Control of Self-assembly of Several Tetrapyrroles by Alkyl Substitution Patterns

Abstract

Six kinds of tetrapyrroles having C[SUB]5[/SUB]H[SUB]11[/SUB], C[SUB]8[/SUB]H[SUB]17[/SUB], or C[SUB]11[/SUB]H[SUB]23[/SUB] at the [I]meso[/I]-positions or the [I]beta[/I]-positions were synthesized. Self-assembly and alignment onto glass substrates of these tetrapyrroles were characterized by DSC, UV-vis spectrum, and XRD.As the alkyl chains are longer, the melting points of these compounds are lower. The [I]meso[/I]-substituted porphyrins are stacked in a [I]head-to-tail [/I]fashion, while the [I]beta[/I]-substituted ones are stacked in a [I]face-to-face[/I] fashion. These results help the design of self-assembled molecules for molecular devices.