Benzene and Tropilium Metal Complexes. Intra- and Intermolecular Interaction Evidenced by Vibrational Analysis:  The Blue-Shift Hydrogen Bond

2006 ◽  
Vol 25 (21) ◽  
pp. 5024-5030 ◽  
Author(s):  
Pier Luigi Stanghellini ◽  
Eliano Diana ◽  
Aldo Arrais ◽  
Andrea Rossin ◽  
Sidney F. A. Kettle
Keyword(s):  
Hydrogen Bond ◽  
Metal Complexes ◽  
Intermolecular Interaction ◽  
Vibrational Analysis ◽  
Blue Shift

Theoretical analysis of the (HNO)2, (HNO···HNS), and (HNS)2 dimers — A case of red and blue shifts of N–H stretching frequency

2010 ◽  
Vol 88 (8) ◽  
pp. 849-857 ◽  
Author(s):  
Nguyen Tien Trung ◽  
Tran Thanh Hue ◽  
Minh Tho Nguyen
Keyword(s):  
Hydrogen Bond ◽  
Quantum Chemical ◽  
Bond Formation ◽  
Blue Shift ◽  
Proton Donor ◽  
Basis Sets ◽  
Coupled Cluster ◽  
Hydrogen Bond Formation ◽  
Length Contraction ◽  
Moller Plesset

The hydrogen-bonded interactions in the simple (HNZ)2 dimers, with Z = O and S, were investigated using quantum chemical calculations with the second-order Møller–Plesset perturbation (MP2), coupled-cluster with single, double (CCSD), and triple excitations (CCSD(T)) methods in conjunction with the 6-311++G(2d,2p), aug-cc-pVDZ, and aug-cc-pVTZ basis sets. Six-membered cyclic structures were found to be stable complexes for the dimers (HNO)2, (HNS)2, and (HNO–HNS). The pair (HNS)2 has the largest complexation energy (–11 kJ/mol), and (HNO)2 the smallest one (–9 kJ/mol). A bond length contraction and a frequency blue shift of the N–H bond simultaneously occur upon hydrogen bond formation of the N–H···S type, which has rarely been observed before. The stronger the intramolecular hyperconjugation and the lower the polarization of the X–H bond involved as proton donor in the hydrogen bond, the more predominant is the formation of a blue-shifting hydrogen bond.

Supramolecular Architectures and Hydrogen-Bond Directionalities of 4,4′-Biimidazole Metal Complexes Depending on Coordination Geometries

2010 ◽  
Vol 10 (11) ◽  
pp. 4898-4905 ◽  
Author(s):  
Tsuyoshi Murata ◽  
Yumi Yakiyama ◽  
Kazuhiro Nakasuji ◽  
Yasushi Morita
Keyword(s):  
Hydrogen Bond ◽  
Metal Complexes ◽  
Supramolecular Architectures

scholarly journals Crystal structures of four indole derivatives as possible cannabinoid allosteric antagonists

2015 ◽  
Vol 71 (6) ◽  
pp. 654-659 ◽  
Author(s):  
Jamie R. Kerr ◽  
Laurent Trembleau ◽  
John M. D. Storey ◽  
James L. Wardell ◽  
William T. A. Harrison
Keyword(s):  
Hydrogen Bond ◽  
Crystal Structures ◽  
Intermolecular Interaction ◽  
Ring System ◽  
Consistent Pattern ◽  
Indole Derivatives ◽  
Π Interactions

The crystal structures of four indole derivatives with various substituents at the 2-, 3- and 5-positions of the ring system are described, namely, ethyl 3-(5-chloro-2-phenyl-1H-indol-3-yl)-3-phenylpropanoate, C25H22ClNO2, (I), 2-bromo-3-(2-nitro-1-phenylethyl)-1H-indole, C16H13BrN2O2, (II), 5-methoxy-3-(2-nitro-1-phenylethyl)-2-phenyl-1H-indole, C23H20N2O3, (III), and 5-chloro-3-(2-nitro-1-phenylethyl)-2-phenyl-1H-indole, C22H17ClN2O2, (IV). The dominant intermolecular interaction in each case is an N—H...O hydrogen bond, which generates either chains or inversion dimers. Weak C—H...O, C—H...π and π–π interactions occur in these structures but there is no consistent pattern amongst them. Two of these compounds act as modest enhancers of CB1 cannabanoid signalling and two are inactive.

scholarly journals A theoretical study on the red- and blue-shift hydrogen bonds of cis-trans formic acid dimer in excited states

2013 ◽  
Vol 11 (2) ◽  
pp. 171-179 ◽  
Author(s):  
Dapeng Yang ◽  
Yonggang Yang ◽  
Yufang Liu
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Formic Acid ◽  
Excited States ◽  
Density Functional ◽  
Blue Shift ◽  
Red Shift ◽  
Functional Theory ◽  
Photophysical Study ◽  
Tddft Method

AbstractThe excited states of cis-trans formic acid dimer and its monomers have been investigated by time-dependent density functional theory (TDDFT) method. The formation of intermolecular hydrogen bonds O1-H1...O2=C2 and C2-H2...O4=C1 induces bond length lengthening of the groups related to the hydrogen bond, while that of the C2-H2 group is shortened. It is demonstrated that the red-shift hydrogen bond O1-H1...O2=C2 and blue-shift hydrogen bond C2-H2...O4=C1 are both weakened when excited to the S1 state. Moreover, it is found that the groups related to the formation of red-shift hydrogen bond O1-H1...O2=C2 are both strengthened in the S1 state, while the groups related to the blue-shift hydrogen bond C2-H2...O4=C1 are both weakened. This will provide information for the photochemistry and photophysical study of red- and blue-shift hydrogen bond.

scholarly journals A third-generation dispersion and third-generation hydrogen bonding corrected PM6 method: PM6-D3H+

2014 ◽  
Author(s):  
Jimmy Charnley Kromann ◽  
Anders Christensen ◽  
Casper Steinmann ◽  
Martin Korth ◽  
Jan H. Jensen
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Interaction Energy ◽  
Vibrational Analysis ◽  
Attractive Alternative ◽  
Third Generation ◽  
Dispersion Correction ◽  
Free Energies ◽  
Small Proteins

We present new dispersion and hydrogen bond corrections to the PM6 method, PM6-D3H+, and its implementation in the GAMESS program. The method combines the DFT-D3 dispersion correction by Grimme et al with a modified version of the H+ hydrogen bond correction by Korth. Overall, the interaction energy of PM6-D3H+ is very similar to PM6-DH2 and PM6-DH+, with RMSD and MAD values within 0.02 kcal/mol of one another. The main difference is that the geometry optimizations of 88 complexes result in 82, 6, 0, and 0 geometries with 0, 1, 2, and $\ge$ 3 imaginary frequencies using PM6-D3H+ implemented in GAMESS, while the corresponding numbers for PM6-DH+ implemented in MOPAC are 54, 17, 15, and 2. The PM6-D3H+ method as implemented in GAMESS offers an attractive alternative to PM6-DH+ in MOPAC in cases where the LBFGS optimizer must be used and a vibrational analysis is needed, e.g. when computing vibrational free energies. While the GAMESS implementation is up to 10 times slower for geometry optimizations of proteins in bulk solvent, compared to MOPAC, it is sufficiently fast to make geometry optimizations of small proteins practically feasible.

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