Dipole-Controlled Self-Assembly of 2,7-Bis(n-alkoxy)-9-fluorenone: Odd–Even and Chain-Length Effects

Abstract

Fluorenone derivatives (F−OC n ) with various lengths of peripheral alkyl chains (with carbon numbers of n = 12−18) were synthesized, and their self-assembled adlayers were investigated in solvents with different polarities and functionalities by scanning tunneling microscopy (STM) on a highly oriented pyrolytic graphite (HOPG) surface. The chain-length effect on the self-assembly of F− OC even was observed in 1-phenyloctane. With the shortening of the side chain, the self-assembled pattern changed from a dense-and loose-packed structure to a pliers-like structure. Self-assembly of F− OC odd showed a uniform lamellar pattern. An even−odd effect was observed resulting from the direction of the end methyl group in the alkyl chain unit. Furthermore, when the samples using dichloromethane as solvent were observed within 3 h, a less ordered lamellar structure appeared in most cases. The pliers-like pattern was observed for self-assembly of F−OC 16 and F−OC 14 . However, F− OC 17 formed a zigzag structure. Observation of the odd−even and chain-length effects on the self-assembled adlayers might provide an analytical method for examining the structural and chemical homogeneities.

Chiral Transition of the Supramolecular Assembly by Concentration Modulation at the Liquid/Solid Interface

“…20,21 HPF molecules in the peripheral rosette petals forming a dimer with the back-to-back fashion could eliminate the polarity of a single molecule and lead to the lowest energy ( Figure S4). No intermolecular hydrogen bonds are formed in the peripheral rosette.…”

Effects of Alkyl Chain Length and Hydrogen Bonds on the Cooperative Self‐Assembly of 2‐Thienyl‐Type Diarylethenes at a Liquid/Highly Oriented Pyrolytic Graphite (HOPG) Interface

“…Regardless of the alkyl chain length, the ordering patterns of the amide derivatives 1o-Cn were similar. [61] High-resolution STM images of 1o-C14 and 1o-C20 are shown in Figure 2. [62] The molecular ordering pattern of 1o-C14-C22 was consistent with that previously determined for 1o-C16 by using amolecular mechanics/molecular dynamics (MM/MD) model.T he patterns showt hat the open-ring isomer is folded into the parallel conformer and the conformers are arranged in ah ead-to-head orientation on the substrate to form as triped lamellar arrangement comprising twofold networks of alternate intra-and intermolecularh ydrogen bonding.…”

Self-assembly of tetraalkoxydinaphthophenazines in monolayers on HOPG by scanning tunneling microscopy

“…It is therefore a question of fundamental importance to determine the influence of the number, length and position of these substituents on the spontaneous organization of molecules. STM techniques have been frequently used for such investigations in monolayers of organic molecules of very different chemical natures, for example alkyl (alkoxy) derivatives of: benzoic acids [18], thiophene [15,16,[19][20][21][22], annulene [23,24], fluorenone [25,26], stilbene [27], and others [28][29][30][31].…”