Adhesion, forces and the stability of interfaces

• Robin Guttmann,
• Johannes Hoja,
• Christoph Lechner,
• Reinhard J. Maurer and
• Alexander F. Sax

Beilstein J. Org. Chem. 2019, 15, 106–129, doi:10.3762/bjoc.15.12

Evaluation of dispersion type metal···π arene interaction in arylbismuth compounds – an experimental and theoretical study

• Ana-Maria Preda,
• Małgorzata Krasowska,
• Lydia Wrobel,
• Philipp Kitschke,
• Phil C. Andrews,
• Jonathan G. MacLellan,
• Lutz Mertens,
• Marcus Korb,
• Tobias Rüffer,
• Heinrich Lang,
• Alexander A. Auer and
• Michael Mehring

Beilstein J. Org. Chem. 2018, 14, 2125–2145, doi:10.3762/bjoc.14.187

• ···Cl and Bi···π arene interactions, resulting in an intermolecular pincer-type coordination at the bismuth atom. A detailed analysis of three polymorphs of Ph3Bi (1), which were chosen as model systems, at the DFT-D level of theory supported by DLPNO-CCSD(T) calculations reveals how van der Waals

• dispersion energy donors in previous work. Keywords: arylbismuth compounds; DFT-D; dispersion type Bi···π arene interaction; DLPNO-CCSD(T); electronic structure calculations; polymorphism; single crystal X-ray structure; Introduction Although known for more than a century, the interest on metal···π arene

• consisting of strongly interacting dimers which themselves interact weakly with their surroundings based on the actual interaction energies. Elucidation of this is already possible at the DFT-D level of theory, if functionals with established accuracy are used, or at the DLPNO-CCSD(T) level of theory, which

Theoretical study of the adsorption of benzene on coinage metals

• Werner Reckien,
• Melanie Eggers and
• Thomas Bredow

Beilstein J. Org. Chem. 2014, 10, 1775–1784, doi:10.3762/bjoc.10.185

• that the benzene molecule and the underlying surfaces are only slightly affected by adsorption. Therefore, the following comparison of different DFT-D approaches has been performed on the basis of potential curves with fixed structures of benzene and surface. The results of these calculations are

• or rather 5 kJ/mol. The deviation of PBE-D3(BJ) (overestimation) and PBE-D3(ABC) (underestimation) are of the order of 10 kJ/mol. It appears that all standard DFT-D methods tend to overestimate Eads on the Cu(111) and Au(111) surfaces by at least 10 (Au(111)) to 24 kJ/mol (Cu(111)). The deviations

• aromatic organic compounds on these metal surfaces. However, the application of the other DFT-D methods treated in this work can be recommended. The differences in adsorption distances for the recommended methods are in the range from 0.03 to 0.18 Å. As expected, PBE-D3(ABC) gives the largest distances for

Synthesis and evaluation of new guanidine-thiourea organocatalyst for the nitro-Michael reaction: Theoretical studies on mechanism and enantioselectivity

• Tatyana E. Shubina,
• Matthias Freund,
• Sebastian Schenker,
• Timothy Clark and
• Svetlana B. Tsogoeva

Beilstein J. Org. Chem. 2012, 8, 1485–1498, doi:10.3762/bjoc.8.168

• (Figure 1), gas-phase DFT, MP2 and DFT-D with van der Waals correction predict 7a to be more stable than 7b by between 1.8 and 7.4 kcal·mol−1 (Figure 1). The MP2 and DFT-D energies agree very well. The two other conformers, 7c and 7d, are less stable than 7a/7b at all levels employed and were therefore

• complex between 7 and 14. Formation of Complex1 between catalyst 7 and malonate 14 is exothermic (−6.5, −15.0 and −16.6 kcal·mol–1 B3PW91/6–31G(d), MP2 and DFT-D, respectively, Scheme 4). Two energetically almost equivalent complexes Complex1 and Complex2 are connected by the H-abstraction transition

• state with a rather low activation barrier of 4.4 kcal·mol−1 at the B3PW91/6–31G(d) level. Inclusion of PCM, MP2 and DFT-D corrections increases the activation barrier to 12.2, 9.4 and 8.0 kcal·mol−1, in the DFT-PCM, MP2 and DFT-D results, respectively. We were also able to find a second complex