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1.
Guangzhan Han Yanli Ding Ping Qian Chao Zhang Wei Song 《International journal of quantum chemistry》2013,113(10):1511-1521
Various properties (such as optimal structures, structural parameters, hydrogen bonds, natural bond orbital charge distributions, binding energies, electron densities at hydrogen bond critical points, cooperative effects, and so on) of gas phase ethanol–(water)n (n = 1–5) clusters with the change in the number of water molecules have been systematically explored at the MP2/aug‐cc‐pVTZ//MP2/6‐311++G(d,p) computational level. The study of optimal structures shows that the most stable ethanol‐water heterodimer is the one where exists one primary hydrogen bond (O? H…O) and one secondary hydrogen bond (C? H …O) simultaneously. The cyclic geometric pattern formed by the primary hydrogen bonds, where all the molecules are proton acceptor and proton donor simultaneously, is the most stable configuration for ethanol–(water)n (n = 2–4) clusters, and a transition from two‐dimensional cyclic to three‐dimensional structures occurs at n = 5. At the same time, the cluster stability seems to correlate with the number of primary hydrogen bonds, because the secondary hydrogen bond was extremely weaker than the primary hydrogen bond. Furthermore, the comparison of cooperative effects between ethanol–water clusters and gas phase pure water clusters has been analyzed from two aspects. First of all, for the cyclic structure, the cooperative effect in the former is slightly stronger than that of the latter with the increasing of water molecules. Second, for the ethanol–(water)5 and (water)6 structure, the cooperative effect in the former is also correspondingly stronger than that of the latter except for the ethanol–(water)5 book structure. © 2012 Wiley Periodicals, Inc. 相似文献
2.
Density functional theory B3LYP method with 6‐31G* basis set has been used to optimize the geometries of the catechin, water and catechin‐(H2O)n complexes. The vibrational frequencies have been studied at the same level to analyze these complexes. Six and eleven stable structures for the catechin‐H2O and catechin‐(H2O)2 have been found, respectively. Theories of atoms in molecules (AIM) and natural bond orbital (NBO) have been utilized to investigate the hydrogen bonds involved in all the systems. The interaction energies of all the complexes corrected by basis set superposition error, are from ?13.27 to ?83.56 kJ/mol. All calculations also indicate that there are strong hydrogen‐bonding interactions in catechin‐water complexes. The strong hydrogen‐bonding contributes to the interaction energies dominantly. The O–H stretching motions in all the complexes are red‐shifted relative to that of the monomer. 相似文献
3.
Ping Qian Wei Song Linan Lu Zhongzhi Yang 《International journal of quantum chemistry》2010,110(10):1923-1937
Various properties of typical structures of water clusters in the n = 2–34 size regime with the change of cluster size have been systematically explored. Full optimizations are carried out for the structures presented in this article at the Hartree–Fock (HF) level using the 6‐31G(d) basis set by taking into account the positions of all atoms within the cluster. The influence of the HF level on the results has been reflected by the comparison between the binding energies of (H2O)n (n = 2–6, 8, 11, 13, 20) calculated at the HF level and those obtained from high‐level ab initio calculations at the second‐order Møller–Plesset (MP2) perturbation theory and the coupled cluster method including singles and doubles with perturbative triples (CCSD(T)) levels. HF is inaccurate when compared with MP2 and CCSD(T), but it is more practical and allows us to study larger systems. The computed properties characterizing water clusters (H2O)n (n = 2–34) include optimal structures, structural parameters, binding energies, hydrogen bonds, charge distributions, dipole moments, and so on. When the cluster size increases, trends of the above various properties have been presented to provide important reference for understanding and describing the nature of the hydrogen bond. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010 相似文献
4.
Tarakanova E. G. Tsoi O. Yu. Yukhnevich G. V. Kislina I. S. Librovich N. B. 《Kinetics and Catalysis》2004,45(3):359-366
Based on the results of ab initio calculations (B3LYP, 6-31++G(d,p)), the structures and stability of the complexes DMFA · HCl, (DMF)2 · HCl, DFF · (HCl)2, and (DMF · HCl)2 are compared. In the complex with a 1 : 1 composition, DMF and HCl form a hydrogen bond of the molecular type. In the heterotrimers with compositions 1 : 2 and 2 : 1, the hydrogen bond noticeably strengthens. In the tetramer (DMF · HCl)2, the most pronounced proton transfer takes place and two quasi-symmetric hydrogen bridges O···H···Cl are formed and stabilize this complex. The results of calculations are compared with data on the structure of complexes between HCl and DMF obtained by crystal-structure XRD and vibrational spectroscopy in solutions. 相似文献
5.
Structure and electronic properties of hollow‐caged C60 fullerene‐derived (MN4)nC6(10 − n) (M = Zn,Mg, Fe,n = 1−6) complexes
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Vladimir A. Pomogaev Pavel V. Avramov Alex A. Kuzubov Victor Ya. Artyukhov 《International journal of quantum chemistry》2015,115(4):239-244
Unique hollow‐caged (MN4)nC6(10 ? n) (M = Zn, Mg, Fe, n = 1?6) complexes designed by introduction of n porphyrinoid fragments in C60 fullerene structure were proposed and the atomic and electronic structures were calculated using LC‐DFT MPWB95 and M06 potentials and 6‐311G(d)/6‐31G(d) basis sets. The complexes were optimized using various symmetric configurations from the highest Oh to the lowest C1 point groups in different spin states from S = 0 (singlet) to S = 7 (quindectet) for M = Fe to define energetically preferable atomic and electronic structures. Several metastable complexes were determined and the key role of the metal ions in stabilization of the atomic structure of the complexes was revealed. For Fe6N24C24, the minimum energy was reported for C2h, D2h, and D4h symmetry of pentet state S = 2, so the complex can be regarded as unique molecular magnet. It was found that the metal partial density of states determine the nature of HOMO and LUMO levels making the clusters promising catalysts. © 2014 Wiley Periodicals, Inc. 相似文献
6.
Theoretical study of the interaction of fluorinated dimethyl ethers and the ClF and HF molecules. Comparison between halogen and hydrogen bonds
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Dipankar Sutradhar Asit K. Chandra Thérèse Zeegers‐Huyskens 《International journal of quantum chemistry》2016,116(9):670-680
A theoretical study of the halogen‐bonded complexes formed between fluorinated dimethyl ethers (nF = 0–4) and ClF is carried out using the wB97XD method combined with the 6‐311++G(d,p) basis set. The properties of the complexes are compared with the corresponding properties of the hydrogen‐bonded complexes formed between the same electron donors and HF. The optimized geometries, the interaction energies, relevant natural bonding orbital characteristics along with some vibrational data are calculated. The analyzed properties also include the symmetry adapted perturbation theory decomposition of the energies along with the atoms‐in molecule analysis. For both the halogen and hydrogen bonds, the interaction energies are ruled by the intermolecular hyperconjugation energies. In contrast, the correlations between the binding energies and the basic properties of the ethers or the charge transfer are different for the halogen and hydrogen bonds. The applicability of the Bent's rule to these systems is discussed. © 2016 Wiley Periodicals, Inc. 相似文献
7.
LIU Ruiping YANG Xuwu WANG Lijun LIU Fei ZHANG Lingling YU Fushan CHEN Sanping 《中国化学》2009,27(9):1827-1832
Two new complexes, [Mn2(L)2(H2bta)2(H2O)]n ( 1 ) and [Cu2(L)(H2bta)0.5(H2O)]n ( 2 ) (H4bta=1,2,4,5‐benzene‐tetracarboxylic acid, L=imidazo[4,5‐f][1,10]phenathroline) were prepared under hydrothermal conditions and their structures determined by single‐crystal X‐ray diffration. The X‐ray diffraction reveals that complex 1 , consisting of two crystallographically independent fragments A1 and A2, displays an interesting 3D supramolecular network constructed with ABAB sequence through hydrogen bonding interactions. In complex 2 , the copper atoms connected by the H2bta2? ligands, the chains also are assembled into a 3D honeycomb configuration network formed by moleculars and aromatic π‐π stacking interactions. 相似文献
8.
Marek J. Wjcik Gilbert J. Mains J. Paul Devlin 《International journal of quantum chemistry》1995,53(1):49-56
The geometries, successive binding energies, vibrational frequencies, and infrared intensities are calculated for the [Li(H2O)n]+ and [K(H2O)n]+ (n = 1?4) complexes. The basis sets used are 6-31G* and LANL 1DZ (Los Alamos ECP +DZ ) at the SCF and MP 2 levels. There is an agreement for calculated structures and frequencies between the MP 2/6-31G* and MP 2/LANL 1DZ basis sets, which indicates that the latter can be used for calculations of water complexes with heavier ions. Our results are in a reasonable agreement with available experimental data and facilitate experimental study of these complexes. © 1995 John Wiley & Sons, Inc. 相似文献
9.
10.
Synthesis,Structures, and Photocatalytic Properties of Zinc(II) and Cobalt(II) Supramolecular Complexes Constructed with Flexible Bis(thiabendazole) and Dicarboxylate Linkers
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Three coordination complexes, namely, [Zn(btbp)(3‐npa)]n ( 1 ), [Co(btbh)(3‐npa)]n ( 2 ), and {[Co(btbb)(5‐nipa)(H2O)] · H2O}n ( 3 ) (btbp = 1,3‐bis(thiabendazole)propane, btbh = 1,6‐bis(thiabendazole)hexane, btbb = 1,4‐bis(thiabendazole)butane, 3‐H2npa = 3‐nitrophthalic acid and 5‐H2nipa = 5‐nitroisophthalic acid) were synthesized under hydrothermal conditions and characterized by physicochemical and spectroscopic methods as well as by single‐crystal X‐ray diffraction. Complex 1 features a fascinating meso‐helical chain, which is further extended into a 2D supramolecular framework involving π ··· π stacking interactions. Complexes 2 and 3 show dinuclear structures. Complex 2 is further connected through C–H ··· O hydrogen bonding interactions to afford a 2D supramolecular layer, whereas complex 3 is further extended to a rare 2‐nodal (3,4)‐connected supramolecular sheet with a point symbol of {3.42.5.6.7}2{3.82} by O–H ··· O hydrogen bonding interactions. The electrochemical behaviors of the two cobalt complexes 2 and 3 were reported. Moreover, the luminescent properties for 1 and the photocatalytic properties for the complexes were investigated. 相似文献
11.
Toshihiko Sawada Tomohiro Hashimoto Hirofumi Nakano Hideharu Ishida 《Journal of carbohydrate chemistry》2013,32(5):387-405
The stable structures of α‐N‐acetyl‐D‐neuraminic acid (Neu5Acα) in the gas phase were studied at the B3LYP level of theory using 6‐31G(d,p) and 6‐31++G(d,p) basis sets. They are classified into five types according to the patterns of the intramolecular hydrogen bond formations. One of the stable structures had intramolecular hydrogen bond network of O9HO9 … O8HO8 … O?C1‐O1HO1 and O7HO7…O?CHN‐C5 similar to the crystal structure of Neu5Ac‐α‐methyl glycoside methyl ester. The stable structures of Neu5Acα are reasonable for the following sialooligosaccharide ligand studies with respect to the relationship between OH group orientations and intramolecular hydrogen bond formations. The barrier heights for isomerizations between the stable structures were computed to be 2.8 to 6.7 kcal/mol at the B3LYP/6‐31++G(d,p)//B3LYP/6‐31G(d,p) level, which are basic factors for the conformational behavior of Neu5Acα before its interactions with receptors. We also calculated Neu5Acα–4 or 5‐water complexes to take account of the solvent effect on the intramolecular hydrogen bonds in the stable structures. Consequently, the structures of Neu5Acα in the complexes are similar to each other, which is consistent with the known NMR data. Thus, the optimum Neu5Acα‐water complexes are some of the reasonable pseudohydrous Neu5Acα. 相似文献
12.
Zhengyu Zhou Yuhui Qu Aiping Fu Benni Du Faxin He Hongwei Gao 《International journal of quantum chemistry》2002,89(6):550-558
The hydrogen bonding complexes formed between the H2O and OH radical have been completely investigated for the first time in this study using density functional theory (DFT). A larger basis set 6‐311++G(2d,2p) has been employed in conjunction with a hybrid density functional method, namely, UB3LYP/6‐311++G(2d,2p). The two degenerate components of the OH radical 2Π ground electronic state give rise to independent states upon interaction with the water molecule, with hydrogen bonding occurring between the oxygen atom of H2O and the hydrogen atom of the OH radical. Another hydrogen bond occurs between one of the H atoms of H2O and the O atom of the OH radical. The extensive calculation reveals that there is still more hydrogen bonding form found first in this investigation, in which two or three hydrogen bonds occur at the same time. The optimized geometry parameter and interaction energy for various isomers at the present level of theory was estimated. The infrared (IR) spectrum frequencies, IR intensities, and vibrational frequency shifts are reported. The estimates of the H2O · OH complex's vibrational modes and predicted IR spectra for these structures are also made. It should be noted that a total of 10 stationary points have been confirmed to be genuine minima and transition states on the potential energy hypersurface of the H2O · HO system. Among them, four genuine minima were located. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002 相似文献
13.
The stability, infrared spectra and electronic structures of (ZrO2)n (n=3–6) clusters have been investigated by using density‐functional theory (DFT) at B3LYP/6‐31G* level. The lowest‐energy structures have been recognized by considering a number of structural isomers for each cluster size. It is found that the lowest‐energy (ZrO2)5 cluster is the most stable among the (ZrO2)n (n=3–6) clusters. The vibration spectra of Zr? O stretching motion from terminal oxygen atom locate between 900 and 1000 cm?1, and the vibrational band of Zr? O? Zr? O four member ring is obtained at 600–700 cm?1, which are in good agreement with the experimental results. Mulliken populations and NBO charges of (ZrO2)n clusters indicate that the charge transfers occur between 4d orbital of Zr atoms and 2p orbital of O atoms. HOMO‐LUMO gaps illustrate that chemical stabilities of the lowest‐energy (ZrO2)n (n=3–6) clusters display an even‐odd alternating pattern with increasing cluster size. 相似文献
14.
The structure and harmonic vibrations of MgnOn (n = 3–10) clusters have been investigated using density functional theory. All structures are found to be cumulenic Dnh rings (equal bonds, alternating angles), with one intense out‐of‐plane mode and three infrared (IR)‐active degenerate modes, of which the highest one is extremely intense and increases asymptotically to 1000 cm?1 for n = 10 at the B3LYP/6‐311++G(2d,2p) level. Comparisons with C2n clusters show that BnNn and BenOn clusters, the structure and bonding type for the MgnOn clusters are consistent with those of the C2n (n = 3, 5, 7,…) clusters BnNn(n = 3–10) and BenOn(n = 3–10) clusters. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007 相似文献
15.
Dr. Naruyoshi Komiya Dr. Minoru Okada Kanako Fukumoto Kenji Kaneta Atsushi Yoshida Prof. Takeshi Naota 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(15):4798-4811
The synthesis, structure, and solid‐state emission of vaulted trans‐bis(salicylaldiminato)platinum(II) complexes are described. A series of polymethylene ( 1 : n=8; 2 : n=9; 3 : n=10; 4 : n=11; 5 : n=12; 6 : n=13) and polyoxyethylene ( 7 : m=2; 8 : m=3; 9 : m=4) vaulted complexes (R=H ( a ), 3‐MeO ( b ), 4‐MeO ( c ), 5‐MeO ( d ), 6‐MeO ( e ), 4‐CF3O ( f ), 5‐CF3O ( g )) was prepared by treating [PtCl2(CH3CN)2] with the corresponding N,N′‐bis(salicylidene)‐1,ω‐alkanediamines. The trans coordination, vaulted structures, and the crystal packing of 1 – 9 have been unequivocally established from X‐ray diffraction studies. Unpredictable, structure‐dependent phosphorescent emission has been observed for crystals of the complexes under UV excitation at ambient temperature, whereas these complexes are entirely nonemissive in the solution state under the same conditions. The long‐linked complex crystals 4 – 6 , 8 , and 9 exhibit intense emission (Φ77K=0.22–0.88) at 77 K, whereas short‐linked complexes 1 – 3 and 7 are non‐ or slightly emissive at the same temperature (Φ77K<0.01–0.18). At 298 K, some of the long‐linked crystals, 4 a , 4 b , 5 c , 5 e , 6 c , 6 e , and 9 b , completely lose their high‐emission properties with elevation of the temperature (Φ298K<0.01–0.02), whereas the other long‐linked crystals, 5 a , 6 a , 9 a , and 9 d , exhibit high heat resistance towards emission decay with increasing temperature (Φ298K=0.21–0.38). Chromogenic control of solid‐state emission over the range of 98 nm can be performed simply by introducing MeO groups at different positions on the aromatic rings. Orange, yellow‐green, red, and yellow emissions are observed in the glass and crystalline state upon 3‐, 4‐, 5‐, and 6‐MeO substitution, respectively, whereas those with CF3O substituents have orange emission, irrespective of the substitution position. DFT calculations (B3LYP/6‐31G*, LanL2DZ) showed that such chromatic variation is ascribed to the position‐specific influence of the substituents on the highest‐occupied molecular orbital (HOMO) and lowest‐unoccupied molecular orbital (LUMO) levels of the trans‐bis(salicylaldiminato)platinum(II) platform. The solid‐state emission and its heat resistance have been discussed on the basis of X‐ray diffraction studies. The planarity of the trans‐coordination sites is strongly correlated to the solid‐state emission intensities of crystals 1 – 9 at lower temperatures. The specific heat‐resistance properties shown exclusively by the 5 a , 6 a , 9 a , and 9 d crystals are due to their strong three‐dimensional hydrogen‐bonding interactions and/or Pt???Pt contacts, whereas heat‐quenchable crystals 4 a , 4 b , 5 c , 5 e , 6 c , 6 e , and 9 b are poorly bound with limited interactions, such as non‐, one‐, or two‐dimensional hydrogen‐bonding networks. These results lead to the conclusion that Pt???Pt contacts are an important factor in the heat resistance of solid‐state phosphorescence at ambient temperature, although the role of Pt???Pt contacts can be substituted by only higher‐ordered hydrogen‐bonding fixation. 相似文献
16.
İskender Muz Osman Canko Murat Atiş Erdem Kamil Yıldırım 《Journal of computational chemistry》2015,36(6):385-391
The global minimum structures of AlB3H2n (n = 0–6) clusters are determined using the stochastic search method at the B3LYP/6–31G level of theory. These initially specified geometries are recalculated using B3LYP and CCSD(T) methods using the 6–311++G** basis set. The structural and electronic properties of the two lowest‐lying isomers are presented. The structural parameters obtained for aluminum borohydride are compared with the experimental and theoretical results. The H2 fragmentation energies of the most stable isomers are investigated. Chemical bonding analyses for the global minimum of AlB3H2n (n = 0–6) clusters are performed using the adaptive natural density partitioning method. © 2014 Wiley Periodicals, Inc. 相似文献
17.
Dongmei Du Mei Qin Zhengyu Zhou Aiping Fu 《International journal of quantum chemistry》2012,112(2):351-358
The accurate pKa determinations for three carboxylic acids have been investigated using the combination of the extended clusters‐continuum model at B3LYP/6‐31+g(d,p) and B3LYP/6‐311++g(d,p) levels. To take into account of the effect of the water combined with carboxylic acids in different positions, eleven molecular clusters were considered. Among these clusters, the one involving the carboxylic acid wrapped up with water molecules and saturated with hydrogen bonds (four hydrogen bonds around ? COOH) leads to the best B3LYP pKa results compared to the experimental data. For those clusters saturated with hydrogen bonds, when n = 3 (the number of water molecules), the average absolute errors between the calculated pKa results and experimental data of these three carboxylic acids were 0.19 (0.23) and 0.12 (0.22) pKa at B3LYP/6‐31+g(d,p)//PCM (IEFPCM) and B3LYP/6‐311++g(d,p)//PCM (IEFPCM) levels, respectively; when n = 4, they are 0.53 (1.23) and 1.09 (1.03) pKa, respectively. On the basis of the above results, the molecular cluster saturated with four hydrogen bonds formed by three waters and one carboxylic acid molecule was the chief existence in the carboxylic acid solution. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012 相似文献
18.
Self‐Assembled Multimetallic/Peptide Complexes: Structures and Unimolecular Reactions of [Mn(GlyGly−H)2n−1]+ and Mn+1(GlyGly−H2n]2+ Clusters in the Gas Phase
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The unimolecular chemistry and structures of self‐assembled complexes containing multiple alkaline‐earth‐metal dications and deprotonated GlyGly ligands are investigated. Singly and doubly charged ions [Mn(GlyGly?H)n‐1]+ (n=2–4), [Mn+1(GlyGly?H)2n]2+ (n=2,4,6), and [M(GlyGly?H)GlyGly]+ were observed. The losses of 132 Da (GlyGly) and 57 Da (determined to be aminoketene) were the major dissociation pathways for singly charged ions. Doubly charged Mg2+ clusters mainly lost GlyGly, whereas those containing Ca2+ or Sr2+ also underwent charge separation. Except for charge separation, no loss of metal cations was observed. Infrared multiple photon dissociation spectra were the most consistent with the computed IR spectra for the lowest energy structures, in which deprotonation occurs at the carboxyl acid groups and all amide and carboxylate oxygen atoms are complexed to the metal cations. The N?H stretch band, observed at 3350 cm?1, is indicative of hydrogen bonding between the amine nitrogen atoms and the amide hydrogen atom. This study represents the first into large self‐assembled multimetallic complexes bound by peptide ligands. 相似文献
19.
Wenwen Cui Cheng Wang Jingling Shao Xiaolei Zhu 《International journal of quantum chemistry》2013,113(20):2251-2260
We perform a systematic study on the geometry, stability, nature of bonding, and potential energy surface of low‐lying isomers of planar and cyclic BnN2 (n = 1?6) at the CCSD(T)/6‐311+G(d)//B3LYP/6‐311+G(d) level. BnN2 (n = 2?4) clusters are structurally similar to pure boron clusters. The evolution of the binding energy per atom, incremental binding energy, and second‐order difference of total energy with the size of BnN2 reveals that the lowest energy isomer of B3N2 has high stability. B5N2 and B6N2 possess π‐aromaticity according to Hückel (4n + 2) rule. The aromaticity of some isomers of B4N2 and B6N2 is examined based on their valence molecular orbitals. At the CCSD(T)/6‐311+G(d)//B3LYP/6‐311+G(d) level, several B2N2, B3N2, B4N2, and B5N2 isomers are predicted to be stable both thermodynamically and kinetically, and detectable in future experiments. © 2013 Wiley Periodicals, Inc. 相似文献
20.
Rodolfo Moreno‐Fuquen Juan C. Tenorio Javier Ellena Carlos A. De Simone Leandro Ribeiro 《Acta Crystallographica. Section C, Structural Chemistry》2011,67(2):o67-o70
In the title compound, C11H7NO4, there is a dihedral angle of 45.80 (7)° between the planes of the benzene and maleimide rings. The presence of O—H...O hydrogen bonding and weak C—H...O interactions allows the formation of R33(19) edge‐connected rings parallel to the (010) plane. Structural, spectroscopic and theoretical studies were carried out. Density functional theory (DFT) optimized structures at the B3LYP/6–311 G(d,p) and 6–31++G(d,p) levels are compared with the experimentally determined molecular structure in the solid state. Additional IR and UV theoretical studies allowed the presence of functional groups and the transition bands of the system to be identified. 相似文献