Role of chain length on the surface chemistry of dienes studiedby scanning tunneling microscopy

Abstract

The scanning tunneling microscope has been used to observe sites selection of diene molecules on Si͑111͒ 7ϫ7 as a function of their chain length. The molecules 1,6-heptadiene and 1,7-octadiene can chemisorb on either of three geometries on the surface. The different relative affinity of the molecules to these sites is explained by matching between the molecules length and the surface sites. For 1,13-tetradecadiene, each end of the molecule reacts with a different half of the unit cell. ͓S0163-1829͑97͒05315-0͔

Tetra-σ attachment of allyl cyanide onSi(111)−7×7

“…32 In this experiment, our results show that allyl cyanide is mainly covalently attached to Si(111)-7ϫ7 with a tetra-binding mechanism through two ͓2ϩ2͔-like cycloaddition reactions between the CvC and CwN groups and the surface. Considering the feasible ͓2ϩ2͔-like cycloaddition between CvC of ethylene 7,8 ͑the CwN group in acetonitrile 19 ͒ and the neighboring adatomrest atom pair, it is reasonably deduced that allyl cyanide is bound to two neighboring adatom-rest atom pairs of the Si surface with four newly formed bonds.…”

Self-assembly of zwitterionic molecules on a Au(232321) surface at low temperature

“…Therefore, the aliphatic part of MSPS is not visible by STM [33,34]. Based on these results, a model of adsorption can be proposed in which MSPS are adsorbed in a ''scorpion shape" with their p-skeleton parallel to the surface and the aliphatic chain pointing out of the plane, as described in Fig.…”

Chemical manipulation of multifunctional hydrocarbons on silicon surfaces

“…Cyclohexene [300], 1,4-cyclohexadiene [300] and several linear unconjugated dienes [312] also react by [2 + 2] addition chemistry, with the unconjugated dienes forming a large variety of surface products as the two C=C double bonds act as two independent functional groups attaching to various adatom-rest atom pairs to form tetra-σ -bonded adducts. For 1,6-heptadiene and 1,7-octadiene, the different relative affinity of the molecules to these sites is explained by matching between the molecules length and the surface sites.…”

“…The possible adsorption geometries analyzed with the STM are presented in Fig. 3.48 [312]. For 1,13-tetradecadiene, the two ends of the molecule react with different halves of the unit cell as shown in the STM image in Fig.…”