the alkanethiol matrix, the discrepancy in their apperent heights demonstrates a significant correlation between the metal-metal interactions and their conductane.