The Description of Non-Covalent Interactions in Terms of Bent´s Rule
Sławomir J. Grabowski
Faculty of Chemistry, University of the Basque Country UPV/EHU,and Donostia International Physics Center (DIPC),
P.K. 1072, 20080 Donostia, Spain
IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spaine-mail: [email protected]
Studies on non-covalent interactions
Rovira, C.; Novoa, J.J. Strength and Directianolity of the S…S Intermolecular Interactions, Chem. Eur. J. 1999, 5, 3689-3697
Braga, D.; Bazzi, C.; Grepioni, F.; Novoa, J.J. Electrostatic compression on non-covalent interactions : the case of π stacks involving ions, New.J.Chem. 1999, 23, 577.
Müller-Dethlefs , Hobza, P, Noncovalent Interactions: A Challenge for Experiment and Theory, Chem. Rev. 2000, 100, 143-167
Hobza, P.; Müller-Dethlefs, K. Non-Covalent Interactions, Theory and Experiment, Royal Society of Chemistry, Thomas Graham House, Science Park, Milton Road, Cambridge, 2010.
Lewis acid – Lewis base
Electron charge transfer
A-H+…-B hydrogen bond
A-H+…-H-B dihydrogen bond
A+…-H-B hydride bond
C-X+…-H-B halogen-hydride bond
C-X+…-B halogen bond
P.Lipkowski, S.J.Grabowski, J.Leszczynski J.Phys.Chem. A 2006, 110, 10296.
Hydrogen bondHB
A-H…B
Hydride bondHeB
A…H-B
Halogen bondXB
A-X…B
Dihydrogen bondDHB
A-H…H-B
Halogen-hydride bondXHeB
A-X…H-B
Dihalogen bondDXB
A-X…X-B
Halide bondXeB
A…X-B
S.J.Grabowski, J. Phys. Chem. A 2011, 115, 12340–12347S.J.Grabowski, J. Phys. Chem. A 2012, 116, 1838−1845
A-H…B hydrogen bond formation is a combination of two effects
F. Weinhold, C. Landis, Valency and Bonding, A Natural Bond Orbital Donor – Acceptor Perspective, Cambridge University Press 2005V. Alabugin, M. Manoharan, S. Peabody, F. Weinhold, J.Am.Chem.Soc. 2003, 125, 5973-5987 1. the hyperconjugative A-H bond weakening the charge transfer from the lone pair of B into the antibonding σ* orbital of the A-H bondoften attributed to covalency of the hydrogen bond
Reed, A.E.; Curtiss, L.A.; Weinhold, F. Chem.Rev. 1988, 88, 899-926.Sobczyk, L.; Grabowski, S.J.; Krygowski, T.M. Chem.Rev. 2005, 105, 3513-3560. Grabowski, S.J. Chem.Rev. 2011, 11, 2597-2625.
2. the rehybridization-promoted bond A-H strengthening.the increase of the s-character in the A-atom hybrid orbital of the A-H bonda consequence of Bent´s rule
A – H B
e e e
- + -
- - -
According to Bent´s rule
atoms maximize the s-character in hybrid orbitals aimed toward electropositive substituents and maximize their p-character in such orbitals aimed toward electronegative substituents
H. A. Bent, Chem.Rev. 1961, 61, 275-311
C Hal
greatest exchange repulsion
least exchange repulsionC Hal
electrostatic repulsion of nucleophiles
electrostatic attraction or small repulsionof nucleophiles
F.Zordan et al., J.Am.Chem.Soc. 127 (2005), 5979-5989.
Clark, T.; Hennemann, M.; Murray, J.S.; Politzer, P. J.Mol.Mod. 2007, 13, 291. Murray, J.; Concha, M.C.; Lane, P.; Hobza, P.; Politzer, P. J.Mol.Mod. 2008, 14, 699.
Lewis acidHydrogen bond
Halide bond
Lewis baseHalogen bond
Dihalogen bondHalogen-hydride bond
F3CCl…H3O+ - CAHB(+)
F3CCl…HF - HB
F3CCl…HMgH - XHeB
F3CCl…ClCH3 – DXB
F3CCl…OCH2 - XB
MP2/6-311++G(d,p) calculations
Moiety Cl…A(B) C-Cl C-Cl…B(A) Ebin
OCH2 3.059 1.740 179.8 -1.42Cl- 3.098 1.721 180.0 -7.30OH- 2.460 1.734 175.5 -13.76FCl 2.990 1.744 175.6 -0.43
ClCH3 3.467 1.745 168.8 -0.69MgH2 2.964 1.742 169.4 -1.10
HF 2.592 1.758 96.6 -0.13H3O+ 1.979 1.795 94.1 -7.53
HCl2O+ 1.787 1.823 95.6 -9.02Li+ 2.482 1.773 78.7 -12.13
F3CCl - 1.746 - -
The chlorine – Lewis acid/Lewis base center distance (Cl…A(B), in Å), C-Cl bond length (Å), C-Cl…B(A) angle (degrees) as well as binding energy, Ebin (corrected for BSSE, in kcal/mol).
Moiety Eltrans C-charge Cl-charge Pol(%C) s(%C)OCH2 1.5 0.9844 0.0318 47.76 27.27
Cl- 54.2 0.9426 0.0967 50.18 29.96OH- 123.4 0.9162 0.1060 51.88 31.54FCl 2.2 0.9904 0.0154 47.29 26.90
ClCH3 6.0 0.9906 0.0116 47.28 26.89MgH2 2.6 0.9882 0.0234 47.53 27.16
HF -5.6 1.0021 -0.0129 46.38 25.95H3O+ -122.7 1.0318 0.0241 44.28 23.84
HCl2O+ -221.7 1.0507 0.0652 42.23 22.25Li+ -69.2 1.0122 0.0110 45.99 25.4
F3CCl - 0.9942 0.0073 47.0 26.62
Eltrans (in milielectrons) - the amount of electrons transferring, Pol(%C) - the CCl proton donating bond polarization (% at C-atom), s(%C) - the percentage s-character in C orbital of the CCl proton donating bond
y = -68.864x - 0.1459R² = 0.9844
-6
-4
-2
0
2
4
6
-0.1 -0.08 -0.06 -0.04 -0.02 0 0.02 0.04 0.06 0.08
Δ C-charge (au)
Δ C-Cl polarization (% at C)F3CCl - Lewis acid
F3CCl -Lewis base
y = 0.9865x + 0.0171R² = 0.9964
-6
-4
-2
0
2
4
6
-6 -4 -2 0 2 4 6
Δ C-Cl polarization (% at C)
Δ s-character in C-orbital of C-Cl (%)
F3CCl - Lewis base
F3CCl - Lewis acid
Pol(%F) 79.3S(%F) 24.2
Pol(%C) 50.4S(%C) 43.0
Pol(%F) 77.6S(%F) 20.7
Pol(%C) 47.9S(%C) 41.1
Pol(%F) 78.6S(%F) 23.3
Pol(%C) 49.8S(%C) 42.7
Santiago de Compostela- WATOC 2011
Thank you for attention
Financial support comes from Eusko Jaurlaritza (GIC 07/85 IT-330-07) and the Spanish Office for Scientific Research (CTQ2011-27374). Technical and human support provided by IZO-SGI SGIker (UPV/EHU, MICINN, GV/EJ, ESF) is gratefully acknowledged.
