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Depart
ment
of
Chem
istr
y,
Univ
ers
ity o
f Jy
väsk
ylä
The Hydrogen Bond
Jan LundellDepartment of Chemistry, University of Jyväskylä
Depart
ment
of
Chem
istr
y,
Univ
ers
ity o
f Jy
väsk
ylä
The Hydrogen Bond
Adenine Thymine
CytosineGuanine
Peter Agre (Nobel Prize, 2003): The purest form of hydrogen bond there is…
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The Hydrogen Bond
”The hydrogen nucleus held by two octets constitutes a weak bond”
W.M.Latimer and W.H.Rodebush, JACS 42, 1920, 1419
”Under certain conditions an atom of hydrogen is attracted by rather strong forces to two atoms instead of only one, so that it may be considered to be acting as a bond between them. This is called a hydrogen bond.”
L. Pauling, Nature of Chemical Bond, 1939
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The Hydrogen Bond
Wavenumber
Ab
sorb
ance
HCOOH in the gas phase – IR ( from webbook.nist.gov )
Depart
ment
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The Hydrogen Bond
”A hydrogen bond exists between the functional group, A-H, and an atom or a group of atoms, B, in the same or different molecules when
(a) there is evidence of bond formation (association or chelation)
(b) there is evidence that this new bond linking A-H and B specifically involves a hydrogen atom already bonded to A”
G.C.Pimentel, A.L.McClellan, The Hydrogen Bond, 1960
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bond distance A-H H...B A-H < H...B A-H << H...B
H...B (Å) 1.2 - 1.5 1.5 - 2.2 2.2 - 3.2
A...B (Å) 2.2 - 2.5 2.5 - 3.2 3.2 - 4.0
bond angle (º) 175 - 180 130 - 180 90 - 150
binding energy (kJ/mol)
60 - 170 15 - 60 < 15
Strong Medium Weak
The Hydrogen Bond
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Strong Medium Weak
The Hydrogen Bond
dimers of strong acids and bases in the gas phase
acids dimers of weak acids and bases in the gas phase
Acid salts alcohols, phenols
C-H...O/N
Proton sponges hydrates O/N-H...
HF complexes all biological molecules
dihydrogen bonds
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The Hydrogen Bond
”A hydrogen atom with only one stable orbital cannot form more than one pure covalent bond and the attraction of the two atoms observed in hydrogen bond formation must be due largely to ionic forces””
L.Pauling, The Nature of Chemical Bond, 1939
+
+
-
+
+
-
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The Hydrogen Bond
HB = aa + bb + cc + dd + ee
a A-H…B covalent A-H bond
b A- -H+ …B ionic A-H bond
c A- -H…B+ charge transfer , A…B bond
d A+ -H- …B ionic A-H bond
a A-H- …B+ charge transfer, H…B bond
C.A.Coulson, In Hydrogen Bonding, D.Hadzi (Ed.) 1959, pp. 339-360.
O-H … O with O … O = 2.8 Å
b + d contribute 65 % of the hydrogen bond energy
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Interaction energy of a H-bond
Supermolecular approach
Eint = EAB – (EA + EB)
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HCN…HCN ( MP2 )
A.Heikkilä, J.Lundell, J.Phys.Chem. A 104, 2000, 6637-6643
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K.Szalewicz, K.Patkowski, B.Jeziorski ,Struct.Chem. 116, 2005, 43-117
Symmetry-Adapted Perturbation Theory (SAPT)
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R.A.Christie, K.D.Jordan, Struct.Chem. 116, 2005, 27-41
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S.S.Xantheas Struct.Chem. 116, 2005, 119-148
Having more than two molecules?
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S.S.Xantheas Struct.Chem. 116, 2005, 119-148
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S.S.Xantheas Struct.Chem. 116, 2005, 119-148
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Basis set superposition error (BSSE)
Not perfect basis sets, so needs to borrow from the neighbour…
The ”cure”: Counterpoise correction (Boys-Bernardi )
HNC…HCN
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S.S.Xantheas Struct.Chem. 116, 2005, 119-148
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J.R.Lane, H.G.Kjaergaard, J.Phys.Chem. 131, 2009, 034307
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G.A.Jeffrey, An Introduction to Hydrogen Bonding, 1997
Changes upon hydrogen bonding…
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HCOOH photochemistry in matrices
J.Lundell, M.Räsänen, J.Phys.Chem. 99, 1995, 14301.
t-HCOOH h
H2O + CO
vs
CO2 + H2
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H2O...CO : Two stable complex structures
2.3232.365
CCSD(T)/6-311++G(2d,2p)
Eint,cp = -5.29 kJ mol-1 Eint,cp = -3.17 kJ mol-1
J.Lundell, J.Phys.Chem. 99, 1995,14290J.Lundell, Z.Latajka, J.Phys.Chem. A 101, 1997, 5004
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H2O...CO : Experiments
In situ photolysis of formic acid in a solid argon matrix
+132130+102148
+101656+21596
-223826-93628
-173864-93724
calc.exp.
JPC 99, 1995, 14290: MP2/6-311++G(2d,2p) JPC 99, 1995, 14301: Ng-matrices
HOH...CO
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H2O...CO : Experiments
Annealing the matrix after photolysis
argon krypton xenon
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H2O...CO : Experiments
Both HOH...CO and HOH...OC can be made
-22118+102130calc.
-52128+82142Xe
-62130+92145Kr
+112149Ar
+112154Gas phase
HOH...CO HOH...OC
MP2/6-311++G(2d,2p)
CO stretch
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Can we do more?
3660368037003720
-0.2
-0.1
0.0
0.1
0.2
0.3
Wavenumbers
Emissivity
71807200722072407260728073007320
-0.38
-0.36
-0.34
-0.32
Wavenumbers
Emissivity
268027002720274027602780
-1.0
-0.5
0.0
0.5
1.0
Wavenumbers
Emissivity
53005400550056005700
0.3
0.4
0.5
0.6
0.7
Wavenumbers
Emissivity
OH free OD bond
? ?
OH free OD bond
?
HOD ... CO
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Anharmonic calculations: cc-VSCF
Vibrational Schrödinger equation in mass-weighted normal mode coordinates
single-mode wavefunctions, energies and effective potentials
2nd order perturbation theory for correlation effects between different vibrational modes
pairwise interactions between normal modes
2
1 1 121
1( ,..., ) ( ,..., ) ( ,..., )
2
N
N n N n n Nj j
V Q Q Q Q E Q QQ
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Anharmonic calculations: cc-VSCF
Grid-approach of PES: - 8 8 or 16 16 grids- points chosen equidistantly over an interval defined by the harmonic frequency of a vibrational mode:Qmax ~ inverse square root of the frequency
G.M.Chaban, J.O.Jung, R.B.Gerber, J.Phys.Chem. A 104, 2000, 2772
Implemented in GAMESS-US
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0 20 40 60 80 100 120 140 160 180
0
1000
2000
3000
4000
5000
Re
lative
en
erg
y
[cm
-1]
O=C-O-H torsional angle [deg]
MP2/6-311++G(2d,2p)
4544 cm-1
1488 cm-1
trans
cis
Exp: 4842 cm-1
Exp: 1362 cm-1
The formic acid monomer: Two conformers
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M.Pettersson, J.Lundell, L.Khriachtchev, M.Räsänen, JACS 119, 1997, 11715
IR-pumping at
6934 cm-1 (2 OH)
trans
cis
IR
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HCOOH anharmonic calculations
E.M.S.Macoas, J.Lundell, M. Pettersson, L.Khriachtchev, R.Fausto, M.Räsänen, J.Mol.Spectrosc. 219, 2003, 70.
trans-HCOOH
cis-HCOOH
5000 4000 3000 2000 1000
0
20
40
60
80
100
120
140
Co
mp
ute
d in
ten
sity
[km
mo
l-1]
5000 4000 3000 2000 1000
0
20
40
60
80
100
120
140
Co
mp
ute
d in
ten
sity
[km
mo
l-1]
Wavenumber [cm-1]
harmonic
anharmonic
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Isomerisation of formic acid: The monomer
transcis
tunneling
vibr exc
K. Marushkevich, L.Khriachtchev, M.Räsänen, J.Phys.Chem. A 111, 2007, 2040
Tunneling can be stopped by complexation
X
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FAD-tt1
1.684
1.684
Ecp,int (MP2)= -66.71 kJ mol-1
FAD-tt2
1.774
2.337
Ecp,int (MP2)= -37.21
FAD-tt3
2.408
2.509
Ecp,int (MP2)= -11.81
FAD-tt4
1.927
1.968
Ecp,int (MP2)= -28.68
FAD-tt5
1.896
2.406
Ecp,int (MP2)= -23.36
FAD-tt6
2.417
2.417
Ecp,int (MP2)= -15.39
MP2/6-311++G(2d,2p)
The trans-trans formic acid dimers
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From M.Gantenberg, M.Halupka, W.Sander, Chem.Eur.J. 6, 2000, 1865
4000 3500 3000 2500 2000 1500 1000 500
Computed wavenumber [cm-1]
MP2/6-311++G(2d,2p) cc-VSCF without mode coupling
FAD-tt1 in solid argon
The trans-trans –dimer (FAD-tt1)
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FAD-tt1 FAD-tt2
A.Olbert-Majkut, J.Ahokas, J.Lundell, M.Pettersson, Chem.Phys.Lett. 468, 2009, 176.
Solid argon
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The trans-trans formic acid dimers
Computed relative energies
0
20
40
60
80
Re
lativ
e e
ne
rgy
[kJ
mo
l-1]
FAD-tt2
FAD-tt3
FAD-tt4
FAD-tt5FAD-tc2
FAD-tt6
FAD-cc3
FAD-tt1
FAD-tc3
FAD-tc4
FAD-tc5
FAD-tc1
FAD-cc4FAD-cc2FAD-cc1FAD-cc5
cis-FA
trans-FA Experimentally observedexcitation at 3168 cm-1 (C-H str)
FAD-tt3 FAD-tt6
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FAD-tt1 (CD)
K.Marushkevich, L.Khriachtchev, J.Lundell, M.Räsänen, JACS 128, 2006, 12060
Pumping O-H str in trans-trans dimer ?
**
*
*
FAD-tt2 ( * )
Excitation at 3540 cm-1
*
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FAD-tc1
1.761
2.287
Ecp,int (MP2)= -41.31 kJ mol-1
FAD-tc2
1.950
1.852
Ecp,int (MP2)= -38.02
FAD-tc3
1.814
Ecp,int (MP2)= -29.79
FAD-tc4
2.502
2.387
Ecp,int (MP2)= -12.74
FAD-tc5
1.857
Ecp,int (MP2)= -23.20
MP2/6-311++G(2d,2p)
The cis-trans formic acid dimers
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cc-VSCF//MP2 computed wavenumbers [cm-1]
3625 3600 3575 3550 3525 3500
x 5
FAD-tc1
FAD-tt2
trans-FA
1900 1850 1800 1750 1700 1650
FAD-tc1
FAD-tt2
trans-FA
x 1
FAD-tc1FAD-tt2
1.774
2.337
1.761
2.287
h (IR)
The cis-trans formic acid dimers
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0 20 40 60 80 100 120 140 160 180
0
1000
2000
3000
4000
5000
Re
l. e
ne
rgy
[ cm
-1 ]
Torsional angle [ deg ]
Mon Dim
1488.0 cm-1
4543.7 cm-1 4771.5 cm-1
1180.3 cm-1
The cis-trans formic acid dimers
MP2/6-311++G(2d,2p)
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Photoisomerisation of formic acid dimers:
Computed relative energies
0
20
40
60
80
Re
lativ
e e
ne
rgy
[kJ
mo
l-1]
FAD-tt2
FAD-tt3
FAD-tt4
FAD-tt5FAD-tc2
FAD-tt6
FAD-tt1
FAD-tc3
FAD-tc4
FAD-tc5
FAD-tc1
FAD-cc1FAD-cc5
cis-FA
trans-FA Experimentally observed
FAD-cc4FAD-cc2
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FAD-cc1
Ecp,int (MP2)= -31.82 kJ mol-1
1.878
2.765
FAD-cc2
1.853
Ecp,int (MP2)= -32.10
FAD-cc3
2.370
Ecp,int (MP2)= -20.95
2.370
FAD-cc4
2.006
Ecp,int (MP2)= -24.47
2.684
FAD-cc5
1.816
Ecp,int (MP2)= -31.99
MP2/6-311++G(2d,2p)
The cis-cis formic acid dimers
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Computed relative energies
0
20
40
60
80
Re
lativ
e e
ne
rgy
[kJ
mo
l-1]
FAD-tt2
FAD-tt3
FAD-tt4
FAD-tt5FAD-tc2
FAD-tt6
FAD-cc3
FAD-tt1
FAD-tc3
FAD-tc4
FAD-tc5
FAD-tc1
FAD-cc4FAD-cc2FAD-cc1FAD-cc5
cis-FA
trans-FA Experimentally observed
The cis-cis formic acid dimers
?
?
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Current topics(Horizons in Hydrogen Bond Research, Paris, Sept 2009)
Blue-shifting hydrogen bonds vs red-shifting hydrogen bonds
Dihydrogen bonds (for example, H-O-H…HXeH )
Biomolecular systems
- Water as biolubricant
“Fast spectroscopy” (also dynamic simulations )