TY  - JOUR
A1  - Emmerling, Franziska
A1  - Orgzall, Ingo
A1  - Reck, Günter
A1  - Schulz, Burkhard W.
A1  - Stockhause, Sabine
A1  - Schulz, Burkhard
T1  - Structures of substituted di-aryl-1, 3,4-oxadiazole derivatives: 2,5-bis(pyridyl)- and 2,5-bis(aminophenyl)-substitution
JF  - Journal of molecular structure
N2  - Crystal structures of four different di-aryl-1,3,4-oxadiazole compounds (aryl = 2-pyridyl-, 3-pyridyl-, 2-aminophenyl-, 3-aminophenyl-) are determined. Crystallization of di(2-pyridyl)-1,3,4-oxadiazole yielded monoclinic and triclinic polymorphs. The structures are characterized by the occurrence of pi-pi interactions. Additionally, in case of the aminophenyl compounds intra- as well as intermolecular hydrogen bonds are found that influence the packing motif as well. Since these molecules are often used as ligands in metal-organic complexes similarities and differences of the molecular conformation between the molecules in the pure crystals and that of the ligands in the complexes are discussed. (c) 2006 Elsevier B.V. All rights reserved.
KW  - crystal structure
KW  - 1,3,4-oxadiazole
KW  - molecular conformation
KW  - hydrogen bonds
Y1  - 2006
U6  - https://doi.org/10.1016/j.molstruc.2006.03.076
SN  - 0022-2860
VL  - 800
IS  - 1-3
SP  - 74
EP  - 84
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Boese, Adrian Daniel
T1  - Density Functional Theory and Hydrogen Bonds: Are We There Yet?
JF  - ChemPhysChem : a European journal of chemical physics and physical chemistry
N2  - Density functional theory (DFT) has become more successful at introducing dispersion interactions, and can be thus applied to a wide range of systems. Amongst these are systems that contain hydrogen bonds, which are extremely important for the biological regime. Here, the description of hydrogen-bonded interactions by DFT with and without dispersion corrections is investigated. For small complexes, for which electrostatics are the determining factor in the intermolecular interactions, the inclusion of dispersion with most functionals yields large errors. Only for larger systems, in which van der Waals interactions are more important, do dispersion corrections improve the performance of DFT for hydrogen-bonded systems. None of the studied functionals, including double hybrid functionals (with the exception of DSD-PBEP86 without dispersion corrections), are more accurate than MP2 for the investigated species.
KW  - ab initio calculations
KW  - basis sets
KW  - density functional calculations
KW  - hydrogen bonds
KW  - intermolecular interactions
Y1  - 2015
U6  - https://doi.org/10.1002/cphc.201402786
SN  - 1439-4235
SN  - 1439-7641
VL  - 16
IS  - 5
SP  - 978
EP  - 985
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Boese, Adrian Daniel
T1  - Basis set limit coupled-cluster studies of hydrogen-bonded systems
JF  - Molecular physics
N2  - As hydrogen-bonded systems are of utmost importance in especially biological and chemical systems, a new set of highly accurate reference dissociation energies, denoted HB49, is devised. For the molecules in this set, the basis set convergence of post-Hartree-Fock methods, including F12 methods, is investigated. Using combined Moller-Plesset perturbation theory (MP2) and CCSD(T) approaches for energies and MP2 and QCISD(T) for gradients, we achieve CCSD(T) accuracy, which has been determined before to yield an accuracy of 0.2 kJ/mol for a subset of HB49. Both conventional extrapolation techniques and F12 techniques are competitive with each other. By using MP2+Delta CCSD(T), a rather fast basis set convergence is obtained when both basis sets are carefully chosen.
KW  - coupled-cluster
KW  - hydrogen bonds
KW  - ab initio
KW  - F12 methods
Y1  - 2015
U6  - https://doi.org/10.1080/00268976.2014.1001806
SN  - 0026-8976
SN  - 1362-3028
VL  - 113
IS  - 13-14
SP  - 1618
EP  - 1629
PB  - Routledge, Taylor & Francis Group
CY  - Abingdon
ER  -