AFM in Organic Solid State Reactions

Kaupp, Gerd; Schmeyers, Jens; Haak, Michael; Marquardt, Thorsten; Herrmann, Andreas

doi:10.1080/10587259608039392

Cited by 38 publications

(30 citation statements)

References 17 publications

(1 reference statement)

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“…Again the sequences phase rebuilding and, at a certain point, sudden phase transformations are seen in Figures 7 and 8 of Ref. [66]. The feature shapes correlate with the crystal packing in the phase rebuilding stages.…”

Section: Salt Formationmentioning

confidence: 75%

“…Conversely, on the (1 0 0) face "volcano-type" features of about 40 nm height ensued, which did not change any more due to passivation on that face ( Figure 5 in Ref. [66]). Thus, no puzzle remains with the gas penetration into crystals along channels or slip planes.…”

Section: Salt Formationmentioning

confidence: 99%

“…The experimental phase rebuilding mechanism was, however, not known in 1974 and 1977. An AFM investigation [66] clarified the situation. For example, the bis-ammonium salt of adipic acid is quantitatively formed.…”

Section: Salt Formationmentioning

confidence: 99%

“…These must be cooled to avoid elimination of HBr or HCl at room temperature to give 1-bromo-or 1-chloro-1,2,2-triphenylethene (not shown in Scheme 29) [91]. The tetrasubstituted cyclohexylidene-thiohydantoin adds chlorine to the stable dichloride [66], whereas monocyclic trisubstituted exocyclic alkenes immediately liberate HX upon addition of Cl 2 or Br 2 to form the exocyclic halogenoalkenes [31]. The S-vinyl thio-enol ethers of benzoxazole or of benzothiazole add quantitatively gaseous chlorine at −45 ∘ C without melting.…”

Section: Halogen Additionsmentioning

confidence: 99%

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Organic Solid-State Reactions

Kaupp

2016

Encyclopedia of Physical Organic Chemistry, 5 Volume Set

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Section: Salt Formationmentioning

confidence: 75%

Section: Salt Formationmentioning

confidence: 99%

Section: Salt Formationmentioning

confidence: 99%

Section: Halogen Additionsmentioning

confidence: 99%

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Organic Solid-State Reactions

Kaupp

2016

Encyclopedia of Physical Organic Chemistry, 5 Volume Set

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“…The fiber tip with a nominal radius of р 15 nm is dithered laterally and provides the 'shear-force' feedback signal. The large diameter of the illuminated spot, which may reach у 1 m, 14 does not impede high resolution, because the reflected light enters the tip in the near-field. 10 Hence, only a small portion of the illuminated area contributes to the reflection signal and collection of reflected light works also at slopes that may reach 30Њ or more.…”

Section: Reflection-back-to-the-fiber Snommentioning

confidence: 99%

Chemical contrast in scanning near-field optical microscopy

Kaupp

Herrmann

1997

J. Phys. Org. Chem.

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Repeatable and stable scanning near-field optical microscopy (SNOM) images are obtained under shear-force control if uncoated, i.e. cold and sharp, tapered fiber tips are used. True chemical contrast is seen for the first time on organic crystals due to the different near-field reflectivities of different chemical species on partly oxidized anthracene. The topography spans a Z-range of 500 nm. The surface roughness is tolerable and the sites of reaction can be related to crystal structure data. A submicroscopic local resolution of 18 nm has been obtained for chemical contrast, discriminating different chemical species even with poorly reflecting organics on rough crystal surfaces. Thus, reflectionback-to-the-fiber SNOM will find wide applications for both transparent and opaque samples. All drawbacks with blunt and hot metal-coated tips at a < 10 nm distance from the surface in previous SNOM setups are overcome. ©

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Mechanism of solid-solid resolution of pantolactone

Kaupp

Schmeyers

Toda

et al. 1996

J. Phys. Org. Chem.

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The enantioselective solid-solid clathration of (S)-pantolactone ( I ) into (R,R)-trans-2,3-bis(diphenylhydroxymethyl)-l,4-dioxaspiro[4~4]nonane (2) and -[4.5]decane (3) was studied preparatively and mechanistically using atomic force microscopy (AFM) measurements and crystal packing data. Shortdistance solid-to-solid sublimation mechanisms occur in both cases with initial formation of epitaxial floes along the b-axis in 2 and random craters in 3. The bulk control in the phase rebuilding stage is understood from the particular crystal packings. Bulk control was largely lost in the phase transformation stage when passivation of the surfaces occurred in both cases. The host lattices of 2 and 3 exhibit closed molecular double layers with all hydroxyl groups inside and lacking access for intercalation of I. The reaction has to start at isolated surface defects. Once started, new doors for further entrance of guest molecules (S)-I are opened in the double layer. For practical use, both the crystallographic difficulties and the passivation have to be overcome. A slurry technique involving addition of stoichiometric amounts of water to the solids provided useful conditions for the preparative resolution of (R/S)-I or further racemates exhibiting passivation, whereas heating alone speeded up the resolution of 2-methylpiperwine with 2.

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AFM in Organic Solid State Reactions

Cited by 38 publications

References 17 publications

Organic Solid-State Reactions

Organic Solid-State Reactions

Chemical contrast in scanning near-field optical microscopy

Mechanism of solid-solid resolution of pantolactone

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