A Chiral Self‐Assembled Monolayer Derived from a Resolving Agent and its Performance as a Crystallization Template for an Organic Compound from Organic Solvents

Abstract

A new chiral nonracemic thiol derived from a popular acidic resolving agent that incorporates a cyclic disubstituted phosphate group (phencyphos) has been prepared in enantiomerically pure form. The stereochemistry and absolute configuration were established by performing a single-crystal X-ray structural analysis of a synthetic intermediate. The thiol compound was used for the preparation of self-assembled monolayers (SAMs) on both monocrystalline and polycrystalline metallic gold, which have very different surface roughness. The monolayers were used to promote the nucleation and growth of crystals from nonaqueous solutions of an organic molecule (the parent phencyphos) of similar structure to the compound present in the monolayer. The template layers influence the nucleation and growth of the phencyphos crystals despite the lack of two-dimensional order in the surfaces. Heterogeneous nucleation of phencyphos takes place upon evaporation of either CHCl(3) or isopropanol solutions of the compound on the SAM surfaces, where the evaporation rate merely influences the size and homogeneity of the crystals. The roughness of the surface also plays an important role; the polycrystalline gold produces more homogeneous samples because of the greater number of nucleation sites. Clear evidence for nucleation and growth on the surfaces is shown by scanning electron microscopy. The variation in crystal form achieved by using different surfaces and solvents suggests that the layers are applicable for the preparation of organic crystals from organic solutions.

Properties of the gold–sulphur interface: from self-assembled monolayers to clusters

“…Similarly, Amabilino and coworkers prepared SAMs from a chiral resolving agent containing a cyclic disubstituted phosphate group. 109 These SAMs were used as templates for the growth of crystals of organic molecules with a similar structure as the ones used for SAM formation.…”

A Tale of Tails: Alkyl Chain Directed Formation of 2D Porous Networks Reveals Odd–Even Effects and Unexpected Bicomponent Phase Behavior

“…Many applications involve the interaction of molecules with surfaces. Patterning surfaces in view of tuning its interfacial properties can be realized via the templating with organic molecules. − Bestowing self-assembled monolayers (SAMs) to the surface is an inexpensive and versatile bottom-up method. − Understanding and controlling the phase behavior on adsorption onto a solid support is important in developing robust strategies for engineering interfaces. In general, the coadsorption of the components present in the liquid mixture can lead to several possibilities. − The compounds can display eutectic behavior. , As such, the molecules are adsorbed in separate phases, each representing a structure identical to the pure system.…”

A Concise Synthesis of 4-Vinylphencyphos

“…[3][4][5][6] A vinyl substituent is particularly attractive. Attachment strategies include coupling to a thiol-functionalized silicon surface [7][8][9] or preparation of polymer-bound materials that might be used both for resolutions or as catalysts.…”

“…We have been particularly interested in the development of derivatives of 1 that lend themselves for attachment to solids. [3][4][5][6] A vinyl substituent is particularly attractive. Attachment strategies include coupling to a thiol-functionalized silicon surface [7][8][9] or preparation of polymer-bound materials that might be used both for resolutions or as catalysts.…”