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The Description of Non-Covalent Interactions in
Terms of Bents Rule Slawomir 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,
Spain e-mail s.grabowski_at_ikerbasque.org
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Studies on non-covalent interactions Rovira, C.
Novoa, J.J. Strength and Directianolity of the
SS 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 p 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.
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Lewis acid Lewis base Electron charge
transfer A-H?-?B hydrogen bond A-H?-?H-B d
ihydrogen 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.
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S.J.Grabowski, J. Phys. Chem. A 2011, 115,
1234012347 S.J.Grabowski, J. Phys. Chem. A 2012,
116, 1838-1845
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A-HB 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 2005 V.
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 s orbital of the A-H bond often
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 bond a consequence of Bents rule
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According to Bents 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
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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.
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MP2/6-311G(d,p) calculations
F3CClOCH2 - XB
F3CClHF - HB
F3CClHMgH - XHeB
F3CClH3O - CAHB()
F3CClClCH3 DXB
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The chlorine Lewis acid/Lewis base center
distance (ClA(B), in Å), C-Cl bond length (Å),
C-ClB(A) angle (degrees) as well as binding
energy, Ebin (corrected for BSSE, in kcal/mol).
Moiety ClA(B) C-Cl C-ClB(A) Ebin
OCH2 3.059 1.740 179.8 -1.42
Cl- 3.098 1.721 180.0 -7.30
OH- 2.460 1.734 175.5 -13.76
FCl 2.990 1.744 175.6 -0.43
ClCH3 3.467 1.745 168.8 -0.69
MgH2 2.964 1.742 169.4 -1.10
HF 2.592 1.758 96.6 -0.13
H3O 1.979 1.795 94.1 -7.53
HCl2O 1.787 1.823 95.6 -9.02
Li 2.482 1.773 78.7 -12.13
F3CCl - 1.746 - -
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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
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 29.96
OH- 123.4 0.9162 0.1060 51.88 31.54
FCl 2.2 0.9904 0.0154 47.29 26.90
ClCH3 6.0 0.9906 0.0116 47.28 26.89
MgH2 2.6 0.9882 0.0234 47.53 27.16
HF -5.6 1.0021 -0.0129 46.38 25.95
H3O -122.7 1.0318 0.0241 44.28 23.84
HCl2O -221.7 1.0507 0.0652 42.23 22.25
Li -69.2 1.0122 0.0110 45.99 25.4
F3CCl - 0.9942 0.0073 47.0 26.62
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Pol(F) 79.3 S(F) 24.2
Pol(F) 77.6 S(F) 20.7
Pol(C) 50.4 S(C) 43.0
Pol(C) 47.9 S(C) 41.1
Pol(F) 78.6 S(F) 23.3
Pol(C) 49.8 S(C) 42.7
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Santiago de Compostela- WATOC 2011
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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.